On Mon, May 16, 2016 at 11:24:53PM +0900, Namhyung Kim wrote:
> > -GLOBAL(ftrace_stub)
> > +/* This is weak to keep gas from relaxing the jumps */
> > +WEAK(ftrace_stub)
> > retq
> > END(ftrace_caller)
You could also force the 5-byte jump. I guess you could also write
simply ".long 0" in there but this way it is more robust if someone
decides to add other stuff between the JMP and the ftrace_stub label.
---
diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
index ed48a9f465f8..b1db8a584c06 100644
--- a/arch/x86/kernel/mcount_64.S
+++ b/arch/x86/kernel/mcount_64.S
@@ -179,7 +179,9 @@ GLOBAL(ftrace_epilogue)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
GLOBAL(ftrace_graph_call)
- jmp ftrace_stub
+ .byte 0xe9
+ .long ftrace_stub - 1f
+1:
#endif
GLOBAL(ftrace_stub)
--
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284
(AG Nürnberg)
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