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From: Aleksa Sarai <cyphar@cyphar.com>
To: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
	Aleksa Sarai <cyphar@cyphar.com>
Subject: [PATCH] kselftest: save-and-restore errno to allow for %m formatting
Date: Sat, 20 Jul 2019 10:03:32 +1000	[thread overview]
Message-ID: <20190720000332.4701-1-cyphar@cyphar.com> (raw)
In-Reply-To: <b32d95a1-8a49-65ef-4ddd-fe86a7ca01d5@kernel.org>

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(+)

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 {
-- 
2.22.0


  reply	other threads:[~2019-07-20  0:03 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-19 16:42 [PATCH v10 0/9] namei: openat2(2) path resolution restrictions Aleksa Sarai
2019-07-19 16:42 ` [PATCH v10 1/9] namei: obey trailing magic-link DAC permissions Aleksa Sarai
2019-07-19 16:42 ` [PATCH v10 2/9] procfs: switch magic-link modes to be more sane Aleksa Sarai
2019-07-19 16:42 ` [PATCH v10 3/9] open: O_EMPTYPATH: procfs-less file descriptor re-opening Aleksa Sarai
2019-07-19 16:42 ` [PATCH v10 4/9] namei: O_BENEATH-style path resolution flags Aleksa Sarai
2019-07-19 16:42 ` [PATCH v10 5/9] namei: LOOKUP_IN_ROOT: chroot-like path resolution Aleksa Sarai
2019-07-19 16:42 ` [PATCH v10 6/9] namei: aggressively check for nd->root escape on ".." resolution Aleksa Sarai
2019-07-19 16:42 ` [PATCH v10 7/9] open: openat2(2) syscall Aleksa Sarai
2019-07-19 16:42 ` [PATCH v10 8/9] kselftest: save-and-restore errno to allow for %m formatting Aleksa Sarai
2019-07-19 22:25   ` shuah
2019-07-20  0:03     ` Aleksa Sarai [this message]
2019-07-20  0:09     ` Aleksa Sarai
2019-07-19 16:42 ` [PATCH v10 9/9] selftests: add openat2(2) selftests Aleksa Sarai

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