linux-dev/arch/x86/kernel/umip.c, branch linus/master

x86/umip: Downgrade warning messages to debug loglevel

2021-09-25T11:23:28Z

After four years in the wild, those have not fullfilled their initial purpose of pushing people to fix their software to not use UMIP-emulated instructions, and to warn users about the degraded emulation performance. Yet, the only thing that "degrades" performance is overflowing dmesg with those: [Di Sep 7 00:24:05 2021] umip_printk: 1345 callbacks suppressed [Di Sep 7 00:24:05 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b7c0: SIDT instruction cannot be used by applications. [Di Sep 7 00:24:05 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b7c0: For now, expensive software emulation returns the result. ... [Di Sep 7 00:26:06 2021] umip_printk: 2227 callbacks suppressed [Di Sep 7 00:26:06 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b940: SIDT instruction cannot be used by applications. and users don't really care about that - they just want to play their games in wine. So convert those to debug loglevel - in case someone is still interested in them, someone can boot with "debug" on the kernel cmdline. Reported-by: Marcus Rückert Signed-off-by: Borislav Petkov Reviewed-by: Ricardo Neri Link: https://lkml.kernel.org/r/20210907200454.30458-1-bp@alien8.de

x86/insn: Extend error reporting from insn_fetch_from_user[_inatomic]()

2021-06-15T09:39:30Z

The error reporting from the insn_fetch_from_user*() functions is not very verbose. Extend it to include information on whether the linear RIP could not be calculated or whether the memory access faulted. This will be used in the SEV-ES code to propagate the correct exception depending on what went wrong during instruction fetch. [ bp: Massage comments. ] Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210614135327.9921-6-joro@8bytes.org

Merge tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-04-28T00:45:09Z

Pull x86 updates from Borislav Petkov: - Turn the stack canary into a normal __percpu variable on 32-bit which gets rid of the LAZY_GS stuff and a lot of code. - Add an insn_decode() API which all users of the instruction decoder should preferrably use. Its goal is to keep the details of the instruction decoder away from its users and simplify and streamline how one decodes insns in the kernel. Convert its users to it. - kprobes improvements and fixes - Set the maximum DIE per package variable on Hygon - Rip out the dynamic NOP selection and simplify all the machinery around selecting NOPs. Use the simplified NOPs in objtool now too. - Add Xeon Sapphire Rapids to list of CPUs that support PPIN - Simplify the retpolines by folding the entire thing into an alternative now that objtool can handle alternatives with stack ops. Then, have objtool rewrite the call to the retpoline with the alternative which then will get patched at boot time. - Document Intel uarch per models in intel-family.h - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the exception on Intel. * tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) x86, sched: Treat Intel SNC topology as default, COD as exception x86/cpu: Comment Skylake server stepping too x86/cpu: Resort and comment Intel models objtool/x86: Rewrite retpoline thunk calls objtool: Skip magical retpoline .altinstr_replacement objtool: Cache instruction relocs objtool: Keep track of retpoline call sites objtool: Add elf_create_undef_symbol() objtool: Extract elf_symbol_add() objtool: Extract elf_strtab_concat() objtool: Create reloc sections implicitly objtool: Add elf_create_reloc() helper objtool: Rework the elf_rebuild_reloc_section() logic objtool: Fix static_call list generation objtool: Handle per arch retpoline naming objtool: Correctly handle retpoline thunk calls x86/retpoline: Simplify retpolines x86/alternatives: Optimize optimize_nops() x86: Add insn_decode_kernel() x86/kprobes: Move 'inline' to the beginning of the kprobe_is_ss() declaration ...

x86: Fix various typos in comments, take #2

2021-03-21T22:50:28Z

Fix another ~42 single-word typos in arch/x86/ code comments, missed a few in the first pass, in particular in .S files. Signed-off-by: Ingo Molnar Cc: Borislav Petkov Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Paolo Bonzini Cc: Bjorn Helgaas Cc: linux-kernel@vger.kernel.org

x86/insn: Rename insn_decode() to insn_decode_from_regs()

2021-03-15T09:53:10Z

Rename insn_decode() to insn_decode_from_regs() to denote that it receives regs as param and uses registers from there during decoding. Free the former name for a more generic version of the function. No functional changes. Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210304174237.31945-2-bp@alien8.de

x86/umip: Factor out instruction decoding

2020-09-07T17:45:24Z

Factor out the code used to decode an instruction with the correct address and operand sizes to a helper function. No functional changes. Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200907131613.12703-10-joro@8bytes.org

x86/umip: Factor out instruction fetch

2020-09-07T17:45:24Z

Factor out the code to fetch the instruction from user-space to a helper function. No functional changes. Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200907131613.12703-9-joro@8bytes.org

x86/umip: Add emulation/spoofing for SLDT and STR instructions

2020-08-20T17:10:26Z

Add emulation/spoofing of SLDT and STR for both 32- and 64-bit processes. Wine users have found a small number of Windows apps using SLDT that were crashing when run on UMIP-enabled systems. Originally-by: Ricardo Neri Reported-by: Andreas Rammhold Signed-off-by: Brendan Shanks Signed-off-by: Borislav Petkov Acked-by: Andy Lutomirski Reviewed-by: Ricardo Neri Tested-by: Ricardo Neri Link: https://lkml.kernel.org/r/20200710224525.21966-1-bshanks@codeweavers.com

x86/umip: Make umip_insns static

2020-04-15T09:13:12Z

Fix the following sparse warning: arch/x86/kernel/umip.c:84:12: warning: symbol 'umip_insns' was not declared. Should it be static? Reported-by: Hulk Robot Signed-off-by: Jason Yan Signed-off-by: Thomas Gleixner Acked-by: Ricardo Neri Link: https://lkml.kernel.org/r/20200413082213.22934-1-yanaijie@huawei.com

Merge branches 'x86-cpu-for-linus' and 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-11-26T16:58:08Z

Pull x86 cpu and fpu updates from Ingo Molnar: - math-emu fixes - CPUID updates - sanity-check RDRAND output to see whether the CPU at least pretends to produce random data - various unaligned-access across cachelines fixes in preparation of hardware level split-lock detection - fix MAXSMP constraints to not allow !CPUMASK_OFFSTACK kernels with larger than 512 NR_CPUS - misc FPU related cleanups * 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Align the x86_capability array to size of unsigned long x86/cpu: Align cpu_caps_cleared and cpu_caps_set to unsigned long x86/umip: Make the comments vendor-agnostic x86/Kconfig: Rename UMIP config parameter x86/Kconfig: Enforce limit of 512 CPUs with MAXSMP and no CPUMASK_OFFSTACK x86/cpufeatures: Add feature bit RDPRU on AMD x86/math-emu: Limit MATH_EMULATION to 486SX compatibles x86/math-emu: Check __copy_from_user() result x86/rdrand: Sanity-check RDRAND output * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu: Use XFEATURE_FP/SSE enum values instead of hardcoded numbers x86/fpu: Shrink space allocated for xstate_comp_offsets x86/fpu: Update stale variable name in comment