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authorPeter Zijlstra <peterz@infradead.org>2021-11-10 11:01:10 +0100
committerPeter Zijlstra <peterz@infradead.org>2021-12-11 09:09:47 +0100
commitd52a7344bdfa9c3442d3f86fb3501d9343726c76 (patch)
tree3d077f4a2f9e9bba140ce7139810f233993f3fc3 /arch/x86/include
parentx86/extable: Extend extable functionality (diff)
downloadlinux-d52a7344bdfa9c3442d3f86fb3501d9343726c76.tar.xz
linux-d52a7344bdfa9c3442d3f86fb3501d9343726c76.zip
x86/msr: Remove .fixup usage
Rework the MSR accessors to remove .fixup usage. Add two new extable types (to the 4 already existing msr ones) using the new register infrastructure to record which register should get the error value. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20211110101325.364084212@infradead.org
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/extable_fixup_types.h23
-rw-r--r--arch/x86/include/asm/msr.h26
2 files changed, 19 insertions, 30 deletions
diff --git a/arch/x86/include/asm/extable_fixup_types.h b/arch/x86/include/asm/extable_fixup_types.h
index 944f8329022a..9d597fe1017d 100644
--- a/arch/x86/include/asm/extable_fixup_types.h
+++ b/arch/x86/include/asm/extable_fixup_types.h
@@ -32,17 +32,16 @@
#define EX_TYPE_COPY 4
#define EX_TYPE_CLEAR_FS 5
#define EX_TYPE_FPU_RESTORE 6
-#define EX_TYPE_WRMSR 7
-#define EX_TYPE_RDMSR 8
-#define EX_TYPE_BPF 9
-
-#define EX_TYPE_WRMSR_IN_MCE 10
-#define EX_TYPE_RDMSR_IN_MCE 11
-
-#define EX_TYPE_DEFAULT_MCE_SAFE 12
-#define EX_TYPE_FAULT_MCE_SAFE 13
-
-#define EX_TYPE_POP_ZERO 14
-#define EX_TYPE_IMM_REG 15 /* reg := (long)imm */
+#define EX_TYPE_BPF 7
+#define EX_TYPE_WRMSR 8
+#define EX_TYPE_RDMSR 9
+#define EX_TYPE_WRMSR_SAFE 10 /* reg := -EIO */
+#define EX_TYPE_RDMSR_SAFE 11 /* reg := -EIO */
+#define EX_TYPE_WRMSR_IN_MCE 12
+#define EX_TYPE_RDMSR_IN_MCE 13
+#define EX_TYPE_DEFAULT_MCE_SAFE 14
+#define EX_TYPE_FAULT_MCE_SAFE 15
+#define EX_TYPE_POP_ZERO 16
+#define EX_TYPE_IMM_REG 17 /* reg := (long)imm */
#endif
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 6b52182e178a..d42e6c6b47b1 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -137,17 +137,11 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr,
{
DECLARE_ARGS(val, low, high);
- asm volatile("2: rdmsr ; xor %[err],%[err]\n"
- "1:\n\t"
- ".section .fixup,\"ax\"\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)
+ asm volatile("1: rdmsr ; xor %[err],%[err]\n"
+ "2:\n\t"
+ _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_RDMSR_SAFE, %[err])
: [err] "=r" (*err), EAX_EDX_RET(val, low, high)
- : "c" (msr), [fault] "i" (-EIO));
+ : "c" (msr));
if (tracepoint_enabled(read_msr))
do_trace_read_msr(msr, EAX_EDX_VAL(val, low, high), *err);
return EAX_EDX_VAL(val, low, high);
@@ -169,15 +163,11 @@ native_write_msr_safe(unsigned int msr, u32 low, u32 high)
{
int err;
- asm volatile("2: wrmsr ; xor %[err],%[err]\n"
- "1:\n\t"
- ".section .fixup,\"ax\"\n\t"
- "3: mov %[fault],%[err] ; jmp 1b\n\t"
- ".previous\n\t"
- _ASM_EXTABLE(2b, 3b)
+ asm volatile("1: wrmsr ; xor %[err],%[err]\n"
+ "2:\n\t"
+ _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_WRMSR_SAFE, %[err])
: [err] "=a" (err)
- : "c" (msr), "0" (low), "d" (high),
- [fault] "i" (-EIO)
+ : "c" (msr), "0" (low), "d" (high)
: "memory");
if (tracepoint_enabled(write_msr))
do_trace_write_msr(msr, ((u64)high << 32 | low), err);