From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 8517F2836A0 for ; Mon, 13 Jul 2026 07:06:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783926387; cv=none; b=I+4GnA9LcIRSVapgTuQJjGOnUlVR5WAxax957vg+W3dIX5+Ylmlo8YSpzSA3h9T5zY6qwKUdHkslCnMs/bnB/T2C3FD9fPfUZfvJ55ZF5FItdC+uapNgxh5dtOO5S3IswQqaos81uYjqy8hixL6G8YjJNMK1D9LaRCK+Y1awtgs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783926387; c=relaxed/simple; bh=hCeMAFawqUQZK5TTzZSun5coCAr0fqMieti9jZqRw7A=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=XZ0pmwADOTKOYNHIwfdx3Vr2cpo0EjLslb3QjLyhJJxE5hh7GIQ0a0Pdf61qC8WzaJCxtMEjQVRsO9QwPThmUlBjlm83gAzJZ4b/MLSNtkTeq4R4nltRouco/sb7xQIowf6p4AD5C1Sw+s/rfTN/ZWoLEHJdIZNmoI4P8ZRD1/g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TbglOxZr; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TbglOxZr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 199B51F000E9 for ; Mon, 13 Jul 2026 07:06:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783926384; bh=MaoMLNzrQSdilHBAPxvn7cFGYo6KCQRZiQrYmmdeSDg=; h=References:In-Reply-To:From:Date:Subject:To:Cc; b=TbglOxZrZc+8ho1Z2BcK0IhS3egNUSq0c5Yekd6nxDBKZQhVPPnrHghm6ItjXrvW8 myYXJ6x6lFh7QX5ecmuh/vq7Qwc4aN3eTk8kvvmFs1d8wRQY7vrvAGfQK8ML7sZ4Yj k2WeLrzUteazWoeRwgjCCUDZJ2+PWRLzL1ozd2prV95l5uW3ki91C/T/KpUndY2saf +I1D4H0CLwMJu74DptZISJOOYDmUct5uhnCyLsAUx2HSrcK3fC5VZsBannIxQYZ7Rq GNjV6d1+IgN8jsegZ7lli5dbQ5dULez5iyH6dt+oUZzipNLSJVSN9n9AB3HDQyztKw NLk2nciGwWqEA== Received: by mail-wr1-f52.google.com with SMTP id ffacd0b85a97d-4759b4f0897so1456303f8f.1 for ; Mon, 13 Jul 2026 00:06:24 -0700 (PDT) X-Gm-Message-State: AOJu0YwOY48h86EJIY351ZJmdliroldVp2RPpafBaoD4T3AYrOHBBu/O wkhVtNa02u9pD0FrHYOHLnOdxQbfaOXj81Se6OVpoK6BK3iqGzrumrBY57QWc9L7yeQmLZimluE /rPk8xRDlPaKL86ZQZKDB7RWLOCM6ZmU= X-Received: by 2002:a05:6000:186c:b0:476:d13f:bb74 with SMTP id ffacd0b85a97d-47f2dc9bac8mr8770361f8f.15.1783926382749; Mon, 13 Jul 2026 00:06:22 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20260707181957.433213175@kernel.org> <20260707190253.974626922@kernel.org> In-Reply-To: <20260707190253.974626922@kernel.org> From: Guo Ren Date: Mon, 13 Jul 2026 15:06:10 +0800 X-Gmail-Original-Message-ID: X-Gm-Features: AUfX_mzuKA4JwmuMUWB774bzpkP7q4a7PrJvxtp8N1GWwrENQwGP0BULxiqlyqc Message-ID: Subject: Re: [patch 06/18] riscv/syscall: Use syscall_enter_from_user_mode_randomize_stack() To: Thomas Gleixner Cc: LKML , Peter Zijlstra , Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Michael Ellerman , Shrikanth Hegde , linuxppc-dev@lists.ozlabs.org, Kees Cook , Huacai Chen , loongarch@lists.linux.dev, Sven Schnelle , linux-s390@vger.kernel.org, x86@kernel.org, Mark Rutland , Jinjie Ruan , Andy Lutomirski , Oleg Nesterov , Richard Henderson , Russell King , Catalin Marinas , Geert Uytterhoeven , Thomas Bogendoerfer , Helge Deller , Yoshinori Sato , Richard Weinberger , Chris Zankel , linux-arm-kernel@lists.infradead.org, linux-alpha@vger.kernel.org, linux-csky@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org, linux-um@lists.infradead.org, Arnd Bergmann , Vineet Gupta , Will Deacon , Brian Cain , Michal Simek , Dinh Nguyen , "David S. Miller" , Andreas Larsson , linux-snps-arc@lists.infradead.org, linux-hexagon@vger.kernel.org, linux-openrisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, =?UTF-8?Q?Michal_Such=C3=A1nek?= , Jonathan Corbet , linux-doc@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, Jul 8, 2026 at 3:06=E2=80=AFAM Thomas Gleixner wr= ote: > > syscall_enter_from_user_mode_randomize_stack() replaces > syscall_enter_from_user_mode() and the subsequent invocation of > add_random_kstack_offset(). > > The advantage is that it applies the stack randomization right after > enter_from_user_mode() and thereby avoids the overhead of get/put_cpu_var= () > as that code is invoked with interrupts disabled. > > No functional change. > > Signed-off-by: Thomas Gleixner > Cc: Paul Walmsley > Cc: Palmer Dabbelt > Cc: linux-riscv@lists.infradead.org > --- > arch/riscv/kernel/traps.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > --- a/arch/riscv/kernel/traps.c > +++ b/arch/riscv/kernel/traps.c > @@ -7,7 +7,6 @@ > #include > #include > #include > -#include > #include > #include > #include > @@ -333,9 +332,7 @@ void do_trap_ecall_u(struct pt_regs *reg > > riscv_v_vstate_discard(regs); > > - syscall =3D syscall_enter_from_user_mode(regs, syscall); > - > - add_random_kstack_offset(); > + syscall =3D syscall_enter_from_user_mode_randomize_stack(= regs, syscall); Reviewed-by: Guo Ren --=20 Best Regards Guo Ren