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Subject[PATCH 03/16] x86/microcode: Convert to bare minimum MSR accessors
Date
From: Borislav Petkov <bp@suse.de>

Having tracepoints to the MSR accessors makes them unsuitable for early
microcode loading: think 32-bit before paging is enabled and us chasing
pointers to test whether a tracepoint is enabled or not. Results in a
reliable triple fault.

Convert to the bare ones.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/include/asm/microcode.h | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h
index 38711df3bcb5..90b22bbdfce9 100644
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -7,18 +7,17 @@

#define native_rdmsr(msr, val1, val2) \
do { \
- u64 __val = native_read_msr((msr)); \
+ u64 __val = __rdmsr((msr)); \
(void)((val1) = (u32)__val); \
(void)((val2) = (u32)(__val >> 32)); \
} while (0)

#define native_wrmsr(msr, low, high) \
- native_write_msr(msr, low, high)
+ __wrmsr(msr, low, high)

#define native_wrmsrl(msr, val) \
- native_write_msr((msr), \
- (u32)((u64)(val)), \
- (u32)((u64)(val) >> 32))
+ __wrmsr((msr), (u32)((u64)(val)), \
+ (u32)((u64)(val) >> 32))

struct ucode_patch {
struct list_head plist;
--
2.11.0
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