Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1356515
| From | Andy Lutomirski <luto@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v4 5/5] x86/msr: Set the return value to zero when native_rdmsr_safe fails |
| Date | 2016-03-12 19:20 +0100 |
| Message-ID | <rbWiS-1L9-13@gated-at.bofh.it> (permalink) |
| References | <rbW9c-1Em-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
This will cause unchecked native_rdmsr_safe failures to return
deterministic results.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/include/asm/msr.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 13da359881d7..e97e79f8a22b 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -109,7 +109,10 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr,
asm volatile("2: rdmsr ; xor %[err],%[err]\n"
"1:\n\t"
".section .fixup,\"ax\"\n\t"
- "3: mov %[fault],%[err] ; jmp 1b\n\t"
+ "3: mov %[fault],%[err]\n\t"
+ "xorl %%eax, %%eax\n\t"
+ "xorl %%edx, %%edx\n\t"
+ "jmp 1b\n\t"
".previous\n\t"
_ASM_EXTABLE(2b, 3b)
: [err] "=r" (*err), EAX_EDX_RET(val, low, high)
--
2.5.0
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v4 0/5] [PATCH v3 0/5] Improve non-"safe" MSR access failure handling Andy Lutomirski <luto@kernel.org> - 2016-03-12 19:10 +0100
[PATCH v4 1/5] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks Andy Lutomirski <luto@kernel.org> - 2016-03-12 19:20 +0100
Re: [PATCH v4 1/5] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks Borislav Petkov <bp@alien8.de> - 2016-03-14 13:00 +0100
Re: [PATCH v4 1/5] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks Andy Lutomirski <luto@amacapital.net> - 2016-03-14 18:10 +0100
[PATCH v4 5/5] x86/msr: Set the return value to zero when native_rdmsr_safe fails Andy Lutomirski <luto@kernel.org> - 2016-03-12 19:20 +0100
Re: [Xen-devel] [PATCH v4 0/5] [PATCH v3 0/5] Improve non-"safe" MSR access failure handling Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2016-03-14 15:40 +0100
csiph-web