This reverts commit b6959a362177 ("x86/unwind: Detect bad stack return
address").
Andrey Konovalov reported an unwinder warning:
WARNING: unrecognized kernel stack return address ffffffffa0000001 at
ffff88006377fa18 in a.out:4467
The unwind was initiated from an interrupt which occurred while running in the
generated code for a kprobe. The unwinder printed the warning because it
expected regs->ip to point to a valid text address, but instead it pointed to
the generated code.
Eventually we may want come up with a way to identify generated kprobe
code so the unwinder can know that it's a valid return address. Until
then, just remove the warning.
Reported-by: Andrey Konovalov <andreyk...@google.com>
Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
---
arch/x86/kernel/unwind_frame.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
index 20d4b4e..4443e49 100644
--- a/arch/x86/kernel/unwind_frame.c
+++ b/arch/x86/kernel/unwind_frame.c
@@ -51,16 +51,7 @@ unsigned long unwind_get_return_address(struct unwind_state
*state)
addr = ftrace_graph_ret_addr(state->task, &state->graph_idx, *addr_p,
addr_p);
- if (!__kernel_text_address(addr)) {
- printk_deferred_once(KERN_WARNING
- "WARNING: unrecognized kernel stack return address %p
at %p in %s:%d\n",
- (void *)addr, addr_p, state->task->comm,
- state->task->pid);
- unwind_dump(state, addr_p);
- return 0;
- }
-
- return addr;
+ return __kernel_text_address(addr) ? addr : 0;
}
EXPORT_SYMBOL_GPL(unwind_get_return_address);
--
2.7.4
