kernel.git/arch/x86/kernel/fpu, branch linux-5.6.y

copy_xstate_to_kernel(): don't leave parts of destination uninitialized

2020-06-03T06:23:28Z

commit 9e4636545933131de15e1ecd06733538ae939b2f upstream. copy the corresponding pieces of init_fpstate into the gaps instead. Cc: stable@kernel.org Tested-by: Alexander Potapenko Acked-by: Borislav Petkov Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

x86/fpu: Deactivate FPU state after failure during state load

2020-01-07T12:44:42Z

In __fpu__restore_sig(), fpu_fpregs_owner_ctx needs to be reset if the FPU state was not fully restored. Otherwise the following may happen (on the same CPU): Task A Task B fpu_fpregs_owner_ctx *active* A.fpu __fpu__restore_sig() ctx switch load B.fpu *active* B.fpu fpregs_lock() copy_user_to_fpregs_zeroing() copy_kernel_to_xregs() *modify* copy_user_to_xregs() *fails* fpregs_unlock() ctx switch skip loading B.fpu, *active* B.fpu In the success case, fpu_fpregs_owner_ctx is set to the current task. In the failure case, the FPU state might have been modified by loading the init state. In this case, fpu_fpregs_owner_ctx needs to be reset in order to ensure that the FPU state of the following task is loaded from saved state (and not skipped because it was the previous state). Reset fpu_fpregs_owner_ctx after a failure during restore occurred, to ensure that the FPU state for the next task is always loaded. The problem was debugged-by Yu-cheng Yu . [ bp: Massage commit message. ] Fixes: 5f409e20b7945 ("x86/fpu: Defer FPU state load until return to userspace") Reported-by: Yu-cheng Yu Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jann Horn Cc: Peter Zijlstra Cc: "Ravi V. Shankar" Cc: Rik van Riel Cc: Thomas Gleixner Cc: Tony Luck Cc: x86-ml Link: https://lkml.kernel.org/r/20191220195906.plk6kpmsrikvbcfn@linutronix.de

x86/fpu/xstate: Make xfeature_is_supervisor()/xfeature_is_user() return bool

2020-01-06T18:08:40Z

Have both xfeature_is_supervisor()/xfeature_is_user() return bool because they are used only in boolean context. Suggested-by: Borislav Petkov Signed-off-by: Yu-cheng Yu Signed-off-by: Borislav Petkov Acked-by: Sebastian Andrzej Siewior Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Peter Zijlstra Cc: "Ravi V. Shankar" Cc: Rik van Riel Cc: Thomas Gleixner Cc: Tony Luck Cc: x86-ml Link: https://lkml.kernel.org/r/20191212210855.19260-3-yu-cheng.yu@intel.com

x86/fpu/xstate: Fix small issues

2020-01-06T16:31:11Z

In response to earlier comments, fix small issues before introducing XSAVES supervisor states: - Fix comments of xfeature_is_supervisor(). - Replace ((u64)1 << 63) with XCOMP_BV_COMPACTED_FORMAT. No functional changes. Signed-off-by: Yu-cheng Yu Signed-off-by: Borislav Petkov Reviewed-by: Dave Hansen Reviewed-by: Tony Luck Acked-by: Sebastian Andrzej Siewior Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Peter Zijlstra Cc: "Ravi V. Shankar" Cc: Rik van Riel Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20191212210855.19260-2-yu-cheng.yu@intel.com

treewide: Use sizeof_field() macro

2019-12-09T18:36:44Z

Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except at places where these are defined. Later patches will remove the unused definition of FIELD_SIZEOF(). This patch is generated using following script: EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h" git grep -l -e "\bFIELD_SIZEOF\b" | while read file; do if [[ "$file" =~ $EXCLUDE_FILES ]]; then continue fi sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file; done Signed-off-by: Pankaj Bharadiya Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com Co-developed-by: Kees Cook Signed-off-by: Kees Cook Acked-by: David Miller # for net

x86/fpu: Use XFEATURE_FP/SSE enum values instead of hardcoded numbers

2019-11-04T21:10:07Z

When setting up sizes and offsets for legacy header entries the code uses hardcoded 0/1 instead of the corresponding enum values XFEATURE_FP and XFEATURE_SSE. Replace the hardcoded numbers which enhances readability of the code and also makes this code the first user of those enum values.. Signed-off-by: Cyrill Gorcunov Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20191101130153.GG1615@uranus.lan

x86/fpu: Shrink space allocated for xstate_comp_offsets

2019-11-04T21:04:19Z

commit 8ff925e10f2c ("x86/xsaves: Clean up code in xstate offsets computation in xsave area") introduced an allocation of 64 entries for xstate_comp_offsets while the code only handles up to XFEATURE_MAX entries. For this reason xstate_offsets and xstate_sizes are already defined with the explicit XFEATURE_MAX limit. Do the same for compressed format for consistency sake. As the changelog of that commit is not giving any information it's assumed that the main idea was to cover all possible bits in xfeatures_mask, but this doesn't explain why other variables such as the non-compacted offsets and sizes are explicitely limited to XFEATURE_MAX. For consistency it's better to use the XFEATURE_MAX limit everywhere and extend it on demand when new features get implemented at the hardware level and subsequently supported by the kernel. Signed-off-by: Cyrill Gorcunov Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20191101124228.GF1615@uranus.lan

x86/fpu: Update stale variable name in comment

2019-11-04T21:04:19Z

When the fpu code was reworked pcntxt_mask was renamed to xfeatures_mask. Reflect it in the comment as well. Signed-off-by: Cyrill Gorcunov Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20191101123850.GE1615@uranus.lan

Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-07-09T00:28:57Z

Pull x86 AVX512 status update from Ingo Molnar: "This adds a new ABI that the main scheduler probably doesn't want to deal with but HPC job schedulers might want to use: the AVX512_elapsed_ms field in the new /proc//arch_status task status file, which allows the user-space job scheduler to cluster such tasks, to avoid turbo frequency drops" * 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation/filesystems/proc.txt: Add arch_status file x86/process: Add AVX-512 usage elapsed time to /proc/pid/arch_status proc: Add /proc//arch_status

x86/fpu: Inline fpu__xstate_clear_all_cpu_caps()

2019-07-07T10:01:47Z

All fpu__xstate_clear_all_cpu_caps() does is to invoke one simple function since commit 73e3a7d2a7c3b ("x86/fpu: Remove the explicit clearing of XSAVE dependent features") so invoke that function directly and remove the wrapper. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190704060743.rvew4yrjd6n33uzx@linutronix.de