Commit-ID: b6959a362177053c1c90db6dc1af25b6bddd8548 Gitweb: http://git.kernel.org/tip/b6959a362177053c1c90db6dc1af25b6bddd8548 Author: Josh Poimboeuf <jpoim...@redhat.com> AuthorDate: Wed, 26 Oct 2016 10:41:51 -0500 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 27 Oct 2016 08:32:38 +0200
x86/unwind: Detect bad stack return address If __kernel_text_address() doesn't recognize a return address on the stack, it probably means that it's some generated code which __kernel_text_address() doesn't know about yet. Otherwise there's probably some stack corruption. Either way, warn about it. Use printk_deferred_once() because the unwinder can be called with the console lock by lockdep via save_stack_trace(). Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/2d897898f324e275943b590d160b55e482bba65f.1477496147.git.jpoim...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/unwind_frame.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index 9be9a8f..5639db6 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -20,7 +20,15 @@ unsigned long unwind_get_return_address(struct unwind_state *state) addr = ftrace_graph_ret_addr(state->task, &state->graph_idx, *addr_p, addr_p); - return __kernel_text_address(addr) ? addr : 0; + 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); + return 0; + } + + return addr; } EXPORT_SYMBOL_GPL(unwind_get_return_address);
