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 91C6A1A3BD7 for ; Thu, 10 Apr 2025 18:14:26 +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=1744308867; cv=none; b=MUjzq7GLbznp2UcbYWO5WSTP2kMX7oj9d3/95rjcWi37p9QW5vTQKPz+DmZM203j/06EnklN68s5BYHUg8fPW8M+sb024hAQGeL90nc7vNHuMZE72xP2hJD6yw2cVqhQcm1N2pY8sVheWU7JkP+i9IBjdVkEjf39tVFGTALzYlo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744308867; c=relaxed/simple; bh=wn3mPPR27RYVkuHWJkv09h07bHWGcncI5FZuMl88yoY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=J+w60d3cHgQ/NM50BdEULCk99wcYMsqZscpDKvwCfnl6DiVYDcepMUYfTzsvftFRxGZ1ti5fwIa41ET+MekoSLBSe/6tQQk+CWLJJT3bOrTRtvI2ts20UPCDPBp223IwqFBN6RPBV4NFfYuuZo5rwFbMdkqNxCEy4V6hee03Oa8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KEwQefQH; 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="KEwQefQH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11F7CC4CEDD; Thu, 10 Apr 2025 18:14:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744308866; bh=wn3mPPR27RYVkuHWJkv09h07bHWGcncI5FZuMl88yoY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KEwQefQHMvoaGAPG5Jq1tyUxVrHdrtUKIqxCAYJU99HmpQSU677N0ZPBiJXv3NIyf VGb9OtOZXSVbihGsbbvNzX8WPzcPPx36xbK8MWa6P8r25IJzavqyF7efUwnJxi0pRY H46RO/VR4zQF36e10Juec6x5qb/Cv+lfCOUKG9/0Sj+Cl0kqBGuB9oWXCJ8I29Q0QW IpCCdbf2X/j1vNCXC4HwCWg54ojPhXBbzE/vsRWtqUEz4jJ7n9HFVi0RCqdlQKWEIG ibbxP5/bF7AOobnmz1uJiR0J5jQNEQcUuicn8gx5vOLd1Q+K47znTeUUX9/HGfH5Tr tmSt0AkwI3nvA== Date: Thu, 10 Apr 2025 11:14:22 -0700 From: Nathan Chancellor To: Andrew Morton Cc: "Dmitry V. Levin" , Oleg Nesterov , Charlie Jenkins , Arnd Bergmann , strace-devel@lists.strace.io, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v7 2/6] syscall.h: add syscall_set_arguments() Message-ID: <20250410181422.GA3431770@ax162> References: <20250303111910.GA24170@strace.io> <20250303112009.GC24170@strace.io> <20250408213131.GA2872426@ax162> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250408213131.GA2872426@ax162> Hi Andrew, Can you please fold the diff at the end of my message into syscallh-add-syscall_set_arguments.patch? It sounds like Palmer will apply the same diff to syscall_get_arguments(): https://lore.kernel.org/mhng-cf999eb1-59c4-4784-8c01-44b1e2482a50@palmer-ri-x1c9a/ Thanks! Nathan On Tue, Apr 08, 2025 at 02:31:31PM -0700, Nathan Chancellor wrote: > Hi Dmitry, > > [dropping majority of folks since this seems irrelevant to them] > > On Mon, Mar 03, 2025 at 01:20:09PM +0200, Dmitry V. Levin wrote: > > This function is going to be needed on all HAVE_ARCH_TRACEHOOK > > architectures to implement PTRACE_SET_SYSCALL_INFO API. > > > > This partially reverts commit 7962c2eddbfe ("arch: remove unused > > function syscall_set_arguments()") by reusing some of old > > syscall_set_arguments() implementations. > > > > Signed-off-by: Dmitry V. Levin > > Tested-by: Charlie Jenkins > > Reviewed-by: Charlie Jenkins > > Acked-by: Helge Deller # parisc > > Reviewed-by: Maciej W. Rozycki # mips > ... > > diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h > > index 121fff429dce..8d389ba995c8 100644 > > --- a/arch/riscv/include/asm/syscall.h > > +++ b/arch/riscv/include/asm/syscall.h > > @@ -66,6 +66,15 @@ static inline void syscall_get_arguments(struct task_struct *task, > > memcpy(args, ®s->a1, 5 * sizeof(args[0])); > > } > > > > +static inline void syscall_set_arguments(struct task_struct *task, > > + struct pt_regs *regs, > > + const unsigned long *args) > > +{ > > + regs->orig_a0 = args[0]; > > + args++; > > + memcpy(®s->a1, args, 5 * sizeof(regs->a1)); > > +} > > This upsets the compiletime fortify checks, as I see a warning after > syscall_set_arguments() starts being used in kernel/ptrace.c later in > the series. > > $ make -skj"$(nproc)" ARCH=riscv CROSS_COMPILE=riscv64-linux- allmodconfig kernel/ptrace.o > 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_set_arguments.isra' at arch/riscv/include/asm/syscall.h:82:2: > include/linux/fortify-string.h:571:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] > 571 | __write_overflow_field(p_size_field, size); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors > > The compiler knows the size of the destination and the size to be copied > so it knows there will be an (intentional) overwrite here. > struct_group() would normally work but I think this structure already > has a struct_group() around some of the members that would be needed. I > build tested eliminating the memcpy() altogether, which would appear to > work, but I am not sure if there is a better solution, hence just the > report. > > Cheers, > Nathan > > diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h > index a5281cdf2b10..70ec19dc8506 100644 > --- a/arch/riscv/include/asm/syscall.h > +++ b/arch/riscv/include/asm/syscall.h > @@ -78,8 +78,11 @@ static inline void syscall_set_arguments(struct task_struct *task, > const unsigned long *args) > { > regs->orig_a0 = args[0]; > - args++; > - memcpy(®s->a1, args, 5 * sizeof(regs->a1)); > + regs->a1 = args[1]; > + regs->a2 = args[2]; > + regs->a3 = args[3]; > + regs->a4 = args[4]; > + regs->a5 = args[5]; > } > > static inline int syscall_get_arch(struct task_struct *task)