From: Andi Kleen <ak@suse.de>
Date: Sat, 16 Apr 2005 22:25:00 +0000 (-0700)
Subject: [PATCH] x86_64: Dump stack and prevent recursion on early fault
X-Git-Tag: v2.6.12-rc3~167
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b957591fee753101f289615abab1c54ff7b1d29d;p=linux-2.6

[PATCH] x86_64: Dump stack and prevent recursion on early fault

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/arch/x86_64/kernel/head.S b/arch/x86_64/kernel/head.S
index b6d8725c1f..9bd2e7a4b8 100644
--- a/arch/x86_64/kernel/head.S
+++ b/arch/x86_64/kernel/head.S
@@ -200,14 +200,22 @@ init_rsp:
 	.quad  init_thread_union+THREAD_SIZE-8
 
 ENTRY(early_idt_handler)
+	cmpl $2,early_recursion_flag(%rip)
+	jz  1f
+	incl early_recursion_flag(%rip)
 	xorl %eax,%eax
 	movq 8(%rsp),%rsi	# get rip
 	movq (%rsp),%rdx
 	movq %cr2,%rcx
 	leaq early_idt_msg(%rip),%rdi
 	call early_printk
+	cmpl $2,early_recursion_flag(%rip)
+	jz  1f
+	call dump_stack
 1:	hlt
 	jmp 1b
+early_recursion_flag:
+	.long 0
 
 early_idt_msg:
 	.asciz "PANIC: early exception rip %lx error %lx cr2 %lx\n"