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Shutemov" To: "H. Peter Anvin" Cc: Sohil Mehta , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Peter Zijlstra , Ard Biesheuvel , "Paul E. McKenney" , Josh Poimboeuf , Xiongwei Song , Xin Li , "Mike Rapoport (IBM)" , Brijesh Singh , Michael Roth , Tony Luck , Alexey Kardashevskiy , Alexander Shishkin , Jonathan Corbet , Ingo Molnar , Pawan Gupta , Daniel Sneddon , Kai Huang , Sandipan Das , Breno Leitao , Rick Edgecombe , Alexei Starovoitov , Hou Tao , Juergen Gross , Vegard Nossum , Kees Cook , Eric Biggers , Jason Gunthorpe , "Masami Hiramatsu (Google)" , Andrew Morton , Luis Chamberlain , Yuntao Wang , Rasmus Villemoes , Christophe Leroy , Tejun Heo , Changbin Du , Huang Shijie , Geert Uytterhoeven , Namhyung Kim , Arnaldo Carvalho de Melo , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv8 14/17] x86/traps: Handle LASS thrown #SS Message-ID: <6vihhfk5z33nrpy53ck2c6tkscjas4fhi6hqorenknbnjo4k3j@ywybd4obx76m> References: <20250701095849.2360685-1-kirill.shutemov@linux.intel.com> <20250701095849.2360685-15-kirill.shutemov@linux.intel.com> <95dc18fd-73b0-4019-92d2-c0e6aaf22c96@intel.com> <4DE45AFD-C1E0-4FB8-BE01-44A72C5C6E1E@zytor.com> <5q2zbkzyjknusd3feqolycqialetqfe52yfyzasnr6zp24pmej@4cg2r2hi4pf2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: A0EA4A0002 X-Stat-Signature: kf4185ss1oeznujni347b8y8rtk4bt65 X-Rspam-User: X-HE-Tag: 1751467664-443019 X-HE-Meta: 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 MF4Den9W ONDfTo9u3SbpgSBrmcUCfkSRaUJiAIvVra1uC78199jbors9KcFsdLt4B0B4VWnWRpE+Xm0sFdrjVpfXaEDxmze4yivsAYxkYS7tbIuiiTUaBL8ihj0L2CNst/FsI/sot3Cx2EktgG64xwCPG/X1h31LWtSM9FwaoL3/DI0T7Ako0AAnHKLGpZTSxIgt+tTyon4n+6A+Nf1XKfwNh5p045CJzxBRkWr+6C3P8Z7FmU8BZw8kEsobSyQB8Gw6VV5Z2rRDU+4ETByIlgLoQYrErTxOrUEtYQ5Oz98mi X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Jul 02, 2025 at 07:37:12AM -0700, H. Peter Anvin wrote: > A LASS violation of any kind in the kernel (unless handled by fixup, > including user access fixup) ought to be fatal, correct? Yes, LASS violation is fatal for !user_mode(regs), unless addressed by fixups. For user_mode(regs), emulate_vsyscall_gp() is the notable exception. -- Kiryl Shutsemau / Kirill A. Shutemov