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-rw-r--r--arch/um/os-Linux/skas/process.c732
1 files changed, 732 insertions, 0 deletions
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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 02:01:31 +0000