kselftest/arm64: mte: Report filename on failing temp file creation

The MTE selftests create temporary files in /dev/shm, for later mmap-ing
them. When there is no tmpfs mounted on /dev/shm, or /dev/shm does not
exist in the first place (on minimal filesystems), the error message is
not giving good hints:
    # FAIL: Unable to open temporary file
    # FAIL: memory allocation
    not ok 17 Check initial tags with private mapping, ...

Add a perror() call, that gives both the filename and the actual error
reason, so that users get a chance of correcting that.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Mark Brown <broone@kernel.org>
Link: https://lore.kernel.org/r/20210319165334.29213-12-andre.przywara@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/tools/testing/selftests/arm64/mte/mte_common_util.c b/tools/testing/selftests/arm64/mte/mte_common_util.c
index 040abdc..f50ac31 100644 (file)
--- a/tools/testing/selftests/arm64/mte/mte_common_util.c
+++ b/tools/testing/selftests/arm64/mte/mte_common_util.c
@@ -337,6 +337,7 @@ int create_temp_file(void)
        /* Create a file in the tmpfs filesystem */
        fd = mkstemp(&filename[0]);
        if (fd == -1) {
+               perror(filename);
                ksft_print_msg("FAIL: Unable to open temporary file\n");
                return 0;
        }