Test that the fdinfo field of a pidfd referring to a dead process correctly shows Pid: -1 and NSpid: -1.
Cc: Christian Kellner christian@kellner.me Cc: linux-kselftest@vger.kernel.org Reviewed-by: Christian Kellner christian@kellner.me Signed-off-by: Christian Brauner christian.brauner@ubuntu.com --- /* pidfd selftests */ passed
/* v1 */ Link: https://lore.kernel.org/r/20191015141332.4055-2-christian.brauner@ubuntu.com
/* v2 */ Link: https://lore.kernel.org/r/20191016153606.2326-2-christian.brauner@ubuntu.com unchanged
/* v3 */ unchanged --- .../selftests/pidfd/pidfd_fdinfo_test.c | 59 ++++++++++++++----- 1 file changed, 45 insertions(+), 14 deletions(-)
diff --git a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c index 3721be994abd..22558524f71c 100644 --- a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c +++ b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c @@ -113,11 +113,15 @@ static struct child clone_newns(int (*fn)(void *), void *args, return ret; }
+static inline void child_close(struct child *child) +{ + close(child->fd); +} + static inline int child_join(struct child *child, struct error *err) { int r;
- (void)close(child->fd); r = wait_for_pid(child->pid); if (r < 0) error_set(err, PIDFD_ERROR, "waitpid failed (ret %d, errno %d)", @@ -128,6 +132,12 @@ static inline int child_join(struct child *child, struct error *err) return r; }
+static inline int child_join_close(struct child *child, struct error *err) +{ + child_close(child); + return child_join(child, err); +} + static inline void trim_newline(char *str) { char *pos = strrchr(str, '\n'); @@ -136,8 +146,8 @@ static inline void trim_newline(char *str) *pos = '\0'; }
-static int verify_fdinfo_nspid(int pidfd, struct error *err, - const char *expect, ...) +static int verify_fdinfo(int pidfd, struct error *err, const char *prefix, + size_t prefix_len, const char *expect, ...) { char buffer[512] = {0, }; char path[512] = {0, }; @@ -160,17 +170,20 @@ static int verify_fdinfo_nspid(int pidfd, struct error *err, pidfd);
while (getline(&line, &n, f) != -1) { - if (strncmp(line, "NSpid:", 6)) + char *val; + + if (strncmp(line, prefix, prefix_len)) continue;
found = 1;
- r = strcmp(line + 6, buffer); + val = line + prefix_len; + r = strcmp(val, buffer); if (r != 0) { trim_newline(line); trim_newline(buffer); - error_set(err, PIDFD_FAIL, "NSpid: '%s' != '%s'", - line + 6, buffer); + error_set(err, PIDFD_FAIL, "%s '%s' != '%s'", + prefix, val, buffer); } break; } @@ -179,8 +192,8 @@ static int verify_fdinfo_nspid(int pidfd, struct error *err, fclose(f);
if (found == 0) - return error_set(err, PIDFD_FAIL, "NSpid not found for fd %d", - pidfd); + return error_set(err, PIDFD_FAIL, "%s not found for fd %d", + prefix, pidfd);
return PIDFD_PASS; } @@ -213,7 +226,7 @@ static int child_fdinfo_nspid_test(void *args) }
pidfd = *(int *)args; - r = verify_fdinfo_nspid(pidfd, &err, "\t0\n"); + r = verify_fdinfo(pidfd, &err, "NSpid:", 6, "\t0\n");
if (r != PIDFD_PASS) ksft_print_msg("NSpid fdinfo check failed: %s\n", err.msg); @@ -242,24 +255,42 @@ static void test_pidfd_fdinfo_nspid(void) /* The children will have pid 1 in the new pid namespace, * so the line must be 'NSPid:\t<pid>\t1'. */ - verify_fdinfo_nspid(a.fd, &err, "\t%d\t%d\n", a.pid, 1); - verify_fdinfo_nspid(b.fd, &err, "\t%d\t%d\n", b.pid, 1); + verify_fdinfo(a.fd, &err, "NSpid:", 6, "\t%d\t%d\n", a.pid, 1); + verify_fdinfo(b.fd, &err, "NSpid:", 6, "\t%d\t%d\n", b.pid, 1);
/* wait for the process, check the exit status and set * 'err' accordingly, if it is not already set. */ + child_join_close(&a, &err); + child_join_close(&b, &err); + + error_report(&err, test_name); +} + +static void test_pidfd_dead_fdinfo(void) +{ + struct child a; + struct error err = {0, }; + const char *test_name = "pidfd check fdinfo for dead process"; + + /* Create a new child in a new pid and mount namespace */ + a = clone_newns(child_fdinfo_nspid_test, NULL, &err); + error_check(&err, test_name); child_join(&a, &err); - child_join(&b, &err);
+ verify_fdinfo(a.fd, &err, "Pid:", 4, "\t-1\n"); + verify_fdinfo(a.fd, &err, "NSpid:", 6, "\t-1\n"); + child_close(&a); error_report(&err, test_name); }
int main(int argc, char **argv) { ksft_print_header(); - ksft_set_plan(1); + ksft_set_plan(2);
test_pidfd_fdinfo_nspid(); + test_pidfd_dead_fdinfo();
return ksft_exit_pass(); }