The overflow checking of kernel stack checks if the stack pointer points to the available kernel stack range, which is derived from the original overflow checking. It is clear that curbase address is always less than low boundary of available kernel stack. So, this patch removes the first condition that checks if the pointer is higher than curbase. Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> --- arch/x86/kernel/irq_64.c | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 5448bf6..c8c9a78 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -46,10 +46,9 @@ static inline void stack_overflow_check(struct pt_regs *regs) if (user_mode_vm(regs)) return; - if (regs->sp >= curbase && - regs->sp <= curbase + THREAD_SIZE && - regs->sp >= curbase + sizeof(struct thread_info) + - sizeof(struct pt_regs) + 128) + if (regs->sp >= curbase + sizeof(struct thread_info) + + sizeof(struct pt_regs) + 128 && + regs->sp <= curbase + THREAD_SIZE) return; irq_stack_top = (u64)__get_cpu_var(irq_stack_union.irq_stack); -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
