diff options
| author | Brian Foster <bfoster@redhat.com> | 2022-08-15 12:50:04 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-09-11 21:55:06 -0700 |
| commit | f4068af3a6383da3487c07de85db7732de851734 (patch) | |
| tree | 7b4db76e75f9d3b4cd870bbea875db8a0b5b603c /tools | |
| parent | 4f1d2a030db09af4d21695983674a18633cd0ffb (diff) | |
| download | linux-stable-f4068af3a6383da3487c07de85db7732de851734.tar.gz linux-stable-f4068af3a6383da3487c07de85db7732de851734.tar.bz2 linux-stable-f4068af3a6383da3487c07de85db7732de851734.zip | |
proc: save LOC in vsyscall test
Do one fork in vsyscall detection code and let SIGSEGV handler exit and
carry information to the parent saving LOC.
[adobriyan@gmail.com: redo original patch, delete unnecessary variables, minimise code changes]
Link: https://lkml.kernel.org/r/YvoWzAn5dlhF75xa@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Tested-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/proc/proc-pid-vm.c | 56 |
1 files changed, 16 insertions, 40 deletions
diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c index e5962f4794f5..69551bfa215c 100644 --- a/tools/testing/selftests/proc/proc-pid-vm.c +++ b/tools/testing/selftests/proc/proc-pid-vm.c @@ -213,22 +213,22 @@ static int make_exe(const uint8_t *payload, size_t len) /* * 0: vsyscall VMA doesn't exist vsyscall=none - * 1: vsyscall VMA is r-xp vsyscall=emulate - * 2: vsyscall VMA is --xp vsyscall=xonly + * 1: vsyscall VMA is --xp vsyscall=xonly + * 2: vsyscall VMA is r-xp vsyscall=emulate */ -static int g_vsyscall; +static volatile int g_vsyscall; static const char *str_vsyscall; static const char str_vsyscall_0[] = ""; static const char str_vsyscall_1[] = -"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n"; -static const char str_vsyscall_2[] = "ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]\n"; +static const char str_vsyscall_2[] = +"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n"; #ifdef __x86_64__ static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___) { - _exit(1); + _exit(g_vsyscall); } /* @@ -255,6 +255,7 @@ static void vsyscall(void) act.sa_sigaction = sigaction_SIGSEGV; (void)sigaction(SIGSEGV, &act, NULL); + g_vsyscall = 0; /* gettimeofday(NULL, NULL); */ asm volatile ( "call %P0" @@ -262,45 +263,20 @@ static void vsyscall(void) : "i" (0xffffffffff600000), "D" (NULL), "S" (NULL) : "rax", "rcx", "r11" ); - exit(0); - } - waitpid(pid, &wstatus, 0); - if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0) { - /* vsyscall page exists and is executable. */ - } else { - /* vsyscall page doesn't exist. */ - g_vsyscall = 0; - return; - } - - pid = fork(); - if (pid < 0) { - fprintf(stderr, "fork, errno %d\n", errno); - exit(1); - } - if (pid == 0) { - struct rlimit rlim = {0, 0}; - (void)setrlimit(RLIMIT_CORE, &rlim); - - /* Hide "segfault at ffffffffff600000" messages. */ - struct sigaction act; - memset(&act, 0, sizeof(struct sigaction)); - act.sa_flags = SA_SIGINFO; - act.sa_sigaction = sigaction_SIGSEGV; - (void)sigaction(SIGSEGV, &act, NULL); + g_vsyscall = 1; *(volatile int *)0xffffffffff600000UL; - exit(0); + + g_vsyscall = 2; + exit(g_vsyscall); } waitpid(pid, &wstatus, 0); - if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0) { - /* vsyscall page is readable and executable. */ - g_vsyscall = 1; - return; + if (WIFEXITED(wstatus)) { + g_vsyscall = WEXITSTATUS(wstatus); + } else { + fprintf(stderr, "error: wstatus %08x\n", wstatus); + exit(1); } - - /* vsyscall page is executable but unreadable. */ - g_vsyscall = 2; } int main(void) |