linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Yang Ruibin <11162571@vivo.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	Shuah Khan <shuah@kernel.org>,
	linux-mm@kvack.org, linux-kselftest@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: opensource.kernel@vivo.com, Yang Ruibin <11162571@vivo.com>
Subject: [PATCH v1] tools:mm:Check mmap based on return values
Date: Tue, 20 Aug 2024 23:50:03 -0400	[thread overview]
Message-ID: <20240821035005.4423-1-11162571@vivo.com> (raw)

To correctly detect whether mmap is successful, must use if 
(map_ptr == MAP_FAILED)to avoid incorrectly handling a valid mapping.

Signed-off-by: Yang Ruibin <11162571@vivo.com>
---
 tools/testing/selftests/mm/ksm_tests.c     | 2 +-
 tools/testing/selftests/mm/madv_populate.c | 2 +-
 tools/testing/selftests/mm/soft-dirty.c    | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c
index b748c48908d9..dad54840f32e 100644
--- a/tools/testing/selftests/mm/ksm_tests.c
+++ b/tools/testing/selftests/mm/ksm_tests.c
@@ -201,7 +201,7 @@ static void  *allocate_memory(void *ptr, int prot, int mapping, char data, size_
 {
 	void *map_ptr = mmap(ptr, map_size, PROT_WRITE, mapping, -1, 0);
 
-	if (!map_ptr) {
+	if (map_ptr == MAP_FAILED) {
 		perror("mmap");
 		return NULL;
 	}
diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c
index ef7d911da13e..b89cb83ca5c5 100644
--- a/tools/testing/selftests/mm/madv_populate.c
+++ b/tools/testing/selftests/mm/madv_populate.c
@@ -34,7 +34,7 @@ static void sense_support(void)
 
 	addr = mmap(0, pagesize, PROT_READ | PROT_WRITE,
 		    MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
-	if (!addr)
+	if (addr == MAP_FAILED)
 		ksft_exit_fail_msg("mmap failed\n");
 
 	ret = madvise(addr, pagesize, MADV_POPULATE_READ);
diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c
index bdfa5d085f00..4ccbc053bcce 100644
--- a/tools/testing/selftests/mm/soft-dirty.c
+++ b/tools/testing/selftests/mm/soft-dirty.c
@@ -134,7 +134,7 @@ static void test_mprotect(int pagemap_fd, int pagesize, bool anon)
 	if (anon) {
 		map = mmap(NULL, pagesize, PROT_READ|PROT_WRITE,
 			   MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-		if (!map)
+		if (map == MAP_FAILED)
 			ksft_exit_fail_msg("anon mmap failed\n");
 	} else {
 		test_fd = open(fname, O_RDWR | O_CREAT, 0664);
-- 
2.34.1



             reply	other threads:[~2024-08-21  3:50 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-08-21  3:50 Yang Ruibin [this message]
2024-08-22  2:53 ` Shuah Khan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240821035005.4423-1-11162571@vivo.com \
    --to=11162571@vivo.com \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=opensource.kernel@vivo.com \
    --cc=shuah@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox