* [tip:x86/urgent] x86: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD
2017-11-28 21:01 ` [PATCH] x86: make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD Rudolf Marek
@ 2017-11-29 9:34 ` tip-bot for Rudolf Marek
2017-12-06 11:34 ` [tip:x86/urgent] x86/cpufeatures: " tip-bot for Rudolf Marek
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Rudolf Marek @ 2017-11-29 9:34 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, mingo, bp, tglx, r.marek, luto, hpa
Commit-ID: 2b67799bdf25d19690710a88c2bce9127cf3ba6f
Gitweb: https://git.kernel.org/tip/2b67799bdf25d19690710a88c2bce9127cf3ba6f
Author: Rudolf Marek <r.marek@assembler.cz>
AuthorDate: Tue, 28 Nov 2017 22:01:06 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 29 Nov 2017 10:30:43 +0100
x86: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD
The latest AMD AMD64 Architecture Programmer's Manual
adds a CPUID feature XSaveErPtr (CPUID_Fn80000008_EBX[2]).
If this feature is set, the FXSAVE, XSAVE, FXSAVEOPT, XSAVEC, XSAVES
/ FXRSTOR, XRSTOR, XRSTORS always save/restore error pointers,
thus making the X86_BUG_FXSAVE_LEAK workaround obsolete on such CPUs.
Signed-Off-By: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: https://lkml.kernel.org/r/bdcebe90-62c5-1f05-083c-eba7f08b2540@assembler.cz
---
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/kernel/cpu/amd.c | 7 +++++--
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index c0b0e9e..800104c 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -266,6 +266,7 @@
/* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 13 */
#define X86_FEATURE_CLZERO (13*32+ 0) /* CLZERO instruction */
#define X86_FEATURE_IRPERF (13*32+ 1) /* Instructions Retired Count */
+#define X86_FEATURE_XSAVEERPTR (13*32+ 2) /* Always save/restore FP error pointers */
/* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */
#define X86_FEATURE_DTHERM (14*32+ 0) /* Digital Thermal Sensor */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index d58184b..bcb75dc 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -804,8 +804,11 @@ static void init_amd(struct cpuinfo_x86 *c)
case 0x17: init_amd_zn(c); break;
}
- /* Enable workaround for FXSAVE leak */
- if (c->x86 >= 6)
+ /*
+ * Enable workaround for FXSAVE leak on CPUs
+ * without a XSaveErPtr feature
+ */
+ if ((c->x86 >= 6) && (!cpu_has(c, X86_FEATURE_XSAVEERPTR)))
set_cpu_bug(c, X86_BUG_FXSAVE_LEAK);
cpu_detect_cache_sizes(c);
^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip:x86/urgent] x86/cpufeatures: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD
2017-11-28 21:01 ` [PATCH] x86: make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD Rudolf Marek
2017-11-29 9:34 ` [tip:x86/urgent] x86: Make " tip-bot for Rudolf Marek
@ 2017-12-06 11:34 ` tip-bot for Rudolf Marek
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Rudolf Marek @ 2017-12-06 11:34 UTC (permalink / raw)
To: linux-tip-commits; +Cc: tglx, mingo, luto, linux-kernel, bp, r.marek, hpa
Commit-ID: e3811a3f74bd1ad773667b78323f396166891f3a
Gitweb: https://git.kernel.org/tip/e3811a3f74bd1ad773667b78323f396166891f3a
Author: Rudolf Marek <r.marek@assembler.cz>
AuthorDate: Tue, 28 Nov 2017 22:01:06 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 6 Dec 2017 12:27:13 +0100
x86/cpufeatures: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD
The latest AMD AMD64 Architecture Programmer's Manual
adds a CPUID feature XSaveErPtr (CPUID_Fn80000008_EBX[2]).
If this feature is set, the FXSAVE, XSAVE, FXSAVEOPT, XSAVEC, XSAVES
/ FXRSTOR, XRSTOR, XRSTORS always save/restore error pointers,
thus making the X86_BUG_FXSAVE_LEAK workaround obsolete on such CPUs.
Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: https://lkml.kernel.org/r/bdcebe90-62c5-1f05-083c-eba7f08b2540@assembler.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/kernel/cpu/amd.c | 7 +++++--
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index c0b0e9e..800104c 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -266,6 +266,7 @@
/* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 13 */
#define X86_FEATURE_CLZERO (13*32+ 0) /* CLZERO instruction */
#define X86_FEATURE_IRPERF (13*32+ 1) /* Instructions Retired Count */
+#define X86_FEATURE_XSAVEERPTR (13*32+ 2) /* Always save/restore FP error pointers */
/* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */
#define X86_FEATURE_DTHERM (14*32+ 0) /* Digital Thermal Sensor */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index d58184b..bcb75dc 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -804,8 +804,11 @@ static void init_amd(struct cpuinfo_x86 *c)
case 0x17: init_amd_zn(c); break;
}
- /* Enable workaround for FXSAVE leak */
- if (c->x86 >= 6)
+ /*
+ * Enable workaround for FXSAVE leak on CPUs
+ * without a XSaveErPtr feature
+ */
+ if ((c->x86 >= 6) && (!cpu_has(c, X86_FEATURE_XSAVEERPTR)))
set_cpu_bug(c, X86_BUG_FXSAVE_LEAK);
cpu_detect_cache_sizes(c);
^ permalink raw reply [flat|nested] 3+ messages in thread