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-rw-r--r--arch/um/os-Linux/Makefile21
-rw-r--r--arch/um/os-Linux/drivers/Makefile13
-rw-r--r--arch/um/os-Linux/drivers/etap.h21
-rw-r--r--arch/um/os-Linux/drivers/ethertap_kern.c100
-rw-r--r--arch/um/os-Linux/drivers/ethertap_user.c248
-rw-r--r--arch/um/os-Linux/drivers/tuntap.h21
-rw-r--r--arch/um/os-Linux/drivers/tuntap_kern.c86
-rw-r--r--arch/um/os-Linux/drivers/tuntap_user.c215
-rw-r--r--arch/um/os-Linux/elf_aux.c74
-rw-r--r--arch/um/os-Linux/execvp.c150
-rw-r--r--arch/um/os-Linux/file.c707
-rw-r--r--arch/um/os-Linux/helper.c169
-rw-r--r--arch/um/os-Linux/irq.c145
-rw-r--r--arch/um/os-Linux/main.c254
-rw-r--r--arch/um/os-Linux/mem.c232
-rw-r--r--arch/um/os-Linux/process.c287
-rw-r--r--arch/um/os-Linux/registers.c58
-rw-r--r--arch/um/os-Linux/sigio.c550
-rw-r--r--arch/um/os-Linux/signal.c419
-rw-r--r--arch/um/os-Linux/skas/Makefile10
-rw-r--r--arch/um/os-Linux/skas/mem.c206
-rw-r--r--arch/um/os-Linux/skas/process.c732
-rw-r--r--arch/um/os-Linux/start_up.c424
-rw-r--r--arch/um/os-Linux/time.c115
-rw-r--r--arch/um/os-Linux/tty.c60
-rw-r--r--arch/um/os-Linux/umid.c408
-rw-r--r--arch/um/os-Linux/user_syms.c43
-rw-r--r--arch/um/os-Linux/util.c195
28 files changed, 5963 insertions, 0 deletions
diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
new file mode 100644
index 0000000000..544e0b344c
--- /dev/null
+++ b/arch/um/os-Linux/Makefile
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+#
+
+# Don't instrument UML-specific code
+KCOV_INSTRUMENT := n
+
+obj-y = execvp.o file.o helper.o irq.o main.o mem.o process.o \
+ registers.o sigio.o signal.o start_up.o time.o tty.o \
+ umid.o user_syms.o util.o drivers/ skas/
+
+CFLAGS_signal.o += -Wframe-larger-than=4096
+
+obj-$(CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA) += elf_aux.o
+
+USER_OBJS := $(user-objs-y) elf_aux.o execvp.o file.o helper.o irq.o \
+ main.o mem.o process.o registers.o sigio.o signal.o start_up.o time.o \
+ tty.o umid.o util.o
+
+include $(srctree)/arch/um/scripts/Makefile.rules
diff --git a/arch/um/os-Linux/drivers/Makefile b/arch/um/os-Linux/drivers/Makefile
new file mode 100644
index 0000000000..cf2d75bb18
--- /dev/null
+++ b/arch/um/os-Linux/drivers/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
+#
+
+ethertap-objs := ethertap_kern.o ethertap_user.o
+tuntap-objs := tuntap_kern.o tuntap_user.o
+
+obj-y =
+obj-$(CONFIG_UML_NET_ETHERTAP) += ethertap.o
+obj-$(CONFIG_UML_NET_TUNTAP) += tuntap.o
+
+include $(srctree)/arch/um/scripts/Makefile.rules
diff --git a/arch/um/os-Linux/drivers/etap.h b/arch/um/os-Linux/drivers/etap.h
new file mode 100644
index 0000000000..a475259f90
--- /dev/null
+++ b/arch/um/os-Linux/drivers/etap.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __DRIVERS_ETAP_H
+#define __DRIVERS_ETAP_H
+
+#include <net_user.h>
+
+struct ethertap_data {
+ char *dev_name;
+ char *gate_addr;
+ int data_fd;
+ int control_fd;
+ void *dev;
+};
+
+extern const struct net_user_info ethertap_user_info;
+
+#endif
diff --git a/arch/um/os-Linux/drivers/ethertap_kern.c b/arch/um/os-Linux/drivers/ethertap_kern.c
new file mode 100644
index 0000000000..3182e759d8
--- /dev/null
+++ b/arch/um/os-Linux/drivers/ethertap_kern.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
+ * James Leu (jleu@mindspring.net).
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright (C) 2001 by various other people who didn't put their name here.
+ */
+
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include "etap.h"
+#include <net_kern.h>
+
+struct ethertap_init {
+ char *dev_name;
+ char *gate_addr;
+};
+
+static void etap_init(struct net_device *dev, void *data)
+{
+ struct uml_net_private *pri;
+ struct ethertap_data *epri;
+ struct ethertap_init *init = data;
+
+ pri = netdev_priv(dev);
+ epri = (struct ethertap_data *) pri->user;
+ epri->dev_name = init->dev_name;
+ epri->gate_addr = init->gate_addr;
+ epri->data_fd = -1;
+ epri->control_fd = -1;
+ epri->dev = dev;
+
+ printk(KERN_INFO "ethertap backend - %s", epri->dev_name);
+ if (epri->gate_addr != NULL)
+ printk(KERN_CONT ", IP = %s", epri->gate_addr);
+ printk(KERN_CONT "\n");
+}
+
+static int etap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+ int len;
+
+ len = net_recvfrom(fd, skb_mac_header(skb),
+ skb->dev->mtu + 2 + ETH_HEADER_ETHERTAP);
+ if (len <= 0)
+ return(len);
+
+ skb_pull(skb, 2);
+ len -= 2;
+ return len;
+}
+
+static int etap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+ skb_push(skb, 2);
+ return net_send(fd, skb->data, skb->len);
+}
+
+const struct net_kern_info ethertap_kern_info = {
+ .init = etap_init,
+ .protocol = eth_protocol,
+ .read = etap_read,
+ .write = etap_write,
+};
+
+int ethertap_setup(char *str, char **mac_out, void *data)
+{
+ struct ethertap_init *init = data;
+
+ *init = ((struct ethertap_init)
+ { .dev_name = NULL,
+ .gate_addr = NULL });
+ if (tap_setup_common(str, "ethertap", &init->dev_name, mac_out,
+ &init->gate_addr))
+ return 0;
+ if (init->dev_name == NULL) {
+ printk(KERN_ERR "ethertap_setup : Missing tap device name\n");
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct transport ethertap_transport = {
+ .list = LIST_HEAD_INIT(ethertap_transport.list),
+ .name = "ethertap",
+ .setup = ethertap_setup,
+ .user = &ethertap_user_info,
+ .kern = &ethertap_kern_info,
+ .private_size = sizeof(struct ethertap_data),
+ .setup_size = sizeof(struct ethertap_init),
+};
+
+static int register_ethertap(void)
+{
+ register_transport(&ethertap_transport);
+ return 0;
+}
+
+late_initcall(register_ethertap);
diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
new file mode 100644
index 0000000000..9483021d86
--- /dev/null
+++ b/arch/um/os-Linux/drivers/ethertap_user.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
+ * James Leu (jleu@mindspring.net).
+ * Copyright (C) 2001 by various other people who didn't put their name here.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include "etap.h"
+#include <os.h>
+#include <net_user.h>
+#include <um_malloc.h>
+
+#define MAX_PACKET ETH_MAX_PACKET
+
+static int etap_user_init(void *data, void *dev)
+{
+ struct ethertap_data *pri = data;
+
+ pri->dev = dev;
+ return 0;
+}
+
+struct addr_change {
+ enum { ADD_ADDR, DEL_ADDR } what;
+ unsigned char addr[4];
+ unsigned char netmask[4];
+};
+
+static void etap_change(int op, unsigned char *addr, unsigned char *netmask,
+ int fd)
+{
+ struct addr_change change;
+ char *output;
+ int n;
+
+ change.what = op;
+ memcpy(change.addr, addr, sizeof(change.addr));
+ memcpy(change.netmask, netmask, sizeof(change.netmask));
+ CATCH_EINTR(n = write(fd, &change, sizeof(change)));
+ if (n != sizeof(change)) {
+ printk(UM_KERN_ERR "etap_change - request failed, err = %d\n",
+ errno);
+ return;
+ }
+
+ output = uml_kmalloc(UM_KERN_PAGE_SIZE, UM_GFP_KERNEL);
+ if (output == NULL)
+ printk(UM_KERN_ERR "etap_change : Failed to allocate output "
+ "buffer\n");
+ read_output(fd, output, UM_KERN_PAGE_SIZE);
+ if (output != NULL) {
+ printk("%s", output);
+ kfree(output);
+ }
+}
+
+static void etap_open_addr(unsigned char *addr, unsigned char *netmask,
+ void *arg)
+{
+ etap_change(ADD_ADDR, addr, netmask, *((int *) arg));
+}
+
+static void etap_close_addr(unsigned char *addr, unsigned char *netmask,
+ void *arg)
+{
+ etap_change(DEL_ADDR, addr, netmask, *((int *) arg));
+}
+
+struct etap_pre_exec_data {
+ int control_remote;
+ int control_me;
+ int data_me;
+};
+
+static void etap_pre_exec(void *arg)
+{
+ struct etap_pre_exec_data *data = arg;
+
+ dup2(data->control_remote, 1);
+ close(data->data_me);
+ close(data->control_me);
+}
+
+static int etap_tramp(char *dev, char *gate, int control_me,
+ int control_remote, int data_me, int data_remote)
+{
+ struct etap_pre_exec_data pe_data;
+ int pid, err, n;
+ char version_buf[sizeof("nnnnn\0")];
+ char data_fd_buf[sizeof("nnnnnn\0")];
+ char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
+ char *setup_args[] = { "uml_net", version_buf, "ethertap", dev,
+ data_fd_buf, gate_buf, NULL };
+ char *nosetup_args[] = { "uml_net", version_buf, "ethertap",
+ dev, data_fd_buf, NULL };
+ char **args, c;
+
+ sprintf(data_fd_buf, "%d", data_remote);
+ sprintf(version_buf, "%d", UML_NET_VERSION);
+ if (gate != NULL) {
+ strncpy(gate_buf, gate, 15);
+ args = setup_args;
+ }
+ else args = nosetup_args;
+
+ err = 0;
+ pe_data.control_remote = control_remote;
+ pe_data.control_me = control_me;
+ pe_data.data_me = data_me;
+ pid = run_helper(etap_pre_exec, &pe_data, args);
+
+ if (pid < 0)
+ err = pid;
+ close(data_remote);
+ close(control_remote);
+ CATCH_EINTR(n = read(control_me, &c, sizeof(c)));
+ if (n != sizeof(c)) {
+ err = -errno;
+ printk(UM_KERN_ERR "etap_tramp : read of status failed, "
+ "err = %d\n", -err);
+ return err;
+ }
+ if (c != 1) {
+ printk(UM_KERN_ERR "etap_tramp : uml_net failed\n");
+ err = helper_wait(pid);
+ }
+ return err;
+}
+
+static int etap_open(void *data)
+{
+ struct ethertap_data *pri = data;
+ char *output;
+ int data_fds[2], control_fds[2], err, output_len;
+
+ err = tap_open_common(pri->dev, pri->gate_addr);
+ if (err)
+ return err;
+
+ err = socketpair(AF_UNIX, SOCK_DGRAM, 0, data_fds);
+ if (err) {
+ err = -errno;
+ printk(UM_KERN_ERR "etap_open - data socketpair failed - "
+ "err = %d\n", errno);
+ return err;
+ }
+
+ err = socketpair(AF_UNIX, SOCK_STREAM, 0, control_fds);
+ if (err) {
+ err = -errno;
+ printk(UM_KERN_ERR "etap_open - control socketpair failed - "
+ "err = %d\n", errno);
+ goto out_close_data;
+ }
+
+ err = etap_tramp(pri->dev_name, pri->gate_addr, control_fds[0],
+ control_fds[1], data_fds[0], data_fds[1]);
+ output_len = UM_KERN_PAGE_SIZE;
+ output = uml_kmalloc(output_len, UM_GFP_KERNEL);
+ read_output(control_fds[0], output, output_len);
+
+ if (output == NULL)
+ printk(UM_KERN_ERR "etap_open : failed to allocate output "
+ "buffer\n");
+ else {
+ printk("%s", output);
+ kfree(output);
+ }
+
+ if (err < 0) {
+ printk(UM_KERN_ERR "etap_tramp failed - err = %d\n", -err);
+ goto out_close_control;
+ }
+
+ pri->data_fd = data_fds[0];
+ pri->control_fd = control_fds[0];
+ iter_addresses(pri->dev, etap_open_addr, &pri->control_fd);
+ return data_fds[0];
+
+out_close_control:
+ close(control_fds[0]);
+ close(control_fds[1]);
+out_close_data:
+ close(data_fds[0]);
+ close(data_fds[1]);
+ return err;
+}
+
+static void etap_close(int fd, void *data)
+{
+ struct ethertap_data *pri = data;
+
+ iter_addresses(pri->dev, etap_close_addr, &pri->control_fd);
+ close(fd);
+
+ if (shutdown(pri->data_fd, SHUT_RDWR) < 0)
+ printk(UM_KERN_ERR "etap_close - shutdown data socket failed, "
+ "errno = %d\n", errno);
+
+ if (shutdown(pri->control_fd, SHUT_RDWR) < 0)
+ printk(UM_KERN_ERR "etap_close - shutdown control socket "
+ "failed, errno = %d\n", errno);
+
+ close(pri->data_fd);
+ pri->data_fd = -1;
+ close(pri->control_fd);
+ pri->control_fd = -1;
+}
+
+static void etap_add_addr(unsigned char *addr, unsigned char *netmask,
+ void *data)
+{
+ struct ethertap_data *pri = data;
+
+ tap_check_ips(pri->gate_addr, addr);
+ if (pri->control_fd == -1)
+ return;
+ etap_open_addr(addr, netmask, &pri->control_fd);
+}
+
+static void etap_del_addr(unsigned char *addr, unsigned char *netmask,
+ void *data)
+{
+ struct ethertap_data *pri = data;
+
+ if (pri->control_fd == -1)
+ return;
+
+ etap_close_addr(addr, netmask, &pri->control_fd);
+}
+
+const struct net_user_info ethertap_user_info = {
+ .init = etap_user_init,
+ .open = etap_open,
+ .close = etap_close,
+ .remove = NULL,
+ .add_address = etap_add_addr,
+ .delete_address = etap_del_addr,
+ .mtu = ETH_MAX_PACKET,
+ .max_packet = ETH_MAX_PACKET + ETH_HEADER_ETHERTAP,
+};
diff --git a/arch/um/os-Linux/drivers/tuntap.h b/arch/um/os-Linux/drivers/tuntap.h
new file mode 100644
index 0000000000..e364e42abf
--- /dev/null
+++ b/arch/um/os-Linux/drivers/tuntap.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __UM_TUNTAP_H
+#define __UM_TUNTAP_H
+
+#include <net_user.h>
+
+struct tuntap_data {
+ char *dev_name;
+ int fixed_config;
+ char *gate_addr;
+ int fd;
+ void *dev;
+};
+
+extern const struct net_user_info tuntap_user_info;
+
+#endif
diff --git a/arch/um/os-Linux/drivers/tuntap_kern.c b/arch/um/os-Linux/drivers/tuntap_kern.c
new file mode 100644
index 0000000000..adcb6717be
--- /dev/null
+++ b/arch/um/os-Linux/drivers/tuntap_kern.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/netdevice.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <asm/errno.h>
+#include <net_kern.h>
+#include "tuntap.h"
+
+struct tuntap_init {
+ char *dev_name;
+ char *gate_addr;
+};
+
+static void tuntap_init(struct net_device *dev, void *data)
+{
+ struct uml_net_private *pri;
+ struct tuntap_data *tpri;
+ struct tuntap_init *init = data;
+
+ pri = netdev_priv(dev);
+ tpri = (struct tuntap_data *) pri->user;
+ tpri->dev_name = init->dev_name;
+ tpri->fixed_config = (init->dev_name != NULL);
+ tpri->gate_addr = init->gate_addr;
+ tpri->fd = -1;
+ tpri->dev = dev;
+
+ printk(KERN_INFO "TUN/TAP backend - ");
+ if (tpri->gate_addr != NULL)
+ printk(KERN_CONT "IP = %s", tpri->gate_addr);
+ printk(KERN_CONT "\n");
+}
+
+static int tuntap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+ return net_read(fd, skb_mac_header(skb),
+ skb->dev->mtu + ETH_HEADER_OTHER);
+}
+
+static int tuntap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+ return net_write(fd, skb->data, skb->len);
+}
+
+const struct net_kern_info tuntap_kern_info = {
+ .init = tuntap_init,
+ .protocol = eth_protocol,
+ .read = tuntap_read,
+ .write = tuntap_write,
+};
+
+int tuntap_setup(char *str, char **mac_out, void *data)
+{
+ struct tuntap_init *init = data;
+
+ *init = ((struct tuntap_init)
+ { .dev_name = NULL,
+ .gate_addr = NULL });
+ if (tap_setup_common(str, "tuntap", &init->dev_name, mac_out,
+ &init->gate_addr))
+ return 0;
+
+ return 1;
+}
+
+static struct transport tuntap_transport = {
+ .list = LIST_HEAD_INIT(tuntap_transport.list),
+ .name = "tuntap",
+ .setup = tuntap_setup,
+ .user = &tuntap_user_info,
+ .kern = &tuntap_kern_info,
+ .private_size = sizeof(struct tuntap_data),
+ .setup_size = sizeof(struct tuntap_init),
+};
+
+static int register_tuntap(void)
+{
+ register_transport(&tuntap_transport);
+ return 0;
+}
+
+late_initcall(register_tuntap);
diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c
new file mode 100644
index 0000000000..2284e9c1cb
--- /dev/null
+++ b/arch/um/os-Linux/drivers/tuntap_user.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <linux/if_tun.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/uio.h>
+#include <kern_util.h>
+#include <os.h>
+#include "tuntap.h"
+
+static int tuntap_user_init(void *data, void *dev)
+{
+ struct tuntap_data *pri = data;
+
+ pri->dev = dev;
+ return 0;
+}
+
+static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
+ void *data)
+{
+ struct tuntap_data *pri = data;
+
+ tap_check_ips(pri->gate_addr, addr);
+ if ((pri->fd == -1) || pri->fixed_config)
+ return;
+ open_addr(addr, netmask, pri->dev_name);
+}
+
+static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
+ void *data)
+{
+ struct tuntap_data *pri = data;
+
+ if ((pri->fd == -1) || pri->fixed_config)
+ return;
+ close_addr(addr, netmask, pri->dev_name);
+}
+
+struct tuntap_pre_exec_data {
+ int stdout_fd;
+ int close_me;
+};
+
+static void tuntap_pre_exec(void *arg)
+{
+ struct tuntap_pre_exec_data *data = arg;
+
+ dup2(data->stdout_fd, 1);
+ close(data->close_me);
+}
+
+static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
+ char *buffer, int buffer_len, int *used_out)
+{
+ struct tuntap_pre_exec_data data;
+ char version_buf[sizeof("nnnnn\0")];
+ char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
+ NULL };
+ char buf[CMSG_SPACE(sizeof(*fd_out))];
+ struct msghdr msg;
+ struct cmsghdr *cmsg;
+ struct iovec iov;
+ int pid, n, err;
+
+ sprintf(version_buf, "%d", UML_NET_VERSION);
+
+ data.stdout_fd = remote;
+ data.close_me = me;
+
+ pid = run_helper(tuntap_pre_exec, &data, argv);
+
+ if (pid < 0)
+ return pid;
+
+ close(remote);
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ if (buffer != NULL) {
+ iov = ((struct iovec) { buffer, buffer_len });
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+ }
+ else {
+ msg.msg_iov = NULL;
+ msg.msg_iovlen = 0;
+ }
+ msg.msg_control = buf;
+ msg.msg_controllen = sizeof(buf);
+ msg.msg_flags = 0;
+ n = recvmsg(me, &msg, 0);
+ *used_out = n;
+ if (n < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "tuntap_open_tramp : recvmsg failed - "
+ "errno = %d\n", errno);
+ return err;
+ }
+ helper_wait(pid);
+
+ cmsg = CMSG_FIRSTHDR(&msg);
+ if (cmsg == NULL) {
+ printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
+ "message\n");
+ return -EINVAL;
+ }
+ if ((cmsg->cmsg_level != SOL_SOCKET) ||
+ (cmsg->cmsg_type != SCM_RIGHTS)) {
+ printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
+ "descriptor\n");
+ return -EINVAL;
+ }
+ *fd_out = ((int *) CMSG_DATA(cmsg))[0];
+ os_set_exec_close(*fd_out);
+ return 0;
+}
+
+static int tuntap_open(void *data)
+{
+ struct ifreq ifr;
+ struct tuntap_data *pri = data;
+ char *output, *buffer;
+ int err, fds[2], len, used;
+
+ err = tap_open_common(pri->dev, pri->gate_addr);
+ if (err < 0)
+ return err;
+
+ if (pri->fixed_config) {
+ pri->fd = os_open_file("/dev/net/tun",
+ of_cloexec(of_rdwr(OPENFLAGS())), 0);
+ if (pri->fd < 0) {
+ printk(UM_KERN_ERR "Failed to open /dev/net/tun, "
+ "err = %d\n", -pri->fd);
+ return pri->fd;
+ }
+ memset(&ifr, 0, sizeof(ifr));
+ ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+ strscpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
+ if (ioctl(pri->fd, TUNSETIFF, &ifr) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n",
+ errno);
+ close(pri->fd);
+ return err;
+ }
+ }
+ else {
+ err = socketpair(AF_UNIX, SOCK_DGRAM, 0, fds);
+ if (err) {
+ err = -errno;
+ printk(UM_KERN_ERR "tuntap_open : socketpair failed - "
+ "errno = %d\n", errno);
+ return err;
+ }
+
+ buffer = get_output_buffer(&len);
+ if (buffer != NULL)
+ len--;
+ used = 0;
+
+ err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0],
+ fds[1], buffer, len, &used);
+
+ output = buffer;
+ if (err < 0) {
+ printk("%s", output);
+ free_output_buffer(buffer);
+ printk(UM_KERN_ERR "tuntap_open_tramp failed - "
+ "err = %d\n", -err);
+ return err;
+ }
+
+ pri->dev_name = uml_strdup(buffer);
+ output += IFNAMSIZ;
+ printk("%s", output);
+ free_output_buffer(buffer);
+
+ close(fds[0]);
+ iter_addresses(pri->dev, open_addr, pri->dev_name);
+ }
+
+ return pri->fd;
+}
+
+static void tuntap_close(int fd, void *data)
+{
+ struct tuntap_data *pri = data;
+
+ if (!pri->fixed_config)
+ iter_addresses(pri->dev, close_addr, pri->dev_name);
+ close(fd);
+ pri->fd = -1;
+}
+
+const struct net_user_info tuntap_user_info = {
+ .init = tuntap_user_init,
+ .open = tuntap_open,
+ .close = tuntap_close,
+ .remove = NULL,
+ .add_address = tuntap_add_addr,
+ .delete_address = tuntap_del_addr,
+ .mtu = ETH_MAX_PACKET,
+ .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER,
+};
diff --git a/arch/um/os-Linux/elf_aux.c b/arch/um/os-Linux/elf_aux.c
new file mode 100644
index 0000000000..344ac403fb
--- /dev/null
+++ b/arch/um/os-Linux/elf_aux.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/um/kernel/elf_aux.c
+ *
+ * Scan the ELF auxiliary vector provided by the host to extract
+ * information about vsyscall-page, etc.
+ *
+ * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
+ * Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com)
+ */
+#include <elf.h>
+#include <stddef.h>
+#include <init.h>
+#include <elf_user.h>
+#include <mem_user.h>
+
+typedef Elf32_auxv_t elf_auxv_t;
+
+/* These are initialized very early in boot and never changed */
+char * elf_aux_platform;
+extern long elf_aux_hwcap;
+unsigned long vsyscall_ehdr;
+unsigned long vsyscall_end;
+unsigned long __kernel_vsyscall;
+
+__init void scan_elf_aux( char **envp)
+{
+ long page_size = 0;
+ elf_auxv_t * auxv;
+
+ while ( *envp++ != NULL) ;
+
+ for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) {
+ switch ( auxv->a_type ) {
+ case AT_SYSINFO:
+ __kernel_vsyscall = auxv->a_un.a_val;
+ /* See if the page is under TASK_SIZE */
+ if (__kernel_vsyscall < (unsigned long) envp)
+ __kernel_vsyscall = 0;
+ break;
+ case AT_SYSINFO_EHDR:
+ vsyscall_ehdr = auxv->a_un.a_val;
+ /* See if the page is under TASK_SIZE */
+ if (vsyscall_ehdr < (unsigned long) envp)
+ vsyscall_ehdr = 0;
+ break;
+ case AT_HWCAP:
+ elf_aux_hwcap = auxv->a_un.a_val;
+ break;
+ case AT_PLATFORM:
+ /* elf.h removed the pointer elements from
+ * a_un, so we have to use a_val, which is
+ * all that's left.
+ */
+ elf_aux_platform =
+ (char *) (long) auxv->a_un.a_val;
+ break;
+ case AT_PAGESZ:
+ page_size = auxv->a_un.a_val;
+ break;
+ }
+ }
+ if ( ! __kernel_vsyscall || ! vsyscall_ehdr ||
+ ! elf_aux_hwcap || ! elf_aux_platform ||
+ ! page_size || (vsyscall_ehdr % page_size) ) {
+ __kernel_vsyscall = 0;
+ vsyscall_ehdr = 0;
+ elf_aux_hwcap = 0;
+ elf_aux_platform = "i586";
+ }
+ else {
+ vsyscall_end = vsyscall_ehdr + page_size;
+ }
+}
diff --git a/arch/um/os-Linux/execvp.c b/arch/um/os-Linux/execvp.c
new file mode 100644
index 0000000000..c09a5fd5e2
--- /dev/null
+++ b/arch/um/os-Linux/execvp.c
@@ -0,0 +1,150 @@
+/* Copyright (C) 2006 by Paolo Giarrusso - modified from glibc' execvp.c.
+ Original copyright notice follows:
+
+ Copyright (C) 1991,92,1995-99,2002,2004 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+#include <unistd.h>
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+
+#ifndef TEST
+#include <um_malloc.h>
+#else
+#include <stdio.h>
+#define um_kmalloc malloc
+#endif
+#include <os.h>
+
+/* Execute FILE, searching in the `PATH' environment variable if it contains
+ no slashes, with arguments ARGV and environment from `environ'. */
+int execvp_noalloc(char *buf, const char *file, char *const argv[])
+{
+ if (*file == '\0') {
+ return -ENOENT;
+ }
+
+ if (strchr (file, '/') != NULL) {
+ /* Don't search when it contains a slash. */
+ execv(file, argv);
+ } else {
+ int got_eacces;
+ size_t len, pathlen;
+ char *name, *p;
+ char *path = getenv("PATH");
+ if (path == NULL)
+ path = ":/bin:/usr/bin";
+
+ len = strlen(file) + 1;
+ pathlen = strlen(path);
+ /* Copy the file name at the top. */
+ name = memcpy(buf + pathlen + 1, file, len);
+ /* And add the slash. */
+ *--name = '/';
+
+ got_eacces = 0;
+ p = path;
+ do {
+ char *startp;
+
+ path = p;
+ //Let's avoid this GNU extension.
+ //p = strchrnul (path, ':');
+ p = strchr(path, ':');
+ if (!p)
+ p = strchr(path, '\0');
+
+ if (p == path)
+ /* Two adjacent colons, or a colon at the beginning or the end
+ of `PATH' means to search the current directory. */
+ startp = name + 1;
+ else
+ startp = memcpy(name - (p - path), path, p - path);
+
+ /* Try to execute this name. If it works, execv will not return. */
+ execv(startp, argv);
+
+ /*
+ if (errno == ENOEXEC) {
+ }
+ */
+
+ switch (errno) {
+ case EACCES:
+ /* Record the we got a `Permission denied' error. If we end
+ up finding no executable we can use, we want to diagnose
+ that we did find one but were denied access. */
+ got_eacces = 1;
+ break;
+ case ENOENT:
+ case ESTALE:
+ case ENOTDIR:
+ /* Those errors indicate the file is missing or not executable
+ by us, in which case we want to just try the next path
+ directory. */
+ case ENODEV:
+ case ETIMEDOUT:
+ /* Some strange filesystems like AFS return even
+ stranger error numbers. They cannot reasonably mean
+ anything else so ignore those, too. */
+ case ENOEXEC:
+ /* We won't go searching for the shell
+ * if it is not executable - the Linux
+ * kernel already handles this enough,
+ * for us. */
+ break;
+
+ default:
+ /* Some other error means we found an executable file, but
+ something went wrong executing it; return the error to our
+ caller. */
+ return -errno;
+ }
+ } while (*p++ != '\0');
+
+ /* We tried every element and none of them worked. */
+ if (got_eacces)
+ /* At least one failure was due to permissions, so report that
+ error. */
+ return -EACCES;
+ }
+
+ /* Return the error from the last attempt (probably ENOENT). */
+ return -errno;
+}
+#ifdef TEST
+int main(int argc, char**argv)
+{
+ char buf[PATH_MAX];
+ int ret;
+ argc--;
+ if (!argc) {
+ os_warn("Not enough arguments\n");
+ return 1;
+ }
+ argv++;
+ if (ret = execvp_noalloc(buf, argv[0], argv)) {
+ errno = -ret;
+ perror("execvp_noalloc");
+ }
+ return 0;
+}
+#endif
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
new file mode 100644
index 0000000000..fc4450db59
--- /dev/null
+++ b/arch/um/os-Linux/file.c
@@ -0,0 +1,707 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <linux/falloc.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <sys/un.h>
+#include <sys/types.h>
+#include <sys/eventfd.h>
+#include <poll.h>
+#include <os.h>
+
+static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
+{
+ *dst = ((struct uml_stat) {
+ .ust_dev = src->st_dev, /* device */
+ .ust_ino = src->st_ino, /* inode */
+ .ust_mode = src->st_mode, /* protection */
+ .ust_nlink = src->st_nlink, /* number of hard links */
+ .ust_uid = src->st_uid, /* user ID of owner */
+ .ust_gid = src->st_gid, /* group ID of owner */
+ .ust_size = src->st_size, /* total size, in bytes */
+ .ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
+ .ust_blocks = src->st_blocks, /* number of blocks allocated */
+ .ust_atime = src->st_atime, /* time of last access */
+ .ust_mtime = src->st_mtime, /* time of last modification */
+ .ust_ctime = src->st_ctime, /* time of last change */
+ });
+}
+
+int os_stat_fd(const int fd, struct uml_stat *ubuf)
+{
+ struct stat64 sbuf;
+ int err;
+
+ CATCH_EINTR(err = fstat64(fd, &sbuf));
+ if (err < 0)
+ return -errno;
+
+ if (ubuf != NULL)
+ copy_stat(ubuf, &sbuf);
+ return err;
+}
+
+int os_stat_file(const char *file_name, struct uml_stat *ubuf)
+{
+ struct stat64 sbuf;
+ int err;
+
+ CATCH_EINTR(err = stat64(file_name, &sbuf));
+ if (err < 0)
+ return -errno;
+
+ if (ubuf != NULL)
+ copy_stat(ubuf, &sbuf);
+ return err;
+}
+
+int os_access(const char *file, int mode)
+{
+ int amode, err;
+
+ amode = (mode & OS_ACC_R_OK ? R_OK : 0) |
+ (mode & OS_ACC_W_OK ? W_OK : 0) |
+ (mode & OS_ACC_X_OK ? X_OK : 0) |
+ (mode & OS_ACC_F_OK ? F_OK : 0);
+
+ err = access(file, amode);
+ if (err < 0)
+ return -errno;
+
+ return 0;
+}
+
+/* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
+int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
+{
+ int err;
+
+ err = ioctl(fd, cmd, arg);
+ if (err < 0)
+ return -errno;
+
+ return err;
+}
+
+/* FIXME: ensure namebuf in os_get_if_name is big enough */
+int os_get_ifname(int fd, char* namebuf)
+{
+ if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
+ return -errno;
+
+ return 0;
+}
+
+int os_set_slip(int fd)
+{
+ int disc, sencap;
+
+ disc = N_SLIP;
+ if (ioctl(fd, TIOCSETD, &disc) < 0)
+ return -errno;
+
+ sencap = 0;
+ if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
+ return -errno;
+
+ return 0;
+}
+
+int os_mode_fd(int fd, int mode)
+{
+ int err;
+
+ CATCH_EINTR(err = fchmod(fd, mode));
+ if (err < 0)
+ return -errno;
+
+ return 0;
+}
+
+int os_file_type(char *file)
+{
+ struct uml_stat buf;
+ int err;
+
+ err = os_stat_file(file, &buf);
+ if (err < 0)
+ return err;
+
+ if (S_ISDIR(buf.ust_mode))
+ return OS_TYPE_DIR;
+ else if (S_ISLNK(buf.ust_mode))
+ return OS_TYPE_SYMLINK;
+ else if (S_ISCHR(buf.ust_mode))
+ return OS_TYPE_CHARDEV;
+ else if (S_ISBLK(buf.ust_mode))
+ return OS_TYPE_BLOCKDEV;
+ else if (S_ISFIFO(buf.ust_mode))
+ return OS_TYPE_FIFO;
+ else if (S_ISSOCK(buf.ust_mode))
+ return OS_TYPE_SOCK;
+ else return OS_TYPE_FILE;
+}
+
+int os_file_mode(const char *file, struct openflags *mode_out)
+{
+ int err;
+
+ *mode_out = OPENFLAGS();
+
+ err = access(file, W_OK);
+ if (err && (errno != EACCES))
+ return -errno;
+ else if (!err)
+ *mode_out = of_write(*mode_out);
+
+ err = access(file, R_OK);
+ if (err && (errno != EACCES))
+ return -errno;
+ else if (!err)
+ *mode_out = of_read(*mode_out);
+
+ return err;
+}
+
+int os_open_file(const char *file, struct openflags flags, int mode)
+{
+ int fd, err, f = 0;
+
+ if (flags.r && flags.w)
+ f = O_RDWR;
+ else if (flags.r)
+ f = O_RDONLY;
+ else if (flags.w)
+ f = O_WRONLY;
+ else f = 0;
+
+ if (flags.s)
+ f |= O_SYNC;
+ if (flags.c)
+ f |= O_CREAT;
+ if (flags.t)
+ f |= O_TRUNC;
+ if (flags.e)
+ f |= O_EXCL;
+ if (flags.a)
+ f |= O_APPEND;
+
+ fd = open64(file, f, mode);
+ if (fd < 0)
+ return -errno;
+
+ if (flags.cl && fcntl(fd, F_SETFD, 1)) {
+ err = -errno;
+ close(fd);
+ return err;
+ }
+
+ return fd;
+}
+
+int os_connect_socket(const char *name)
+{
+ struct sockaddr_un sock;
+ int fd, err;
+
+ sock.sun_family = AF_UNIX;
+ snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
+
+ fd = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (fd < 0) {
+ err = -errno;
+ goto out;
+ }
+
+ err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
+ if (err) {
+ err = -errno;
+ goto out_close;
+ }
+
+ return fd;
+
+out_close:
+ close(fd);
+out:
+ return err;
+}
+
+void os_close_file(int fd)
+{
+ close(fd);
+}
+int os_fsync_file(int fd)
+{
+ if (fsync(fd) < 0)
+ return -errno;
+ return 0;
+}
+
+int os_seek_file(int fd, unsigned long long offset)
+{
+ unsigned long long actual;
+
+ actual = lseek64(fd, offset, SEEK_SET);
+ if (actual != offset)
+ return -errno;
+ return 0;
+}
+
+int os_read_file(int fd, void *buf, int len)
+{
+ int n = read(fd, buf, len);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
+int os_pread_file(int fd, void *buf, int len, unsigned long long offset)
+{
+ int n = pread(fd, buf, len, offset);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
+int os_write_file(int fd, const void *buf, int len)
+{
+ int n = write(fd, (void *) buf, len);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
+int os_sync_file(int fd)
+{
+ int n = fdatasync(fd);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
+int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset)
+{
+ int n = pwrite(fd, (void *) buf, len, offset);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
+
+int os_file_size(const char *file, unsigned long long *size_out)
+{
+ struct uml_stat buf;
+ int err;
+
+ err = os_stat_file(file, &buf);
+ if (err < 0) {
+ printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
+ -err);
+ return err;
+ }
+
+ if (S_ISBLK(buf.ust_mode)) {
+ int fd;
+ long blocks;
+
+ fd = open(file, O_RDONLY, 0);
+ if (fd < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "Couldn't open \"%s\", "
+ "errno = %d\n", file, errno);
+ return err;
+ }
+ if (ioctl(fd, BLKGETSIZE, &blocks) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "Couldn't get the block size of "
+ "\"%s\", errno = %d\n", file, errno);
+ close(fd);
+ return err;
+ }
+ *size_out = ((long long) blocks) * 512;
+ close(fd);
+ }
+ else *size_out = buf.ust_size;
+
+ return 0;
+}
+
+int os_file_modtime(const char *file, long long *modtime)
+{
+ struct uml_stat buf;
+ int err;
+
+ err = os_stat_file(file, &buf);
+ if (err < 0) {
+ printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
+ -err);
+ return err;
+ }
+
+ *modtime = buf.ust_mtime;
+ return 0;
+}
+
+int os_set_exec_close(int fd)
+{
+ int err;
+
+ CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC));
+
+ if (err < 0)
+ return -errno;
+ return err;
+}
+
+int os_pipe(int *fds, int stream, int close_on_exec)
+{
+ int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
+
+ err = socketpair(AF_UNIX, type, 0, fds);
+ if (err < 0)
+ return -errno;
+
+ if (!close_on_exec)
+ return 0;
+
+ err = os_set_exec_close(fds[0]);
+ if (err < 0)
+ goto error;
+
+ err = os_set_exec_close(fds[1]);
+ if (err < 0)
+ goto error;
+
+ return 0;
+
+ error:
+ printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n",
+ -err);
+ close(fds[1]);
+ close(fds[0]);
+ return err;
+}
+
+int os_set_fd_async(int fd)
+{
+ int err, flags;
+
+ flags = fcntl(fd, F_GETFL);
+ if (flags < 0)
+ return -errno;
+
+ flags |= O_ASYNC | O_NONBLOCK;
+ if (fcntl(fd, F_SETFL, flags) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC "
+ "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
+ return err;
+ }
+
+ if ((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
+ (fcntl(fd, F_SETOWN, os_getpid()) < 0)) {
+ err = -errno;
+ printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN "
+ "(or F_SETSIG) fd %d, errno = %d\n", fd, errno);
+ return err;
+ }
+
+ return 0;
+}
+
+int os_clear_fd_async(int fd)
+{
+ int flags;
+
+ flags = fcntl(fd, F_GETFL);
+ if (flags < 0)
+ return -errno;
+
+ flags &= ~(O_ASYNC | O_NONBLOCK);
+ if (fcntl(fd, F_SETFL, flags) < 0)
+ return -errno;
+ return 0;
+}
+
+int os_set_fd_block(int fd, int blocking)
+{
+ int flags;
+
+ flags = fcntl(fd, F_GETFL);
+ if (flags < 0)
+ return -errno;
+
+ if (blocking)
+ flags &= ~O_NONBLOCK;
+ else
+ flags |= O_NONBLOCK;
+
+ if (fcntl(fd, F_SETFL, flags) < 0)
+ return -errno;
+
+ return 0;
+}
+
+int os_accept_connection(int fd)
+{
+ int new;
+
+ new = accept(fd, NULL, 0);
+ if (new < 0)
+ return -errno;
+ return new;
+}
+
+#ifndef SHUT_RD
+#define SHUT_RD 0
+#endif
+
+#ifndef SHUT_WR
+#define SHUT_WR 1
+#endif
+
+#ifndef SHUT_RDWR
+#define SHUT_RDWR 2
+#endif
+
+int os_shutdown_socket(int fd, int r, int w)
+{
+ int what, err;
+
+ if (r && w)
+ what = SHUT_RDWR;
+ else if (r)
+ what = SHUT_RD;
+ else if (w)
+ what = SHUT_WR;
+ else
+ return -EINVAL;
+
+ err = shutdown(fd, what);
+ if (err < 0)
+ return -errno;
+ return 0;
+}
+
+int os_rcv_fd(int fd, int *helper_pid_out)
+{
+ int new, n;
+ char buf[CMSG_SPACE(sizeof(new))];
+ struct msghdr msg;
+ struct cmsghdr *cmsg;
+ struct iovec iov;
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ iov = ((struct iovec) { .iov_base = helper_pid_out,
+ .iov_len = sizeof(*helper_pid_out) });
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+ msg.msg_control = buf;
+ msg.msg_controllen = sizeof(buf);
+ msg.msg_flags = 0;
+
+ n = recvmsg(fd, &msg, 0);
+ if (n < 0)
+ return -errno;
+ else if (n != iov.iov_len)
+ *helper_pid_out = -1;
+
+ cmsg = CMSG_FIRSTHDR(&msg);
+ if (cmsg == NULL) {
+ printk(UM_KERN_ERR "rcv_fd didn't receive anything, "
+ "error = %d\n", errno);
+ return -1;
+ }
+ if ((cmsg->cmsg_level != SOL_SOCKET) ||
+ (cmsg->cmsg_type != SCM_RIGHTS)) {
+ printk(UM_KERN_ERR "rcv_fd didn't receive a descriptor\n");
+ return -1;
+ }
+
+ new = ((int *) CMSG_DATA(cmsg))[0];
+ return new;
+}
+
+int os_create_unix_socket(const char *file, int len, int close_on_exec)
+{
+ struct sockaddr_un addr;
+ int sock, err;
+
+ sock = socket(PF_UNIX, SOCK_DGRAM, 0);
+ if (sock < 0)
+ return -errno;
+
+ if (close_on_exec) {
+ err = os_set_exec_close(sock);
+ if (err < 0)
+ printk(UM_KERN_ERR "create_unix_socket : "
+ "close_on_exec failed, err = %d", -err);
+ }
+
+ addr.sun_family = AF_UNIX;
+
+ snprintf(addr.sun_path, len, "%s", file);
+
+ err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
+ if (err < 0)
+ return -errno;
+
+ return sock;
+}
+
+void os_flush_stdout(void)
+{
+ fflush(stdout);
+}
+
+int os_lock_file(int fd, int excl)
+{
+ int type = excl ? F_WRLCK : F_RDLCK;
+ struct flock lock = ((struct flock) { .l_type = type,
+ .l_whence = SEEK_SET,
+ .l_start = 0,
+ .l_len = 0 } );
+ int err, save;
+
+ err = fcntl(fd, F_SETLK, &lock);
+ if (!err)
+ goto out;
+
+ save = -errno;
+ err = fcntl(fd, F_GETLK, &lock);
+ if (err) {
+ err = -errno;
+ goto out;
+ }
+
+ printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n",
+ lock.l_pid);
+ err = save;
+ out:
+ return err;
+}
+
+unsigned os_major(unsigned long long dev)
+{
+ return major(dev);
+}
+
+unsigned os_minor(unsigned long long dev)
+{
+ return minor(dev);
+}
+
+unsigned long long os_makedev(unsigned major, unsigned minor)
+{
+ return makedev(major, minor);
+}
+
+int os_falloc_punch(int fd, unsigned long long offset, int len)
+{
+ int n = fallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, offset, len);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
+int os_falloc_zeroes(int fd, unsigned long long offset, int len)
+{
+ int n = fallocate(fd, FALLOC_FL_ZERO_RANGE|FALLOC_FL_KEEP_SIZE, offset, len);
+
+ if (n < 0)
+ return -errno;
+ return n;
+}
+
+int os_eventfd(unsigned int initval, int flags)
+{
+ int fd = eventfd(initval, flags);
+
+ if (fd < 0)
+ return -errno;
+ return fd;
+}
+
+int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds,
+ unsigned int fds_num)
+{
+ struct iovec iov = {
+ .iov_base = (void *) buf,
+ .iov_len = len,
+ };
+ union {
+ char control[CMSG_SPACE(sizeof(*fds) * OS_SENDMSG_MAX_FDS)];
+ struct cmsghdr align;
+ } u;
+ unsigned int fds_size = sizeof(*fds) * fds_num;
+ struct msghdr msg = {
+ .msg_iov = &iov,
+ .msg_iovlen = 1,
+ .msg_control = u.control,
+ .msg_controllen = CMSG_SPACE(fds_size),
+ };
+ struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
+ int err;
+
+ if (fds_num > OS_SENDMSG_MAX_FDS)
+ return -EINVAL;
+ memset(u.control, 0, sizeof(u.control));
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_RIGHTS;
+ cmsg->cmsg_len = CMSG_LEN(fds_size);
+ memcpy(CMSG_DATA(cmsg), fds, fds_size);
+ err = sendmsg(fd, &msg, 0);
+
+ if (err < 0)
+ return -errno;
+ return err;
+}
+
+int os_poll(unsigned int n, const int *fds)
+{
+ /* currently need 2 FDs at most so avoid dynamic allocation */
+ struct pollfd pollfds[2] = {};
+ unsigned int i;
+ int ret;
+
+ if (n > ARRAY_SIZE(pollfds))
+ return -EINVAL;
+
+ for (i = 0; i < n; i++) {
+ pollfds[i].fd = fds[i];
+ pollfds[i].events = POLLIN;
+ }
+
+ ret = poll(pollfds, n, -1);
+ if (ret < 0)
+ return -errno;
+
+ /* Return the index of the available FD */
+ for (i = 0; i < n; i++) {
+ if (pollfds[i].revents)
+ return i;
+ }
+
+ return -EIO;
+}
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
new file mode 100644
index 0000000000..b459745f52
--- /dev/null
+++ b/arch/um/os-Linux/helper.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sched.h>
+#include <linux/limits.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <kern_util.h>
+#include <os.h>
+#include <um_malloc.h>
+
+struct helper_data {
+ void (*pre_exec)(void*);
+ void *pre_data;
+ char **argv;
+ int fd;
+ char *buf;
+};
+
+static int helper_child(void *arg)
+{
+ struct helper_data *data = arg;
+ char **argv = data->argv;
+ int err, ret;
+
+ if (data->pre_exec != NULL)
+ (*data->pre_exec)(data->pre_data);
+ err = execvp_noalloc(data->buf, argv[0], argv);
+
+ /* If the exec succeeds, we don't get here */
+ CATCH_EINTR(ret = write(data->fd, &err, sizeof(err)));
+
+ return 0;
+}
+
+/* Returns either the pid of the child process we run or -E* on failure. */
+int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
+{
+ struct helper_data data;
+ unsigned long stack, sp;
+ int pid, fds[2], ret, n;
+
+ stack = alloc_stack(0, __cant_sleep());
+ if (stack == 0)
+ return -ENOMEM;
+
+ ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
+ if (ret < 0) {
+ ret = -errno;
+ printk(UM_KERN_ERR "run_helper : pipe failed, errno = %d\n",
+ errno);
+ goto out_free;
+ }
+
+ ret = os_set_exec_close(fds[1]);
+ if (ret < 0) {
+ printk(UM_KERN_ERR "run_helper : setting FD_CLOEXEC failed, "
+ "ret = %d\n", -ret);
+ goto out_close;
+ }
+
+ sp = stack + UM_KERN_PAGE_SIZE;
+ data.pre_exec = pre_exec;
+ data.pre_data = pre_data;
+ data.argv = argv;
+ data.fd = fds[1];
+ data.buf = __cant_sleep() ? uml_kmalloc(PATH_MAX, UM_GFP_ATOMIC) :
+ uml_kmalloc(PATH_MAX, UM_GFP_KERNEL);
+ pid = clone(helper_child, (void *) sp, CLONE_VM, &data);
+ if (pid < 0) {
+ ret = -errno;
+ printk(UM_KERN_ERR "run_helper : clone failed, errno = %d\n",
+ errno);
+ goto out_free2;
+ }
+
+ close(fds[1]);
+ fds[1] = -1;
+
+ /*
+ * Read the errno value from the child, if the exec failed, or get 0 if
+ * the exec succeeded because the pipe fd was set as close-on-exec.
+ */
+ n = read(fds[0], &ret, sizeof(ret));
+ if (n == 0) {
+ ret = pid;
+ } else {
+ if (n < 0) {
+ n = -errno;
+ printk(UM_KERN_ERR "run_helper : read on pipe failed, "
+ "ret = %d\n", -n);
+ ret = n;
+ }
+ CATCH_EINTR(waitpid(pid, NULL, __WALL));
+ }
+
+ if (ret < 0)
+ printk(UM_KERN_ERR "run_helper : failed to exec %s on host: %s\n",
+ argv[0], strerror(-ret));
+
+out_free2:
+ kfree(data.buf);
+out_close:
+ if (fds[1] != -1)
+ close(fds[1]);
+ close(fds[0]);
+out_free:
+ free_stack(stack, 0);
+ return ret;
+}
+
+int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
+ unsigned long *stack_out)
+{
+ unsigned long stack, sp;
+ int pid, status, err;
+
+ stack = alloc_stack(0, __cant_sleep());
+ if (stack == 0)
+ return -ENOMEM;
+
+ sp = stack + UM_KERN_PAGE_SIZE;
+ pid = clone(proc, (void *) sp, flags, arg);
+ if (pid < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "run_helper_thread : clone failed, "
+ "errno = %d\n", errno);
+ return err;
+ }
+ if (stack_out == NULL) {
+ CATCH_EINTR(pid = waitpid(pid, &status, __WALL));
+ if (pid < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "run_helper_thread - wait failed, "
+ "errno = %d\n", errno);
+ pid = err;
+ }
+ if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
+ printk(UM_KERN_ERR "run_helper_thread - thread "
+ "returned status 0x%x\n", status);
+ free_stack(stack, 0);
+ } else
+ *stack_out = stack;
+ return pid;
+}
+
+int helper_wait(int pid)
+{
+ int ret, status;
+ int wflags = __WALL;
+
+ CATCH_EINTR(ret = waitpid(pid, &status, wflags));
+ if (ret < 0) {
+ printk(UM_KERN_ERR "helper_wait : waitpid process %d failed, "
+ "errno = %d\n", pid, errno);
+ return -errno;
+ } else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+ printk(UM_KERN_ERR "helper_wait : process %d exited with "
+ "status 0x%x\n", pid, status);
+ return -ECHILD;
+ } else
+ return 0;
+}
diff --git a/arch/um/os-Linux/irq.c b/arch/um/os-Linux/irq.c
new file mode 100644
index 0000000000..cf7e49c08b
--- /dev/null
+++ b/arch/um/os-Linux/irq.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 - Cambridge Greys Ltd
+ * Copyright (C) 2011 - 2014 Cisco Systems Inc
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/epoll.h>
+#include <signal.h>
+#include <string.h>
+#include <irq_user.h>
+#include <os.h>
+#include <um_malloc.h>
+
+/* Epoll support */
+
+static int epollfd = -1;
+
+#define MAX_EPOLL_EVENTS 64
+
+static struct epoll_event epoll_events[MAX_EPOLL_EVENTS];
+
+/* Helper to return an Epoll data pointer from an epoll event structure.
+ * We need to keep this one on the userspace side to keep includes separate
+ */
+
+void *os_epoll_get_data_pointer(int index)
+{
+ return epoll_events[index].data.ptr;
+}
+
+/* Helper to compare events versus the events in the epoll structure.
+ * Same as above - needs to be on the userspace side
+ */
+
+
+int os_epoll_triggered(int index, int events)
+{
+ return epoll_events[index].events & events;
+}
+/* Helper to set the event mask.
+ * The event mask is opaque to the kernel side, because it does not have
+ * access to the right includes/defines for EPOLL constants.
+ */
+
+int os_event_mask(enum um_irq_type irq_type)
+{
+ if (irq_type == IRQ_READ)
+ return EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP | EPOLLRDHUP;
+ if (irq_type == IRQ_WRITE)
+ return EPOLLOUT;
+ return 0;
+}
+
+/*
+ * Initial Epoll Setup
+ */
+int os_setup_epoll(void)
+{
+ epollfd = epoll_create(MAX_EPOLL_EVENTS);
+ return epollfd;
+}
+
+/*
+ * Helper to run the actual epoll_wait
+ */
+int os_waiting_for_events_epoll(void)
+{
+ int n, err;
+
+ n = epoll_wait(epollfd,
+ (struct epoll_event *) &epoll_events, MAX_EPOLL_EVENTS, 0);
+ if (n < 0) {
+ err = -errno;
+ if (errno != EINTR)
+ printk(
+ UM_KERN_ERR "os_waiting_for_events:"
+ " epoll returned %d, error = %s\n", n,
+ strerror(errno)
+ );
+ return err;
+ }
+ return n;
+}
+
+
+/*
+ * Helper to add a fd to epoll
+ */
+int os_add_epoll_fd(int events, int fd, void *data)
+{
+ struct epoll_event event;
+ int result;
+
+ event.data.ptr = data;
+ event.events = events | EPOLLET;
+ result = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event);
+ if ((result) && (errno == EEXIST))
+ result = os_mod_epoll_fd(events, fd, data);
+ if (result)
+ printk("epollctl add err fd %d, %s\n", fd, strerror(errno));
+ return result;
+}
+
+/*
+ * Helper to mod the fd event mask and/or data backreference
+ */
+int os_mod_epoll_fd(int events, int fd, void *data)
+{
+ struct epoll_event event;
+ int result;
+
+ event.data.ptr = data;
+ event.events = events;
+ result = epoll_ctl(epollfd, EPOLL_CTL_MOD, fd, &event);
+ if (result)
+ printk(UM_KERN_ERR
+ "epollctl mod err fd %d, %s\n", fd, strerror(errno));
+ return result;
+}
+
+/*
+ * Helper to delete the epoll fd
+ */
+int os_del_epoll_fd(int fd)
+{
+ struct epoll_event event;
+ /* This is quiet as we use this as IO ON/OFF - so it is often
+ * invoked on a non-existent fd
+ */
+ return epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, &event);
+}
+
+void os_set_ioignore(void)
+{
+ signal(SIGIO, SIG_IGN);
+}
+
+void os_close_epoll_fd(void)
+{
+ /* Needed so we do not leak an fd when rebooting */
+ os_close_file(epollfd);
+}
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
new file mode 100644
index 0000000000..c8a42ecbd7
--- /dev/null
+++ b/arch/um/os-Linux/main.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <as-layout.h>
+#include <init.h>
+#include <kern_util.h>
+#include <os.h>
+#include <um_malloc.h>
+
+#define PGD_BOUND (4 * 1024 * 1024)
+#define STACKSIZE (8 * 1024 * 1024)
+#define THREAD_NAME_LEN (256)
+
+long elf_aux_hwcap;
+
+static void set_stklim(void)
+{
+ struct rlimit lim;
+
+ if (getrlimit(RLIMIT_STACK, &lim) < 0) {
+ perror("getrlimit");
+ exit(1);
+ }
+ if ((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)) {
+ lim.rlim_cur = STACKSIZE;
+ if (setrlimit(RLIMIT_STACK, &lim) < 0) {
+ perror("setrlimit");
+ exit(1);
+ }
+ }
+}
+
+static void last_ditch_exit(int sig)
+{
+ uml_cleanup();
+ exit(1);
+}
+
+static void install_fatal_handler(int sig)
+{
+ struct sigaction action;
+
+ /* All signals are enabled in this handler ... */
+ sigemptyset(&action.sa_mask);
+
+ /*
+ * ... including the signal being handled, plus we want the
+ * handler reset to the default behavior, so that if an exit
+ * handler is hanging for some reason, the UML will just die
+ * after this signal is sent a second time.
+ */
+ action.sa_flags = SA_RESETHAND | SA_NODEFER;
+ action.sa_restorer = NULL;
+ action.sa_handler = last_ditch_exit;
+ if (sigaction(sig, &action, NULL) < 0) {
+ os_warn("failed to install handler for signal %d "
+ "- errno = %d\n", sig, errno);
+ exit(1);
+ }
+}
+
+#define UML_LIB_PATH ":" OS_LIB_PATH "/uml"
+
+static void setup_env_path(void)
+{
+ char *new_path = NULL;
+ char *old_path = NULL;
+ int path_len = 0;
+
+ old_path = getenv("PATH");
+ /*
+ * if no PATH variable is set or it has an empty value
+ * just use the default + /usr/lib/uml
+ */
+ if (!old_path || (path_len = strlen(old_path)) == 0) {
+ if (putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH))
+ perror("couldn't putenv");
+ return;
+ }
+
+ /* append /usr/lib/uml to the existing path */
+ path_len += strlen("PATH=" UML_LIB_PATH) + 1;
+ new_path = malloc(path_len);
+ if (!new_path) {
+ perror("couldn't malloc to set a new PATH");
+ return;
+ }
+ snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path);
+ if (putenv(new_path)) {
+ perror("couldn't putenv to set a new PATH");
+ free(new_path);
+ }
+}
+
+extern void scan_elf_aux( char **envp);
+
+int __init main(int argc, char **argv, char **envp)
+{
+ char **new_argv;
+ int ret, i, err;
+
+ set_stklim();
+
+ setup_env_path();
+
+ setsid();
+
+ new_argv = malloc((argc + 1) * sizeof(char *));
+ if (new_argv == NULL) {
+ perror("Mallocing argv");
+ exit(1);
+ }
+ for (i = 0; i < argc; i++) {
+ new_argv[i] = strdup(argv[i]);
+ if (new_argv[i] == NULL) {
+ perror("Mallocing an arg");
+ exit(1);
+ }
+ }
+ new_argv[argc] = NULL;
+
+ /*
+ * Allow these signals to bring down a UML if all other
+ * methods of control fail.
+ */
+ install_fatal_handler(SIGINT);
+ install_fatal_handler(SIGTERM);
+
+#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
+ scan_elf_aux(envp);
+#endif
+
+ change_sig(SIGPIPE, 0);
+ ret = linux_main(argc, argv);
+
+ /*
+ * Disable SIGPROF - I have no idea why libc doesn't do this or turn
+ * off the profiling time, but UML dies with a SIGPROF just before
+ * exiting when profiling is active.
+ */
+ change_sig(SIGPROF, 0);
+
+ /*
+ * This signal stuff used to be in the reboot case. However,
+ * sometimes a timer signal can come in when we're halting (reproducably
+ * when writing out gcov information, presumably because that takes
+ * some time) and cause a segfault.
+ */
+
+ /* stop timers and set timer signal to be ignored */
+ os_timer_disable();
+
+ /* disable SIGIO for the fds and set SIGIO to be ignored */
+ err = deactivate_all_fds();
+ if (err)
+ os_warn("deactivate_all_fds failed, errno = %d\n", -err);
+
+ /*
+ * Let any pending signals fire now. This ensures
+ * that they won't be delivered after the exec, when
+ * they are definitely not expected.
+ */
+ unblock_signals();
+
+ os_info("\n");
+ /* Reboot */
+ if (ret) {
+ execvp(new_argv[0], new_argv);
+ perror("Failed to exec kernel");
+ ret = 1;
+ }
+ return uml_exitcode;
+}
+
+extern void *__real_malloc(int);
+
+void *__wrap_malloc(int size)
+{
+ void *ret;
+
+ if (!kmalloc_ok)
+ return __real_malloc(size);
+ else if (size <= UM_KERN_PAGE_SIZE)
+ /* finding contiguous pages can be hard*/
+ ret = uml_kmalloc(size, UM_GFP_KERNEL);
+ else ret = vmalloc(size);
+
+ /*
+ * glibc people insist that if malloc fails, errno should be
+ * set by malloc as well. So we do.
+ */
+ if (ret == NULL)
+ errno = ENOMEM;
+
+ return ret;
+}
+
+void *__wrap_calloc(int n, int size)
+{
+ void *ptr = __wrap_malloc(n * size);
+
+ if (ptr == NULL)
+ return NULL;
+ memset(ptr, 0, n * size);
+ return ptr;
+}
+
+extern void __real_free(void *);
+
+extern unsigned long high_physmem;
+
+void __wrap_free(void *ptr)
+{
+ unsigned long addr = (unsigned long) ptr;
+
+ /*
+ * We need to know how the allocation happened, so it can be correctly
+ * freed. This is done by seeing what region of memory the pointer is
+ * in -
+ * physical memory - kmalloc/kfree
+ * kernel virtual memory - vmalloc/vfree
+ * anywhere else - malloc/free
+ * If kmalloc is not yet possible, then either high_physmem and/or
+ * end_vm are still 0 (as at startup), in which case we call free, or
+ * we have set them, but anyway addr has not been allocated from those
+ * areas. So, in both cases __real_free is called.
+ *
+ * CAN_KMALLOC is checked because it would be bad to free a buffer
+ * with kmalloc/vmalloc after they have been turned off during
+ * shutdown.
+ * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so
+ * there is a possibility for memory leaks.
+ */
+
+ if ((addr >= uml_physmem) && (addr < high_physmem)) {
+ if (kmalloc_ok)
+ kfree(ptr);
+ }
+ else if ((addr >= start_vm) && (addr < end_vm)) {
+ if (kmalloc_ok)
+ vfree(ptr);
+ }
+ else __real_free(ptr);
+}
diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
new file mode 100644
index 0000000000..8530b2e086
--- /dev/null
+++ b/arch/um/os-Linux/mem.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/vfs.h>
+#include <linux/magic.h>
+#include <init.h>
+#include <os.h>
+
+/*
+ * kasan_map_memory - maps memory from @start with a size of @len.
+ * The allocated memory is filled with zeroes upon success.
+ * @start: the start address of the memory to be mapped
+ * @len: the length of the memory to be mapped
+ *
+ * This function is used to map shadow memory for KASAN in uml
+ */
+void kasan_map_memory(void *start, size_t len)
+{
+ if (mmap(start,
+ len,
+ PROT_READ|PROT_WRITE,
+ MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE,
+ -1,
+ 0) == MAP_FAILED) {
+ os_info("Couldn't allocate shadow memory: %s\n.",
+ strerror(errno));
+ exit(1);
+ }
+}
+
+/* Set by make_tempfile() during early boot. */
+static char *tempdir = NULL;
+
+/* Check if dir is on tmpfs. Return 0 if yes, -1 if no or error. */
+static int __init check_tmpfs(const char *dir)
+{
+ struct statfs st;
+
+ os_info("Checking if %s is on tmpfs...", dir);
+ if (statfs(dir, &st) < 0) {
+ os_info("%s\n", strerror(errno));
+ } else if (st.f_type != TMPFS_MAGIC) {
+ os_info("no\n");
+ } else {
+ os_info("OK\n");
+ return 0;
+ }
+ return -1;
+}
+
+/*
+ * Choose the tempdir to use. We want something on tmpfs so that our memory is
+ * not subject to the host's vm.dirty_ratio. If a tempdir is specified in the
+ * environment, we use that even if it's not on tmpfs, but we warn the user.
+ * Otherwise, we try common tmpfs locations, and if no tmpfs directory is found
+ * then we fall back to /tmp.
+ */
+static char * __init choose_tempdir(void)
+{
+ static const char * const vars[] = {
+ "TMPDIR",
+ "TMP",
+ "TEMP",
+ NULL
+ };
+ static const char fallback_dir[] = "/tmp";
+ static const char * const tmpfs_dirs[] = {
+ "/dev/shm",
+ fallback_dir,
+ NULL
+ };
+ int i;
+ const char *dir;
+
+ os_info("Checking environment variables for a tempdir...");
+ for (i = 0; vars[i]; i++) {
+ dir = getenv(vars[i]);
+ if ((dir != NULL) && (*dir != '\0')) {
+ os_info("%s\n", dir);
+ if (check_tmpfs(dir) >= 0)
+ goto done;
+ else
+ goto warn;
+ }
+ }
+ os_info("none found\n");
+
+ for (i = 0; tmpfs_dirs[i]; i++) {
+ dir = tmpfs_dirs[i];
+ if (check_tmpfs(dir) >= 0)
+ goto done;
+ }
+
+ dir = fallback_dir;
+warn:
+ os_warn("Warning: tempdir %s is not on tmpfs\n", dir);
+done:
+ /* Make a copy since getenv results may not remain valid forever. */
+ return strdup(dir);
+}
+
+/*
+ * Create an unlinked tempfile in a suitable tempdir. template must be the
+ * basename part of the template with a leading '/'.
+ */
+static int __init make_tempfile(const char *template)
+{
+ char *tempname;
+ int fd;
+
+ if (tempdir == NULL) {
+ tempdir = choose_tempdir();
+ if (tempdir == NULL) {
+ os_warn("Failed to choose tempdir: %s\n",
+ strerror(errno));
+ return -1;
+ }
+ }
+
+#ifdef O_TMPFILE
+ fd = open(tempdir, O_CLOEXEC | O_RDWR | O_EXCL | O_TMPFILE, 0700);
+ /*
+ * If the running system does not support O_TMPFILE flag then retry
+ * without it.
+ */
+ if (fd != -1 || (errno != EINVAL && errno != EISDIR &&
+ errno != EOPNOTSUPP))
+ return fd;
+#endif
+
+ tempname = malloc(strlen(tempdir) + strlen(template) + 1);
+ if (tempname == NULL)
+ return -1;
+
+ strcpy(tempname, tempdir);
+ strcat(tempname, template);
+ fd = mkstemp(tempname);
+ if (fd < 0) {
+ os_warn("open - cannot create %s: %s\n", tempname,
+ strerror(errno));
+ goto out;
+ }
+ if (unlink(tempname) < 0) {
+ perror("unlink");
+ goto close;
+ }
+ free(tempname);
+ return fd;
+close:
+ close(fd);
+out:
+ free(tempname);
+ return -1;
+}
+
+#define TEMPNAME_TEMPLATE "/vm_file-XXXXXX"
+
+static int __init create_tmp_file(unsigned long long len)
+{
+ int fd, err;
+ char zero;
+
+ fd = make_tempfile(TEMPNAME_TEMPLATE);
+ if (fd < 0)
+ exit(1);
+
+ /*
+ * Seek to len - 1 because writing a character there will
+ * increase the file size by one byte, to the desired length.
+ */
+ if (lseek64(fd, len - 1, SEEK_SET) < 0) {
+ perror("lseek64");
+ exit(1);
+ }
+
+ zero = 0;
+
+ err = write(fd, &zero, 1);
+ if (err != 1) {
+ perror("write");
+ exit(1);
+ }
+
+ return fd;
+}
+
+int __init create_mem_file(unsigned long long len)
+{
+ int err, fd;
+
+ fd = create_tmp_file(len);
+
+ err = os_set_exec_close(fd);
+ if (err < 0) {
+ errno = -err;
+ perror("exec_close");
+ }
+ return fd;
+}
+
+void __init check_tmpexec(void)
+{
+ void *addr;
+ int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);
+
+ addr = mmap(NULL, UM_KERN_PAGE_SIZE,
+ PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
+ os_info("Checking PROT_EXEC mmap in %s...", tempdir);
+ if (addr == MAP_FAILED) {
+ err = errno;
+ os_warn("%s\n", strerror(err));
+ close(fd);
+ if (err == EPERM)
+ os_warn("%s must be not mounted noexec\n", tempdir);
+ exit(1);
+ }
+ os_info("OK\n");
+ munmap(addr, UM_KERN_PAGE_SIZE);
+
+ close(fd);
+}
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
new file mode 100644
index 0000000000..e52dd37dda
--- /dev/null
+++ b/arch/um/os-Linux/process.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <asm/unistd.h>
+#include <init.h>
+#include <longjmp.h>
+#include <os.h>
+
+#define ARBITRARY_ADDR -1
+#define FAILURE_PID -1
+
+#define STAT_PATH_LEN sizeof("/proc/#######/stat\0")
+#define COMM_SCANF "%*[^)])"
+
+unsigned long os_process_pc(int pid)
+{
+ char proc_stat[STAT_PATH_LEN], buf[256];
+ unsigned long pc = ARBITRARY_ADDR;
+ int fd, err;
+
+ sprintf(proc_stat, "/proc/%d/stat", pid);
+ fd = open(proc_stat, O_RDONLY, 0);
+ if (fd < 0) {
+ printk(UM_KERN_ERR "os_process_pc - couldn't open '%s', "
+ "errno = %d\n", proc_stat, errno);
+ goto out;
+ }
+ CATCH_EINTR(err = read(fd, buf, sizeof(buf)));
+ if (err < 0) {
+ printk(UM_KERN_ERR "os_process_pc - couldn't read '%s', "
+ "err = %d\n", proc_stat, errno);
+ goto out_close;
+ }
+ os_close_file(fd);
+ pc = ARBITRARY_ADDR;
+ if (sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d "
+ "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d "
+ "%*d %*d %*d %*d %*d %lu", &pc) != 1)
+ printk(UM_KERN_ERR "os_process_pc - couldn't find pc in '%s'\n",
+ buf);
+ out_close:
+ close(fd);
+ out:
+ return pc;
+}
+
+int os_process_parent(int pid)
+{
+ char stat[STAT_PATH_LEN];
+ char data[256];
+ int parent = FAILURE_PID, n, fd;
+
+ if (pid == -1)
+ return parent;
+
+ snprintf(stat, sizeof(stat), "/proc/%d/stat", pid);
+ fd = open(stat, O_RDONLY, 0);
+ if (fd < 0) {
+ printk(UM_KERN_ERR "Couldn't open '%s', errno = %d\n", stat,
+ errno);
+ return parent;
+ }
+
+ CATCH_EINTR(n = read(fd, data, sizeof(data)));
+ close(fd);
+
+ if (n < 0) {
+ printk(UM_KERN_ERR "Couldn't read '%s', errno = %d\n", stat,
+ errno);
+ return parent;
+ }
+
+ parent = FAILURE_PID;
+ n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent);
+ if (n != 1)
+ printk(UM_KERN_ERR "Failed to scan '%s'\n", data);
+
+ return parent;
+}
+
+void os_alarm_process(int pid)
+{
+ kill(pid, SIGALRM);
+}
+
+void os_stop_process(int pid)
+{
+ kill(pid, SIGSTOP);
+}
+
+void os_kill_process(int pid, int reap_child)
+{
+ kill(pid, SIGKILL);
+ if (reap_child)
+ CATCH_EINTR(waitpid(pid, NULL, __WALL));
+}
+
+/* Kill off a ptraced child by all means available. kill it normally first,
+ * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
+ * which it can't exit directly.
+ */
+
+void os_kill_ptraced_process(int pid, int reap_child)
+{
+ kill(pid, SIGKILL);
+ ptrace(PTRACE_KILL, pid);
+ ptrace(PTRACE_CONT, pid);
+ if (reap_child)
+ CATCH_EINTR(waitpid(pid, NULL, __WALL));
+}
+
+/* Don't use the glibc version, which caches the result in TLS. It misses some
+ * syscalls, and also breaks with clone(), which does not unshare the TLS.
+ */
+
+int os_getpid(void)
+{
+ return syscall(__NR_getpid);
+}
+
+int os_getpgrp(void)
+{
+ return getpgrp();
+}
+
+int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len,
+ int r, int w, int x)
+{
+ void *loc;
+ int prot;
+
+ prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
+ (x ? PROT_EXEC : 0);
+
+ loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED,
+ fd, off);
+ if (loc == MAP_FAILED)
+ return -errno;
+ return 0;
+}
+
+int os_protect_memory(void *addr, unsigned long len, int r, int w, int x)
+{
+ int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
+ (x ? PROT_EXEC : 0));
+
+ if (mprotect(addr, len, prot) < 0)
+ return -errno;
+
+ return 0;
+}
+
+int os_unmap_memory(void *addr, int len)
+{
+ int err;
+
+ err = munmap(addr, len);
+ if (err < 0)
+ return -errno;
+ return 0;
+}
+
+#ifndef MADV_REMOVE
+#define MADV_REMOVE KERNEL_MADV_REMOVE
+#endif
+
+int os_drop_memory(void *addr, int length)
+{
+ int err;
+
+ err = madvise(addr, length, MADV_REMOVE);
+ if (err < 0)
+ err = -errno;
+ return err;
+}
+
+int __init can_drop_memory(void)
+{
+ void *addr;
+ int fd, ok = 0;
+
+ printk(UM_KERN_INFO "Checking host MADV_REMOVE support...");
+ fd = create_mem_file(UM_KERN_PAGE_SIZE);
+ if (fd < 0) {
+ printk(UM_KERN_ERR "Creating test memory file failed, "
+ "err = %d\n", -fd);
+ goto out;
+ }
+
+ addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
+ MAP_SHARED, fd, 0);
+ if (addr == MAP_FAILED) {
+ printk(UM_KERN_ERR "Mapping test memory file failed, "
+ "err = %d\n", -errno);
+ goto out_close;
+ }
+
+ if (madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0) {
+ printk(UM_KERN_ERR "MADV_REMOVE failed, err = %d\n", -errno);
+ goto out_unmap;
+ }
+
+ printk(UM_KERN_CONT "OK\n");
+ ok = 1;
+
+out_unmap:
+ munmap(addr, UM_KERN_PAGE_SIZE);
+out_close:
+ close(fd);
+out:
+ return ok;
+}
+
+static int os_page_mincore(void *addr)
+{
+ char vec[2];
+ int ret;
+
+ ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
+ if (ret < 0) {
+ if (errno == ENOMEM || errno == EINVAL)
+ return 0;
+ else
+ return -errno;
+ }
+
+ return vec[0] & 1;
+}
+
+int os_mincore(void *addr, unsigned long len)
+{
+ char *vec;
+ int ret, i;
+
+ if (len <= UM_KERN_PAGE_SIZE)
+ return os_page_mincore(addr);
+
+ vec = calloc(1, (len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE);
+ if (!vec)
+ return -ENOMEM;
+
+ ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
+ if (ret < 0) {
+ if (errno == ENOMEM || errno == EINVAL)
+ ret = 0;
+ else
+ ret = -errno;
+
+ goto out;
+ }
+
+ for (i = 0; i < ((len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); i++) {
+ if (!(vec[i] & 1)) {
+ ret = 0;
+ goto out;
+ }
+ }
+
+ ret = 1;
+out:
+ free(vec);
+ return ret;
+}
+
+void init_new_thread_signals(void)
+{
+ set_handler(SIGSEGV);
+ set_handler(SIGTRAP);
+ set_handler(SIGFPE);
+ set_handler(SIGILL);
+ set_handler(SIGBUS);
+ signal(SIGHUP, SIG_IGN);
+ set_handler(SIGIO);
+ signal(SIGWINCH, SIG_IGN);
+}
diff --git a/arch/um/os-Linux/registers.c b/arch/um/os-Linux/registers.c
new file mode 100644
index 0000000000..b123955be7
--- /dev/null
+++ b/arch/um/os-Linux/registers.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2004 PathScale, Inc
+ * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <sys/ptrace.h>
+#include <sysdep/ptrace.h>
+#include <sysdep/ptrace_user.h>
+#include <registers.h>
+
+int save_registers(int pid, struct uml_pt_regs *regs)
+{
+ int err;
+
+ err = ptrace(PTRACE_GETREGS, pid, 0, regs->gp);
+ if (err < 0)
+ return -errno;
+ return 0;
+}
+
+int restore_pid_registers(int pid, struct uml_pt_regs *regs)
+{
+ int err;
+
+ err = ptrace(PTRACE_SETREGS, pid, 0, regs->gp);
+ if (err < 0)
+ return -errno;
+ return 0;
+}
+
+/* This is set once at boot time and not changed thereafter */
+
+static unsigned long exec_regs[MAX_REG_NR];
+static unsigned long exec_fp_regs[FP_SIZE];
+
+int init_pid_registers(int pid)
+{
+ int err;
+
+ err = ptrace(PTRACE_GETREGS, pid, 0, exec_regs);
+ if (err < 0)
+ return -errno;
+
+ arch_init_registers(pid);
+ get_fp_registers(pid, exec_fp_regs);
+ return 0;
+}
+
+void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
+{
+ memcpy(regs, exec_regs, sizeof(exec_regs));
+
+ if (fp_regs)
+ memcpy(fp_regs, exec_fp_regs, sizeof(exec_fp_regs));
+}
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
new file mode 100644
index 0000000000..9e71794839
--- /dev/null
+++ b/arch/um/os-Linux/sigio.c
@@ -0,0 +1,550 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <pty.h>
+#include <sched.h>
+#include <signal.h>
+#include <string.h>
+#include <kern_util.h>
+#include <init.h>
+#include <os.h>
+#include <sigio.h>
+#include <um_malloc.h>
+
+/*
+ * Protected by sigio_lock(), also used by sigio_cleanup, which is an
+ * exitcall.
+ */
+static int write_sigio_pid = -1;
+static unsigned long write_sigio_stack;
+
+/*
+ * These arrays are initialized before the sigio thread is started, and
+ * the descriptors closed after it is killed. So, it can't see them change.
+ * On the UML side, they are changed under the sigio_lock.
+ */
+#define SIGIO_FDS_INIT {-1, -1}
+
+static int write_sigio_fds[2] = SIGIO_FDS_INIT;
+static int sigio_private[2] = SIGIO_FDS_INIT;
+
+struct pollfds {
+ struct pollfd *poll;
+ int size;
+ int used;
+};
+
+/*
+ * Protected by sigio_lock(). Used by the sigio thread, but the UML thread
+ * synchronizes with it.
+ */
+static struct pollfds current_poll;
+static struct pollfds next_poll;
+static struct pollfds all_sigio_fds;
+
+static int write_sigio_thread(void *unused)
+{
+ struct pollfds *fds, tmp;
+ struct pollfd *p;
+ int i, n, respond_fd;
+ char c;
+
+ os_fix_helper_signals();
+ fds = &current_poll;
+ while (1) {
+ n = poll(fds->poll, fds->used, -1);
+ if (n < 0) {
+ if (errno == EINTR)
+ continue;
+ printk(UM_KERN_ERR "write_sigio_thread : poll returned "
+ "%d, errno = %d\n", n, errno);
+ }
+ for (i = 0; i < fds->used; i++) {
+ p = &fds->poll[i];
+ if (p->revents == 0)
+ continue;
+ if (p->fd == sigio_private[1]) {
+ CATCH_EINTR(n = read(sigio_private[1], &c,
+ sizeof(c)));
+ if (n != sizeof(c))
+ printk(UM_KERN_ERR
+ "write_sigio_thread : "
+ "read on socket failed, "
+ "err = %d\n", errno);
+ tmp = current_poll;
+ current_poll = next_poll;
+ next_poll = tmp;
+ respond_fd = sigio_private[1];
+ }
+ else {
+ respond_fd = write_sigio_fds[1];
+ fds->used--;
+ memmove(&fds->poll[i], &fds->poll[i + 1],
+ (fds->used - i) * sizeof(*fds->poll));
+ }
+
+ CATCH_EINTR(n = write(respond_fd, &c, sizeof(c)));
+ if (n != sizeof(c))
+ printk(UM_KERN_ERR "write_sigio_thread : "
+ "write on socket failed, err = %d\n",
+ errno);
+ }
+ }
+
+ return 0;
+}
+
+static int need_poll(struct pollfds *polls, int n)
+{
+ struct pollfd *new;
+
+ if (n <= polls->size)
+ return 0;
+
+ new = uml_kmalloc(n * sizeof(struct pollfd), UM_GFP_ATOMIC);
+ if (new == NULL) {
+ printk(UM_KERN_ERR "need_poll : failed to allocate new "
+ "pollfds\n");
+ return -ENOMEM;
+ }
+
+ memcpy(new, polls->poll, polls->used * sizeof(struct pollfd));
+ kfree(polls->poll);
+
+ polls->poll = new;
+ polls->size = n;
+ return 0;
+}
+
+/*
+ * Must be called with sigio_lock held, because it's needed by the marked
+ * critical section.
+ */
+static void update_thread(void)
+{
+ unsigned long flags;
+ int n;
+ char c;
+
+ flags = um_set_signals_trace(0);
+ CATCH_EINTR(n = write(sigio_private[0], &c, sizeof(c)));
+ if (n != sizeof(c)) {
+ printk(UM_KERN_ERR "update_thread : write failed, err = %d\n",
+ errno);
+ goto fail;
+ }
+
+ CATCH_EINTR(n = read(sigio_private[0], &c, sizeof(c)));
+ if (n != sizeof(c)) {
+ printk(UM_KERN_ERR "update_thread : read failed, err = %d\n",
+ errno);
+ goto fail;
+ }
+
+ um_set_signals_trace(flags);
+ return;
+ fail:
+ /* Critical section start */
+ if (write_sigio_pid != -1) {
+ os_kill_process(write_sigio_pid, 1);
+ free_stack(write_sigio_stack, 0);
+ }
+ write_sigio_pid = -1;
+ close(sigio_private[0]);
+ close(sigio_private[1]);
+ close(write_sigio_fds[0]);
+ close(write_sigio_fds[1]);
+ /* Critical section end */
+ um_set_signals_trace(flags);
+}
+
+int __add_sigio_fd(int fd)
+{
+ struct pollfd *p;
+ int err, i, n;
+
+ for (i = 0; i < all_sigio_fds.used; i++) {
+ if (all_sigio_fds.poll[i].fd == fd)
+ break;
+ }
+ if (i == all_sigio_fds.used)
+ return -ENOSPC;
+
+ p = &all_sigio_fds.poll[i];
+
+ for (i = 0; i < current_poll.used; i++) {
+ if (current_poll.poll[i].fd == fd)
+ return 0;
+ }
+
+ n = current_poll.used;
+ err = need_poll(&next_poll, n + 1);
+ if (err)
+ return err;
+
+ memcpy(next_poll.poll, current_poll.poll,
+ current_poll.used * sizeof(struct pollfd));
+ next_poll.poll[n] = *p;
+ next_poll.used = n + 1;
+ update_thread();
+
+ return 0;
+}
+
+
+int add_sigio_fd(int fd)
+{
+ int err;
+
+ sigio_lock();
+ err = __add_sigio_fd(fd);
+ sigio_unlock();
+
+ return err;
+}
+
+int __ignore_sigio_fd(int fd)
+{
+ struct pollfd *p;
+ int err, i, n = 0;
+
+ /*
+ * This is called from exitcalls elsewhere in UML - if
+ * sigio_cleanup has already run, then update_thread will hang
+ * or fail because the thread is no longer running.
+ */
+ if (write_sigio_pid == -1)
+ return -EIO;
+
+ for (i = 0; i < current_poll.used; i++) {
+ if (current_poll.poll[i].fd == fd)
+ break;
+ }
+ if (i == current_poll.used)
+ return -ENOENT;
+
+ err = need_poll(&next_poll, current_poll.used - 1);
+ if (err)
+ return err;
+
+ for (i = 0; i < current_poll.used; i++) {
+ p = &current_poll.poll[i];
+ if (p->fd != fd)
+ next_poll.poll[n++] = *p;
+ }
+ next_poll.used = current_poll.used - 1;
+
+ update_thread();
+
+ return 0;
+}
+
+int ignore_sigio_fd(int fd)
+{
+ int err;
+
+ sigio_lock();
+ err = __ignore_sigio_fd(fd);
+ sigio_unlock();
+
+ return err;
+}
+
+static struct pollfd *setup_initial_poll(int fd)
+{
+ struct pollfd *p;
+
+ p = uml_kmalloc(sizeof(struct pollfd), UM_GFP_KERNEL);
+ if (p == NULL) {
+ printk(UM_KERN_ERR "setup_initial_poll : failed to allocate "
+ "poll\n");
+ return NULL;
+ }
+ *p = ((struct pollfd) { .fd = fd,
+ .events = POLLIN,
+ .revents = 0 });
+ return p;
+}
+
+static void write_sigio_workaround(void)
+{
+ struct pollfd *p;
+ int err;
+ int l_write_sigio_fds[2];
+ int l_sigio_private[2];
+ int l_write_sigio_pid;
+
+ /* We call this *tons* of times - and most ones we must just fail. */
+ sigio_lock();
+ l_write_sigio_pid = write_sigio_pid;
+ sigio_unlock();
+
+ if (l_write_sigio_pid != -1)
+ return;
+
+ err = os_pipe(l_write_sigio_fds, 1, 1);
+ if (err < 0) {
+ printk(UM_KERN_ERR "write_sigio_workaround - os_pipe 1 failed, "
+ "err = %d\n", -err);
+ return;
+ }
+ err = os_pipe(l_sigio_private, 1, 1);
+ if (err < 0) {
+ printk(UM_KERN_ERR "write_sigio_workaround - os_pipe 2 failed, "
+ "err = %d\n", -err);
+ goto out_close1;
+ }
+
+ p = setup_initial_poll(l_sigio_private[1]);
+ if (!p)
+ goto out_close2;
+
+ sigio_lock();
+
+ /*
+ * Did we race? Don't try to optimize this, please, it's not so likely
+ * to happen, and no more than once at the boot.
+ */
+ if (write_sigio_pid != -1)
+ goto out_free;
+
+ current_poll = ((struct pollfds) { .poll = p,
+ .used = 1,
+ .size = 1 });
+
+ if (write_sigio_irq(l_write_sigio_fds[0]))
+ goto out_clear_poll;
+
+ memcpy(write_sigio_fds, l_write_sigio_fds, sizeof(l_write_sigio_fds));
+ memcpy(sigio_private, l_sigio_private, sizeof(l_sigio_private));
+
+ write_sigio_pid = run_helper_thread(write_sigio_thread, NULL,
+ CLONE_FILES | CLONE_VM,
+ &write_sigio_stack);
+
+ if (write_sigio_pid < 0)
+ goto out_clear;
+
+ sigio_unlock();
+ return;
+
+out_clear:
+ write_sigio_pid = -1;
+ write_sigio_fds[0] = -1;
+ write_sigio_fds[1] = -1;
+ sigio_private[0] = -1;
+ sigio_private[1] = -1;
+out_clear_poll:
+ current_poll = ((struct pollfds) { .poll = NULL,
+ .size = 0,
+ .used = 0 });
+out_free:
+ sigio_unlock();
+ kfree(p);
+out_close2:
+ close(l_sigio_private[0]);
+ close(l_sigio_private[1]);
+out_close1:
+ close(l_write_sigio_fds[0]);
+ close(l_write_sigio_fds[1]);
+}
+
+void sigio_broken(int fd)
+{
+ int err;
+
+ write_sigio_workaround();
+
+ sigio_lock();
+ err = need_poll(&all_sigio_fds, all_sigio_fds.used + 1);
+ if (err) {
+ printk(UM_KERN_ERR "maybe_sigio_broken - failed to add pollfd "
+ "for descriptor %d\n", fd);
+ goto out;
+ }
+
+ all_sigio_fds.poll[all_sigio_fds.used++] =
+ ((struct pollfd) { .fd = fd,
+ .events = POLLIN,
+ .revents = 0 });
+out:
+ sigio_unlock();
+}
+
+/* Changed during early boot */
+static int pty_output_sigio;
+
+void maybe_sigio_broken(int fd)
+{
+ if (!isatty(fd))
+ return;
+
+ if (pty_output_sigio)
+ return;
+
+ sigio_broken(fd);
+}
+
+static void sigio_cleanup(void)
+{
+ if (write_sigio_pid == -1)
+ return;
+
+ os_kill_process(write_sigio_pid, 1);
+ free_stack(write_sigio_stack, 0);
+ write_sigio_pid = -1;
+}
+
+__uml_exitcall(sigio_cleanup);
+
+/* Used as a flag during SIGIO testing early in boot */
+static int got_sigio;
+
+static void __init handler(int sig)
+{
+ got_sigio = 1;
+}
+
+struct openpty_arg {
+ int master;
+ int slave;
+ int err;
+};
+
+static void openpty_cb(void *arg)
+{
+ struct openpty_arg *info = arg;
+
+ info->err = 0;
+ if (openpty(&info->master, &info->slave, NULL, NULL, NULL))
+ info->err = -errno;
+}
+
+static int async_pty(int master, int slave)
+{
+ int flags;
+
+ flags = fcntl(master, F_GETFL);
+ if (flags < 0)
+ return -errno;
+
+ if ((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
+ (fcntl(master, F_SETOWN, os_getpid()) < 0))
+ return -errno;
+
+ if ((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))
+ return -errno;
+
+ return 0;
+}
+
+static void __init check_one_sigio(void (*proc)(int, int))
+{
+ struct sigaction old, new;
+ struct openpty_arg pty = { .master = -1, .slave = -1 };
+ int master, slave, err;
+
+ initial_thread_cb(openpty_cb, &pty);
+ if (pty.err) {
+ printk(UM_KERN_ERR "check_one_sigio failed, errno = %d\n",
+ -pty.err);
+ return;
+ }
+
+ master = pty.master;
+ slave = pty.slave;
+
+ if ((master == -1) || (slave == -1)) {
+ printk(UM_KERN_ERR "check_one_sigio failed to allocate a "
+ "pty\n");
+ return;
+ }
+
+ /* Not now, but complain so we now where we failed. */
+ err = raw(master);
+ if (err < 0) {
+ printk(UM_KERN_ERR "check_one_sigio : raw failed, errno = %d\n",
+ -err);
+ return;
+ }
+
+ err = async_pty(master, slave);
+ if (err < 0) {
+ printk(UM_KERN_ERR "check_one_sigio : sigio_async failed, "
+ "err = %d\n", -err);
+ return;
+ }
+
+ if (sigaction(SIGIO, NULL, &old) < 0) {
+ printk(UM_KERN_ERR "check_one_sigio : sigaction 1 failed, "
+ "errno = %d\n", errno);
+ return;
+ }
+
+ new = old;
+ new.sa_handler = handler;
+ if (sigaction(SIGIO, &new, NULL) < 0) {
+ printk(UM_KERN_ERR "check_one_sigio : sigaction 2 failed, "
+ "errno = %d\n", errno);
+ return;
+ }
+
+ got_sigio = 0;
+ (*proc)(master, slave);
+
+ close(master);
+ close(slave);
+
+ if (sigaction(SIGIO, &old, NULL) < 0)
+ printk(UM_KERN_ERR "check_one_sigio : sigaction 3 failed, "
+ "errno = %d\n", errno);
+}
+
+static void tty_output(int master, int slave)
+{
+ int n;
+ char buf[512];
+
+ printk(UM_KERN_INFO "Checking that host ptys support output SIGIO...");
+
+ memset(buf, 0, sizeof(buf));
+
+ while (write(master, buf, sizeof(buf)) > 0) ;
+ if (errno != EAGAIN)
+ printk(UM_KERN_ERR "tty_output : write failed, errno = %d\n",
+ errno);
+ while (((n = read(slave, buf, sizeof(buf))) > 0) &&
+ !({ barrier(); got_sigio; }))
+ ;
+
+ if (got_sigio) {
+ printk(UM_KERN_CONT "Yes\n");
+ pty_output_sigio = 1;
+ } else if (n == -EAGAIN)
+ printk(UM_KERN_CONT "No, enabling workaround\n");
+ else
+ printk(UM_KERN_CONT "tty_output : read failed, err = %d\n", n);
+}
+
+static void __init check_sigio(void)
+{
+ if ((access("/dev/ptmx", R_OK) < 0) &&
+ (access("/dev/ptyp0", R_OK) < 0)) {
+ printk(UM_KERN_WARNING "No pseudo-terminals available - "
+ "skipping pty SIGIO check\n");
+ return;
+ }
+ check_one_sigio(tty_output);
+}
+
+/* Here because it only does the SIGIO testing for now */
+void __init os_check_bugs(void)
+{
+ check_sigio();
+}
diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
new file mode 100644
index 0000000000..24a403a70a
--- /dev/null
+++ b/arch/um/os-Linux/signal.c
@@ -0,0 +1,419 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
+ * Copyright (C) 2004 PathScale, Inc
+ * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <strings.h>
+#include <as-layout.h>
+#include <kern_util.h>
+#include <os.h>
+#include <sysdep/mcontext.h>
+#include <um_malloc.h>
+#include <sys/ucontext.h>
+#include <timetravel.h>
+
+void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = {
+ [SIGTRAP] = relay_signal,
+ [SIGFPE] = relay_signal,
+ [SIGILL] = relay_signal,
+ [SIGWINCH] = winch,
+ [SIGBUS] = bus_handler,
+ [SIGSEGV] = segv_handler,
+ [SIGIO] = sigio_handler,
+};
+
+static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc)
+{
+ struct uml_pt_regs r;
+ int save_errno = errno;
+
+ r.is_user = 0;
+ if (sig == SIGSEGV) {
+ /* For segfaults, we want the data from the sigcontext. */
+ get_regs_from_mc(&r, mc);
+ GET_FAULTINFO_FROM_MC(r.faultinfo, mc);
+ }
+
+ /* enable signals if sig isn't IRQ signal */
+ if ((sig != SIGIO) && (sig != SIGWINCH))
+ unblock_signals_trace();
+
+ (*sig_info[sig])(sig, si, &r);
+
+ errno = save_errno;
+}
+
+/*
+ * These are the asynchronous signals. SIGPROF is excluded because we want to
+ * be able to profile all of UML, not just the non-critical sections. If
+ * profiling is not thread-safe, then that is not my problem. We can disable
+ * profiling when SMP is enabled in that case.
+ */
+#define SIGIO_BIT 0
+#define SIGIO_MASK (1 << SIGIO_BIT)
+
+#define SIGALRM_BIT 1
+#define SIGALRM_MASK (1 << SIGALRM_BIT)
+
+int signals_enabled;
+#ifdef UML_CONFIG_UML_TIME_TRAVEL_SUPPORT
+static int signals_blocked;
+#else
+#define signals_blocked 0
+#endif
+static unsigned int signals_pending;
+static unsigned int signals_active = 0;
+
+void sig_handler(int sig, struct siginfo *si, mcontext_t *mc)
+{
+ int enabled = signals_enabled;
+
+ if ((signals_blocked || !enabled) && (sig == SIGIO)) {
+ /*
+ * In TT_MODE_EXTERNAL, need to still call time-travel
+ * handlers unless signals are also blocked for the
+ * external time message processing. This will mark
+ * signals_pending by itself (only if necessary.)
+ */
+ if (!signals_blocked && time_travel_mode == TT_MODE_EXTERNAL)
+ sigio_run_timetravel_handlers();
+ else
+ signals_pending |= SIGIO_MASK;
+ return;
+ }
+
+ block_signals_trace();
+
+ sig_handler_common(sig, si, mc);
+
+ um_set_signals_trace(enabled);
+}
+
+static void timer_real_alarm_handler(mcontext_t *mc)
+{
+ struct uml_pt_regs regs;
+
+ if (mc != NULL)
+ get_regs_from_mc(&regs, mc);
+ else
+ memset(&regs, 0, sizeof(regs));
+ timer_handler(SIGALRM, NULL, &regs);
+}
+
+void timer_alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc)
+{
+ int enabled;
+
+ enabled = signals_enabled;
+ if (!signals_enabled) {
+ signals_pending |= SIGALRM_MASK;
+ return;
+ }
+
+ block_signals_trace();
+
+ signals_active |= SIGALRM_MASK;
+
+ timer_real_alarm_handler(mc);
+
+ signals_active &= ~SIGALRM_MASK;
+
+ um_set_signals_trace(enabled);
+}
+
+void deliver_alarm(void) {
+ timer_alarm_handler(SIGALRM, NULL, NULL);
+}
+
+void timer_set_signal_handler(void)
+{
+ set_handler(SIGALRM);
+}
+
+void set_sigstack(void *sig_stack, int size)
+{
+ stack_t stack = {
+ .ss_flags = 0,
+ .ss_sp = sig_stack,
+ .ss_size = size
+ };
+
+ if (sigaltstack(&stack, NULL) != 0)
+ panic("enabling signal stack failed, errno = %d\n", errno);
+}
+
+static void sigusr1_handler(int sig, struct siginfo *unused_si, mcontext_t *mc)
+{
+ uml_pm_wake();
+}
+
+void register_pm_wake_signal(void)
+{
+ set_handler(SIGUSR1);
+}
+
+static void (*handlers[_NSIG])(int sig, struct siginfo *si, mcontext_t *mc) = {
+ [SIGSEGV] = sig_handler,
+ [SIGBUS] = sig_handler,
+ [SIGILL] = sig_handler,
+ [SIGFPE] = sig_handler,
+ [SIGTRAP] = sig_handler,
+
+ [SIGIO] = sig_handler,
+ [SIGWINCH] = sig_handler,
+ [SIGALRM] = timer_alarm_handler,
+
+ [SIGUSR1] = sigusr1_handler,
+};
+
+static void hard_handler(int sig, siginfo_t *si, void *p)
+{
+ ucontext_t *uc = p;
+ mcontext_t *mc = &uc->uc_mcontext;
+ unsigned long pending = 1UL << sig;
+
+ do {
+ int nested, bail;
+
+ /*
+ * pending comes back with one bit set for each
+ * interrupt that arrived while setting up the stack,
+ * plus a bit for this interrupt, plus the zero bit is
+ * set if this is a nested interrupt.
+ * If bail is true, then we interrupted another
+ * handler setting up the stack. In this case, we
+ * have to return, and the upper handler will deal
+ * with this interrupt.
+ */
+ bail = to_irq_stack(&pending);
+ if (bail)
+ return;
+
+ nested = pending & 1;
+ pending &= ~1;
+
+ while ((sig = ffs(pending)) != 0){
+ sig--;
+ pending &= ~(1 << sig);
+ (*handlers[sig])(sig, (struct siginfo *)si, mc);
+ }
+
+ /*
+ * Again, pending comes back with a mask of signals
+ * that arrived while tearing down the stack. If this
+ * is non-zero, we just go back, set up the stack
+ * again, and handle the new interrupts.
+ */
+ if (!nested)
+ pending = from_irq_stack(nested);
+ } while (pending);
+}
+
+void set_handler(int sig)
+{
+ struct sigaction action;
+ int flags = SA_SIGINFO | SA_ONSTACK;
+ sigset_t sig_mask;
+
+ action.sa_sigaction = hard_handler;
+
+ /* block irq ones */
+ sigemptyset(&action.sa_mask);
+ sigaddset(&action.sa_mask, SIGIO);
+ sigaddset(&action.sa_mask, SIGWINCH);
+ sigaddset(&action.sa_mask, SIGALRM);
+
+ if (sig == SIGSEGV)
+ flags |= SA_NODEFER;
+
+ if (sigismember(&action.sa_mask, sig))
+ flags |= SA_RESTART; /* if it's an irq signal */
+
+ action.sa_flags = flags;
+ action.sa_restorer = NULL;
+ if (sigaction(sig, &action, NULL) < 0)
+ panic("sigaction failed - errno = %d\n", errno);
+
+ sigemptyset(&sig_mask);
+ sigaddset(&sig_mask, sig);
+ if (sigprocmask(SIG_UNBLOCK, &sig_mask, NULL) < 0)
+ panic("sigprocmask failed - errno = %d\n", errno);
+}
+
+void send_sigio_to_self(void)
+{
+ kill(os_getpid(), SIGIO);
+}
+
+int change_sig(int signal, int on)
+{
+ sigset_t sigset;
+
+ sigemptyset(&sigset);
+ sigaddset(&sigset, signal);
+ if (sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, NULL) < 0)
+ return -errno;
+
+ return 0;
+}
+
+void block_signals(void)
+{
+ signals_enabled = 0;
+ /*
+ * This must return with signals disabled, so this barrier
+ * ensures that writes are flushed out before the return.
+ * This might matter if gcc figures out how to inline this and
+ * decides to shuffle this code into the caller.
+ */
+ barrier();
+}
+
+void unblock_signals(void)
+{
+ int save_pending;
+
+ if (signals_enabled == 1)
+ return;
+
+ signals_enabled = 1;
+#ifdef UML_CONFIG_UML_TIME_TRAVEL_SUPPORT
+ deliver_time_travel_irqs();
+#endif
+
+ /*
+ * We loop because the IRQ handler returns with interrupts off. So,
+ * interrupts may have arrived and we need to re-enable them and
+ * recheck signals_pending.
+ */
+ while (1) {
+ /*
+ * Save and reset save_pending after enabling signals. This
+ * way, signals_pending won't be changed while we're reading it.
+ *
+ * Setting signals_enabled and reading signals_pending must
+ * happen in this order, so have the barrier here.
+ */
+ barrier();
+
+ save_pending = signals_pending;
+ if (save_pending == 0)
+ return;
+
+ signals_pending = 0;
+
+ /*
+ * We have pending interrupts, so disable signals, as the
+ * handlers expect them off when they are called. They will
+ * be enabled again above. We need to trace this, as we're
+ * expected to be enabling interrupts already, but any more
+ * tracing that happens inside the handlers we call for the
+ * pending signals will mess up the tracing state.
+ */
+ signals_enabled = 0;
+ um_trace_signals_off();
+
+ /*
+ * Deal with SIGIO first because the alarm handler might
+ * schedule, leaving the pending SIGIO stranded until we come
+ * back here.
+ *
+ * SIGIO's handler doesn't use siginfo or mcontext,
+ * so they can be NULL.
+ */
+ if (save_pending & SIGIO_MASK)
+ sig_handler_common(SIGIO, NULL, NULL);
+
+ /* Do not reenter the handler */
+
+ if ((save_pending & SIGALRM_MASK) && (!(signals_active & SIGALRM_MASK)))
+ timer_real_alarm_handler(NULL);
+
+ /* Rerun the loop only if there is still pending SIGIO and not in TIMER handler */
+
+ if (!(signals_pending & SIGIO_MASK) && (signals_active & SIGALRM_MASK))
+ return;
+
+ /* Re-enable signals and trace that we're doing so. */
+ um_trace_signals_on();
+ signals_enabled = 1;
+ }
+}
+
+int um_set_signals(int enable)
+{
+ int ret;
+ if (signals_enabled == enable)
+ return enable;
+
+ ret = signals_enabled;
+ if (enable)
+ unblock_signals();
+ else block_signals();
+
+ return ret;
+}
+
+int um_set_signals_trace(int enable)
+{
+ int ret;
+ if (signals_enabled == enable)
+ return enable;
+
+ ret = signals_enabled;
+ if (enable)
+ unblock_signals_trace();
+ else
+ block_signals_trace();
+
+ return ret;
+}
+
+#ifdef UML_CONFIG_UML_TIME_TRAVEL_SUPPORT
+void mark_sigio_pending(void)
+{
+ signals_pending |= SIGIO_MASK;
+}
+
+void block_signals_hard(void)
+{
+ if (signals_blocked)
+ return;
+ signals_blocked = 1;
+ barrier();
+}
+
+void unblock_signals_hard(void)
+{
+ if (!signals_blocked)
+ return;
+ /* Must be set to 0 before we check the pending bits etc. */
+ signals_blocked = 0;
+ barrier();
+
+ if (signals_pending && signals_enabled) {
+ /* this is a bit inefficient, but that's not really important */
+ block_signals();
+ unblock_signals();
+ } else if (signals_pending & SIGIO_MASK) {
+ /* we need to run time-travel handlers even if not enabled */
+ sigio_run_timetravel_handlers();
+ }
+}
+#endif
+
+int os_is_signal_stack(void)
+{
+ stack_t ss;
+ sigaltstack(NULL, &ss);
+
+ return ss.ss_flags & SS_ONSTACK;
+}
diff --git a/arch/um/os-Linux/skas/Makefile b/arch/um/os-Linux/skas/Makefile
new file mode 100644
index 0000000000..75f11989d2
--- /dev/null
+++ b/arch/um/os-Linux/skas/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
+#
+
+obj-y := mem.o process.o
+
+USER_OBJS := $(obj-y)
+
+include $(srctree)/arch/um/scripts/Makefile.rules
diff --git a/arch/um/os-Linux/skas/mem.c b/arch/um/os-Linux/skas/mem.c
new file mode 100644
index 0000000000..953fb10f3f
--- /dev/null
+++ b/arch/um/os-Linux/skas/mem.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stddef.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <init.h>
+#include <as-layout.h>
+#include <mm_id.h>
+#include <os.h>
+#include <ptrace_user.h>
+#include <registers.h>
+#include <skas.h>
+#include <sysdep/ptrace.h>
+#include <sysdep/stub.h>
+
+extern char batch_syscall_stub[], __syscall_stub_start[];
+
+extern void wait_stub_done(int pid);
+
+static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
+ unsigned long *stack)
+{
+ if (stack == NULL) {
+ stack = (unsigned long *) mm_idp->stack + 2;
+ *stack = 0;
+ }
+ return stack;
+}
+
+static unsigned long syscall_regs[MAX_REG_NR];
+
+static int __init init_syscall_regs(void)
+{
+ get_safe_registers(syscall_regs, NULL);
+ syscall_regs[REGS_IP_INDEX] = STUB_CODE +
+ ((unsigned long) batch_syscall_stub -
+ (unsigned long) __syscall_stub_start);
+ syscall_regs[REGS_SP_INDEX] = STUB_DATA;
+
+ return 0;
+}
+
+__initcall(init_syscall_regs);
+
+static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
+{
+ int n, i;
+ long ret, offset;
+ unsigned long * data;
+ unsigned long * syscall;
+ int err, pid = mm_idp->u.pid;
+
+ n = ptrace_setregs(pid, syscall_regs);
+ if (n < 0) {
+ printk(UM_KERN_ERR "Registers - \n");
+ for (i = 0; i < MAX_REG_NR; i++)
+ printk(UM_KERN_ERR "\t%d\t0x%lx\n", i, syscall_regs[i]);
+ panic("%s : PTRACE_SETREGS failed, errno = %d\n",
+ __func__, -n);
+ }
+
+ err = ptrace(PTRACE_CONT, pid, 0, 0);
+ if (err)
+ panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
+ errno);
+
+ wait_stub_done(pid);
+
+ /*
+ * When the stub stops, we find the following values on the
+ * beginning of the stack:
+ * (long )return_value
+ * (long )offset to failed sycall-data (0, if no error)
+ */
+ ret = *((unsigned long *) mm_idp->stack);
+ offset = *((unsigned long *) mm_idp->stack + 1);
+ if (offset) {
+ data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
+ printk(UM_KERN_ERR "%s : ret = %ld, offset = %ld, data = %p\n",
+ __func__, ret, offset, data);
+ syscall = (unsigned long *)((unsigned long)data + data[0]);
+ printk(UM_KERN_ERR "%s: syscall %ld failed, return value = 0x%lx, expected return value = 0x%lx\n",
+ __func__, syscall[0], ret, syscall[7]);
+ printk(UM_KERN_ERR " syscall parameters: 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
+ syscall[1], syscall[2], syscall[3],
+ syscall[4], syscall[5], syscall[6]);
+ for (n = 1; n < data[0]/sizeof(long); n++) {
+ if (n == 1)
+ printk(UM_KERN_ERR " additional syscall data:");
+ if (n % 4 == 1)
+ printk("\n" UM_KERN_ERR " ");
+ printk(" 0x%lx", data[n]);
+ }
+ if (n > 1)
+ printk("\n");
+ }
+ else ret = 0;
+
+ *addr = check_init_stack(mm_idp, NULL);
+
+ return ret;
+}
+
+long run_syscall_stub(struct mm_id * mm_idp, int syscall,
+ unsigned long *args, long expected, void **addr,
+ int done)
+{
+ unsigned long *stack = check_init_stack(mm_idp, *addr);
+
+ *stack += sizeof(long);
+ stack += *stack / sizeof(long);
+
+ *stack++ = syscall;
+ *stack++ = args[0];
+ *stack++ = args[1];
+ *stack++ = args[2];
+ *stack++ = args[3];
+ *stack++ = args[4];
+ *stack++ = args[5];
+ *stack++ = expected;
+ *stack = 0;
+
+ if (!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) <
+ UM_KERN_PAGE_SIZE - 10 * sizeof(long))) {
+ *addr = stack;
+ return 0;
+ }
+
+ return do_syscall_stub(mm_idp, addr);
+}
+
+long syscall_stub_data(struct mm_id * mm_idp,
+ unsigned long *data, int data_count,
+ void **addr, void **stub_addr)
+{
+ unsigned long *stack;
+ int ret = 0;
+
+ /*
+ * If *addr still is uninitialized, it *must* contain NULL.
+ * Thus in this case do_syscall_stub correctly won't be called.
+ */
+ if ((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >=
+ UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) {
+ ret = do_syscall_stub(mm_idp, addr);
+ /* in case of error, don't overwrite data on stack */
+ if (ret)
+ return ret;
+ }
+
+ stack = check_init_stack(mm_idp, *addr);
+ *addr = stack;
+
+ *stack = data_count * sizeof(long);
+
+ memcpy(stack + 1, data, data_count * sizeof(long));
+
+ *stub_addr = (void *)(((unsigned long)(stack + 1) &
+ ~UM_KERN_PAGE_MASK) + STUB_DATA);
+
+ return 0;
+}
+
+int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
+ int phys_fd, unsigned long long offset, int done, void **data)
+{
+ int ret;
+ unsigned long args[] = { virt, len, prot,
+ MAP_SHARED | MAP_FIXED, phys_fd,
+ MMAP_OFFSET(offset) };
+
+ ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
+ data, done);
+
+ return ret;
+}
+
+int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
+ int done, void **data)
+{
+ int ret;
+ unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
+ 0 };
+
+ ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
+ data, done);
+
+ return ret;
+}
+
+int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
+ unsigned int prot, int done, void **data)
+{
+ int ret;
+ unsigned long args[] = { addr, len, prot, 0, 0, 0 };
+
+ ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
+ data, done);
+
+ return ret;
+}
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
new file mode 100644
index 0000000000..9464833e74
--- /dev/null
+++ b/arch/um/os-Linux/skas/process.c
@@ -0,0 +1,732 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
+ * Copyright (C) 2002- 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <sched.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
+#include <asm/unistd.h>
+#include <as-layout.h>
+#include <init.h>
+#include <kern_util.h>
+#include <mem.h>
+#include <os.h>
+#include <ptrace_user.h>
+#include <registers.h>
+#include <skas.h>
+#include <sysdep/stub.h>
+#include <linux/threads.h>
+
+int is_skas_winch(int pid, int fd, void *data)
+{
+ return pid == getpgrp();
+}
+
+static const char *ptrace_reg_name(int idx)
+{
+#define R(n) case HOST_##n: return #n
+
+ switch (idx) {
+#ifdef __x86_64__
+ R(BX);
+ R(CX);
+ R(DI);
+ R(SI);
+ R(DX);
+ R(BP);
+ R(AX);
+ R(R8);
+ R(R9);
+ R(R10);
+ R(R11);
+ R(R12);
+ R(R13);
+ R(R14);
+ R(R15);
+ R(ORIG_AX);
+ R(CS);
+ R(SS);
+ R(EFLAGS);
+#elif defined(__i386__)
+ R(IP);
+ R(SP);
+ R(EFLAGS);
+ R(AX);
+ R(BX);
+ R(CX);
+ R(DX);
+ R(SI);
+ R(DI);
+ R(BP);
+ R(CS);
+ R(SS);
+ R(DS);
+ R(FS);
+ R(ES);
+ R(GS);
+ R(ORIG_AX);
+#endif
+ }
+ return "";
+}
+
+static int ptrace_dump_regs(int pid)
+{
+ unsigned long regs[MAX_REG_NR];
+ int i;
+
+ if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
+ return -errno;
+
+ printk(UM_KERN_ERR "Stub registers -\n");
+ for (i = 0; i < ARRAY_SIZE(regs); i++) {
+ const char *regname = ptrace_reg_name(i);
+
+ printk(UM_KERN_ERR "\t%s\t(%2d): %lx\n", regname, i, regs[i]);
+ }
+
+ return 0;
+}
+
+/*
+ * Signals that are OK to receive in the stub - we'll just continue it.
+ * SIGWINCH will happen when UML is inside a detached screen.
+ */
+#define STUB_SIG_MASK ((1 << SIGALRM) | (1 << SIGWINCH))
+
+/* Signals that the stub will finish with - anything else is an error */
+#define STUB_DONE_MASK (1 << SIGTRAP)
+
+void wait_stub_done(int pid)
+{
+ int n, status, err;
+
+ while (1) {
+ CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL));
+ if ((n < 0) || !WIFSTOPPED(status))
+ goto bad_wait;
+
+ if (((1 << WSTOPSIG(status)) & STUB_SIG_MASK) == 0)
+ break;
+
+ err = ptrace(PTRACE_CONT, pid, 0, 0);
+ if (err) {
+ printk(UM_KERN_ERR "%s : continue failed, errno = %d\n",
+ __func__, errno);
+ fatal_sigsegv();
+ }
+ }
+
+ if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0)
+ return;
+
+bad_wait:
+ err = ptrace_dump_regs(pid);
+ if (err)
+ printk(UM_KERN_ERR "Failed to get registers from stub, errno = %d\n",
+ -err);
+ printk(UM_KERN_ERR "%s : failed to wait for SIGTRAP, pid = %d, n = %d, errno = %d, status = 0x%x\n",
+ __func__, pid, n, errno, status);
+ fatal_sigsegv();
+}
+
+extern unsigned long current_stub_stack(void);
+
+static void get_skas_faultinfo(int pid, struct faultinfo *fi, unsigned long *aux_fp_regs)
+{
+ int err;
+
+ err = get_fp_registers(pid, aux_fp_regs);
+ if (err < 0) {
+ printk(UM_KERN_ERR "save_fp_registers returned %d\n",
+ err);
+ fatal_sigsegv();
+ }
+ err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV);
+ if (err) {
+ printk(UM_KERN_ERR "Failed to continue stub, pid = %d, "
+ "errno = %d\n", pid, errno);
+ fatal_sigsegv();
+ }
+ wait_stub_done(pid);
+
+ /*
+ * faultinfo is prepared by the stub_segv_handler at start of
+ * the stub stack page. We just have to copy it.
+ */
+ memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
+
+ err = put_fp_registers(pid, aux_fp_regs);
+ if (err < 0) {
+ printk(UM_KERN_ERR "put_fp_registers returned %d\n",
+ err);
+ fatal_sigsegv();
+ }
+}
+
+static void handle_segv(int pid, struct uml_pt_regs *regs, unsigned long *aux_fp_regs)
+{
+ get_skas_faultinfo(pid, &regs->faultinfo, aux_fp_regs);
+ segv(regs->faultinfo, 0, 1, NULL);
+}
+
+/*
+ * To use the same value of using_sysemu as the caller, ask it that value
+ * (in local_using_sysemu
+ */
+static void handle_trap(int pid, struct uml_pt_regs *regs,
+ int local_using_sysemu)
+{
+ int err, status;
+
+ if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END))
+ fatal_sigsegv();
+
+ if (!local_using_sysemu)
+ {
+ err = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET,
+ __NR_getpid);
+ if (err < 0) {
+ printk(UM_KERN_ERR "%s - nullifying syscall failed, errno = %d\n",
+ __func__, errno);
+ fatal_sigsegv();
+ }
+
+ err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
+ if (err < 0) {
+ printk(UM_KERN_ERR "%s - continuing to end of syscall failed, errno = %d\n",
+ __func__, errno);
+ fatal_sigsegv();
+ }
+
+ CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL));
+ if ((err < 0) || !WIFSTOPPED(status) ||
+ (WSTOPSIG(status) != SIGTRAP + 0x80)) {
+ err = ptrace_dump_regs(pid);
+ if (err)
+ printk(UM_KERN_ERR "Failed to get registers from process, errno = %d\n",
+ -err);
+ printk(UM_KERN_ERR "%s - failed to wait at end of syscall, errno = %d, status = %d\n",
+ __func__, errno, status);
+ fatal_sigsegv();
+ }
+ }
+
+ handle_syscall(regs);
+}
+
+extern char __syscall_stub_start[];
+
+/**
+ * userspace_tramp() - userspace trampoline
+ * @stack: pointer to the new userspace stack page, can be NULL, if? FIXME:
+ *
+ * The userspace trampoline is used to setup a new userspace process in start_userspace() after it was clone()'ed.
+ * This function will run on a temporary stack page.
+ * It ptrace()'es itself, then
+ * Two pages are mapped into the userspace address space:
+ * - STUB_CODE (with EXEC), which contains the skas stub code
+ * - STUB_DATA (with R/W), which contains a data page that is used to transfer certain data between the UML userspace process and the UML kernel.
+ * Also for the userspace process a SIGSEGV handler is installed to catch pagefaults in the userspace process.
+ * And last the process stops itself to give control to the UML kernel for this userspace process.
+ *
+ * Return: Always zero, otherwise the current userspace process is ended with non null exit() call
+ */
+static int userspace_tramp(void *stack)
+{
+ void *addr;
+ int fd;
+ unsigned long long offset;
+
+ ptrace(PTRACE_TRACEME, 0, 0, 0);
+
+ signal(SIGTERM, SIG_DFL);
+ signal(SIGWINCH, SIG_IGN);
+
+ fd = phys_mapping(uml_to_phys(__syscall_stub_start), &offset);
+ addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE,
+ PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
+ if (addr == MAP_FAILED) {
+ printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, errno = %d\n",
+ STUB_CODE, errno);
+ exit(1);
+ }
+
+ if (stack != NULL) {
+ fd = phys_mapping(uml_to_phys(stack), &offset);
+ addr = mmap((void *) STUB_DATA,
+ STUB_DATA_PAGES * UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
+ MAP_FIXED | MAP_SHARED, fd, offset);
+ if (addr == MAP_FAILED) {
+ printk(UM_KERN_ERR "mapping segfault stack at 0x%lx failed, errno = %d\n",
+ STUB_DATA, errno);
+ exit(1);
+ }
+ }
+ if (stack != NULL) {
+ struct sigaction sa;
+
+ unsigned long v = STUB_CODE +
+ (unsigned long) stub_segv_handler -
+ (unsigned long) __syscall_stub_start;
+
+ set_sigstack((void *) STUB_DATA, STUB_DATA_PAGES * UM_KERN_PAGE_SIZE);
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_ONSTACK | SA_NODEFER | SA_SIGINFO;
+ sa.sa_sigaction = (void *) v;
+ sa.sa_restorer = NULL;
+ if (sigaction(SIGSEGV, &sa, NULL) < 0) {
+ printk(UM_KERN_ERR "%s - setting SIGSEGV handler failed - errno = %d\n",
+ __func__, errno);
+ exit(1);
+ }
+ }
+
+ kill(os_getpid(), SIGSTOP);
+ return 0;
+}
+
+int userspace_pid[NR_CPUS];
+int kill_userspace_mm[NR_CPUS];
+
+/**
+ * start_userspace() - prepare a new userspace process
+ * @stub_stack: pointer to the stub stack. Can be NULL, if? FIXME:
+ *
+ * Setups a new temporary stack page that is used while userspace_tramp() runs
+ * Clones the kernel process into a new userspace process, with FDs only.
+ *
+ * Return: When positive: the process id of the new userspace process,
+ * when negative: an error number.
+ * FIXME: can PIDs become negative?!
+ */
+int start_userspace(unsigned long stub_stack)
+{
+ void *stack;
+ unsigned long sp;
+ int pid, status, n, flags, err;
+
+ /* setup a temporary stack page */
+ stack = mmap(NULL, UM_KERN_PAGE_SIZE,
+ PROT_READ | PROT_WRITE | PROT_EXEC,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ if (stack == MAP_FAILED) {
+ err = -errno;
+ printk(UM_KERN_ERR "%s : mmap failed, errno = %d\n",
+ __func__, errno);
+ return err;
+ }
+
+ /* set stack pointer to the end of the stack page, so it can grow downwards */
+ sp = (unsigned long)stack + UM_KERN_PAGE_SIZE;
+
+ flags = CLONE_FILES | SIGCHLD;
+
+ /* clone into new userspace process */
+ pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
+ if (pid < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "%s : clone failed, errno = %d\n",
+ __func__, errno);
+ return err;
+ }
+
+ do {
+ CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL));
+ if (n < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "%s : wait failed, errno = %d\n",
+ __func__, errno);
+ goto out_kill;
+ }
+ } while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGALRM));
+
+ if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) {
+ err = -EINVAL;
+ printk(UM_KERN_ERR "%s : expected SIGSTOP, got status = %d\n",
+ __func__, status);
+ goto out_kill;
+ }
+
+ if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
+ (void *) PTRACE_O_TRACESYSGOOD) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "%s : PTRACE_OLDSETOPTIONS failed, errno = %d\n",
+ __func__, errno);
+ goto out_kill;
+ }
+
+ if (munmap(stack, UM_KERN_PAGE_SIZE) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "%s : munmap failed, errno = %d\n",
+ __func__, errno);
+ goto out_kill;
+ }
+
+ return pid;
+
+ out_kill:
+ os_kill_ptraced_process(pid, 1);
+ return err;
+}
+
+void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs)
+{
+ int err, status, op, pid = userspace_pid[0];
+ /* To prevent races if using_sysemu changes under us.*/
+ int local_using_sysemu;
+ siginfo_t si;
+
+ /* Handle any immediate reschedules or signals */
+ interrupt_end();
+
+ while (1) {
+ if (kill_userspace_mm[0])
+ fatal_sigsegv();
+
+ /*
+ * This can legitimately fail if the process loads a
+ * bogus value into a segment register. It will
+ * segfault and PTRACE_GETREGS will read that value
+ * out of the process. However, PTRACE_SETREGS will
+ * fail. In this case, there is nothing to do but
+ * just kill the process.
+ */
+ if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp)) {
+ printk(UM_KERN_ERR "%s - ptrace set regs failed, errno = %d\n",
+ __func__, errno);
+ fatal_sigsegv();
+ }
+
+ if (put_fp_registers(pid, regs->fp)) {
+ printk(UM_KERN_ERR "%s - ptrace set fp regs failed, errno = %d\n",
+ __func__, errno);
+ fatal_sigsegv();
+ }
+
+ /* Now we set local_using_sysemu to be used for one loop */
+ local_using_sysemu = get_using_sysemu();
+
+ op = SELECT_PTRACE_OPERATION(local_using_sysemu,
+ singlestepping(NULL));
+
+ if (ptrace(op, pid, 0, 0)) {
+ printk(UM_KERN_ERR "%s - ptrace continue failed, op = %d, errno = %d\n",
+ __func__, op, errno);
+ fatal_sigsegv();
+ }
+
+ CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL));
+ if (err < 0) {
+ printk(UM_KERN_ERR "%s - wait failed, errno = %d\n",
+ __func__, errno);
+ fatal_sigsegv();
+ }
+
+ regs->is_user = 1;
+ if (ptrace(PTRACE_GETREGS, pid, 0, regs->gp)) {
+ printk(UM_KERN_ERR "%s - PTRACE_GETREGS failed, errno = %d\n",
+ __func__, errno);
+ fatal_sigsegv();
+ }
+
+ if (get_fp_registers(pid, regs->fp)) {
+ printk(UM_KERN_ERR "%s - get_fp_registers failed, errno = %d\n",
+ __func__, errno);
+ fatal_sigsegv();
+ }
+
+ UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
+
+ if (WIFSTOPPED(status)) {
+ int sig = WSTOPSIG(status);
+
+ /* These signal handlers need the si argument.
+ * The SIGIO and SIGALARM handlers which constitute the
+ * majority of invocations, do not use it.
+ */
+ switch (sig) {
+ case SIGSEGV:
+ case SIGTRAP:
+ case SIGILL:
+ case SIGBUS:
+ case SIGFPE:
+ case SIGWINCH:
+ ptrace(PTRACE_GETSIGINFO, pid, 0, (struct siginfo *)&si);
+ break;
+ }
+
+ switch (sig) {
+ case SIGSEGV:
+ if (PTRACE_FULL_FAULTINFO) {
+ get_skas_faultinfo(pid,
+ &regs->faultinfo, aux_fp_regs);
+ (*sig_info[SIGSEGV])(SIGSEGV, (struct siginfo *)&si,
+ regs);
+ }
+ else handle_segv(pid, regs, aux_fp_regs);
+ break;
+ case SIGTRAP + 0x80:
+ handle_trap(pid, regs, local_using_sysemu);
+ break;
+ case SIGTRAP:
+ relay_signal(SIGTRAP, (struct siginfo *)&si, regs);
+ break;
+ case SIGALRM:
+ break;
+ case SIGIO:
+ case SIGILL:
+ case SIGBUS:
+ case SIGFPE:
+ case SIGWINCH:
+ block_signals_trace();
+ (*sig_info[sig])(sig, (struct siginfo *)&si, regs);
+ unblock_signals_trace();
+ break;
+ default:
+ printk(UM_KERN_ERR "%s - child stopped with signal %d\n",
+ __func__, sig);
+ fatal_sigsegv();
+ }
+ pid = userspace_pid[0];
+ interrupt_end();
+
+ /* Avoid -ERESTARTSYS handling in host */
+ if (PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET)
+ PT_SYSCALL_NR(regs->gp) = -1;
+ }
+ }
+}
+
+static unsigned long thread_regs[MAX_REG_NR];
+static unsigned long thread_fp_regs[FP_SIZE];
+
+static int __init init_thread_regs(void)
+{
+ get_safe_registers(thread_regs, thread_fp_regs);
+ /* Set parent's instruction pointer to start of clone-stub */
+ thread_regs[REGS_IP_INDEX] = STUB_CODE +
+ (unsigned long) stub_clone_handler -
+ (unsigned long) __syscall_stub_start;
+ thread_regs[REGS_SP_INDEX] = STUB_DATA + STUB_DATA_PAGES * UM_KERN_PAGE_SIZE -
+ sizeof(void *);
+#ifdef __SIGNAL_FRAMESIZE
+ thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
+#endif
+ return 0;
+}
+
+__initcall(init_thread_regs);
+
+int copy_context_skas0(unsigned long new_stack, int pid)
+{
+ int err;
+ unsigned long current_stack = current_stub_stack();
+ struct stub_data *data = (struct stub_data *) current_stack;
+ struct stub_data *child_data = (struct stub_data *) new_stack;
+ unsigned long long new_offset;
+ int new_fd = phys_mapping(uml_to_phys((void *)new_stack), &new_offset);
+
+ /*
+ * prepare offset and fd of child's stack as argument for parent's
+ * and child's mmap2 calls
+ */
+ *data = ((struct stub_data) {
+ .offset = MMAP_OFFSET(new_offset),
+ .fd = new_fd,
+ .parent_err = -ESRCH,
+ .child_err = 0,
+ });
+
+ *child_data = ((struct stub_data) {
+ .child_err = -ESRCH,
+ });
+
+ err = ptrace_setregs(pid, thread_regs);
+ if (err < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "%s : PTRACE_SETREGS failed, pid = %d, errno = %d\n",
+ __func__, pid, -err);
+ return err;
+ }
+
+ err = put_fp_registers(pid, thread_fp_regs);
+ if (err < 0) {
+ printk(UM_KERN_ERR "%s : put_fp_registers failed, pid = %d, err = %d\n",
+ __func__, pid, err);
+ return err;
+ }
+
+ /*
+ * Wait, until parent has finished its work: read child's pid from
+ * parent's stack, and check, if bad result.
+ */
+ err = ptrace(PTRACE_CONT, pid, 0, 0);
+ if (err) {
+ err = -errno;
+ printk(UM_KERN_ERR "Failed to continue new process, pid = %d, errno = %d\n",
+ pid, errno);
+ return err;
+ }
+
+ wait_stub_done(pid);
+
+ pid = data->parent_err;
+ if (pid < 0) {
+ printk(UM_KERN_ERR "%s - stub-parent reports error %d\n",
+ __func__, -pid);
+ return pid;
+ }
+
+ /*
+ * Wait, until child has finished too: read child's result from
+ * child's stack and check it.
+ */
+ wait_stub_done(pid);
+ if (child_data->child_err != STUB_DATA) {
+ printk(UM_KERN_ERR "%s - stub-child %d reports error %ld\n",
+ __func__, pid, data->child_err);
+ err = data->child_err;
+ goto out_kill;
+ }
+
+ if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
+ (void *)PTRACE_O_TRACESYSGOOD) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "%s : PTRACE_OLDSETOPTIONS failed, errno = %d\n",
+ __func__, errno);
+ goto out_kill;
+ }
+
+ return pid;
+
+ out_kill:
+ os_kill_ptraced_process(pid, 1);
+ return err;
+}
+
+void new_thread(void *stack, jmp_buf *buf, void (*handler)(void))
+{
+ (*buf)[0].JB_IP = (unsigned long) handler;
+ (*buf)[0].JB_SP = (unsigned long) stack + UM_THREAD_SIZE -
+ sizeof(void *);
+}
+
+#define INIT_JMP_NEW_THREAD 0
+#define INIT_JMP_CALLBACK 1
+#define INIT_JMP_HALT 2
+#define INIT_JMP_REBOOT 3
+
+void switch_threads(jmp_buf *me, jmp_buf *you)
+{
+ if (UML_SETJMP(me) == 0)
+ UML_LONGJMP(you, 1);
+}
+
+static jmp_buf initial_jmpbuf;
+
+/* XXX Make these percpu */
+static void (*cb_proc)(void *arg);
+static void *cb_arg;
+static jmp_buf *cb_back;
+
+int start_idle_thread(void *stack, jmp_buf *switch_buf)
+{
+ int n;
+
+ set_handler(SIGWINCH);
+
+ /*
+ * Can't use UML_SETJMP or UML_LONGJMP here because they save
+ * and restore signals, with the possible side-effect of
+ * trying to handle any signals which came when they were
+ * blocked, which can't be done on this stack.
+ * Signals must be blocked when jumping back here and restored
+ * after returning to the jumper.
+ */
+ n = setjmp(initial_jmpbuf);
+ switch (n) {
+ case INIT_JMP_NEW_THREAD:
+ (*switch_buf)[0].JB_IP = (unsigned long) uml_finishsetup;
+ (*switch_buf)[0].JB_SP = (unsigned long) stack +
+ UM_THREAD_SIZE - sizeof(void *);
+ break;
+ case INIT_JMP_CALLBACK:
+ (*cb_proc)(cb_arg);
+ longjmp(*cb_back, 1);
+ break;
+ case INIT_JMP_HALT:
+ kmalloc_ok = 0;
+ return 0;
+ case INIT_JMP_REBOOT:
+ kmalloc_ok = 0;
+ return 1;
+ default:
+ printk(UM_KERN_ERR "Bad sigsetjmp return in %s - %d\n",
+ __func__, n);
+ fatal_sigsegv();
+ }
+ longjmp(*switch_buf, 1);
+
+ /* unreachable */
+ printk(UM_KERN_ERR "impossible long jump!");
+ fatal_sigsegv();
+ return 0;
+}
+
+void initial_thread_cb_skas(void (*proc)(void *), void *arg)
+{
+ jmp_buf here;
+
+ cb_proc = proc;
+ cb_arg = arg;
+ cb_back = &here;
+
+ block_signals_trace();
+ if (UML_SETJMP(&here) == 0)
+ UML_LONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
+ unblock_signals_trace();
+
+ cb_proc = NULL;
+ cb_arg = NULL;
+ cb_back = NULL;
+}
+
+void halt_skas(void)
+{
+ block_signals_trace();
+ UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
+}
+
+static bool noreboot;
+
+static int __init noreboot_cmd_param(char *str, int *add)
+{
+ noreboot = true;
+ return 0;
+}
+
+__uml_setup("noreboot", noreboot_cmd_param,
+"noreboot\n"
+" Rather than rebooting, exit always, akin to QEMU's -no-reboot option.\n"
+" This is useful if you're using CONFIG_PANIC_TIMEOUT in order to catch\n"
+" crashes in CI\n");
+
+void reboot_skas(void)
+{
+ block_signals_trace();
+ UML_LONGJMP(&initial_jmpbuf, noreboot ? INIT_JMP_HALT : INIT_JMP_REBOOT);
+}
+
+void __switch_mm(struct mm_id *mm_idp)
+{
+ userspace_pid[0] = mm_idp->u.pid;
+ kill_userspace_mm[0] = mm_idp->kill;
+}
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
new file mode 100644
index 0000000000..e3ee4db58b
--- /dev/null
+++ b/arch/um/os-Linux/start_up.c
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <asm/unistd.h>
+#include <init.h>
+#include <os.h>
+#include <mem_user.h>
+#include <ptrace_user.h>
+#include <registers.h>
+#include <skas.h>
+
+static void ptrace_child(void)
+{
+ int ret;
+ /* Calling os_getpid because some libcs cached getpid incorrectly */
+ int pid = os_getpid(), ppid = getppid();
+ int sc_result;
+
+ if (change_sig(SIGWINCH, 0) < 0 ||
+ ptrace(PTRACE_TRACEME, 0, 0, 0) < 0) {
+ perror("ptrace");
+ kill(pid, SIGKILL);
+ }
+ kill(pid, SIGSTOP);
+
+ /*
+ * This syscall will be intercepted by the parent. Don't call more than
+ * once, please.
+ */
+ sc_result = os_getpid();
+
+ if (sc_result == pid)
+ /* Nothing modified by the parent, we are running normally. */
+ ret = 1;
+ else if (sc_result == ppid)
+ /*
+ * Expected in check_ptrace and check_sysemu when they succeed
+ * in modifying the stack frame
+ */
+ ret = 0;
+ else
+ /* Serious trouble! This could be caused by a bug in host 2.6
+ * SKAS3/2.6 patch before release -V6, together with a bug in
+ * the UML code itself.
+ */
+ ret = 2;
+
+ exit(ret);
+}
+
+static void fatal_perror(const char *str)
+{
+ perror(str);
+ exit(1);
+}
+
+static void fatal(char *fmt, ...)
+{
+ va_list list;
+
+ va_start(list, fmt);
+ vfprintf(stderr, fmt, list);
+ va_end(list);
+
+ exit(1);
+}
+
+static void non_fatal(char *fmt, ...)
+{
+ va_list list;
+
+ va_start(list, fmt);
+ vfprintf(stderr, fmt, list);
+ va_end(list);
+}
+
+static int start_ptraced_child(void)
+{
+ int pid, n, status;
+
+ fflush(stdout);
+
+ pid = fork();
+ if (pid == 0)
+ ptrace_child();
+ else if (pid < 0)
+ fatal_perror("start_ptraced_child : fork failed");
+
+ CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
+ if (n < 0)
+ fatal_perror("check_ptrace : waitpid failed");
+ if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
+ fatal("check_ptrace : expected SIGSTOP, got status = %d",
+ status);
+
+ return pid;
+}
+
+/* When testing for SYSEMU support, if it is one of the broken versions, we
+ * must just avoid using sysemu, not panic, but only if SYSEMU features are
+ * broken.
+ * So only for SYSEMU features we test mustpanic, while normal host features
+ * must work anyway!
+ */
+static int stop_ptraced_child(int pid, int exitcode, int mustexit)
+{
+ int status, n, ret = 0;
+
+ if (ptrace(PTRACE_CONT, pid, 0, 0) < 0) {
+ perror("stop_ptraced_child : ptrace failed");
+ return -1;
+ }
+ CATCH_EINTR(n = waitpid(pid, &status, 0));
+ if (!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
+ int exit_with = WEXITSTATUS(status);
+ if (exit_with == 2)
+ non_fatal("check_ptrace : child exited with status 2. "
+ "\nDisabling SYSEMU support.\n");
+ non_fatal("check_ptrace : child exited with exitcode %d, while "
+ "expecting %d; status 0x%x\n", exit_with,
+ exitcode, status);
+ if (mustexit)
+ exit(1);
+ ret = -1;
+ }
+
+ return ret;
+}
+
+/* Changed only during early boot */
+static int force_sysemu_disabled = 0;
+
+static int __init nosysemu_cmd_param(char *str, int* add)
+{
+ force_sysemu_disabled = 1;
+ return 0;
+}
+
+__uml_setup("nosysemu", nosysemu_cmd_param,
+"nosysemu\n"
+" Turns off syscall emulation patch for ptrace (SYSEMU).\n"
+" SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n"
+" behaviour of ptrace() and helps reduce host context switch rates.\n"
+" To make it work, you need a kernel patch for your host, too.\n"
+" See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n"
+" information.\n\n");
+
+static void __init check_sysemu(void)
+{
+ unsigned long regs[MAX_REG_NR];
+ int pid, n, status, count=0;
+
+ os_info("Checking syscall emulation patch for ptrace...");
+ sysemu_supported = 0;
+ pid = start_ptraced_child();
+
+ if (ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0)
+ goto fail;
+
+ CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
+ if (n < 0)
+ fatal_perror("check_sysemu : wait failed");
+ if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
+ fatal("check_sysemu : expected SIGTRAP, got status = %d\n",
+ status);
+
+ if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
+ fatal_perror("check_sysemu : PTRACE_GETREGS failed");
+ if (PT_SYSCALL_NR(regs) != __NR_getpid) {
+ non_fatal("check_sysemu got system call number %d, "
+ "expected %d...", PT_SYSCALL_NR(regs), __NR_getpid);
+ goto fail;
+ }
+
+ n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET, os_getpid());
+ if (n < 0) {
+ non_fatal("check_sysemu : failed to modify system call "
+ "return");
+ goto fail;
+ }
+
+ if (stop_ptraced_child(pid, 0, 0) < 0)
+ goto fail_stopped;
+
+ sysemu_supported = 1;
+ os_info("OK\n");
+ set_using_sysemu(!force_sysemu_disabled);
+
+ os_info("Checking advanced syscall emulation patch for ptrace...");
+ pid = start_ptraced_child();
+
+ if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
+ (void *) PTRACE_O_TRACESYSGOOD) < 0))
+ fatal_perror("check_sysemu: PTRACE_OLDSETOPTIONS failed");
+
+ while (1) {
+ count++;
+ if (ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
+ goto fail;
+ CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
+ if (n < 0)
+ fatal_perror("check_sysemu: wait failed");
+
+ if (WIFSTOPPED(status) &&
+ (WSTOPSIG(status) == (SIGTRAP|0x80))) {
+ if (!count) {
+ non_fatal("check_sysemu: SYSEMU_SINGLESTEP "
+ "doesn't singlestep");
+ goto fail;
+ }
+ n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET,
+ os_getpid());
+ if (n < 0)
+ fatal_perror("check_sysemu : failed to modify "
+ "system call return");
+ break;
+ }
+ else if (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
+ count++;
+ else {
+ non_fatal("check_sysemu: expected SIGTRAP or "
+ "(SIGTRAP | 0x80), got status = %d\n",
+ status);
+ goto fail;
+ }
+ }
+ if (stop_ptraced_child(pid, 0, 0) < 0)
+ goto fail_stopped;
+
+ sysemu_supported = 2;
+ os_info("OK\n");
+
+ if (!force_sysemu_disabled)
+ set_using_sysemu(sysemu_supported);
+ return;
+
+fail:
+ stop_ptraced_child(pid, 1, 0);
+fail_stopped:
+ non_fatal("missing\n");
+}
+
+static void __init check_ptrace(void)
+{
+ int pid, syscall, n, status;
+
+ os_info("Checking that ptrace can change system call numbers...");
+ pid = start_ptraced_child();
+
+ if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
+ (void *) PTRACE_O_TRACESYSGOOD) < 0))
+ fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed");
+
+ while (1) {
+ if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
+ fatal_perror("check_ptrace : ptrace failed");
+
+ CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
+ if (n < 0)
+ fatal_perror("check_ptrace : wait failed");
+
+ if (!WIFSTOPPED(status) ||
+ (WSTOPSIG(status) != (SIGTRAP | 0x80)))
+ fatal("check_ptrace : expected (SIGTRAP|0x80), "
+ "got status = %d", status);
+
+ syscall = ptrace(PTRACE_PEEKUSER, pid, PT_SYSCALL_NR_OFFSET,
+ 0);
+ if (syscall == __NR_getpid) {
+ n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET,
+ __NR_getppid);
+ if (n < 0)
+ fatal_perror("check_ptrace : failed to modify "
+ "system call");
+ break;
+ }
+ }
+ stop_ptraced_child(pid, 0, 1);
+ os_info("OK\n");
+ check_sysemu();
+}
+
+extern void check_tmpexec(void);
+
+static void __init check_coredump_limit(void)
+{
+ struct rlimit lim;
+ int err = getrlimit(RLIMIT_CORE, &lim);
+
+ if (err) {
+ perror("Getting core dump limit");
+ return;
+ }
+
+ os_info("Core dump limits :\n\tsoft - ");
+ if (lim.rlim_cur == RLIM_INFINITY)
+ os_info("NONE\n");
+ else
+ os_info("%llu\n", (unsigned long long)lim.rlim_cur);
+
+ os_info("\thard - ");
+ if (lim.rlim_max == RLIM_INFINITY)
+ os_info("NONE\n");
+ else
+ os_info("%llu\n", (unsigned long long)lim.rlim_max);
+}
+
+void __init get_host_cpu_features(
+ void (*flags_helper_func)(char *line),
+ void (*cache_helper_func)(char *line))
+{
+ FILE *cpuinfo;
+ char *line = NULL;
+ size_t len = 0;
+ int done_parsing = 0;
+
+ cpuinfo = fopen("/proc/cpuinfo", "r");
+ if (cpuinfo == NULL) {
+ os_info("Failed to get host CPU features\n");
+ } else {
+ while ((getline(&line, &len, cpuinfo)) != -1) {
+ if (strstr(line, "flags")) {
+ flags_helper_func(line);
+ done_parsing++;
+ }
+ if (strstr(line, "cache_alignment")) {
+ cache_helper_func(line);
+ done_parsing++;
+ }
+ free(line);
+ line = NULL;
+ if (done_parsing > 1)
+ break;
+ }
+ fclose(cpuinfo);
+ }
+}
+
+
+void __init os_early_checks(void)
+{
+ int pid;
+
+ /* Print out the core dump limits early */
+ check_coredump_limit();
+
+ check_ptrace();
+
+ /* Need to check this early because mmapping happens before the
+ * kernel is running.
+ */
+ check_tmpexec();
+
+ pid = start_ptraced_child();
+ if (init_pid_registers(pid))
+ fatal("Failed to initialize default registers");
+ stop_ptraced_child(pid, 1, 1);
+}
+
+int __init parse_iomem(char *str, int *add)
+{
+ struct iomem_region *new;
+ struct stat64 buf;
+ char *file, *driver;
+ int fd, size;
+
+ driver = str;
+ file = strchr(str,',');
+ if (file == NULL) {
+ os_warn("parse_iomem : failed to parse iomem\n");
+ goto out;
+ }
+ *file = '\0';
+ file++;
+ fd = open(file, O_RDWR, 0);
+ if (fd < 0) {
+ perror("parse_iomem - Couldn't open io file");
+ goto out;
+ }
+
+ if (fstat64(fd, &buf) < 0) {
+ perror("parse_iomem - cannot stat_fd file");
+ goto out_close;
+ }
+
+ new = malloc(sizeof(*new));
+ if (new == NULL) {
+ perror("Couldn't allocate iomem_region struct");
+ goto out_close;
+ }
+
+ size = (buf.st_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1);
+
+ *new = ((struct iomem_region) { .next = iomem_regions,
+ .driver = driver,
+ .fd = fd,
+ .size = size,
+ .phys = 0,
+ .virt = 0 });
+ iomem_regions = new;
+ iomem_size += new->size + UM_KERN_PAGE_SIZE;
+
+ return 0;
+ out_close:
+ close(fd);
+ out:
+ return 1;
+}
diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
new file mode 100644
index 0000000000..4d5591d96d
--- /dev/null
+++ b/arch/um/os-Linux/time.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
+ * Copyright (C) 2012-2014 Cisco Systems
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
+ */
+
+#include <stddef.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <time.h>
+#include <sys/time.h>
+#include <kern_util.h>
+#include <os.h>
+#include <string.h>
+
+static timer_t event_high_res_timer = 0;
+
+static inline long long timespec_to_ns(const struct timespec *ts)
+{
+ return ((long long) ts->tv_sec * UM_NSEC_PER_SEC) + ts->tv_nsec;
+}
+
+long long os_persistent_clock_emulation(void)
+{
+ struct timespec realtime_tp;
+
+ clock_gettime(CLOCK_REALTIME, &realtime_tp);
+ return timespec_to_ns(&realtime_tp);
+}
+
+/**
+ * os_timer_create() - create an new posix (interval) timer
+ */
+int os_timer_create(void)
+{
+ timer_t *t = &event_high_res_timer;
+
+ if (timer_create(CLOCK_MONOTONIC, NULL, t) == -1)
+ return -1;
+
+ return 0;
+}
+
+int os_timer_set_interval(unsigned long long nsecs)
+{
+ struct itimerspec its;
+
+ its.it_value.tv_sec = nsecs / UM_NSEC_PER_SEC;
+ its.it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC;
+
+ its.it_interval.tv_sec = nsecs / UM_NSEC_PER_SEC;
+ its.it_interval.tv_nsec = nsecs % UM_NSEC_PER_SEC;
+
+ if (timer_settime(event_high_res_timer, 0, &its, NULL) == -1)
+ return -errno;
+
+ return 0;
+}
+
+int os_timer_one_shot(unsigned long long nsecs)
+{
+ struct itimerspec its = {
+ .it_value.tv_sec = nsecs / UM_NSEC_PER_SEC,
+ .it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC,
+
+ .it_interval.tv_sec = 0,
+ .it_interval.tv_nsec = 0, // we cheat here
+ };
+
+ timer_settime(event_high_res_timer, 0, &its, NULL);
+ return 0;
+}
+
+/**
+ * os_timer_disable() - disable the posix (interval) timer
+ */
+void os_timer_disable(void)
+{
+ struct itimerspec its;
+
+ memset(&its, 0, sizeof(struct itimerspec));
+ timer_settime(event_high_res_timer, 0, &its, NULL);
+}
+
+long long os_nsecs(void)
+{
+ struct timespec ts;
+
+ clock_gettime(CLOCK_MONOTONIC,&ts);
+ return timespec_to_ns(&ts);
+}
+
+/**
+ * os_idle_sleep() - sleep until interrupted
+ */
+void os_idle_sleep(void)
+{
+ struct itimerspec its;
+ sigset_t set, old;
+
+ /* block SIGALRM while we analyze the timer state */
+ sigemptyset(&set);
+ sigaddset(&set, SIGALRM);
+ sigprocmask(SIG_BLOCK, &set, &old);
+
+ /* check the timer, and if it'll fire then wait for it */
+ timer_gettime(event_high_res_timer, &its);
+ if (its.it_value.tv_sec || its.it_value.tv_nsec)
+ sigsuspend(&old);
+ /* either way, restore the signal mask */
+ sigprocmask(SIG_UNBLOCK, &set, NULL);
+}
diff --git a/arch/um/os-Linux/tty.c b/arch/um/os-Linux/tty.c
new file mode 100644
index 0000000000..f784db83e0
--- /dev/null
+++ b/arch/um/os-Linux/tty.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <kern_util.h>
+#include <os.h>
+
+struct grantpt_info {
+ int fd;
+ int res;
+ int err;
+};
+
+static void grantpt_cb(void *arg)
+{
+ struct grantpt_info *info = arg;
+
+ info->res = grantpt(info->fd);
+ info->err = errno;
+}
+
+int get_pty(void)
+{
+ struct grantpt_info info;
+ int fd, err;
+
+ fd = open("/dev/ptmx", O_RDWR);
+ if (fd < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "get_pty : Couldn't open /dev/ptmx - "
+ "err = %d\n", errno);
+ return err;
+ }
+
+ info.fd = fd;
+ initial_thread_cb(grantpt_cb, &info);
+
+ if (info.res < 0) {
+ err = -info.err;
+ printk(UM_KERN_ERR "get_pty : Couldn't grant pty - "
+ "errno = %d\n", -info.err);
+ goto out;
+ }
+
+ if (unlockpt(fd) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "get_pty : Couldn't unlock pty - "
+ "errno = %d\n", errno);
+ goto out;
+ }
+ return fd;
+out:
+ close(fd);
+ return err;
+}
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
new file mode 100644
index 0000000000..288c422bfa
--- /dev/null
+++ b/arch/um/os-Linux/umid.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <init.h>
+#include <os.h>
+
+#define UML_DIR "~/.uml/"
+
+#define UMID_LEN 64
+
+/* Changed by set_umid, which is run early in boot */
+static char umid[UMID_LEN] = { 0 };
+
+/* Changed by set_uml_dir and make_uml_dir, which are run early in boot */
+static char *uml_dir = UML_DIR;
+
+static int __init make_uml_dir(void)
+{
+ char dir[512] = { '\0' };
+ int len, err;
+
+ if (*uml_dir == '~') {
+ char *home = getenv("HOME");
+
+ err = -ENOENT;
+ if (home == NULL) {
+ printk(UM_KERN_ERR
+ "%s: no value in environment for $HOME\n",
+ __func__);
+ goto err;
+ }
+ strscpy(dir, home, sizeof(dir));
+ uml_dir++;
+ }
+ strlcat(dir, uml_dir, sizeof(dir));
+ len = strlen(dir);
+ if (len > 0 && dir[len - 1] != '/')
+ strlcat(dir, "/", sizeof(dir));
+
+ err = -ENOMEM;
+ uml_dir = malloc(strlen(dir) + 1);
+ if (uml_dir == NULL) {
+ printk(UM_KERN_ERR "%s : malloc failed, errno = %d\n",
+ __func__, errno);
+ goto err;
+ }
+ strcpy(uml_dir, dir);
+
+ if ((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)) {
+ printk(UM_KERN_ERR "Failed to mkdir '%s': %s\n",
+ uml_dir, strerror(errno));
+ err = -errno;
+ goto err_free;
+ }
+ return 0;
+
+err_free:
+ free(uml_dir);
+err:
+ uml_dir = NULL;
+ return err;
+}
+
+/*
+ * Unlinks the files contained in @dir and then removes @dir.
+ * Doesn't handle directory trees, so it's not like rm -rf, but almost such. We
+ * ignore ENOENT errors for anything (they happen, strangely enough - possibly
+ * due to races between multiple dying UML threads).
+ */
+static int remove_files_and_dir(char *dir)
+{
+ DIR *directory;
+ struct dirent *ent;
+ int len;
+ char file[256];
+ int ret;
+
+ directory = opendir(dir);
+ if (directory == NULL) {
+ if (errno != ENOENT)
+ return -errno;
+ else
+ return 0;
+ }
+
+ while ((ent = readdir(directory)) != NULL) {
+ if (!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))
+ continue;
+ len = strlen(dir) + strlen("/") + strlen(ent->d_name) + 1;
+ if (len > sizeof(file)) {
+ ret = -E2BIG;
+ goto out;
+ }
+
+ sprintf(file, "%s/%s", dir, ent->d_name);
+ if (unlink(file) < 0 && errno != ENOENT) {
+ ret = -errno;
+ goto out;
+ }
+ }
+
+ if (rmdir(dir) < 0 && errno != ENOENT) {
+ ret = -errno;
+ goto out;
+ }
+
+ ret = 0;
+out:
+ closedir(directory);
+ return ret;
+}
+
+/*
+ * This says that there isn't already a user of the specified directory even if
+ * there are errors during the checking. This is because if these errors
+ * happen, the directory is unusable by the pre-existing UML, so we might as
+ * well take it over. This could happen either by
+ * the existing UML somehow corrupting its umid directory
+ * something other than UML sticking stuff in the directory
+ * this boot racing with a shutdown of the other UML
+ * In any of these cases, the directory isn't useful for anything else.
+ *
+ * Boolean return: 1 if in use, 0 otherwise.
+ */
+static inline int is_umdir_used(char *dir)
+{
+ char pid[sizeof("nnnnnnnnn")], *end, *file;
+ int fd, p, n, err;
+ size_t filelen = strlen(dir) + sizeof("/pid") + 1;
+
+ file = malloc(filelen);
+ if (!file)
+ return -ENOMEM;
+
+ snprintf(file, filelen, "%s/pid", dir);
+
+ fd = open(file, O_RDONLY);
+ if (fd < 0) {
+ fd = -errno;
+ if (fd != -ENOENT) {
+ printk(UM_KERN_ERR "is_umdir_used : couldn't open pid "
+ "file '%s', err = %d\n", file, -fd);
+ }
+ goto out;
+ }
+
+ err = 0;
+ n = read(fd, pid, sizeof(pid));
+ if (n < 0) {
+ printk(UM_KERN_ERR "is_umdir_used : couldn't read pid file "
+ "'%s', err = %d\n", file, errno);
+ goto out_close;
+ } else if (n == 0) {
+ printk(UM_KERN_ERR "is_umdir_used : couldn't read pid file "
+ "'%s', 0-byte read\n", file);
+ goto out_close;
+ }
+
+ p = strtoul(pid, &end, 0);
+ if (end == pid) {
+ printk(UM_KERN_ERR "is_umdir_used : couldn't parse pid file "
+ "'%s', errno = %d\n", file, errno);
+ goto out_close;
+ }
+
+ if ((kill(p, 0) == 0) || (errno != ESRCH)) {
+ printk(UM_KERN_ERR "umid \"%s\" is already in use by pid %d\n",
+ umid, p);
+ return 1;
+ }
+
+out_close:
+ close(fd);
+out:
+ free(file);
+ return 0;
+}
+
+/*
+ * Try to remove the directory @dir unless it's in use.
+ * Precondition: @dir exists.
+ * Returns 0 for success, < 0 for failure in removal or if the directory is in
+ * use.
+ */
+static int umdir_take_if_dead(char *dir)
+{
+ int ret;
+ if (is_umdir_used(dir))
+ return -EEXIST;
+
+ ret = remove_files_and_dir(dir);
+ if (ret) {
+ printk(UM_KERN_ERR "is_umdir_used - remove_files_and_dir "
+ "failed with err = %d\n", ret);
+ }
+ return ret;
+}
+
+static void __init create_pid_file(void)
+{
+ char pid[sizeof("nnnnnnnnn")], *file;
+ int fd, n;
+
+ n = strlen(uml_dir) + UMID_LEN + sizeof("/pid");
+ file = malloc(n);
+ if (!file)
+ return;
+
+ if (umid_file_name("pid", file, n))
+ goto out;
+
+ fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0644);
+ if (fd < 0) {
+ printk(UM_KERN_ERR "Open of machine pid file \"%s\" failed: "
+ "%s\n", file, strerror(errno));
+ goto out;
+ }
+
+ snprintf(pid, sizeof(pid), "%d\n", getpid());
+ n = write(fd, pid, strlen(pid));
+ if (n != strlen(pid))
+ printk(UM_KERN_ERR "Write of pid file failed - err = %d\n",
+ errno);
+
+ close(fd);
+out:
+ free(file);
+}
+
+int __init set_umid(char *name)
+{
+ if (strlen(name) > UMID_LEN - 1)
+ return -E2BIG;
+
+ strscpy(umid, name, sizeof(umid));
+
+ return 0;
+}
+
+/* Changed in make_umid, which is called during early boot */
+static int umid_setup = 0;
+
+static int __init make_umid(void)
+{
+ int fd, err;
+ char tmp[256];
+
+ if (umid_setup)
+ return 0;
+
+ make_uml_dir();
+
+ if (*umid == '\0') {
+ strscpy(tmp, uml_dir, sizeof(tmp));
+ strlcat(tmp, "XXXXXX", sizeof(tmp));
+ fd = mkstemp(tmp);
+ if (fd < 0) {
+ printk(UM_KERN_ERR "make_umid - mkstemp(%s) failed: "
+ "%s\n", tmp, strerror(errno));
+ err = -errno;
+ goto err;
+ }
+
+ close(fd);
+
+ set_umid(&tmp[strlen(uml_dir)]);
+
+ /*
+ * There's a nice tiny little race between this unlink and
+ * the mkdir below. It'd be nice if there were a mkstemp
+ * for directories.
+ */
+ if (unlink(tmp)) {
+ err = -errno;
+ goto err;
+ }
+ }
+
+ snprintf(tmp, sizeof(tmp), "%s%s", uml_dir, umid);
+ err = mkdir(tmp, 0777);
+ if (err < 0) {
+ err = -errno;
+ if (err != -EEXIST)
+ goto err;
+
+ if (umdir_take_if_dead(tmp) < 0)
+ goto err;
+
+ err = mkdir(tmp, 0777);
+ }
+ if (err) {
+ err = -errno;
+ printk(UM_KERN_ERR "Failed to create '%s' - err = %d\n", umid,
+ errno);
+ goto err;
+ }
+
+ umid_setup = 1;
+
+ create_pid_file();
+
+ err = 0;
+ err:
+ return err;
+}
+
+static int __init make_umid_init(void)
+{
+ if (!make_umid())
+ return 0;
+
+ /*
+ * If initializing with the given umid failed, then try again with
+ * a random one.
+ */
+ printk(UM_KERN_ERR "Failed to initialize umid \"%s\", trying with a "
+ "random umid\n", umid);
+ *umid = '\0';
+ make_umid();
+
+ return 0;
+}
+
+__initcall(make_umid_init);
+
+int __init umid_file_name(char *name, char *buf, int len)
+{
+ int n, err;
+
+ err = make_umid();
+ if (err)
+ return err;
+
+ n = snprintf(buf, len, "%s%s/%s", uml_dir, umid, name);
+ if (n >= len) {
+ printk(UM_KERN_ERR "umid_file_name : buffer too short\n");
+ return -E2BIG;
+ }
+
+ return 0;
+}
+
+char *get_umid(void)
+{
+ return umid;
+}
+
+static int __init set_uml_dir(char *name, int *add)
+{
+ if (*name == '\0') {
+ os_warn("uml_dir can't be an empty string\n");
+ return 0;
+ }
+
+ if (name[strlen(name) - 1] == '/') {
+ uml_dir = name;
+ return 0;
+ }
+
+ uml_dir = malloc(strlen(name) + 2);
+ if (uml_dir == NULL) {
+ os_warn("Failed to malloc uml_dir - error = %d\n", errno);
+
+ /*
+ * Return 0 here because do_initcalls doesn't look at
+ * the return value.
+ */
+ return 0;
+ }
+ sprintf(uml_dir, "%s/", name);
+
+ return 0;
+}
+
+__uml_setup("uml_dir=", set_uml_dir,
+"uml_dir=<directory>\n"
+" The location to place the pid and umid files.\n\n"
+);
+
+static void remove_umid_dir(void)
+{
+ char *dir, err;
+
+ dir = malloc(strlen(uml_dir) + UMID_LEN + 1);
+ if (!dir)
+ return;
+
+ sprintf(dir, "%s%s", uml_dir, umid);
+ err = remove_files_and_dir(dir);
+ if (err)
+ os_warn("%s - remove_files_and_dir failed with err = %d\n",
+ __func__, err);
+
+ free(dir);
+}
+
+__uml_exitcall(remove_umid_dir);
diff --git a/arch/um/os-Linux/user_syms.c b/arch/um/os-Linux/user_syms.c
new file mode 100644
index 0000000000..a310ae27b4
--- /dev/null
+++ b/arch/um/os-Linux/user_syms.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+#define __NO_FORTIFY
+#include <linux/types.h>
+#include <linux/module.h>
+
+/*
+ * This file exports some critical string functions and compiler
+ * built-in functions (where calls are emitted by the compiler
+ * itself that we cannot avoid even in kernel code) to modules.
+ *
+ * "_user.c" code that previously used exports here such as hostfs
+ * really should be considered part of the 'hypervisor' and define
+ * its own API boundary like hostfs does now; don't add exports to
+ * this file for such cases.
+ */
+
+/* If it's not defined, the export is included in lib/string.c.*/
+#ifdef __HAVE_ARCH_STRSTR
+#undef strstr
+EXPORT_SYMBOL(strstr);
+#endif
+
+#ifndef __x86_64__
+#undef memcpy
+extern void *memcpy(void *, const void *, size_t);
+EXPORT_SYMBOL(memcpy);
+extern void *memmove(void *, const void *, size_t);
+EXPORT_SYMBOL(memmove);
+#undef memset
+extern void *memset(void *, int, size_t);
+EXPORT_SYMBOL(memset);
+#endif
+
+#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
+/* needed for __access_ok() */
+EXPORT_SYMBOL(vsyscall_ehdr);
+EXPORT_SYMBOL(vsyscall_end);
+#endif
+
+#ifdef _FORTIFY_SOURCE
+extern int __sprintf_chk(char *str, int flag, size_t len, const char *format);
+EXPORT_SYMBOL(__sprintf_chk);
+#endif
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
new file mode 100644
index 0000000000..fc0f2a9dee
--- /dev/null
+++ b/arch/um/os-Linux/util.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <termios.h>
+#include <sys/wait.h>
+#include <sys/mman.h>
+#include <sys/utsname.h>
+#include <sys/random.h>
+#include <init.h>
+#include <os.h>
+
+void stack_protections(unsigned long address)
+{
+ if (mprotect((void *) address, UM_THREAD_SIZE,
+ PROT_READ | PROT_WRITE | PROT_EXEC) < 0)
+ panic("protecting stack failed, errno = %d", errno);
+}
+
+int raw(int fd)
+{
+ struct termios tt;
+ int err;
+
+ CATCH_EINTR(err = tcgetattr(fd, &tt));
+ if (err < 0)
+ return -errno;
+
+ cfmakeraw(&tt);
+
+ CATCH_EINTR(err = tcsetattr(fd, TCSADRAIN, &tt));
+ if (err < 0)
+ return -errno;
+
+ /*
+ * XXX tcsetattr could have applied only some changes
+ * (and cfmakeraw() is a set of changes)
+ */
+ return 0;
+}
+
+void setup_machinename(char *machine_out)
+{
+ struct utsname host;
+
+ uname(&host);
+#ifdef UML_CONFIG_UML_X86
+# ifndef UML_CONFIG_64BIT
+ if (!strcmp(host.machine, "x86_64")) {
+ strcpy(machine_out, "i686");
+ return;
+ }
+# else
+ if (!strcmp(host.machine, "i686")) {
+ strcpy(machine_out, "x86_64");
+ return;
+ }
+# endif
+#endif
+ strcpy(machine_out, host.machine);
+}
+
+void setup_hostinfo(char *buf, int len)
+{
+ struct utsname host;
+
+ uname(&host);
+ snprintf(buf, len, "%s %s %s %s %s", host.sysname, host.nodename,
+ host.release, host.version, host.machine);
+}
+
+/*
+ * We cannot use glibc's abort(). It makes use of tgkill() which
+ * has no effect within UML's kernel threads.
+ * After that glibc would execute an invalid instruction to kill
+ * the calling process and UML crashes with SIGSEGV.
+ */
+static inline void __attribute__ ((noreturn)) uml_abort(void)
+{
+ sigset_t sig;
+
+ fflush(NULL);
+
+ if (!sigemptyset(&sig) && !sigaddset(&sig, SIGABRT))
+ sigprocmask(SIG_UNBLOCK, &sig, 0);
+
+ for (;;)
+ if (kill(getpid(), SIGABRT) < 0)
+ exit(127);
+}
+
+ssize_t os_getrandom(void *buf, size_t len, unsigned int flags)
+{
+ return getrandom(buf, len, flags);
+}
+
+/*
+ * UML helper threads must not handle SIGWINCH/INT/TERM
+ */
+void os_fix_helper_signals(void)
+{
+ signal(SIGWINCH, SIG_IGN);
+ signal(SIGINT, SIG_DFL);
+ signal(SIGTERM, SIG_DFL);
+}
+
+void os_dump_core(void)
+{
+ int pid;
+
+ signal(SIGSEGV, SIG_DFL);
+
+ /*
+ * We are about to SIGTERM this entire process group to ensure that
+ * nothing is around to run after the kernel exits. The
+ * kernel wants to abort, not die through SIGTERM, so we
+ * ignore it here.
+ */
+
+ signal(SIGTERM, SIG_IGN);
+ kill(0, SIGTERM);
+ /*
+ * Most of the other processes associated with this UML are
+ * likely sTopped, so give them a SIGCONT so they see the
+ * SIGTERM.
+ */
+ kill(0, SIGCONT);
+
+ /*
+ * Now, having sent signals to everyone but us, make sure they
+ * die by ptrace. Processes can survive what's been done to
+ * them so far - the mechanism I understand is receiving a
+ * SIGSEGV and segfaulting immediately upon return. There is
+ * always a SIGSEGV pending, and (I'm guessing) signals are
+ * processed in numeric order so the SIGTERM (signal 15 vs
+ * SIGSEGV being signal 11) is never handled.
+ *
+ * Run a waitpid loop until we get some kind of error.
+ * Hopefully, it's ECHILD, but there's not a lot we can do if
+ * it's something else. Tell os_kill_ptraced_process not to
+ * wait for the child to report its death because there's
+ * nothing reasonable to do if that fails.
+ */
+
+ while ((pid = waitpid(-1, NULL, WNOHANG | __WALL)) > 0)
+ os_kill_ptraced_process(pid, 0);
+
+ uml_abort();
+}
+
+void um_early_printk(const char *s, unsigned int n)
+{
+ printf("%.*s", n, s);
+}
+
+static int quiet_info;
+
+static int __init quiet_cmd_param(char *str, int *add)
+{
+ quiet_info = 1;
+ return 0;
+}
+
+__uml_setup("quiet", quiet_cmd_param,
+"quiet\n"
+" Turns off information messages during boot.\n\n");
+
+void os_info(const char *fmt, ...)
+{
+ va_list list;
+
+ if (quiet_info)
+ return;
+
+ va_start(list, fmt);
+ vfprintf(stderr, fmt, list);
+ va_end(list);
+}
+
+void os_warn(const char *fmt, ...)
+{
+ va_list list;
+
+ va_start(list, fmt);
+ vfprintf(stderr, fmt, list);
+ va_end(list);
+}