Commit-ID: 467e6b7a7c0eb792ebaf322ddb7363742b4ead40 Gitweb: http://git.kernel.org/tip/467e6b7a7c0eb792ebaf322ddb7363742b4ead40 Author: Mitsuo Hayasaka <mitsuo.hayasaka.hu@xxxxxxxxxxx> AuthorDate: Tue, 29 Nov 2011 15:08:45 +0900 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Mon, 5 Dec 2011 11:37:48 +0100 x86: Clean up the range of stack overflow checking 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: yrl.pp-manager.tt@xxxxxxxxxxx Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20111129060845.11076.40916.stgit@xxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxx> 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 42552b0..54e2b2b 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-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html