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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/powerpc/signal/sigreturn_vdso.c | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/powerpc/signal/sigreturn_vdso.c')
-rw-r--r-- | tools/testing/selftests/powerpc/signal/sigreturn_vdso.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/signal/sigreturn_vdso.c b/tools/testing/selftests/powerpc/signal/sigreturn_vdso.c new file mode 100644 index 000000000..e282fff0f --- /dev/null +++ b/tools/testing/selftests/powerpc/signal/sigreturn_vdso.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test that we can take signals with and without the VDSO mapped, which trigger + * different paths in the signal handling code. + * + * See handle_rt_signal64() and setup_trampoline() in signal_64.c + */ + +#define _GNU_SOURCE + +#include <errno.h> +#include <stdio.h> +#include <signal.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mman.h> +#include <sys/types.h> +#include <unistd.h> + +// Ensure assert() is not compiled out +#undef NDEBUG +#include <assert.h> + +#include "utils.h" + +static int search_proc_maps(char *needle, unsigned long *low, unsigned long *high) +{ + unsigned long start, end; + static char buf[4096]; + char name[128]; + FILE *f; + int rc = -1; + + f = fopen("/proc/self/maps", "r"); + if (!f) { + perror("fopen"); + return -1; + } + + while (fgets(buf, sizeof(buf), f)) { + rc = sscanf(buf, "%lx-%lx %*c%*c%*c%*c %*x %*d:%*d %*d %127s\n", + &start, &end, name); + if (rc == 2) + continue; + + if (rc != 3) { + printf("sscanf errored\n"); + rc = -1; + break; + } + + if (strstr(name, needle)) { + *low = start; + *high = end - 1; + rc = 0; + break; + } + } + + fclose(f); + + return rc; +} + +static volatile sig_atomic_t took_signal = 0; + +static void sigusr1_handler(int sig) +{ + took_signal++; +} + +int test_sigreturn_vdso(void) +{ + unsigned long low, high, size; + struct sigaction act; + char *p; + + act.sa_handler = sigusr1_handler; + act.sa_flags = 0; + sigemptyset(&act.sa_mask); + + assert(sigaction(SIGUSR1, &act, NULL) == 0); + + // Confirm the VDSO is mapped, and work out where it is + assert(search_proc_maps("[vdso]", &low, &high) == 0); + size = high - low + 1; + printf("VDSO is at 0x%lx-0x%lx (%lu bytes)\n", low, high, size); + + kill(getpid(), SIGUSR1); + assert(took_signal == 1); + printf("Signal delivered OK with VDSO mapped\n"); + + // Remap the VDSO somewhere else + p = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); + assert(p != MAP_FAILED); + assert(mremap((void *)low, size, size, MREMAP_MAYMOVE|MREMAP_FIXED, p) != MAP_FAILED); + assert(search_proc_maps("[vdso]", &low, &high) == 0); + size = high - low + 1; + printf("VDSO moved to 0x%lx-0x%lx (%lu bytes)\n", low, high, size); + + kill(getpid(), SIGUSR1); + assert(took_signal == 2); + printf("Signal delivered OK with VDSO moved\n"); + + assert(munmap((void *)low, size) == 0); + printf("Unmapped VDSO\n"); + + // Confirm the VDSO is not mapped anymore + assert(search_proc_maps("[vdso]", &low, &high) != 0); + + // Make the stack executable + assert(search_proc_maps("[stack]", &low, &high) == 0); + size = high - low + 1; + mprotect((void *)low, size, PROT_READ|PROT_WRITE|PROT_EXEC); + printf("Remapped the stack executable\n"); + + kill(getpid(), SIGUSR1); + assert(took_signal == 3); + printf("Signal delivered OK with VDSO unmapped\n"); + + return 0; +} + +int main(void) +{ + return test_harness(test_sigreturn_vdso, "sigreturn_vdso"); +} |