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authorJosh Poimboeuf <jpoimboe@redhat.com>2016-12-22 09:02:49 -0600
committerIngo Molnar <mingo@kernel.org>2016-12-23 20:32:30 +0100
commitc280f7736ab26a601932b1ce017a3840dbedcfdc (patch)
treeca07c17a22621acbfec0f03521ba9098de620629
parentcef4402d7627f14a08571e7c816b199edf8cc24b (diff)
downloadlinux-stericsson-c280f7736ab26a601932b1ce017a3840dbedcfdc.tar.gz
Revert "x86/unwind: Detect bad stack return address"
Revert the following commit: b6959a362177 ("x86/unwind: Detect bad stack return address") ... because 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 <andreyknvl@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/02f296848fbf49fb72dfeea706413ecbd9d4caf6.1482418739.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/kernel/unwind_frame.c11
1 files changed, 1 insertions, 10 deletions
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
index 20d4b4e0800c..4443e499f279 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);