From patchwork Wed Mar 12 06:15:57 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuai Xue X-Patchwork-Id: 14012891 Received: from out30-99.freemail.mail.aliyun.com (out30-99.freemail.mail.aliyun.com [115.124.30.99]) (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 8202478C9C; Wed, 12 Mar 2025 06:16:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.99 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741760166; cv=none; b=PQp0hxpcKdIC/Kp0tZUNiavIeZbNHP+MUUrL5cqC/3vmk7WSAtHMdkzTG8qYfhGZlmMKq+HGM/XzRVBXdsIZGzgMHJzCCVLKkWW2lNS36vLtTVoVUMuQ5pJ4UfWNyjUDoPdByymiF01qZbHHxtuOlQk3zqaMKnA/OtbYtTIdM5c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741760166; c=relaxed/simple; bh=cA3SwmYgYeSIyOV2poq56YF76ctfNib2sQffxNFTYNg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=lYEvXVvTkFXun6RfQyWsjXMlF1AAWLiUEmtGyxpMN92t1hzBw1wpilrmDhJkUyXX3cCm2/i8UYKXBjXs3pvRPvCnzsgepImjexEjIkz1+XfDqKxhgXQ3QPkSef84tBuo4oj3jOFDMNm1L/0FIa/HGpKWhjrj+y2C1kYUUzKpkxs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=uQqH4Lvl; arc=none smtp.client-ip=115.124.30.99 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="uQqH4Lvl" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1741760158; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=R5GJYlkXT0vSw2Kc0ay2ukzCBmnnFXXk54xXv2Y6mic=; b=uQqH4LvlU2wfW1TBpgbvJY/yRf4lKRlIiHMfE+rkcebOULya18Sw4NDDInnn1ck4aaAcry/tiHv1eRe1q12s+a3Q6AZ1uaHpkIq+6M9zYt9oguzl6CWmfMdeLLPUnWq4EDPggJnZIE0ethmuvdQkD9bi6NmNV5fhiiUTFESb0cM= Received: from localhost.localdomain(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0WRBa8MG_1741760157 cluster:ay36) by smtp.aliyun-inc.com; Wed, 12 Mar 2025 14:15:58 +0800 From: Shuai Xue To: brauner@kernel.org, shuah@kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: baolin.wang@linux.alibaba.com, tianruidong@linux.alibaba.com, xueshuai@linux.alibaba.com Subject: [PATCH] selftests/pidfd: align stack to fix SP alignment exception Date: Wed, 12 Mar 2025 14:15:57 +0800 Message-ID: <20250312061557.28532-1-xueshuai@linux.alibaba.com> X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The pidfd_test fails on the ARM64 platform with the following error: Bail out! pidfd_poll check for premature notification on child thread exec test: Failed When exception-trace is enabled, the kernel logs the details: #echo 1 > /proc/sys/debug/exception-trace #dmesg | tail -n 20 [48628.713023] pidfd_test[1082142]: unhandled exception: SP Alignment, ESR 0x000000009a000000, SP/PC alignment exception in pidfd_test[400000+4000] [48628.713049] CPU: 21 PID: 1082142 Comm: pidfd_test Kdump: loaded Tainted: G W E 6.6.71-3_rc1.al8.aarch64 #1 [48628.713051] Hardware name: AlibabaCloud AliServer-Xuanwu2.0AM-1UC1P-5B/AS1111MG1, BIOS 1.2.M1.AL.P.157.00 07/29/2023 [48628.713053] pstate: 60001800 (nZCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=-c) [48628.713055] pc : 0000000000402100 [48628.713056] lr : 0000ffff98288f9c [48628.713056] sp : 0000ffffde49daa8 [48628.713057] x29: 0000000000000000 x28: 0000000000000000 x27: 0000000000000000 [48628.713060] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [48628.713062] x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000400e80 [48628.713065] x20: 0000000000000000 x19: 0000000000402650 x18: 0000000000000000 [48628.713067] x17: 00000000004200d8 x16: 0000ffff98288f40 x15: 0000ffffde49b92c [48628.713070] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [48628.713072] x11: 0000000000001011 x10: 0000000000402100 x9 : 0000000000000010 [48628.713074] x8 : 00000000000000dc x7 : 3861616239346564 x6 : 000000000000000a [48628.713077] x5 : 0000ffffde49daa8 x4 : 000000000000000a x3 : 0000ffffde49daa8 [48628.713079] x2 : 0000ffffde49dadc x1 : 0000ffffde49daa8 x0 : 0000000000000000 According to ARM ARM D1.3.10.2 SP alignment checking: > When the SP is used as the base address of a calculation, regardless of > any offset applied by the instruction, if bits [3:0] of the SP are not > 0b0000, there is a misaligned SP. To fix it, align the stack with 16 bytes. Signed-off-by: Shuai Xue --- tools/testing/selftests/pidfd/pidfd_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c index c081ae91313a..ec161a7c3ff9 100644 --- a/tools/testing/selftests/pidfd/pidfd_test.c +++ b/tools/testing/selftests/pidfd/pidfd_test.c @@ -33,7 +33,7 @@ static bool have_pidfd_send_signal; static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) { size_t stack_size = 1024; - char *stack[1024] = { 0 }; + char *stack[1024] __attribute__((aligned(16))) = {0}; #ifdef __ia64__ return __clone2(fn, stack, stack_size, flags | SIGCHLD, NULL, pidfd);