[PATCH 15/16] x86/irq/64: In the stack overflow warning, print the offending IP

From: Andy Lutomirski <luto@kernel.org>
To: X86 ML <x86@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Brian Gerst <brgerst@gmail.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Andy Lutomirski <luto@kernel.org>
Subject: [PATCH 15/16] x86/irq/64: In the stack overflow warning, print the offending IP
Date: Mon, 20 Nov 2017 09:07:46 -0800	[thread overview]
Message-ID: <0805aec810b8eb17f03b0ba63e4b916c8a0aba27.1511195781.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1511195781.git.luto@kernel.org>
In-Reply-To: <cover.1511195781.git.luto@kernel.org>

In case something goes wrong with unwind (not unlikely in case of
overflow), print the offending IP where we detected the overflow.
---
 arch/x86/kernel/irq_64.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 020efbf5786b..d86e344f5b3d 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -57,10 +57,10 @@ static inline void stack_overflow_check(struct pt_regs *regs)
 	if (regs->sp >= estack_top && regs->sp <= estack_bottom)
 		return;
 
-	WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx)\n",
+	WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx,ip:%pF)\n",
 		current->comm, curbase, regs->sp,
 		irq_stack_top, irq_stack_bottom,
-		estack_top, estack_bottom);
+		estack_top, estack_bottom, (void *)regs->ip);
 
 	if (sysctl_panic_on_stackoverflow)
 		panic("low stack detected by irq handler - check messages\n");
-- 
2.13.6
