Merge branch 'for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git

4 files changed, 43 insertions, 10 deletions

diff --git a/tools/testing/selftests/cgroup/lib/cgroup_util.c b/tools/testing/selftests/cgroup/lib/cgroup_util.c
index 2596c12cd864..cd73471e13d7 100644
--- a/tools/testing/selftests/cgroup/lib/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/lib/cgroup_util.c
@@ -24,20 +24,43 @@ bool cg_test_v1_named;
 /* Returns read len on success, or -errno on failure. */
 ssize_t read_text(const char *path, char *buf, size_t max_len)
 {
-	ssize_t len;
+	size_t total = 0;
+	ssize_t len, ret;
 	int fd;
 
 	fd = open(path, O_RDONLY);
 	if (fd < 0)
 		return -errno;
 
-	len = read(fd, buf, max_len - 1);
-
-	if (len >= 0)
-		buf[len] = 0;
+	/*
+	 * A single read() is not enough.  procfs and sysfs are backed by
+	 * seq_file, and seq_read_iter() copies out at most one internal
+	 * buffer (PAGE_SIZE) per call, leaving the rest for the next read().
+	 * Reading only once therefore silently drops everything past the
+	 * first page, no matter how big the caller's buffer is.
+	 *
+	 * Loop until the buffer is full or EOF.  A full buffer still means
+	 * the file may be longer than max_len, but that is now limited by
+	 * the caller's buffer rather than by a page of seq_file output.
+	 */
+	while (total < max_len - 1) {
+		len = read(fd, buf + total, max_len - 1 - total);
+		if (len < 0) {
+			if (errno == EINTR)
+				continue;
+			ret = -errno;
+			goto out;
+		}
+		if (!len)
+			break;
+		total += len;
+	}
 
+	buf[total] = 0;
+	ret = total;
+out:
 	close(fd);
-	return len < 0 ? -errno : len;
+	return ret;
 }
 
 /* Returns written len on success, or -errno on failure. */
@@ -279,6 +302,16 @@ static int cg_find_root(char *root, size_t len, const char *controller,
 		options = strtok(NULL, delim);
 		strtok(NULL, delim);
 		strtok(NULL, delim);
+
+		/*
+		 * A mount entry is "device mountpoint type options freq
+		 * passno".  A field can only be missing if the last entry was
+		 * cut short by the buffer being too small for the file, and
+		 * there is no complete entry left to look at.
+		 */
+		if (!mount || !type || !options)
+			break;
+
 		if (strcmp(type, "cgroup") == 0) {
 			if (!controller || !strstr(options, controller))
 				continue;
diff --git a/tools/testing/selftests/cgroup/settings b/tools/testing/selftests/cgroup/settings
new file mode 100644
index 000000000000..6091b45d226b
--- /dev/null
+++ b/tools/testing/selftests/cgroup/settings
@@ -0,0 +1 @@
+timeout=120
diff --git a/tools/testing/selftests/cgroup/test_cpu.c b/tools/testing/selftests/cgroup/test_cpu.c
index 735a53bb222b..3456e3e988c6 100644
--- a/tools/testing/selftests/cgroup/test_cpu.c
+++ b/tools/testing/selftests/cgroup/test_cpu.c
@@ -835,9 +835,8 @@ int main(int argc, char *argv[])
 	if (cg_find_unified_root(root, sizeof(root), NULL))
 		ksft_exit_skip("cgroup v2 isn't mounted\n");
 
-	if (cg_read_strstr(root, "cgroup.subtree_control", "cpu"))
-		if (cg_write(root, "cgroup.subtree_control", "+cpu"))
-			ksft_exit_skip("Failed to set cpu controller\n");
+	if (cg_write(root, "cgroup.subtree_control", "+cpu"))
+		ksft_exit_skip("Failed to set cpu controller\n");
 
 	ksft_set_plan(ARRAY_SIZE(tests));
 	for (i = 0; i < ARRAY_SIZE(tests); i++) {
diff --git a/tools/testing/selftests/cgroup/with_stress.sh b/tools/testing/selftests/cgroup/with_stress.sh
index e28c35008f5b..a95fb3874644 100755
--- a/tools/testing/selftests/cgroup/with_stress.sh
+++ b/tools/testing/selftests/cgroup/with_stress.sh
@@ -87,7 +87,7 @@ time=0
 start=$(date +%s)
 
 while [ $time -lt $duration ] ; do
-	$*
+	"$@"
 	rc=$?
 	[ $rc -eq 0 ] || break
 	time=$(($(date +%s) - $start))