89 lines
2.2 KiB
C
89 lines
2.2 KiB
C
/*
|
|
* vdso_restorer.c - tests vDSO-based signal restore
|
|
* Copyright (c) 2015 Andrew Lutomirski
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms and conditions of the GNU General Public License,
|
|
* version 2, as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* This makes sure that sa_restorer == NULL keeps working on 32-bit
|
|
* configurations. Modern glibc doesn't use it under any circumstances,
|
|
* so it's easy to overlook breakage.
|
|
*
|
|
* 64-bit userspace has never supported sa_restorer == NULL, so this is
|
|
* 32-bit only.
|
|
*/
|
|
|
|
#define _GNU_SOURCE
|
|
|
|
#include <err.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <signal.h>
|
|
#include <unistd.h>
|
|
#include <syscall.h>
|
|
#include <sys/syscall.h>
|
|
|
|
/* Open-code this -- the headers are too messy to easily use them. */
|
|
struct real_sigaction {
|
|
void *handler;
|
|
unsigned long flags;
|
|
void *restorer;
|
|
unsigned int mask[2];
|
|
};
|
|
|
|
static volatile sig_atomic_t handler_called;
|
|
|
|
static void handler_with_siginfo(int sig, siginfo_t *info, void *ctx_void)
|
|
{
|
|
handler_called = 1;
|
|
}
|
|
|
|
static void handler_without_siginfo(int sig)
|
|
{
|
|
handler_called = 1;
|
|
}
|
|
|
|
int main()
|
|
{
|
|
int nerrs = 0;
|
|
struct real_sigaction sa;
|
|
|
|
memset(&sa, 0, sizeof(sa));
|
|
sa.handler = handler_with_siginfo;
|
|
sa.flags = SA_SIGINFO;
|
|
sa.restorer = NULL; /* request kernel-provided restorer */
|
|
|
|
if (syscall(SYS_rt_sigaction, SIGUSR1, &sa, NULL, 8) != 0)
|
|
err(1, "raw rt_sigaction syscall");
|
|
|
|
raise(SIGUSR1);
|
|
|
|
if (handler_called) {
|
|
printf("[OK]\tSA_SIGINFO handler returned successfully\n");
|
|
} else {
|
|
printf("[FAIL]\tSA_SIGINFO handler was not called\n");
|
|
nerrs++;
|
|
}
|
|
|
|
sa.flags = 0;
|
|
sa.handler = handler_without_siginfo;
|
|
if (syscall(SYS_sigaction, SIGUSR1, &sa, 0) != 0)
|
|
err(1, "raw sigaction syscall");
|
|
handler_called = 0;
|
|
|
|
raise(SIGUSR1);
|
|
|
|
if (handler_called) {
|
|
printf("[OK]\t!SA_SIGINFO handler returned successfully\n");
|
|
} else {
|
|
printf("[FAIL]\t!SA_SIGINFO handler was not called\n");
|
|
nerrs++;
|
|
}
|
|
}
|