From: Borislav Petkov <bp@xxxxxxx>
[ Upstream commit e100777016fdf6ec3a9d7c1773b15a2b5eca6c55 ]
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@xxxxxxx>
Link: https://lkml.kernel.org/r/20200915194020.28807-1-bp@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/x86/kernel/cpu/mce/core.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 14e4b4d17ee5b..d8dca24feccbe 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -371,16 +371,25 @@ static int msr_to_offset(u32 msr)
}
/* MSR access wrappers used for error injection */
-static u64 mce_rdmsrl(u32 msr)
+static noinstr u64 mce_rdmsrl(u32 msr)
{
u64 v;
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)
- return 0;
- return *(u64 *)((char *)this_cpu_ptr(&injectm) + offset);
+ ret = 0;
+ else
+ ret = *(u64 *)((char *)this_cpu_ptr(&injectm) + offset);
+
+ instrumentation_end();
+
+ return ret;
}
if (rdmsrl_safe(msr, &v)) {
@@ -396,13 +405,19 @@ static u64 mce_rdmsrl(u32 msr)
return v;
}
-static void mce_wrmsrl(u32 msr, u64 v)
+static noinstr void mce_wrmsrl(u32 msr, u64 v)
{
if (__this_cpu_read(injectm.finished)) {
- int offset = msr_to_offset(msr);
+ int offset;
+ instrumentation_begin();
+
+ offset = msr_to_offset(msr);
if (offset >= 0)
*(u64 *)((char *)this_cpu_ptr(&injectm) + offset) = v;
+
+ instrumentation_end();
+
return;
}
wrmsrl(msr, v);
--
2.25.1
