diff options
Diffstat (limited to 'tools/testing/selftests/proc/proc-pid-vm.c')
| -rw-r--r-- | tools/testing/selftests/proc/proc-pid-vm.c | 75 |
1 files changed, 68 insertions, 7 deletions
diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c index 28604c9f805c..e5962f4794f5 100644 --- a/tools/testing/selftests/proc/proc-pid-vm.c +++ b/tools/testing/selftests/proc/proc-pid-vm.c @@ -211,10 +211,19 @@ static int make_exe(const uint8_t *payload, size_t len) } #endif -static bool g_vsyscall = false; +/* + * 0: vsyscall VMA doesn't exist vsyscall=none + * 1: vsyscall VMA is r-xp vsyscall=emulate + * 2: vsyscall VMA is --xp vsyscall=xonly + */ +static int g_vsyscall; +static const char *str_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"; #ifdef __x86_64__ static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___) @@ -223,7 +232,7 @@ static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___) } /* - * vsyscall page can't be unmapped, probe it with memory load. + * vsyscall page can't be unmapped, probe it directly. */ static void vsyscall(void) { @@ -246,13 +255,52 @@ static void vsyscall(void) act.sa_sigaction = sigaction_SIGSEGV; (void)sigaction(SIGSEGV, &act, NULL); + /* gettimeofday(NULL, NULL); */ + asm volatile ( + "call %P0" + : + : "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); + *(volatile int *)0xffffffffff600000UL; exit(0); } waitpid(pid, &wstatus, 0); if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0) { - g_vsyscall = true; + /* vsyscall page is readable and executable. */ + g_vsyscall = 1; + return; } + + /* vsyscall page is executable but unreadable. */ + g_vsyscall = 2; } int main(void) @@ -261,6 +309,19 @@ int main(void) int exec_fd; vsyscall(); + switch (g_vsyscall) { + case 0: + str_vsyscall = str_vsyscall_0; + break; + case 1: + str_vsyscall = str_vsyscall_1; + break; + case 2: + str_vsyscall = str_vsyscall_2; + break; + default: + abort(); + } atexit(ate); @@ -314,7 +375,7 @@ int main(void) /* Test /proc/$PID/maps */ { - const size_t len = strlen(buf0) + (g_vsyscall ? strlen(str_vsyscall) : 0); + const size_t len = strlen(buf0) + strlen(str_vsyscall); char buf[256]; ssize_t rv; int fd; @@ -327,7 +388,7 @@ int main(void) rv = read(fd, buf, sizeof(buf)); assert(rv == len); assert(memcmp(buf, buf0, strlen(buf0)) == 0); - if (g_vsyscall) { + if (g_vsyscall > 0) { assert(memcmp(buf + strlen(buf0), str_vsyscall, strlen(str_vsyscall)) == 0); } } @@ -374,7 +435,7 @@ int main(void) assert(memmem(buf, rv, S[i], strlen(S[i]))); } - if (g_vsyscall) { + if (g_vsyscall > 0) { assert(memmem(buf, rv, str_vsyscall, strlen(str_vsyscall))); } } |