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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-29 00:04:38 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-29 00:04:38 +0300
commit4d6245ce8c8b441e01a3a1c1e67a1963a84498dd (patch)
tree20f6b0bf181963aa955e4350d6507468531e9121 /arch
parentc0275ae758f8ce72306da200b195d1e1d66d0a8d (diff)
parentbbc55341b9c67645d1a5471506370caf7dd4a203 (diff)
downloadlinux-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.c3
-rw-r--r--arch/x86/kernel/fpu/xstate.c18
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