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Shutemov" To: Sohil Mehta Cc: Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , 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: [PATCHv9 13/16] x86/traps: Handle LASS thrown #SS Message-ID: References: <20250707080317.3791624-1-kirill.shutemov@linux.intel.com> <20250707080317.3791624-14-kirill.shutemov@linux.intel.com> <1a2f6b4a-114b-4c27-83f9-1aac46f2e7c0@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1a2f6b4a-114b-4c27-83f9-1aac46f2e7c0@intel.com> X-Rspam-User: X-Rspamd-Queue-Id: 37B4F120002 X-Rspamd-Server: rspam03 X-Stat-Signature: c7h5dnea8bz4cmysw5yfsyuaf5x9gxd4 X-HE-Tag: 1752057544-853840 X-HE-Meta: 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 eVybgbu2 xZI5skbfv5XPLC1b62QN70rY1p6GLQ2DzG87brKNWHDkU/SRSlbnOjpudbB/IHV2TyMGHHbdNJnPOKk9XNsgiGRqHr7EWALvCXP81LrupCEg5eyolVjIaEVKxveO8Cq6ECaKP9Ta0PbG/u4ZqqekreJq7Yh6bUTQ4yNe8H/nbDrbxesYs6lOiN1jZI9ulDxBfJAzs0Xfa86DbhaGYBjAG75cJGYKhF2X8ga7gHZCPo818f5D0njwfvI/EMlkEpZYPYHod43c+fbVAR3c= 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 Tue, Jul 08, 2025 at 10:12:28PM -0700, Sohil Mehta wrote: > On 7/7/2025 1:03 AM, Kirill A. Shutemov wrote: > > > + hint = get_kernel_exc_address(regs, &exc_addr); > > + if (hint != EXC_NO_HINT) > > + printk(SSFSTR ", %s 0x%lx", kernel_exc_hint_help[hint], exc_addr); > > + > > + if (hint != EXC_NON_CANONICAL) > > + exc_addr = 0; > > + > > + die_addr(SSFSTR, regs, error_code, exc_addr); > > I see a slight difference between the #GP handling and the #SS handling > here. For the #GP case, we seem to pass the hint string to die_addr(). > > However, for the #SS, the hint is printed above and only SSFSTR gets > passed onto die_addr(). I am curious about the reasoning. I hate how 'desc' size is defined in #GP handler: char desc[sizeof(GPFSTR) + 50 + 2*sizeof(unsigned long) + 1] = GPFSTR; Too much voodoo to my liking. And it will overflow if any hint string is going to be longer than 50. I don't want to repeat this magic for #SS. I would argue we need to print directly in #GP handler as I do in #SS. But, IMO, it is outside of the scope of this patchset. -- Kiryl Shutsemau / Kirill A. Shutemov