1 // SPDX-License-Identifier: GPL-2.0-only
3 * vdso_restorer.c - tests vDSO-based signal restore
4 * Copyright (c) 2015 Andrew Lutomirski
6 * This makes sure that sa_restorer == NULL keeps working on 32-bit
7 * configurations. Modern glibc doesn't use it under any circumstances,
8 * so it's easy to overlook breakage.
10 * 64-bit userspace has never supported sa_restorer == NULL, so this is
23 #include <sys/syscall.h>
25 /* Open-code this -- the headers are too messy to easily use them. */
26 struct real_sigaction {
33 static volatile sig_atomic_t handler_called;
35 static void handler_with_siginfo(int sig, siginfo_t *info, void *ctx_void)
40 static void handler_without_siginfo(int sig)
48 struct real_sigaction sa;
50 void *vdso = dlopen("linux-vdso.so.1",
51 RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
53 vdso = dlopen("linux-gate.so.1",
54 RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
56 printf("[SKIP]\tFailed to find vDSO. Tests are not expected to work.\n");
60 memset(&sa, 0, sizeof(sa));
61 sa.handler = handler_with_siginfo;
62 sa.flags = SA_SIGINFO;
63 sa.restorer = NULL; /* request kernel-provided restorer */
65 printf("[RUN]\tRaise a signal, SA_SIGINFO, sa.restorer == NULL\n");
67 if (syscall(SYS_rt_sigaction, SIGUSR1, &sa, NULL, 8) != 0)
68 err(1, "raw rt_sigaction syscall");
73 printf("[OK]\tSA_SIGINFO handler returned successfully\n");
75 printf("[FAIL]\tSA_SIGINFO handler was not called\n");
79 printf("[RUN]\tRaise a signal, !SA_SIGINFO, sa.restorer == NULL\n");
82 sa.handler = handler_without_siginfo;
83 if (syscall(SYS_sigaction, SIGUSR1, &sa, 0) != 0)
84 err(1, "raw sigaction syscall");
90 printf("[OK]\t!SA_SIGINFO handler returned successfully\n");
92 printf("[FAIL]\t!SA_SIGINFO handler was not called\n");