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Shutemov" , 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 Cc: Jonathan Corbet , Sohil Mehta , 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 References: <20250620135325.3300848-1-kirill.shutemov@linux.intel.com> <20250620135325.3300848-8-kirill.shutemov@linux.intel.com> From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzUVEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gKEludGVsIFdvcmsgQWRkcmVzcykgPGRhdmUuaGFuc2VuQGludGVs LmNvbT7CwXgEEwECACIFAlQ+9J0CGwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEGg1 lTBwyZKwLZUP/0dnbhDc229u2u6WtK1s1cSd9WsflGXGagkR6liJ4um3XCfYWDHvIdkHYC1t MNcVHFBwmQkawxsYvgO8kXT3SaFZe4ISfB4K4CL2qp4JO+nJdlFUbZI7cz/Td9z8nHjMcWYF IQuTsWOLs/LBMTs+ANumibtw6UkiGVD3dfHJAOPNApjVr+M0P/lVmTeP8w0uVcd2syiaU5jB aht9CYATn+ytFGWZnBEEQFnqcibIaOrmoBLu2b3fKJEd8Jp7NHDSIdrvrMjYynmc6sZKUqH2 I1qOevaa8jUg7wlLJAWGfIqnu85kkqrVOkbNbk4TPub7VOqA6qG5GCNEIv6ZY7HLYd/vAkVY E8Plzq/NwLAuOWxvGrOl7OPuwVeR4hBDfcrNb990MFPpjGgACzAZyjdmYoMu8j3/MAEW4P0z F5+EYJAOZ+z212y1pchNNauehORXgjrNKsZwxwKpPY9qb84E3O9KYpwfATsqOoQ6tTgr+1BR CCwP712H+E9U5HJ0iibN/CDZFVPL1bRerHziuwuQuvE0qWg0+0SChFe9oq0KAwEkVs6ZDMB2 P16MieEEQ6StQRlvy2YBv80L1TMl3T90Bo1UUn6ARXEpcbFE0/aORH/jEXcRteb+vuik5UGY 5TsyLYdPur3TXm7XDBdmmyQVJjnJKYK9AQxj95KlXLVO38lczsFNBFRjzmoBEACyAxbvUEhd GDGNg0JhDdezyTdN8C9BFsdxyTLnSH31NRiyp1QtuxvcqGZjb2trDVuCbIzRrgMZLVgo3upr MIOx1CXEgmn23Zhh0EpdVHM8IKx9Z7V0r+rrpRWFE8/wQZngKYVi49PGoZj50ZEifEJ5qn/H Nsp2+Y+bTUjDdgWMATg9DiFMyv8fvoqgNsNyrrZTnSgoLzdxr89FGHZCoSoAK8gfgFHuO54B lI8QOfPDG9WDPJ66HCodjTlBEr/Cwq6GruxS5i2Y33YVqxvFvDa1tUtl+iJ2SWKS9kCai2DR 3BwVONJEYSDQaven/EHMlY1q8Vln3lGPsS11vSUK3QcNJjmrgYxH5KsVsf6PNRj9mp8Z1kIG qjRx08+nnyStWC0gZH6NrYyS9rpqH3j+hA2WcI7De51L4Rv9pFwzp161mvtc6eC/GxaiUGuH BNAVP0PY0fqvIC68p3rLIAW3f97uv4ce2RSQ7LbsPsimOeCo/5vgS6YQsj83E+AipPr09Caj 0hloj+hFoqiticNpmsxdWKoOsV0PftcQvBCCYuhKbZV9s5hjt9qn8CE86A5g5KqDf83Fxqm/ vXKgHNFHE5zgXGZnrmaf6resQzbvJHO0Fb0CcIohzrpPaL3YepcLDoCCgElGMGQjdCcSQ+Ci FCRl0Bvyj1YZUql+ZkptgGjikQARAQABwsFfBBgBAgAJBQJUY85qAhsMAAoJEGg1lTBwyZKw l4IQAIKHs/9po4spZDFyfDjunimEhVHqlUt7ggR1Hsl/tkvTSze8pI1P6dGp2XW6AnH1iayn yRcoyT0ZJ+Zmm4xAH1zqKjWplzqdb/dO28qk0bPso8+1oPO8oDhLm1+tY+cOvufXkBTm+whm +AyNTjaCRt6aSMnA/QHVGSJ8grrTJCoACVNhnXg/R0g90g8iV8Q+IBZyDkG0tBThaDdw1B2l asInUTeb9EiVfL/Zjdg5VWiF9LL7iS+9hTeVdR09vThQ/DhVbCNxVk+DtyBHsjOKifrVsYep WpRGBIAu3bK8eXtyvrw1igWTNs2wazJ71+0z2jMzbclKAyRHKU9JdN6Hkkgr2nPb561yjcB8 sIq1pFXKyO+nKy6SZYxOvHxCcjk2fkw6UmPU6/j/nQlj2lfOAgNVKuDLothIxzi8pndB8Jju KktE5HJqUUMXePkAYIxEQ0mMc8Po7tuXdejgPMwgP7x65xtfEqI0RuzbUioFltsp1jUaRwQZ MTsCeQDdjpgHsj+P2ZDeEKCbma4m6Ez/YWs4+zDm1X8uZDkZcfQlD9NldbKDJEXLIjYWo1PH hYepSffIWPyvBMBTW2W5FRjJ4vLRrJSUoEfJuPQ3vW9Y73foyo/qFoURHO48AinGPZ7PC7TF vUaNOTjKedrqHkaOcqB185ahG2had0xnFsDPlx5y In-Reply-To: <20250620135325.3300848-8-kirill.shutemov@linux.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Queue-Id: 2BEB8C000D X-Rspamd-Server: rspam01 X-Stat-Signature: mk354s4jha983g4k17o55m65xwqq9e9n X-HE-Tag: 1750445009-165460 X-HE-Meta: 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 LeyXf2qn u9UweWVTN2dmsuuKRIZGkEGZrE8eJDNVbBx5Qj2NqOk/jhckcjWg63OeQAj25pm78FFdgzdqJIYCvKOQzdFpSpkwgj095D2Kuk3ey17TCPTOM4MQcxv3AZ4ESrzdd2yZGDY7FdU3M7LRljt4Ku1rwkURR9tnm47oJzve0a4D6snJfM8ebrn3V2+8CQjE8A1GVO1MT387V9MPRAmS3IpirmGHOYkFPmm5NiFOgxYRGNrZdTgdQWsB1LX3FMaYCw7cGgWCZyPmzIxsBi+xznWaa5V6QiJcANm5yk9X8V41wYCFI6os2Mp3njQk11A== 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 6/20/25 06:53, Kirill A. Shutemov wrote: > +bool emulate_vsyscall_pf(unsigned long error_code, struct pt_regs *regs, > + unsigned long address) > +{ > + /* Write faults or kernel-privilege faults never get fixed up. */ > + if ((error_code & (X86_PF_WRITE | X86_PF_USER)) != X86_PF_USER) > + return false; > + > + if (!(error_code & X86_PF_INSTR)) { > + /* Failed vsyscall read */ > + if (vsyscall_mode == EMULATE) > + return false; > + > + /* > + * User code tried and failed to read the vsyscall page. > + */ > + warn_bad_vsyscall(KERN_INFO, regs, > + "vsyscall read attempt denied -- look up the vsyscall kernel parameter if you need a workaround"); > + return false; > + } > + > + return __emulate_vsyscall(regs, address); > +} For this patch that just moves the code: Acked-by: Dave Hansen But, the resulting code is wonky. It needs to do something more like this: if ((error_code & (X86_PF_WRITE | X86_PF_USER)) != X86_PF_USER) return false; if (error_code & X86_PF_INSTR)) return __emulate_vsyscall(regs, address); /* Failed vsyscall read */ if (vsyscall_mode == EMULATE) return false; /* * User code tried and failed to read the vsyscall page. */ warn_bad_vsyscall(KERN_INFO, regs, ... return false; That's much more linear to read.