From nobody Fri Jun 12 19:58:09 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96B651EA7DB; Wed, 13 May 2026 02:58:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778641089; cv=none; b=Ul8YX74fAzJGM5bRxakqEPCzLRX6fvjdRk3DCjB841uiQ5v6Dh5Ak6wCm6oyNQgKVVwyht9T11RWKENdl97E9ejs2HsuA86kAtzoNY1xNJpRUe5pko2L4VNOcdSTCuv2VpgxJZx+FHb5eyPfq7oqo2dKO2WsHmJQn9ODmk05d4w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778641089; c=relaxed/simple; bh=qdAcFIQzQTvttALS46yHVztLI/WcK2WSt4+wYkjO1TA=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=i2x8spMpGkbLEL3h/b6StlZTpCkGLNvBnvzF20XfHZNzudfEJYXc4mnvHehYPh93cYVquTqXAN1Z3kSqwMfCYurQ72H9brLI1ZKnyekCBeA8vONEDH9mnhWOcz+fgehA71w6rr0g4Q0uOixRnqMi5tclC99NGmlk/TUDBljS/Jg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: 8daff6224e7711f1aa26b74ffac11d73-20260513 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NAME, HR_CC_NO_NAME, HR_CTE_8B HR_CTT_MISS, HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM, HR_SJ_PHRASE HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT, HR_TO_NO_NAME IP_TRUSTED, SRC_TRUSTED, DN_TRUSTED, SA_TRUSTED, SA_EXISTED SN_TRUSTED, SN_EXISTED, SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS CIE_GOOD, CIE_GOOD_SPF, GTI_FG_BS, GTI_RG_INFO, GTI_C_BU AMN_GOOD, ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.12,REQID:d943919f-db3d-47e1-9895-69d23bfc994a,IP:10, URL:0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:5 X-CID-INFO: VERSION:1.3.12,REQID:d943919f-db3d-47e1-9895-69d23bfc994a,IP:10,UR L:0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:5 X-CID-META: VersionHash:e7bac3a,CLOUDID:f2261abd433741342e87a4e9743dbeec,BulkI D:260513105801RV2ZSDY2,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|102|127| 850|898,TC:nil,Content:0|15|50,EDM:-3,IP:-2,URL:0,File:nil,RT:nil,Bulk:nil ,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR:0,BRE: 0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_FAS,TF_CID_SPAM_FSD X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: 8daff6224e7711f1aa26b74ffac11d73-20260513 X-User: lihongfu@kylinos.cn Received: from localhost.localdomain [(223.70.159.239)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA with TLSv1.3 TLS_AES_256_GCM_SHA384 256/256) with ESMTP id 1415261681; Wed, 13 May 2026 10:58:01 +0800 From: Hongfu Li To: shuah@kernel.org, akpm@linux-foundation.org, reddybalavignesh9979@gmail.com, richard.weiyang@gmail.com, mic@digikod.net, sj@kernel.org Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Hongfu Li Subject: [PATCH] selftests/perf_events: Fix mmap() error check in sigtrap_threads Date: Wed, 13 May 2026 10:58:38 +0800 Message-Id: <20260513025838.594945-1-lihongfu@kylinos.cn> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In sigtrap_threads(), the return value of mmap() is checked against NULL. mmap() returns MAP_FAILED, which is (void *)-1, not NULL, when it fails. Since MAP_FAILED is non-zero and non-NULL, the condition "p =3D=3D NULL" will never be true on failure, causing the program to proceed with an invalid pointer and segfault if mmap() actually fails under memory pressure. Signed-off-by: Hongfu Li Reviewed-by: Wei Yang --- tools/testing/selftests/perf_events/watermark_signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/perf_events/watermark_signal.c b/tools= /testing/selftests/perf_events/watermark_signal.c index 0f64b9b17081..a84709cabd8b 100644 --- a/tools/testing/selftests/perf_events/watermark_signal.c +++ b/tools/testing/selftests/perf_events/watermark_signal.c @@ -102,7 +102,7 @@ TEST(watermark_signal) } =20 p =3D mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0= ); - if (p =3D=3D NULL) { + if (p =3D=3D MAP_FAILED) { perror("mmap"); goto cleanup; } --=20 2.25.1