[PATCH v3 08/10] x86/asm: add unwind hint annotations to sync_core()

From: Josh Poimboeuf
Date: Tue Jul 11 2017 - 11:34:27 EST


This enables objtool to grok the iret in the middle of a C function.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/include/asm/processor.h | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 6a79547..b27dc9b 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -22,6 +22,7 @@ struct vm86;
#include <asm/nops.h>
#include <asm/special_insns.h>
#include <asm/fpu/types.h>
+#include <asm/unwind_hints.h>

#include <linux/personality.h>
#include <linux/cache.h>
@@ -684,6 +685,7 @@ static inline void sync_core(void)
unsigned int tmp;

asm volatile (
+ UNWIND_HINT_SAVE
"mov %%ss, %0\n\t"
"pushq %q0\n\t"
"pushq %%rsp\n\t"
@@ -693,6 +695,7 @@ static inline void sync_core(void)
"pushq %q0\n\t"
"pushq $1f\n\t"
"iretq\n\t"
+ UNWIND_HINT_RESTORE
"1:"
: "=&r" (tmp), "+r" (__sp) : : "cc", "memory");
#endif
--
2.7.5