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x86/mce: Annotate mce_rd/wrmsrl() with noinstr

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They do get called from the #MC handler which is already marked
"noinstr".

Commit

  e2def7d49d08 ("x86/mce: Make mce_rdmsrl() panic on an inaccessible MSR")

already got rid of the instrumentation in the MSR accessors, fix the
annotation now too, in order to get rid of:

  vmlinux.o: warning: objtool: do_machine_check()+0x4a: call to mce_rdmsrl() leaves .noinstr.text section

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200915194020.28807-1-bp@alien8.de
This commit is contained in:
Borislav Petkov 2020-09-14 19:21:28 +02:00
parent dc0592b737
commit e100777016
1 changed files with 21 additions and 6 deletions
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27
arch/x86/kernel/cpu/mce/core.c
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@ -392,16 +392,25 @@ __visible bool ex_handler_rdmsr_fault(const struct exception_table_entry *fixup,
} }
/* MSR access wrappers used for error injection */ /* MSR access wrappers used for error injection */
static u64 mce_rdmsrl(u32 msr) static noinstr u64 mce_rdmsrl(u32 msr)
{ {
DECLARE_ARGS(val, low, high); DECLARE_ARGS(val, low, high);
if (__this_cpu_read(injectm.finished)) { if (__this_cpu_read(injectm.finished)) {
int offset = msr_to_offset(msr); int offset;
u64 ret;
instrumentation_begin();
offset = msr_to_offset(msr);
if (offset < 0) if (offset < 0)
return 0; ret = 0;
return *(u64 *)((char *)this_cpu_ptr(&injectm) + offset); else
ret = *(u64 *)((char *)this_cpu_ptr(&injectm) + offset);
instrumentation_end();
return ret;
} }
/* /*
@ -437,15 +446,21 @@ __visible bool ex_handler_wrmsr_fault(const struct exception_table_entry *fixup,
return true; return true;
} }
static void mce_wrmsrl(u32 msr, u64 v) static noinstr void mce_wrmsrl(u32 msr, u64 v)
{ {
u32 low, high; u32 low, high;
if (__this_cpu_read(injectm.finished)) { if (__this_cpu_read(injectm.finished)) {
int offset = msr_to_offset(msr); int offset;
instrumentation_begin();
offset = msr_to_offset(msr);
if (offset >= 0) if (offset >= 0)
*(u64 *)((char *)this_cpu_ptr(&injectm) + offset) = v; *(u64 *)((char *)this_cpu_ptr(&injectm) + offset) = v;
instrumentation_end();
return; return;
} }