From 3085a0d0bdeea45178be79c1f39a6c7b98c709ca Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 12 Apr 2012 12:49:17 -0700 Subject: [PATCH] panic: fix stack dump print on direct call to panic() Commit d6dca568f16f ("panic: don't print redundant backtraces on oops") causes a regression where no stack trace will be printed at all for the case where kernel code calls panic() directly while not processing an oops, and of course there are 100's of instances of this type of call. The original commit executed the check (!oops_in_progress), but this will always be false because just before the dump_stack() there is a call to bust_spinlocks(1), which does the following: void __attribute__((weak)) bust_spinlocks(int yes) { if (yes) { ++oops_in_progress; The proper way to resolve the problem that original commit tried to solve is to avoid printing a stack dump from panic() when the either of the following conditions is true: 1) TAINT_DIE has been set (this is done by oops_end()) This indicates and oops has already been printed. 2) oops_in_progress > 1 This guards against the rare case where panic() is invoked a second time, or in between oops_begin() and oops_end() Signed-off-by: Jason Wessel Cc: Andi Kleen Cc: [3.3+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/panic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/panic.c b/kernel/panic.c index 80aed44e345ab..8ed89a175d793 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -97,7 +97,7 @@ void panic(const char *fmt, ...) /* * Avoid nested stack-dumping if a panic occurs during oops processing */ - if (!oops_in_progress) + if (!test_taint(TAINT_DIE) && oops_in_progress <= 1) dump_stack(); #endif -- 2.39.5