From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E76CF267705; Tue, 22 Apr 2025 02:18:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745288305; cv=none; b=V3G/Zv5RQTQis7kttJowEOpiFN5m2Lanixk8ahhTZg6uQubw39Fm985+GECzORhcEcQFq5us3eeSSba3Jhdxo0w4EQkQsxmCsbu1rOfPQXcawO7Y/RTHURpayzW5SkZo7lkfwEJ74VHbAntjdQj8hxXG8FDspU8rbelX/ycyuQg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745288305; c=relaxed/simple; bh=q/f9f0tVSdoiT/mcDWBVx7/ZzrlTcfC7wdM9rl9lXuA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XZD0F0TVkw0dArOZ1S7UG1pq1LrlVJzloadf+uHmWofrYO/lEoGRVvIDckK4h9pW8U3lQdiweJqUPDeQ2HvHMk9jL/C5HtOjkfFLueTbKNhvdff9TDIc5cM4JuDDS203c+CXeUubyoxD6MNwubiF4DmCZ8Obojz4VM3YMgdGILs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C8yHbPgs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="C8yHbPgs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C7B0C4CEE4; Tue, 22 Apr 2025 02:18:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745288304; bh=q/f9f0tVSdoiT/mcDWBVx7/ZzrlTcfC7wdM9rl9lXuA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C8yHbPgsgH6FBrrHVJjEg4CVn5+WhywK9C5hGxuFlsV+pMOBTCJJGpJCFA0ihGQFt SBYWoOVlIH1Giay3nf+1JKO0kkh7jWE6VYVvN4SeCcZQfYvNSwAQwr/gRXAcMRxbLG c5ZBTD3e/rUbtBEE4GiWKq3imsXLmXZAqc+Aix+WBvch09qEzMSHL0iVY5THiowgNs hrDV0wRojsbda22uo3UQFuD52GQKL9R/NJjKKS3b2fTcbKbQ7v64sFxHjcaCSm0REE gciVrZRgR7nlSUFYDdcxBm/FxJM0H+ZMKis3PO0665G4ZXaJwc8Ov07vbvZ6wNZbLQ 0ieymdQuMiRlQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nathan Chancellor , Alexandre Ghiti , "Dmitry V . Levin" , Sasha Levin , paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, linux-riscv@lists.infradead.org Subject: [PATCH AUTOSEL 6.6 14/15] riscv: Avoid fortify warning in syscall_get_arguments() Date: Mon, 21 Apr 2025 22:17:58 -0400 Message-Id: <20250422021759.1941570-14-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250422021759.1941570-1-sashal@kernel.org> References: <20250422021759.1941570-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.87 Content-Transfer-Encoding: 8bit From: Nathan Chancellor [ Upstream commit 1413708f990cb7d025affd706ba9c23e2bfc1a27 ] When building with CONFIG_FORTIFY_SOURCE=y and W=1, there is a warning because of the memcpy() in syscall_get_arguments(): In file included from include/linux/string.h:392, from include/linux/bitmap.h:13, from include/linux/cpumask.h:12, from arch/riscv/include/asm/processor.h:55, from include/linux/sched.h:13, from kernel/ptrace.c:13: In function 'fortify_memcpy_chk', inlined from 'syscall_get_arguments.isra' at arch/riscv/include/asm/syscall.h:66:2: include/linux/fortify-string.h:580:25: error: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror=attribute-warning] 580 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors The fortified memcpy() routine enforces that the source is not overread and the destination is not overwritten if the size of either field and the size of the copy are known at compile time. The memcpy() in syscall_get_arguments() intentionally overreads from a1 to a5 in 'struct pt_regs' but this is bigger than the size of a1. Normally, this could be solved by wrapping a1 through a5 with struct_group() but there was already a struct_group() applied to these members in commit bba547810c66 ("riscv: tracing: Fix __write_overflow_field in ftrace_partial_regs()"). Just avoid memcpy() altogether and write the copying of args from regs manually, which clears up the warning at the expense of three extra lines of code. Signed-off-by: Nathan Chancellor Reviewed-by: Alexandre Ghiti Reviewed-by: Dmitry V. Levin Link: https://lore.kernel.org/r/20250409-riscv-avoid-fortify-warning-syscall_get_arguments-v1-1-7853436d4755@kernel.org Signed-off-by: Alexandre Ghiti Signed-off-by: Sasha Levin --- arch/riscv/include/asm/syscall.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h index 121fff429dce6..eceabf59ae482 100644 --- a/arch/riscv/include/asm/syscall.h +++ b/arch/riscv/include/asm/syscall.h @@ -62,8 +62,11 @@ static inline void syscall_get_arguments(struct task_struct *task, unsigned long *args) { args[0] = regs->orig_a0; - args++; - memcpy(args, ®s->a1, 5 * sizeof(args[0])); + args[1] = regs->a1; + args[2] = regs->a2; + args[3] = regs->a3; + args[4] = regs->a4; + args[5] = regs->a5; } static inline int syscall_get_arch(struct task_struct *task) -- 2.39.5