From nobody Mon Feb 9 13:42:46 2026 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B45F1264F90 for ; Tue, 8 Apr 2025 09:28:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744104490; cv=none; b=TMknX3Q3+PmaATDIe3ex31Cv5ECt9o8ZeU5NVKHbtBTZ7ij83KUaSna0PLu8qiyg6jROrAVFQKGmYh3HrAkMGiCKTR0+sPkr/yGsdNB+wDhYB5Y4t0IdLfi4pNwbsQjy6r0eAkvb3zNz2fg/3gh25xKu51XSUH6E7zVXsCV3tlU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744104490; c=relaxed/simple; bh=eyqOzFeAfWPRcomofF0iPt9yEMcU5b0bxRDqwp3CnvM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=ZIwcXu7aSX/jDpg+1x4WuDBM+x0rkGm1jMwSJbc6Rr/rSGXxPnez7Z5Vn37tm2IYgFkiixBgGZ0GKh1o3Fa7ctoLFpGtJznE4jm4e2smBVldwXJ1+TaLwm7mZSqeAjhZ7YWjful7sLkTeN28RxLTPf/8nkd2tawNF1/vNnsMEjA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8Bx364f7PRnRRC1AA--.21063S3; Tue, 08 Apr 2025 17:27:59 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by front1 (Coremail) with SMTP id qMiowMBxLscd7PRnF350AA--.24496S2; Tue, 08 Apr 2025 17:27:58 +0800 (CST) From: Tiezhu Yang To: Huacai Chen Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH] LoongArch: Enhance robust of kprobe Date: Tue, 8 Apr 2025 17:27:56 +0800 Message-ID: <20250408092756.22339-1-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.42.0 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 X-CM-TRANSID: qMiowMBxLscd7PRnF350AA--.24496S2 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoW7Cr1kKFyfJw1DGFW7XFy5trc_yoW8WryfpF 47Cas5tr4kW3W0va4qv34xur10yFWDCrWxWw4UA345Kws8uwn0vr1xG3WDXF95W3yFqr1S vF1rKrWIqF1DCFgCm3ZEXasCq-sJn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUkjb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Jr0_Gr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44I27wAqx4 xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_JrI_JrylYx0Ex4A2jsIE14v2 6r4j6F4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwI xGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480 Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jrv_JF1lIxkGc2Ij64vIr41lIxAIcVC0I7 IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k2 6cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxV AFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07jnUUUUUUUU= Content-Type: text/plain; charset="utf-8" Currently, interrupts need to be disabled before single-step mode is set, it requires that the CSR_PRMD_PIE must be cleared in save_local_irqflag() which is called by setup_singlestep(), this is reasonable. But in the first kprobe breakpoint exception, if the irq is enabled at the beginning of do_bp(), it will not be disabled at the end of do_bp() due to the CSR_PRMD_PIE has been cleared in save_local_irqflag(). For this case, it may corrupt exception context when restoring exception after do_bp() in handle_bp(), this is not reasonable. Based on the above analysis, in order to make sure the irq is disabled at the end of do_bp() for the first kprobe breakpoint exception, it is proper to disable irq first before clearing CSR_PRMD_PIE in save_local_irqflag(). Fixes: 6d4cc40fb5f5 ("LoongArch: Add kprobes support") Co-developed-by: Tianyang Zhang Signed-off-by: Tianyang Zhang Signed-off-by: Tiezhu Yang --- arch/loongarch/kernel/kprobes.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobe= s.c index 8ba391cfabb0..6eab97636e6b 100644 --- a/arch/loongarch/kernel/kprobes.c +++ b/arch/loongarch/kernel/kprobes.c @@ -113,6 +113,7 @@ NOKPROBE_SYMBOL(set_current_kprobe); static void save_local_irqflag(struct kprobe_ctlblk *kcb, struct pt_regs *regs) { + local_irq_disable(); kcb->saved_status =3D regs->csr_prmd; regs->csr_prmd &=3D ~CSR_PRMD_PIE; } --=20 2.42.0