[v9,09/10] kselftest: save-and-restore errno to allow for %m formatting

Submitted by Aleksa Sarai on July 6, 2019, 2:57 p.m.

Details

Message ID 20190706145737.5299-10-cyphar@cyphar.com
State New
Series "namei: openat2(2) path resolution restrictions"
Headers show

Commit Message

Aleksa Sarai July 6, 2019, 2:57 p.m.
Previously, using "%m" in a ksft_* format string can result in strange
output because the errno value wasn't saved before calling other libc
functions. The solution is to simply save and restore the errno before
we format the user-supplied format string.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
---
 tools/testing/selftests/kselftest.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Patch hide | download patch | download mbox

diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index ec15c4f6af55..0ac49d91a260 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -10,6 +10,7 @@ 
 #ifndef __KSELFTEST_H
 #define __KSELFTEST_H
 
+#include <errno.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdarg.h>
@@ -81,58 +82,68 @@  static inline void ksft_print_cnts(void)
 
 static inline void ksft_print_msg(const char *msg, ...)
 {
+	int saved_errno = errno;
 	va_list args;
 
 	va_start(args, msg);
 	printf("# ");
+	errno = saved_errno;
 	vprintf(msg, args);
 	va_end(args);
 }
 
 static inline void ksft_test_result_pass(const char *msg, ...)
 {
+	int saved_errno = errno;
 	va_list args;
 
 	ksft_cnt.ksft_pass++;
 
 	va_start(args, msg);
 	printf("ok %d ", ksft_test_num());
+	errno = saved_errno;
 	vprintf(msg, args);
 	va_end(args);
 }
 
 static inline void ksft_test_result_fail(const char *msg, ...)
 {
+	int saved_errno = errno;
 	va_list args;
 
 	ksft_cnt.ksft_fail++;
 
 	va_start(args, msg);
 	printf("not ok %d ", ksft_test_num());
+	errno = saved_errno;
 	vprintf(msg, args);
 	va_end(args);
 }
 
 static inline void ksft_test_result_skip(const char *msg, ...)
 {
+	int saved_errno = errno;
 	va_list args;
 
 	ksft_cnt.ksft_xskip++;
 
 	va_start(args, msg);
 	printf("not ok %d # SKIP ", ksft_test_num());
+	errno = saved_errno;
 	vprintf(msg, args);
 	va_end(args);
 }
 
 static inline void ksft_test_result_error(const char *msg, ...)
 {
+	int saved_errno = errno;
 	va_list args;
 
 	ksft_cnt.ksft_error++;
 
 	va_start(args, msg);
 	printf("not ok %d # error ", ksft_test_num());
+	errno = saved_errno;
 	vprintf(msg, args);
 	va_end(args);
 }
@@ -152,10 +163,12 @@  static inline int ksft_exit_fail(void)
 
 static inline int ksft_exit_fail_msg(const char *msg, ...)
 {
+	int saved_errno = errno;
 	va_list args;
 
 	va_start(args, msg);
 	printf("Bail out! ");
+	errno = saved_errno;
 	vprintf(msg, args);
 	va_end(args);
 
@@ -178,10 +191,12 @@  static inline int ksft_exit_xpass(void)
 static inline int ksft_exit_skip(const char *msg, ...)
 {
 	if (msg) {
+		int saved_errno = errno;
 		va_list args;
 
 		va_start(args, msg);
 		printf("not ok %d # SKIP ", 1 + ksft_test_num());
+		errno = saved_errno;
 		vprintf(msg, args);
 		va_end(args);
 	} else {