1 files changed, 287 insertions, 0 deletions
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
new file mode 100644
index 000000000..e52dd37dd
--- /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);
+}