In commit 24a1bdc35, "Fix ABIv2 issues with __ftrace_make_call", Anton
changed the logic that checks for the expected code sequence when
patching a module.
We missed the typo in the mask, 0xffff00000 should be 0xffff0000, which
has the effect of making the test always true.
That makes it impossible to ftrace against modules, eg:
Unexpected call sequence: 48000008 e8410018
WARNING: at ../kernel/trace/ftrace.c:1638
ftrace failed to modify [<d000000007cf001c>] rng_dev_open+0x1c/0x70 [rng_core]
Reported-by: David Binderman <dcb...@hotmail.com>
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
---
arch/powerpc/kernel/ftrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index f202d07..f5d1a34 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -307,7 +307,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long
addr)
* The load offset is different depending on the ABI. For simplicity
* just mask it out when doing the compare.
*/
- if ((op[0] != 0x48000008) || ((op[1] & 0xffff00000) != 0xe8410000)) {
+ if ((op[0] != 0x48000008) || ((op[1] & 0xffff0000) != 0xe8410000)) {
printk(KERN_ERR "Unexpected call sequence: %x %x\n",
op[0], op[1]);
return -EINVAL;
--
1.9.1
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
