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authorSteven Rostedt <srostedt@redhat.com>2009-02-10 11:53:23 -0500
committerIngo Molnar <mingo@elte.hu>2009-02-11 10:06:13 +0100
commitf47a454db9129d2e61b224a40f4365cdd4f83042 (patch)
tree106e1d50cd407aef60be58711c9ef90a3b4c28db
parent7d6d49b1f5551b87bd59c66c10747b89367760fd (diff)
downloadop-kernel-dev-f47a454db9129d2e61b224a40f4365cdd4f83042.zip
op-kernel-dev-f47a454db9129d2e61b224a40f4365cdd4f83042.tar.gz
tracing, x86: fix constraint for parent variable
The constraint used for retrieving and restoring the parent function pointer is incorrect. The parent variable is a pointer, and the address of the pointer is modified by the asm statement and not the pointer itself. It is incorrect to pass it in as an output constraint since the asm will never update the pointer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/ftrace.c9
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 9d549e4..231bdd3 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -488,8 +488,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
* ignore such a protection.
*/
asm volatile(
- "1: " _ASM_MOV " (%[parent_old]), %[old]\n"
- "2: " _ASM_MOV " %[return_hooker], (%[parent_replaced])\n"
+ "1: " _ASM_MOV " (%[parent]), %[old]\n"
+ "2: " _ASM_MOV " %[return_hooker], (%[parent])\n"
" movl $0, %[faulted]\n"
"3:\n"
@@ -501,9 +501,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
_ASM_EXTABLE(1b, 4b)
_ASM_EXTABLE(2b, 4b)
- : [parent_replaced] "=r" (parent), [old] "=r" (old),
- [faulted] "=r" (faulted)
- : [parent_old] "0" (parent), [return_hooker] "r" (return_hooker)
+ : [old] "=r" (old), [faulted] "=r" (faulted)
+ : [parent] "r" (parent), [return_hooker] "r" (return_hooker)
: "memory"
);
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