tracing, x86: function return tracer, fix assembly constraints

fix:

 arch/x86/kernel/ftrace.c: Assembler messages:
 arch/x86/kernel/ftrace.c:140: Error: missing ')'
 arch/x86/kernel/ftrace.c:140: Error: junk `(%ebp))' after expression
 arch/x86/kernel/ftrace.c:141: Error: missing ')'
 arch/x86/kernel/ftrace.c:141: Error: junk `(%ebp))' after expression

the [parent_replaced] is used in an =rm fashion, so that constraint
is correct in isolation - but [parent_old] aliases register %0 and uses
it in an addressing mode that is only valid with registers - so change
the constraint from =rm to =r.

This fixes the build failure.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index d68033b..9b2325a 100644 (file)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -151,7 +151,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
                "   .long 2b, 3b\n"
                ".previous\n"
 
-               : [parent_replaced] "=rm" (parent), [old] "=r" (old),
+               : [parent_replaced] "=r" (parent), [old] "=r" (old),
                  [faulted] "=r" (faulted)
                : [parent_old] "0" (parent), [return_hooker] "r" (return_hooker)
                : "memory"