diff options
| -rw-r--r-- | tools/testing/selftests/proc/proc-empty-vm.c | 97 |
1 files changed, 92 insertions, 5 deletions
diff --git a/tools/testing/selftests/proc/proc-empty-vm.c b/tools/testing/selftests/proc/proc-empty-vm.c index ee71ce52cb6a..171d46a1ac27 100644 --- a/tools/testing/selftests/proc/proc-empty-vm.c +++ b/tools/testing/selftests/proc/proc-empty-vm.c @@ -303,6 +303,95 @@ static int test_proc_pid_smaps_rollup(pid_t pid) } } +static const char *parse_u64(const char *p, const char *const end, uint64_t *rv) +{ + *rv = 0; + for (; p != end; p += 1) { + if ('0' <= *p && *p <= '9') { + assert(!__builtin_mul_overflow(*rv, 10, rv)); + assert(!__builtin_add_overflow(*rv, *p - '0', rv)); + } else { + break; + } + } + assert(p != end); + return p; +} + +/* + * There seems to be 2 types of valid output: + * "0 A A B 0 0 0\n" for dynamic exeuctables, + * "0 0 0 B 0 0 0\n" for static executables. + */ +static int test_proc_pid_statm(pid_t pid) +{ + char buf[4096]; + snprintf(buf, sizeof(buf), "/proc/%u/statm", pid); + int fd = open(buf, O_RDONLY); + if (fd == -1) { + perror("open /proc/${pid}/statm"); + return EXIT_FAILURE; + } + + ssize_t rv = read(fd, buf, sizeof(buf)); + close(fd); + + assert(rv >= 0); + assert(rv <= sizeof(buf)); + if (0) { + write(1, buf, rv); + } + + const char *p = buf; + const char *const end = p + rv; + + /* size */ + assert(p != end && *p++ == '0'); + assert(p != end && *p++ == ' '); + + uint64_t resident; + p = parse_u64(p, end, &resident); + assert(p != end && *p++ == ' '); + + uint64_t shared; + p = parse_u64(p, end, &shared); + assert(p != end && *p++ == ' '); + + uint64_t text; + p = parse_u64(p, end, &text); + assert(p != end && *p++ == ' '); + + assert(p != end && *p++ == '0'); + assert(p != end && *p++ == ' '); + + /* data */ + assert(p != end && *p++ == '0'); + assert(p != end && *p++ == ' '); + + assert(p != end && *p++ == '0'); + assert(p != end && *p++ == '\n'); + + assert(p == end); + + /* + * "text" is "mm->end_code - mm->start_code" at execve(2) time. + * munmap() doesn't change it. It can be anything (just link + * statically). It can't be 0 because executing to this point + * implies at least 1 page of code. + */ + assert(text > 0); + + /* + * These two are always equal. Always 0 for statically linked + * executables and sometimes 0 for dynamically linked executables. + * There is no way to tell one from another without parsing ELF + * which is too much for this test. + */ + assert(resident == shared); + + return EXIT_SUCCESS; +} + int main(void) { int rv = EXIT_SUCCESS; @@ -389,11 +478,9 @@ int main(void) if (rv == EXIT_SUCCESS) { rv = test_proc_pid_smaps_rollup(pid); } - /* - * TODO test /proc/${pid}/statm, task_statm() - * ->start_code, ->end_code aren't updated by munmap(). - * Output can be "0 0 0 2 0 0 0\n" where "2" can be anything. - */ + if (rv == EXIT_SUCCESS) { + rv = test_proc_pid_statm(pid); + } /* Cut the rope. */ int wstatus; |