From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.mindbit.ro (xs1.mindbit.ro [80.86.107.70]) (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 178D84C77C8; Wed, 8 Jul 2026 18:37:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.86.107.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783535862; cv=none; b=A7q8l0oYpirr0jbIhE5FsFug1SJlolGeGKDp9hegvX+uZU55SNzqdwjgJLO7zLub3tm7Nev/5JQRxc4LCRdQErkKEcwgCgdsR8iv+6YgtEgS5s8Npwvh5sTvVFS0nv4PSdWH561bVq33pIik5Z0DA1PD3bfsog22GK22A53s7Wc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783535862; c=relaxed/simple; bh=47mfftpidT/9Wsw+p7VvEqhivHeFAm8tBlZdw0i+e70=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=S9oWHaFtomVUlmtGsxZty2Pz4tueIXe4+wr9+/lnofLwMKs9TdZhxaI1nk0gkfGZDucYyXrtaOa7kWEqWwEXKCRygXWWUFnEaLdrB9rX+X+0Ev01ReAM56Nxu1INJ1tVe7tXwt3fIqNYx5UfFBMGNppJ8pQGVQk0jE2KSIxca84= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=rendec.net; spf=pass smtp.mailfrom=rendec.net; dkim=pass (2048-bit key) header.d=rendec.net header.i=@rendec.net header.b=MYg2quQs; arc=none smtp.client-ip=80.86.107.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=rendec.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rendec.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rendec.net header.i=@rendec.net header.b="MYg2quQs" Received: from bat.kanata.rendec.net (unknown [24.114.111.125]) by mail.mindbit.ro (Postfix) with ESMTPSA id BD677C343E; Wed, 8 Jul 2026 21:37:17 +0300 (EEST) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.mindbit.ro BD677C343E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rendec.net; s=default; t=1783535859; bh=J8eh6Rp71aMkUZPGbdf4HwpQyZ/mRcCB+VtPzFZfm0s=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=MYg2quQsJUR7e8ayAFMJcRvjHsrwKzUQqkhrJdU4nanpzL1jX14m8Z+Ds91DdqoKn QJReaLyNa/iLaBx/8t9LaIJgpO/V9u0Qk+ctVFHOLXc1PsNN77To6wbQLDR/wbO2Jd LI7Oyckd8G3uDywiL3AEPP+/6veZtLhQL8vDm8MBdhsqbXlk1PXB64z0Yki4BQsRic 1MYR+Jrgudnmn+eQyNCJp23VAJq+mVC5zubA5AQHg1rSP6wds0PtsFuUt0GISnCwHY EbF0YrfTMJrddRnwe6si6lyEajabery7sEfS+bc1aT49zcfePemMerT/qsFH4wmqB6 HEkaGc5AmP+eg== Message-ID: <335387752ace30084a3f709acf34556443300d1f.camel@rendec.net> Subject: Re: [patch 04/18] loongarch/syscall: Use syscall_enter_from_user_mode_randomize_stack() From: Radu Rendec To: Thomas Gleixner , LKML Cc: Peter Zijlstra , Huacai Chen , loongarch@lists.linux.dev, Michael Ellerman , Shrikanth Hegde , linuxppc-dev@lists.ozlabs.org, Kees Cook , Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Sven Schnelle , linux-s390@vger.kernel.org, x86@kernel.org, Mark Rutland , Jinjie Ruan , Andy Lutomirski , Oleg Nesterov , Richard Henderson , Russell King , Catalin Marinas , Guo Ren , 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, Michal =?ISO-8859-1?Q?Such=E1nek?= , Jonathan Corbet , linux-doc@vger.kernel.org Date: Wed, 08 Jul 2026 14:37:13 -0400 In-Reply-To: <20260707190253.865955911@kernel.org> References: <20260707181957.433213175@kernel.org> <20260707190253.865955911@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.3 (3.58.3-1.fc43) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Tue, 2026-07-07 at 21:06 +0200, Thomas Gleixner wrote: > syscall_enter_from_user_mode_randomize_stack() replaces > syscall_enter_from_user_mode() and the subsequent invocation of > add_random_kstack_offset(). >=20 > 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. >=20 > No functional change. >=20 > Signed-off-by: Thomas Gleixner > Cc: Huacai Chen > Cc: loongarch@lists.linux.dev > --- > =C2=A0arch/loongarch/kernel/syscall.c |=C2=A0=C2=A0=C2=A0 5 +---- > =C2=A01 file changed, 1 insertion(+), 4 deletions(-) >=20 > --- a/arch/loongarch/kernel/syscall.c > +++ b/arch/loongarch/kernel/syscall.c > @@ -11,7 +11,6 @@ > =C2=A0#include > =C2=A0#include > =C2=A0#include > -#include > =C2=A0#include > =C2=A0#include > =C2=A0 > @@ -70,9 +69,7 @@ void noinstr __no_stack_protector do_sys > =C2=A0 regs->orig_a0 =3D regs->regs[4]; > =C2=A0 regs->regs[4] =3D -ENOSYS; > =C2=A0 > - nr =3D syscall_enter_from_user_mode(regs, nr); > - > - add_random_kstack_offset(); > + nr =3D syscall_enter_from_user_mode_randomize_stack(regs, nr); > =C2=A0 > =C2=A0 if (nr < NR_syscalls) { > =C2=A0 syscall_fn =3D sys_call_table[array_index_nospec(nr, NR_syscalls)= ]; Reviewed-by: Radu Rendec