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-rw-r--r--arch/x86/kernel/cpu/common.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 82f29e7..6b9333b 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/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 */