Use a more conventional error handling interface in regex_escape():
Return a ssize_t, which is either the number of bytes in the output,
or return -1 and set errno.
Before this change, the (log_match_cursor < 0) check in the call site
was never true because log_match_cursor is a pointer.
Signed-off-by: Günther Noack <redacted>
---
tools/testing/selftests/landlock/common.h | 20 ++++++++++++--------
tools/testing/selftests/landlock/fs_test.c | 12 +++++++-----
2 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/tools/testing/selftests/landlock/common.h b/tools/testing/selftests/landlock/common.h
index a662a68bee7b..dcfdcfecde86 100644
--- a/tools/testing/selftests/landlock/common.h
+++ b/tools/testing/selftests/landlock/common.h
@@ -277,11 +277,11 @@ static void __maybe_unused set_unix_address(struct service_fixture *const srv,
* Escapes characters that have special meaning in POSIX Basic Regular
* Expressions: $ * . [ \ ] ^
*
- * Returns a pointer to the NUL terminator in @dst (cursor-style API for
- * chaining), or (char *)-ENOMEM if the buffer is too small.
+ * Returns the length of the escaped string (excluding the NUL terminator), or
+ * -1 with errno set to ENOMEM if the buffer is too small.
*/
-static __maybe_unused char *regex_escape(const char *const src, char *dst,
- size_t dst_size)
+static __maybe_unused ssize_t regex_escape(const char *const src, char *dst,
+ size_t dst_size)
{
char *d = dst;
@@ -295,21 +295,25 @@ static __maybe_unused char *regex_escape(const char *const src, char *dst,
case ']':
case '^':
if (d >= dst + dst_size - 2)
- return (char *)-ENOMEM;
+ goto err_nomem;
*d++ = '\\';
*d++ = *s;
break;
default:
if (d >= dst + dst_size - 1)
- return (char *)-ENOMEM;
+ goto err_nomem;
*d++ = *s;
}
}
if (d >= dst + dst_size - 1)
- return (char *)-ENOMEM;
+ goto err_nomem;
*d = '\0';
- return d;
+ return d - dst;
+
+err_nomem:
+ errno = ENOMEM;
+ return -1;
}
diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
index 100ef02b5d1a..10a386a573dd 100644
--- a/tools/testing/selftests/landlock/fs_test.c
+++ b/tools/testing/selftests/landlock/fs_test.c
@@ -7450,6 +7450,7 @@ static int matches_log_fs_extra(struct __test_metadata *const _metadata,
char log_match[log_match_remaining];
char *log_match_cursor = log_match;
size_t chunk_len;
+ ssize_t escaped_len;
chunk_len = snprintf(log_match_cursor, log_match_remaining,
REGEX_LANDLOCK_PREFIX " blockers=%s path=\"",
@@ -7467,13 +7468,14 @@ static int matches_log_fs_extra(struct __test_metadata *const _metadata,
log_match_remaining -= chunk_len;
log_match_cursor += chunk_len;
- log_match_cursor = regex_escape(absolute_path, log_match_cursor,
- log_match_remaining);
+ escaped_len = regex_escape(absolute_path, log_match_cursor,
+ log_match_remaining);
free(absolute_path);
- if (log_match_cursor < 0)
- return (long long)log_match_cursor;
+ if (escaped_len < 0)
+ return -errno;
- log_match_remaining -= log_match_cursor - log_match;
+ log_match_remaining -= escaped_len;
+ log_match_cursor += escaped_len;
chunk_len = snprintf(log_match_cursor, log_match_remaining,
"\" dev=\"[^\"]\\+\" ino=[0-9]\\+%s$",
extra ?: "");
--
2.56.0