mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2025-08-16 22:13:31 +00:00
dbd6b649e7
The x86 selftests frequently register and clean up signal handlers, but the sethandler() and clearhandler() functions have been redundantly copied across multiple .c files. Move these functions to helpers.h to enable reuse across tests, eliminating around 250 lines of duplicate code. Converge the error handling by using ksft_exit_fail_msg(), which is functionally equivalent with err() within the selftest framework. This change is a prerequisite for the upcoming xstate selftest, which requires signal handling for registering and cleaning up handlers. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250226010731.2456-2-chang.seok.bae@intel.com
411 lines
12 KiB
C
411 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#define _GNU_SOURCE
|
|
|
|
#include <sys/ptrace.h>
|
|
#include <sys/types.h>
|
|
#include <sys/wait.h>
|
|
#include <sys/syscall.h>
|
|
#include <sys/user.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <stddef.h>
|
|
#include <stdio.h>
|
|
#include <err.h>
|
|
#include <string.h>
|
|
#include <asm/ptrace-abi.h>
|
|
#include <sys/auxv.h>
|
|
|
|
#include "helpers.h"
|
|
|
|
/* Bitness-agnostic defines for user_regs_struct fields. */
|
|
#ifdef __x86_64__
|
|
# define user_syscall_nr orig_rax
|
|
# define user_arg0 rdi
|
|
# define user_arg1 rsi
|
|
# define user_arg2 rdx
|
|
# define user_arg3 r10
|
|
# define user_arg4 r8
|
|
# define user_arg5 r9
|
|
# define user_ip rip
|
|
# define user_ax rax
|
|
#else
|
|
# define user_syscall_nr orig_eax
|
|
# define user_arg0 ebx
|
|
# define user_arg1 ecx
|
|
# define user_arg2 edx
|
|
# define user_arg3 esi
|
|
# define user_arg4 edi
|
|
# define user_arg5 ebp
|
|
# define user_ip eip
|
|
# define user_ax eax
|
|
#endif
|
|
|
|
static int nerrs = 0;
|
|
|
|
struct syscall_args32 {
|
|
uint32_t nr, arg0, arg1, arg2, arg3, arg4, arg5;
|
|
};
|
|
|
|
#ifdef __i386__
|
|
extern void sys32_helper(struct syscall_args32 *, void *);
|
|
extern void int80_and_ret(void);
|
|
#endif
|
|
|
|
/*
|
|
* Helper to invoke int80 with controlled regs and capture the final regs.
|
|
*/
|
|
static void do_full_int80(struct syscall_args32 *args)
|
|
{
|
|
#ifdef __x86_64__
|
|
register unsigned long bp asm("bp") = args->arg5;
|
|
asm volatile ("int $0x80"
|
|
: "+a" (args->nr),
|
|
"+b" (args->arg0), "+c" (args->arg1), "+d" (args->arg2),
|
|
"+S" (args->arg3), "+D" (args->arg4), "+r" (bp)
|
|
: : "r8", "r9", "r10", "r11");
|
|
args->arg5 = bp;
|
|
#else
|
|
sys32_helper(args, int80_and_ret);
|
|
#endif
|
|
}
|
|
|
|
#ifdef __i386__
|
|
static void (*vsyscall32)(void);
|
|
|
|
/*
|
|
* Nasty helper to invoke AT_SYSINFO (i.e. __kernel_vsyscall) with
|
|
* controlled regs and capture the final regs. This is so nasty that it
|
|
* crashes my copy of gdb :)
|
|
*/
|
|
static void do_full_vsyscall32(struct syscall_args32 *args)
|
|
{
|
|
sys32_helper(args, vsyscall32);
|
|
}
|
|
#endif
|
|
|
|
static siginfo_t wait_trap(pid_t chld)
|
|
{
|
|
siginfo_t si;
|
|
if (waitid(P_PID, chld, &si, WEXITED|WSTOPPED) != 0)
|
|
err(1, "waitid");
|
|
if (si.si_pid != chld)
|
|
errx(1, "got unexpected pid in event\n");
|
|
if (si.si_code != CLD_TRAPPED)
|
|
errx(1, "got unexpected event type %d\n", si.si_code);
|
|
return si;
|
|
}
|
|
|
|
static void setsigign(int sig, int flags)
|
|
{
|
|
struct sigaction sa;
|
|
memset(&sa, 0, sizeof(sa));
|
|
sa.sa_sigaction = (void *)SIG_IGN;
|
|
sa.sa_flags = flags;
|
|
sigemptyset(&sa.sa_mask);
|
|
if (sigaction(sig, &sa, 0))
|
|
err(1, "sigaction");
|
|
}
|
|
|
|
#ifdef __x86_64__
|
|
# define REG_BP REG_RBP
|
|
#else
|
|
# define REG_BP REG_EBP
|
|
#endif
|
|
|
|
static void empty_handler(int sig, siginfo_t *si, void *ctx_void)
|
|
{
|
|
}
|
|
|
|
static void test_sys32_regs(void (*do_syscall)(struct syscall_args32 *))
|
|
{
|
|
struct syscall_args32 args = {
|
|
.nr = 224, /* gettid */
|
|
.arg0 = 10, .arg1 = 11, .arg2 = 12,
|
|
.arg3 = 13, .arg4 = 14, .arg5 = 15,
|
|
};
|
|
|
|
do_syscall(&args);
|
|
|
|
if (args.nr != getpid() ||
|
|
args.arg0 != 10 || args.arg1 != 11 || args.arg2 != 12 ||
|
|
args.arg3 != 13 || args.arg4 != 14 || args.arg5 != 15) {
|
|
printf("[FAIL]\tgetpid() failed to preserve regs\n");
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tgetpid() preserves regs\n");
|
|
}
|
|
|
|
sethandler(SIGUSR1, empty_handler, 0);
|
|
|
|
args.nr = 37; /* kill */
|
|
args.arg0 = getpid();
|
|
args.arg1 = SIGUSR1;
|
|
do_syscall(&args);
|
|
if (args.nr != 0 ||
|
|
args.arg0 != getpid() || args.arg1 != SIGUSR1 || args.arg2 != 12 ||
|
|
args.arg3 != 13 || args.arg4 != 14 || args.arg5 != 15) {
|
|
printf("[FAIL]\tkill(getpid(), SIGUSR1) failed to preserve regs\n");
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tkill(getpid(), SIGUSR1) preserves regs\n");
|
|
}
|
|
clearhandler(SIGUSR1);
|
|
}
|
|
|
|
static void test_ptrace_syscall_restart(void)
|
|
{
|
|
printf("[RUN]\tptrace-induced syscall restart\n");
|
|
pid_t chld = fork();
|
|
if (chld < 0)
|
|
err(1, "fork");
|
|
|
|
if (chld == 0) {
|
|
if (ptrace(PTRACE_TRACEME, 0, 0, 0) != 0)
|
|
err(1, "PTRACE_TRACEME");
|
|
|
|
pid_t pid = getpid(), tid = syscall(SYS_gettid);
|
|
|
|
printf("\tChild will make one syscall\n");
|
|
syscall(SYS_tgkill, pid, tid, SIGSTOP);
|
|
|
|
syscall(SYS_gettid, 10, 11, 12, 13, 14, 15);
|
|
_exit(0);
|
|
}
|
|
|
|
int status;
|
|
|
|
/* Wait for SIGSTOP. */
|
|
if (waitpid(chld, &status, 0) != chld || !WIFSTOPPED(status))
|
|
err(1, "waitpid");
|
|
|
|
struct user_regs_struct regs;
|
|
|
|
printf("[RUN]\tSYSEMU\n");
|
|
if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0)
|
|
err(1, "PTRACE_SYSEMU");
|
|
wait_trap(chld);
|
|
|
|
if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0)
|
|
err(1, "PTRACE_GETREGS");
|
|
|
|
if (regs.user_syscall_nr != SYS_gettid ||
|
|
regs.user_arg0 != 10 || regs.user_arg1 != 11 ||
|
|
regs.user_arg2 != 12 || regs.user_arg3 != 13 ||
|
|
regs.user_arg4 != 14 || regs.user_arg5 != 15) {
|
|
printf("[FAIL]\tInitial args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5);
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tInitial nr and args are correct\n");
|
|
}
|
|
|
|
printf("[RUN]\tRestart the syscall (ip = 0x%lx)\n",
|
|
(unsigned long)regs.user_ip);
|
|
|
|
/*
|
|
* This does exactly what it appears to do if syscall is int80 or
|
|
* SYSCALL64. For SYSCALL32 or SYSENTER, though, this is highly
|
|
* magical. It needs to work so that ptrace and syscall restart
|
|
* work as expected.
|
|
*/
|
|
regs.user_ax = regs.user_syscall_nr;
|
|
regs.user_ip -= 2;
|
|
if (ptrace(PTRACE_SETREGS, chld, 0, ®s) != 0)
|
|
err(1, "PTRACE_SETREGS");
|
|
|
|
if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0)
|
|
err(1, "PTRACE_SYSEMU");
|
|
wait_trap(chld);
|
|
|
|
if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0)
|
|
err(1, "PTRACE_GETREGS");
|
|
|
|
if (regs.user_syscall_nr != SYS_gettid ||
|
|
regs.user_arg0 != 10 || regs.user_arg1 != 11 ||
|
|
regs.user_arg2 != 12 || regs.user_arg3 != 13 ||
|
|
regs.user_arg4 != 14 || regs.user_arg5 != 15) {
|
|
printf("[FAIL]\tRestart nr or args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5);
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tRestarted nr and args are correct\n");
|
|
}
|
|
|
|
printf("[RUN]\tChange nr and args and restart the syscall (ip = 0x%lx)\n",
|
|
(unsigned long)regs.user_ip);
|
|
|
|
regs.user_ax = SYS_getpid;
|
|
regs.user_arg0 = 20;
|
|
regs.user_arg1 = 21;
|
|
regs.user_arg2 = 22;
|
|
regs.user_arg3 = 23;
|
|
regs.user_arg4 = 24;
|
|
regs.user_arg5 = 25;
|
|
regs.user_ip -= 2;
|
|
|
|
if (ptrace(PTRACE_SETREGS, chld, 0, ®s) != 0)
|
|
err(1, "PTRACE_SETREGS");
|
|
|
|
if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0)
|
|
err(1, "PTRACE_SYSEMU");
|
|
wait_trap(chld);
|
|
|
|
if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0)
|
|
err(1, "PTRACE_GETREGS");
|
|
|
|
if (regs.user_syscall_nr != SYS_getpid ||
|
|
regs.user_arg0 != 20 || regs.user_arg1 != 21 || regs.user_arg2 != 22 ||
|
|
regs.user_arg3 != 23 || regs.user_arg4 != 24 || regs.user_arg5 != 25) {
|
|
printf("[FAIL]\tRestart nr or args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5);
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tReplacement nr and args are correct\n");
|
|
}
|
|
|
|
if (ptrace(PTRACE_CONT, chld, 0, 0) != 0)
|
|
err(1, "PTRACE_CONT");
|
|
if (waitpid(chld, &status, 0) != chld)
|
|
err(1, "waitpid");
|
|
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
|
|
printf("[FAIL]\tChild failed\n");
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tChild exited cleanly\n");
|
|
}
|
|
}
|
|
|
|
static void test_restart_under_ptrace(void)
|
|
{
|
|
printf("[RUN]\tkernel syscall restart under ptrace\n");
|
|
pid_t chld = fork();
|
|
if (chld < 0)
|
|
err(1, "fork");
|
|
|
|
if (chld == 0) {
|
|
if (ptrace(PTRACE_TRACEME, 0, 0, 0) != 0)
|
|
err(1, "PTRACE_TRACEME");
|
|
|
|
pid_t pid = getpid(), tid = syscall(SYS_gettid);
|
|
|
|
printf("\tChild will take a nap until signaled\n");
|
|
setsigign(SIGUSR1, SA_RESTART);
|
|
syscall(SYS_tgkill, pid, tid, SIGSTOP);
|
|
|
|
syscall(SYS_pause, 0, 0, 0, 0, 0, 0);
|
|
_exit(0);
|
|
}
|
|
|
|
int status;
|
|
|
|
/* Wait for SIGSTOP. */
|
|
if (waitpid(chld, &status, 0) != chld || !WIFSTOPPED(status))
|
|
err(1, "waitpid");
|
|
|
|
struct user_regs_struct regs;
|
|
|
|
printf("[RUN]\tSYSCALL\n");
|
|
if (ptrace(PTRACE_SYSCALL, chld, 0, 0) != 0)
|
|
err(1, "PTRACE_SYSCALL");
|
|
wait_trap(chld);
|
|
|
|
/* We should be stopped at pause(2) entry. */
|
|
|
|
if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0)
|
|
err(1, "PTRACE_GETREGS");
|
|
|
|
if (regs.user_syscall_nr != SYS_pause ||
|
|
regs.user_arg0 != 0 || regs.user_arg1 != 0 ||
|
|
regs.user_arg2 != 0 || regs.user_arg3 != 0 ||
|
|
regs.user_arg4 != 0 || regs.user_arg5 != 0) {
|
|
printf("[FAIL]\tInitial args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5);
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tInitial nr and args are correct\n");
|
|
}
|
|
|
|
/* Interrupt it. */
|
|
kill(chld, SIGUSR1);
|
|
|
|
/* Advance. We should be stopped at exit. */
|
|
printf("[RUN]\tSYSCALL\n");
|
|
if (ptrace(PTRACE_SYSCALL, chld, 0, 0) != 0)
|
|
err(1, "PTRACE_SYSCALL");
|
|
wait_trap(chld);
|
|
|
|
if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0)
|
|
err(1, "PTRACE_GETREGS");
|
|
|
|
if (regs.user_syscall_nr != SYS_pause ||
|
|
regs.user_arg0 != 0 || regs.user_arg1 != 0 ||
|
|
regs.user_arg2 != 0 || regs.user_arg3 != 0 ||
|
|
regs.user_arg4 != 0 || regs.user_arg5 != 0) {
|
|
printf("[FAIL]\tArgs after SIGUSR1 are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5);
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tArgs after SIGUSR1 are correct (ax = %ld)\n",
|
|
(long)regs.user_ax);
|
|
}
|
|
|
|
/* Poke the regs back in. This must not break anything. */
|
|
if (ptrace(PTRACE_SETREGS, chld, 0, ®s) != 0)
|
|
err(1, "PTRACE_SETREGS");
|
|
|
|
/* Catch the (ignored) SIGUSR1. */
|
|
if (ptrace(PTRACE_CONT, chld, 0, 0) != 0)
|
|
err(1, "PTRACE_CONT");
|
|
if (waitpid(chld, &status, 0) != chld)
|
|
err(1, "waitpid");
|
|
if (!WIFSTOPPED(status)) {
|
|
printf("[FAIL]\tChild was stopped for SIGUSR1 (status = 0x%x)\n", status);
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tChild got SIGUSR1\n");
|
|
}
|
|
|
|
/* The next event should be pause(2) again. */
|
|
printf("[RUN]\tStep again\n");
|
|
if (ptrace(PTRACE_SYSCALL, chld, 0, 0) != 0)
|
|
err(1, "PTRACE_SYSCALL");
|
|
wait_trap(chld);
|
|
|
|
/* We should be stopped at pause(2) entry. */
|
|
|
|
if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0)
|
|
err(1, "PTRACE_GETREGS");
|
|
|
|
if (regs.user_syscall_nr != SYS_pause ||
|
|
regs.user_arg0 != 0 || regs.user_arg1 != 0 ||
|
|
regs.user_arg2 != 0 || regs.user_arg3 != 0 ||
|
|
regs.user_arg4 != 0 || regs.user_arg5 != 0) {
|
|
printf("[FAIL]\tpause did not restart (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5);
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tpause(2) restarted correctly\n");
|
|
}
|
|
|
|
/* Kill it. */
|
|
kill(chld, SIGKILL);
|
|
if (waitpid(chld, &status, 0) != chld)
|
|
err(1, "waitpid");
|
|
}
|
|
|
|
int main()
|
|
{
|
|
printf("[RUN]\tCheck int80 return regs\n");
|
|
test_sys32_regs(do_full_int80);
|
|
|
|
#if defined(__i386__) && (!defined(__GLIBC__) || __GLIBC__ > 2 || __GLIBC_MINOR__ >= 16)
|
|
vsyscall32 = (void *)getauxval(AT_SYSINFO);
|
|
if (vsyscall32) {
|
|
printf("[RUN]\tCheck AT_SYSINFO return regs\n");
|
|
test_sys32_regs(do_full_vsyscall32);
|
|
} else {
|
|
printf("[SKIP]\tAT_SYSINFO is not available\n");
|
|
}
|
|
#endif
|
|
|
|
test_ptrace_syscall_restart();
|
|
|
|
test_restart_under_ptrace();
|
|
|
|
return 0;
|
|
}
|