[PATCH AUTOSEL 4.14 14/40] selftests: gpio-mockup-chardev: Check asprintf() for error

[Sasha Levin]

From: Geert Uytterhoeven <geert+rene...@glider.be>

[ Upstream commit 508cacd7da6659ae7b7bdd0a335f675422277758 ]

With gcc 7.3.0:

    gpio-mockup-chardev.c: In function ‘get_debugfs’:
    gpio-mockup-chardev.c:62:3: warning: ignoring return value of ‘asprintf’, 
declared with attribute warn_unused_result [-Wunused-result]
       asprintf(path, "%s/gpio", mnt_fs_get_target(fs));
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Handle asprintf() failures to fix this.

Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be>
Signed-off-by: Shuah Khan <sh...@kernel.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 tools/testing/selftests/gpio/gpio-mockup-chardev.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/gpio/gpio-mockup-chardev.c 
b/tools/testing/selftests/gpio/gpio-mockup-chardev.c
index 667e916fa7cc..6ceeeed4eeb9 100644
--- a/tools/testing/selftests/gpio/gpio-mockup-chardev.c
+++ b/tools/testing/selftests/gpio/gpio-mockup-chardev.c
@@ -37,7 +37,7 @@ static int get_debugfs(char **path)
        struct libmnt_table *tb;
        struct libmnt_iter *itr = NULL;
        struct libmnt_fs *fs;
-       int found = 0;
+       int found = 0, ret;
 
        cxt = mnt_new_context();
        if (!cxt)
@@ -58,8 +58,11 @@ static int get_debugfs(char **path)
                        break;
                }
        }
-       if (found)
-               asprintf(path, "%s/gpio", mnt_fs_get_target(fs));
+       if (found) {
+               ret = asprintf(path, "%s/gpio", mnt_fs_get_target(fs));
+               if (ret < 0)
+                       err(EXIT_FAILURE, "failed to format string");
+       }
 
        mnt_free_iter(itr);
        mnt_free_context(cxt);
-- 
2.19.1