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Thu, 09 Jul 2026 11:42:43 -0700 (PDT) Received: from li-1a3e774c-28e4-11b2-a85c-acc9f2883e29.ibm.com ([106.51.160.236]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-3118ee6080dsm19491362eec.17.2026.07.09.11.42.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jul 2026 11:42:42 -0700 (PDT) Date: Fri, 10 Jul 2026 00:12:23 +0530 From: Mukesh Kumar Chaurasiya 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 , 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 =?utf-8?B?U3VjaMOhbmVr?= , Jonathan Corbet , linux-doc@vger.kernel.org Subject: Re: [patch 06/18] riscv/syscall: Use syscall_enter_from_user_mode_randomize_stack() Message-ID: References: <20260707181957.433213175@kernel.org> <20260707190253.974626922@kernel.org> 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: <20260707190253.974626922@kernel.org> On Tue, Jul 07, 2026 at 09:06:19PM +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(). > > 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 = syscall_enter_from_user_mode(regs, syscall); > - > - add_random_kstack_offset(); > + syscall = syscall_enter_from_user_mode_randomize_stack(regs, syscall); > > if (syscall >= 0 && syscall < NR_syscalls) { > syscall = array_index_nospec(syscall, NR_syscalls); > Reviewed-by: Mukesh Kumar Chaurasiya (IBM)