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yaml --- r: 310397 b: refs/heads/master c: f898817 h: refs/heads/master i: 310395: 17c367b v: v3
git-mirror · Jun 1, 2012 · f1de949 · f1de949
1 parent 2b641c9
commit f1de949
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c0525a6972d3f1fb83058ef503e183475d6e4e26
+refs/heads/master: f8988175fd70874d1fb3712b1c5d3bfc6d455202
diff --git a/trunk/arch/x86/kernel/cpu/common.c b/trunk/arch/x86/kernel/cpu/common.c
@@ -1101,14 +1101,20 @@ int is_debug_stack(unsigned long addr)
 		 addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ));
 }
 
+static DEFINE_PER_CPU(u32, debug_stack_use_ctr);
+
 void debug_stack_set_zero(void)
 {
+	this_cpu_inc(debug_stack_use_ctr);
 	load_idt((const struct desc_ptr *)&nmi_idt_descr);
 }
 
 void debug_stack_reset(void)
 {
-	load_idt((const struct desc_ptr *)&idt_descr);
+	if (WARN_ON(!this_cpu_read(debug_stack_use_ctr)))
+		return;
+	if (this_cpu_dec_return(debug_stack_use_ctr) == 0)
+		load_idt((const struct desc_ptr *)&idt_descr);
 }
 
 #else	/* CONFIG_X86_64 */