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 4E9153B7742; Wed, 8 Jul 2026 20:57:29 +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=1783544252; cv=none; b=ntxVFbb/0m8Pj8BIheu8ko85D2t4RGc4kavFkzTZeouVoTxYm6yIZd+C3YM+pFYmlw2VMviz60KTKEpb7PR+dPhDffarR5QWpiJZxiZoQGA1zd39+lmPuU09Tay63Qrx1BklT29E7uAr3B3tK3J5nPiyJ5Q5TpE2O4l7Pm29jeI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783544252; c=relaxed/simple; bh=2hzi9Savg6iPJ9G2+nDa/XygxlgJhPb8lJ2xty74coc=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=QaP0hj1u+lVPk8r/MCE5cx/UDQuamwyEw77XLC4VR+U4+jmPjukDhtOkJwH+J73c/8zeeFyErGLim/eilvODRKTdxGzgVMhrCHoUE7aW0L1chnT5eDS2b8r5tvjI5irUiPuI5jb5w6dbrMbXMb0+qWphIBfE5qPhpBsFKaEZBh8= 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=ynS36ddU; 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="ynS36ddU" Received: from bat.kanata.rendec.net (unknown [24.114.111.125]) by mail.mindbit.ro (Postfix) with ESMTPSA id 276CAC3437; Wed, 8 Jul 2026 23:57:05 +0300 (EEST) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.mindbit.ro 276CAC3437 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rendec.net; s=default; t=1783544246; bh=up349XAcstBbuMmtgpGoCSrvvL3bQC70drCvWmoD2ds=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=ynS36ddUdp8eq69SvUl6OgUXVC9QL2tj6JdfNjNoPXNVKwC/3CN8EubMigM7yTWhw wN2l7xiScOadwqXH8k1Mr6pkHvNMtNLdr91wDtAcHVTHHdPCMoFrB5PPDCaDQEpQ/7 nrAG0UN1qXnV/0+w7ire/3DQ71IknBguOljyr+0fQFSjwNiLglUjXiqoASKEjWfiP9 hdpfN4vBD8SgIx0jZq/vsbn+u9RcOw90ghJIPsraTy3Kmn5rysmmntnF1EMEJ6MLYT FeMAfAFofJ6Q5u7zyyWHuX3D2olPOI2XjVzaGihUsp+73EBHAshY/LugN1FUs+Ocpp c1dTfe4hj1cHA== Message-ID: Subject: Re: [patch 06/18] riscv/syscall: Use syscall_enter_from_user_mode_randomize_stack() From: Radu Rendec To: Thomas Gleixner , LKML Cc: 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 , 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 16:57:00 -0400 In-Reply-To: <20260707190253.974626922@kernel.org> References: <20260707181957.433213175@kernel.org> <20260707190253.974626922@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-kernel@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: Paul Walmsley > Cc: Palmer Dabbelt > Cc: linux-riscv@lists.infradead.org > --- > =C2=A0arch/riscv/kernel/traps.c |=C2=A0=C2=A0=C2=A0 5 +---- > =C2=A01 file changed, 1 insertion(+), 4 deletions(-) >=20 > --- a/arch/riscv/kernel/traps.c > +++ b/arch/riscv/kernel/traps.c > @@ -7,7 +7,6 @@ > =C2=A0#include > =C2=A0#include > =C2=A0#include > -#include > =C2=A0#include > =C2=A0#include > =C2=A0#include > @@ -333,9 +332,7 @@ void do_trap_ecall_u(struct pt_regs *reg > =C2=A0 > =C2=A0 riscv_v_vstate_discard(regs); > =C2=A0 > - syscall =3D syscall_enter_from_user_mode(regs, syscall); > - > - add_random_kstack_offset(); > + syscall =3D syscall_enter_from_user_mode_randomize_stack(regs, syscall= ); > =C2=A0 > =C2=A0 if (syscall >=3D 0 && syscall < NR_syscalls) { > =C2=A0 syscall =3D array_index_nospec(syscall, NR_syscalls); Reviewed-by: Radu Rendec