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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-01-29 00:04:38 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-01-29 00:04:38 +0300 |
commit | 4d6245ce8c8b441e01a3a1c1e67a1963a84498dd (patch) | |
tree | 20f6b0bf181963aa955e4350d6507468531e9121 /arch | |
parent | c0275ae758f8ce72306da200b195d1e1d66d0a8d (diff) | |
parent | bbc55341b9c67645d1a5471506370caf7dd4a203 (diff) | |
download | linux-4d6245ce8c8b441e01a3a1c1e67a1963a84498dd.tar.xz |
Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 FPU updates from Ingo Molnar:
"Three changes: fix a race that can result in FPU corruption, plus two
cleanups"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Deactivate FPU state after failure during state load
x86/fpu/xstate: Make xfeature_is_supervisor()/xfeature_is_user() return bool
x86/fpu/xstate: Fix small issues
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kernel/fpu/signal.c | 3 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 18 |
2 files changed, 11 insertions, 10 deletions
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 0071b794ed19..400a05e1c1c5 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -352,6 +352,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) fpregs_unlock(); return 0; } + fpregs_deactivate(fpu); fpregs_unlock(); } @@ -403,6 +404,8 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) } if (!ret) fpregs_mark_activate(); + else + fpregs_deactivate(fpu); fpregs_unlock(); err_out: diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index fa31470bbf24..a1806598aaa4 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -107,23 +107,20 @@ int cpu_has_xfeatures(u64 xfeatures_needed, const char **feature_name) } EXPORT_SYMBOL_GPL(cpu_has_xfeatures); -static int xfeature_is_supervisor(int xfeature_nr) +static bool xfeature_is_supervisor(int xfeature_nr) { /* - * We currently do not support supervisor states, but if - * we did, we could find out like this. - * - * SDM says: If state component 'i' is a user state component, - * ECX[0] return 0; if state component i is a supervisor - * state component, ECX[0] returns 1. + * Extended State Enumeration Sub-leaves (EAX = 0DH, ECX = n, n > 1) + * returns ECX[0] set to (1) for a supervisor state, and cleared (0) + * for a user state. */ u32 eax, ebx, ecx, edx; cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); - return !!(ecx & 1); + return ecx & 1; } -static int xfeature_is_user(int xfeature_nr) +static bool xfeature_is_user(int xfeature_nr) { return !xfeature_is_supervisor(xfeature_nr); } @@ -419,7 +416,8 @@ static void __init setup_init_fpu_buf(void) print_xstate_features(); if (boot_cpu_has(X86_FEATURE_XSAVES)) - init_fpstate.xsave.header.xcomp_bv = (u64)1 << 63 | xfeatures_mask; + init_fpstate.xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | + xfeatures_mask; /* * Init all the features state with header.xfeatures being 0x0 |