[PATCH] i386 NMI on debug stack check correction

[Jan Beulich]

(Note: Patch also attached because the inline version is certain to get
line wrapped.)

Stack pointer comparisons for the NMI on debug stack check/fixup were
incorrect.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

--- linux-2.6.12-rc4.base/arch/i386/kernel/entry.S	2005-05-11 17:27:52.217255616 +0200
+++ linux-2.6.12-rc4/arch/i386/kernel/entry.S	2005-05-11 17:50:36.239892656 +0200
@@ -557,11 +557,10 @@ nmi_stack_fixup:
 nmi_debug_stack_check:
 	cmpw $__KERNEL_CS,16(%esp)
 	jne nmi_stack_correct
-	cmpl $debug - 1,(%esp)
-	jle nmi_stack_correct
+	cmpl $debug,(%esp)
+	jb nmi_stack_correct
 	cmpl $debug_esp_fix_insn,(%esp)
-	jle nmi_debug_stack_fixup
-nmi_debug_stack_fixup:
+	ja nmi_stack_correct
 	FIX_STACK(24,nmi_stack_correct, 1)
 	jmp nmi_stack_correct
 


(Note: Patch also attached because the inline version is certain to get
line wrapped.)

Stack pointer comparisons for the NMI on debug stack check/fixup were
incorrect.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

--- linux-2.6.12-rc4.base/arch/i386/kernel/entry.S	2005-05-11 17:27:52.217255616 +0200
+++ linux-2.6.12-rc4/arch/i386/kernel/entry.S	2005-05-11 17:50:36.239892656 +0200
@@ -557,11 +557,10 @@ nmi_stack_fixup:
 nmi_debug_stack_check:
 	cmpw $__KERNEL_CS,16(%esp)
 	jne nmi_stack_correct
-	cmpl $debug - 1,(%esp)
-	jle nmi_stack_correct
+	cmpl $debug,(%esp)
+	jb nmi_stack_correct
 	cmpl $debug_esp_fix_insn,(%esp)
-	jle nmi_debug_stack_fixup
-nmi_debug_stack_fixup:
+	ja nmi_stack_correct
 	FIX_STACK(24,nmi_stack_correct, 1)
 	jmp nmi_stack_correct