Patch "kselftest/arm64: Log fp-stress child startup errors to stdout" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    kselftest/arm64: Log fp-stress child startup errors to stdout

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     kselftest-arm64-log-fp-stress-child-startup-errors-t.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c2201b018ae7841b8bf7066c081f5459e6d7072e
Author: Mark Brown <broonie@xxxxxxxxxx>
Date:   Wed Oct 23 00:20:45 2024 +0100

    kselftest/arm64: Log fp-stress child startup errors to stdout
    
    [ Upstream commit dca93d29845dfed60910ba13dbfb6ae6a0e19f6d ]
    
    Currently if we encounter an error between fork() and exec() of a child
    process we log the error to stderr. This means that the errors don't get
    annotated with the child information which makes diagnostics harder and
    means that if we miss the exit signal from the child we can deadlock
    waiting for output from the child. Improve robustness and output quality
    by logging to stdout instead.
    
    Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20241023-arm64-fp-stress-exec-fail-v1-1-ee3c62932c15@xxxxxxxxxx
    Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/testing/selftests/arm64/fp/fp-stress.c b/tools/testing/selftests/arm64/fp/fp-stress.c
index dd31647b00a22..cf9d7b2e4630c 100644
--- a/tools/testing/selftests/arm64/fp/fp-stress.c
+++ b/tools/testing/selftests/arm64/fp/fp-stress.c
@@ -79,7 +79,7 @@ static void child_start(struct child_data *child, const char *program)
 		 */
 		ret = dup2(pipefd[1], 1);
 		if (ret == -1) {
-			fprintf(stderr, "dup2() %d\n", errno);
+			printf("dup2() %d\n", errno);
 			exit(EXIT_FAILURE);
 		}
 
@@ -89,7 +89,7 @@ static void child_start(struct child_data *child, const char *program)
 		 */
 		ret = dup2(startup_pipe[0], 3);
 		if (ret == -1) {
-			fprintf(stderr, "dup2() %d\n", errno);
+			printf("dup2() %d\n", errno);
 			exit(EXIT_FAILURE);
 		}
 
@@ -107,16 +107,15 @@ static void child_start(struct child_data *child, const char *program)
 		 */
 		ret = read(3, &i, sizeof(i));
 		if (ret < 0)
-			fprintf(stderr, "read(startp pipe) failed: %s (%d)\n",
-				strerror(errno), errno);
+			printf("read(startp pipe) failed: %s (%d)\n",
+			       strerror(errno), errno);
 		if (ret > 0)
-			fprintf(stderr, "%d bytes of data on startup pipe\n",
-				ret);
+			printf("%d bytes of data on startup pipe\n", ret);
 		close(3);
 
 		ret = execl(program, program, NULL);
-		fprintf(stderr, "execl(%s) failed: %d (%s)\n",
-			program, errno, strerror(errno));
+		printf("execl(%s) failed: %d (%s)\n",
+		       program, errno, strerror(errno));
 
 		exit(EXIT_FAILURE);
 	} else {