From: Andy Lutomirski <luto@kernel.org>
To: X86 ML <x86@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
KVM list <kvm@vger.kernel.org>,
Arjan van de Ven <arjan@linux.intel.com>,
xen-devel <Xen-devel@lists.xen.org>,
linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>
Subject: [PATCH v5 9/9] x86/msr: Set the return value to zero when native_rdmsr_safe fails
Date: Sat, 2 Apr 2016 07:01:40 -0700 [thread overview]
Message-ID: <515fb611449a755312a476cfe11675906e7ddf6c.1459605520.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1459605520.git.luto@kernel.org>
In-Reply-To: <cover.1459605520.git.luto@kernel.org>
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)
--
2.5.5
next prev parent reply other threads:[~2016-04-02 14:02 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-02 14:01 [PATCH v5 0/9] Improve non-"safe" MSR access failure handling Andy Lutomirski
2016-04-02 14:01 ` [PATCH v5 1/9] x86/head: Pass a real pt_regs and trapnr to early_fixup_exception Andy Lutomirski
2016-04-13 11:43 ` [tip:x86/asm] x86/head: Pass a real pt_regs and trapnr to early_fixup_exception() tip-bot for Andy Lutomirski
2016-04-02 14:01 ` [PATCH v5 2/9] x86/head: Move the early NMI fixup into C Andy Lutomirski
2016-04-13 11:43 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2016-04-02 14:01 ` [PATCH v5 3/9] x86/head: Move early exception panic code into early_fixup_exception Andy Lutomirski
2016-04-02 18:39 ` Borislav Petkov
2016-04-02 20:13 ` Andy Lutomirski
2016-04-02 20:47 ` Borislav Petkov
2016-04-02 20:58 ` Andy Lutomirski
2016-04-04 11:52 ` Jan Kara
2016-04-04 12:46 ` Peter Zijlstra
2016-04-04 15:32 ` Andy Lutomirski
2016-04-04 15:36 ` Arjan van de Ven
2016-04-04 16:00 ` Peter Zijlstra
2016-04-04 19:38 ` Borislav Petkov
2016-04-04 21:31 ` Andy Lutomirski
2016-04-04 21:40 ` Borislav Petkov
2016-04-13 11:44 ` [tip:x86/asm] x86/head: Move early exception panic code into early_fixup_exception() tip-bot for Andy Lutomirski
2016-04-02 14:01 ` [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early Andy Lutomirski
2016-04-02 18:52 ` Borislav Petkov
2016-04-02 20:16 ` Andy Lutomirski
2016-04-02 20:52 ` Borislav Petkov
2016-04-03 8:07 ` Borislav Petkov
2016-04-03 13:22 ` Andy Lutomirski
2016-04-03 13:51 ` Linus Torvalds
2016-04-03 13:55 ` Andy Lutomirski
2016-04-03 14:10 ` Borislav Petkov
2016-04-04 15:47 ` Andy Lutomirski
2016-04-03 14:17 ` Linus Torvalds
2016-04-13 11:44 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2016-04-02 14:01 ` [PATCH v5 5/9] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks Andy Lutomirski
2016-04-03 8:41 ` Borislav Petkov
2016-04-03 13:23 ` Andy Lutomirski
2016-04-03 14:07 ` Borislav Petkov
2016-04-13 11:44 ` [tip:x86/asm] x86/paravirt: Add _safe to the read_ms()r and write_msr() PV callbacks tip-bot for Andy Lutomirski
2016-04-02 14:01 ` [PATCH v5 6/9] x86/msr: Carry on after a non-"safe" MSR access fails Andy Lutomirski
2016-04-13 11:45 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2016-04-02 14:01 ` [PATCH v5 7/9] x86/paravirt: Add paravirt_{read,write}_msr Andy Lutomirski
2016-04-04 16:33 ` [Xen-devel] [PATCH v5 7/9] x86/paravirt: Add paravirt_{read, write}_msr David Vrabel
2016-04-04 16:40 ` Andy Lutomirski
2016-04-13 11:45 ` [tip:x86/asm] x86/paravirt: Add paravirt_{read,write}_msr() tip-bot for Andy Lutomirski
2016-04-02 14:01 ` [PATCH v5 8/9] x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y Andy Lutomirski
2016-04-13 11:46 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2016-04-02 14:01 ` Andy Lutomirski [this message]
2016-04-13 11:46 ` [tip:x86/asm] x86/msr: Set the return value to zero when native_rdmsr_safe() fails tip-bot for Andy Lutomirski
2016-04-02 14:24 ` [PATCH v5 0/9] Improve non-"safe" MSR access failure handling Linus Torvalds
2016-04-02 15:13 ` Andy Lutomirski
2016-04-02 15:21 ` Linus Torvalds
2016-04-04 16:23 ` Borislav Petkov
2016-04-05 15:38 ` [Xen-devel] " Boris Ostrovsky
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