Commit-ID: 0d2b8579add41e08aa1110da864f1071d58e6048 Gitweb: http://git.kernel.org/tip/0d2b8579add41e08aa1110da864f1071d58e6048 Author: Josh Poimboeuf <jpoim...@redhat.com> AuthorDate: Wed, 26 Oct 2016 10:41:50 -0500 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 27 Oct 2016 08:32:38 +0200
x86/dumpstack: Warn on stack recursion Print a warning if stack recursion is detected. 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/def18247aafaab480844484398e793f552b79bda.1477496147.git.jpoim...@redhat.com [ Unbroke the lines. ] Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/dumpstack_32.c | 4 +++- arch/x86/kernel/dumpstack_64.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index 90cf460..d7d20999 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -109,8 +109,10 @@ recursion_check: * just break out and report an unknown stack type. */ if (visit_mask) { - if (*visit_mask & (1UL << info->type)) + if (*visit_mask & (1UL << info->type)) { + printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type); goto unknown; + } *visit_mask |= 1UL << info->type; } diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 310abf4..ab0f8b9 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -128,8 +128,10 @@ recursion_check: * just break out and report an unknown stack type. */ if (visit_mask) { - if (*visit_mask & (1UL << info->type)) + if (*visit_mask & (1UL << info->type)) { + printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type); goto unknown; + } *visit_mask |= 1UL << info->type; }
