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 <m...@ellerman.id.au>
---
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 8fc0c17..96efc66 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;
}
--
1.9.1
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
