[ 20/73] powerpc/ftrace: Fix assembly trampoline register usage

From: Ben Hutchings
Date: Tue Jul 31 2012 - 00:51:47 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: roger blofeld <blofeldus@xxxxxxxxx>

commit fd5a42980e1cf327b7240adf5e7b51ea41c23437 upstream.

Just like the module loader, ftrace needs to be updated to use r12
instead of r11 with newer gcc's.

Signed-off-by: Roger Blofeld <blofeldus@xxxxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/ftrace.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 6f33296..91b46b7 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -240,9 +240,9 @@ __ftrace_make_nop(struct module *mod,

/*
* On PPC32 the trampoline looks like:
- * 0x3d, 0x60, 0x00, 0x00 lis r11,sym@ha
- * 0x39, 0x6b, 0x00, 0x00 addi r11,r11,sym@l
- * 0x7d, 0x69, 0x03, 0xa6 mtctr r11
+ * 0x3d, 0x80, 0x00, 0x00 lis r12,sym@ha
+ * 0x39, 0x8c, 0x00, 0x00 addi r12,r12,sym@l
+ * 0x7d, 0x89, 0x03, 0xa6 mtctr r12
* 0x4e, 0x80, 0x04, 0x20 bctr
*/

@@ -257,9 +257,9 @@ __ftrace_make_nop(struct module *mod,
pr_devel(" %08x %08x ", jmp[0], jmp[1]);

/* verify that this is what we expect it to be */
- if (((jmp[0] & 0xffff0000) != 0x3d600000) ||
- ((jmp[1] & 0xffff0000) != 0x396b0000) ||
- (jmp[2] != 0x7d6903a6) ||
+ if (((jmp[0] & 0xffff0000) != 0x3d800000) ||
+ ((jmp[1] & 0xffff0000) != 0x398c0000) ||
+ (jmp[2] != 0x7d8903a6) ||
(jmp[3] != 0x4e800420)) {
printk(KERN_ERR "Not a trampoline\n");
return -EINVAL;


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