projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 65cacec1 AL |
1 | /* |
| 2 | * vdso_restorer.c - tests vDSO-based signal restore | |
| 3 | * Copyright (c) 2015 Andrew Lutomirski | |
| 4 | * | |
| 5 | * This program is free software; you can redistribute it and/or modify | |
| 6 | * it under the terms and conditions of the GNU General Public License, | |
| 7 | * version 2, as published by the Free Software Foundation. | |
| 8 | * | |
| 9 | * This program is distributed in the hope it will be useful, but | |
| 10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 12 | * General Public License for more details. | |
| 13 | * | |
| 14 | * This makes sure that sa_restorer == NULL keeps working on 32-bit | |
| 15 | * configurations. Modern glibc doesn't use it under any circumstances, | |
| 16 | * so it's easy to overlook breakage. | |
| 17 | * | |
| 18 | * 64-bit userspace has never supported sa_restorer == NULL, so this is | |
| 19 | * 32-bit only. | |
| 20 | */ | |
| 21 | ||
| 22 | #define _GNU_SOURCE | |
| 23 | ||
| 24 | #include <err.h> | |
| 25 | #include <stdio.h> | |
| 26 | #include <string.h> | |
| 27 | #include <signal.h> | |
| 28 | #include <unistd.h> | |
| 29 | #include <syscall.h> | |
| 30 | #include <sys/syscall.h> | |
| 31 | ||
| 32 | /* Open-code this -- the headers are too messy to easily use them. */ | |
| 33 | struct real_sigaction { | |
| 34 | void *handler; | |
| 35 | unsigned long flags; | |
| 36 | void *restorer; | |
| 37 | unsigned int mask[2]; | |
| 38 | }; | |
| 39 | ||
| 40 | static volatile sig_atomic_t handler_called; | |
| 41 | ||
| 42 | static void handler_with_siginfo(int sig, siginfo_t *info, void *ctx_void) | |
| 43 | { | |
| 44 | handler_called = 1; | |
| 45 | } | |
| 46 | ||
| 47 | static void handler_without_siginfo(int sig) | |
| 48 | { | |
| 49 | handler_called = 1; | |
| 50 | } | |
| 51 | ||
| 52 | int main() | |
| 53 | { | |
| 54 | int nerrs = 0; | |
| 55 | struct real_sigaction sa; | |
| 56 | ||
| 57 | memset(&sa, 0, sizeof(sa)); | |
| 58 | sa.handler = handler_with_siginfo; | |
| 59 | sa.flags = SA_SIGINFO; | |
| 60 | sa.restorer = NULL; /* request kernel-provided restorer */ | |
| 61 | ||
| 62 | if (syscall(SYS_rt_sigaction, SIGUSR1, &sa, NULL, 8) != 0) | |
| 63 | err(1, "raw rt_sigaction syscall"); | |
| 64 | ||
| 65 | raise(SIGUSR1); | |
| 66 | ||
| 67 | if (handler_called) { | |
| 68 | printf("[OK]\tSA_SIGINFO handler returned successfully\n"); | |
| 69 | } else { | |
| 70 | printf("[FAIL]\tSA_SIGINFO handler was not called\n"); | |
| 71 | nerrs++; | |
| 72 | } | |
| 73 | ||
| 74 | sa.flags = 0; | |
| 75 | sa.handler = handler_without_siginfo; | |
| 76 | if (syscall(SYS_sigaction, SIGUSR1, &sa, 0) != 0) | |
| 77 | err(1, "raw sigaction syscall"); | |
| 78 | handler_called = 0; | |
| 79 | ||
| 80 | raise(SIGUSR1); | |
| 81 | ||
| 82 | if (handler_called) { | |
| 83 | printf("[OK]\t!SA_SIGINFO handler returned successfully\n"); | |
| 84 | } else { | |
| 85 | printf("[FAIL]\t!SA_SIGINFO handler was not called\n"); | |
| 86 | nerrs++; | |
| 87 | } | |
| 88 | } |