From b7b348c682fac04cade7b860c49d4a17f158dad4 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 17 Jun 2014 16:15:34 +1000 Subject: [PATCH] powerpc/ftrace: Fix inverted check of create_branch() In commit 24a1bdc35, "Fix ABIv2 issues with __ftrace_make_call", Anton changed the logic that creates and patches the branch, and added a thinko in the check of create_branch(). create_branch() returns the instruction that was generated, so if we get zero then it succeeded. The result is we can't ftrace modules: Branch out of range WARNING: at ../kernel/trace/ftrace.c:1638 ftrace failed to modify [] fuse_req_init_context+0x1c/0x90 [fuse] We should probably fix patch_instruction() to do that check and make the API saner, but that's a separate patch. For now just invert the test. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt --- 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 f5d1a3420192..8fc0c1742498 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -320,7 +320,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) } /* Ensure branch is within 24 bits */ - if (create_branch(ip, rec->arch.mod->arch.tramp, BRANCH_SET_LINK)) { + if (!create_branch(ip, rec->arch.mod->arch.tramp, BRANCH_SET_LINK)) { printk(KERN_ERR "Branch out of range"); return -EINVAL; }