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Peter Anvin" , LKML , Peter Zijlstra , Michael Ellerman , Shrikanth Hegde , linuxppc-dev@lists.ozlabs.org, Kees Cook , Huacai Chen , loongarch@lists.linux.dev, 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@vger.kernel.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 16/18] x86/entry: Get rid of the sys_ni_syscall() indirection Message-ID: <20261023214353.Q3pZID23@linutronix.de> References: <20260707181957.433213175@kernel.org> <20260707190254.493733289@kernel.org> <20261022142425.3Wx-RrU5@linutronix.de> <87fqxx1r80.ffs@fw13> <87cxt11ktr.ffs@fw13> <1149A39E-BEBA-46EA-94F4-4DFFC4733EF5@zytor.com> <871p9g1s3w.ffs@fw13> <87y0boze95.ffs@fw13> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87y0boze95.ffs@fw13> On 2026-10-23 16:24:22 [+0200], Thomas Gleixner wrote: > IOW, a tracer modification of regs->ax is not overwritten when the > syscall number is out of range. > > Between 2.6.19-rc2 and -rc3 x86_64 was changed to _always_ overwrite > regs->ax when the syscall number is out of range. > > In the 3.8 merge window seccomp introduced the -1 == skip bogosity which > got fixed up and made "consistent" in several changes afterwards. Just > that it never reached a state of consistency due to the overloading. > > So are we stuck with this behavior or do we sit down and define what the > correct behavior should be? I wouldn't say we are stuck. The test did reassemble the status we had at the moment. As you wrote yourself the behaviour changed a few times and not on purpose. I would say we define what correct behaviour should be and make sure it is consistent across all the architectures. > Thanks, > > tglx Sebastian