From d84e0d69c26b4d739214974d6ad6baf23f510580 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 17 Jun 2014 16:15:35 +1000 Subject: [PATCH] powerpc/ftrace: Fix nop of modules on 64bit LE (ABIv2) There is a bug in the handling of the function entry when we are nopping out a branch from a module in ftrace. We compare the result of module_trampoline_target() with the value of ppc_function_entry(), and expect them to be true. But they never will be. module_trampoline_target() will always return the global entry point of the function, whereas ppc_function_entry() will always return the local. Fix it by using the newly added ppc_global_function_entry(). Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/ftrace.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 8fc0c1742498..96efc664b49d 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -105,7 +105,7 @@ __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { unsigned int op; - unsigned long ptr; + unsigned long entry, ptr; unsigned long ip = rec->ip; void *tramp; @@ -136,10 +136,11 @@ __ftrace_make_nop(struct module *mod, pr_devel("trampoline target %lx", ptr); + entry = ppc_global_function_entry((void *)addr); /* This should match what was called */ - if (ptr != ppc_function_entry((void *)addr)) { + if (ptr != entry) { printk(KERN_ERR "addr %lx does not match expected %lx\n", - ptr, ppc_function_entry((void *)addr)); + ptr, entry); return -EINVAL; } -- 2.20.1