| Message ID | 1402985736-32180-2-git-send-email-mpe@ellerman.id.au (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | dfc382a19a2478768ef09d1c745b116e4fca9b4e |
| Headers | show |
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;
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 <dcb314@hotmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- arch/powerpc/kernel/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)