From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-239.mta1.migadu.com [95.215.58.239]) (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 626BE42A96 for ; Tue, 8 Sep 2026 02:51:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.239 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788835899; cv=none; b=T21ZsyKHsVoAMMlWXOhqCZVbtw5/V225bdm0YbeaqwBiAsSUHBfYZsM6/Z0g5d2VYoRVH/UsUyjoz6opdam0RUIZEs6HJR4HiX3RVVFXSJY3s15HtLq05Sk9Ykpuk1R0v7Lwt3G/YKeUNpdfkPFvik45dvGNHicMLjPHrloFSvQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788835899; c=relaxed/simple; bh=KbC4/aHSZoRhlEvoZxF6IZ3ATXrmb8tfT9i+DprXs1k=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=P4fDh4GqObpMX8ZJn3zO2KsSkRCKey/4cjpQGrBMw8yTJslGFFvBDJW265bevJkRqD0RrQssvjKaSlyWv07TvT4aD6NaUAcwNfjn2S415CVi3hSiqHWt6jYpnFNsayJZht9mBi0y60RanXdMzKA7Z8YHimb8/mJvxF0Xmo40eBU= 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=MVZQTeUt; arc=none smtp.client-ip=95.215.58.239 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="MVZQTeUt" X-Envelope-To: linux-kernel@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=1788835895; v=1; x=1789440695; b=MVZQTeUt5Y73RsUD+bo1Pz0ULyJqKUfhz98ey6iFrR1imIzR62fky7rF1qsomXtrnFHj3onB k1zSZXb4rDUz5NbZAJpbt0EglYKJVcaBj77EIw8P3olpN15mgaLMfP6aUt/fqswWwjFrARG0cJR N5dkrX1zx4L7BOGtpylsnu40= X-Envelope-To: linux-kernel@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-kernel@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