From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-187.mta0.migadu.com [91.218.175.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 309AE1B4138 for ; Tue, 8 Sep 2026 02:51:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.187 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788835908; cv=none; b=SO8YUS0mxfMeloTSxFcGkoBj2fYAWjajmDXQx7rysgGH/i67winluuLDeUF+NsI+hBj1XJWqMoS1l7t01Ae2h8/hAZmPXAKokBG2iU/GnpsNu/X9EG3e0LnBRX3B67u3om1E3EM5YEGVoHjWdlb8brEzTrymUnKni1hZn/iNdZE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788835908; c=relaxed/simple; bh=KbC4/aHSZoRhlEvoZxF6IZ3ATXrmb8tfT9i+DprXs1k=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=rWzk5J1QPWq7XA5WMozP2jf/d3VYIi1vtSrRfLFM7JbK4lvxClI5VShRo4gC+ccCPBfm3S3F2nbzEZ02AeQHeKg4Ge9aXZ8vKz803y8B7wOoGlgxwrrIpTRRceqtOW9+yFLne6ubHnJWMbMA8EstrdS6MAAWz/THckGjYg++yMY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=NG0LmK0h; arc=none smtp.client-ip=91.218.175.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="NG0LmK0h" X-Envelope-To: linux-kselftest@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=KbC4/aHSZoRhlEvoZxF6IZ3ATXrmb8tfT9i+DprXs1k=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788835905; v=1; x=1789440705; b=NG0LmK0hEva9JVOT1sRB8/22mL2k1uecx3m3hZBbXGOkJgrCikZp5u6yrIt3TCXHquQa+D++ 8cJ3aPVR22uZHoH1JpAKWVZLuGyfU7P80DlSZM339rEIxipKBRMKM+ClShsXoQU7pJjQ+xYMjC1 txxH2npzq5x/Y/xzgRXK2D1A= X-Envelope-To: linux-kselftest@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id f40b372a38627f66; Tue, 08 Sep 2026 02:51:35 +0000 X-Mizu-Trace-ID: f40b372a38627f66 X-Migadu-Flow: FLOW_OUT From: Hongfu Li To: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, shuah@kernel.org, James.Bottomley@HansenPartnership.com Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, hongfu.li@linux.dev, Hongfu Li Subject: [PATCH] selftests/mm: fix ptrace PEEKDATA check in memfd_secret test Date: Tue, 8 Sep 2026 10:51:11 +0800 Message-ID: <20260908025111.34562-1-hongfu.li@linux.dev> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Hongfu Li try_ptrace() treats PTRACE_PEEKDATA return value as a boolean check. A successful read returns non-zero data (memory filled with 0x55), causing the test to incorrectly report PASS when secret memory protection is broken. Check the return value against -1 instead. The test should only pass when PTRACE_PEEKDATA fails, which means secret memory protection works. Fixes: 76fe17ef588a ("secretmem: test: add basic selftest for memfd_secret(2)") Signed-off-by: Hongfu Li --- tools/testing/selftests/mm/memfd_secret.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/memfd_secret.c b/tools/testing/selftests/mm/memfd_secret.c index c55d84c5e613..dd08a3a1ef14 100644 --- a/tools/testing/selftests/mm/memfd_secret.c +++ b/tools/testing/selftests/mm/memfd_secret.c @@ -145,7 +145,7 @@ static void try_ptrace(int fd, int pipefd[2]) exit(KSFT_FAIL); } - if (ptrace(PTRACE_PEEKDATA, ppid, mem, 0)) + if (ptrace(PTRACE_PEEKDATA, ppid, mem, 0) == -1) exit(KSFT_PASS); exit(KSFT_FAIL); -- 2.54.0