On Wed, Apr 27, 2016 at 02:52:56PM -0400, David Long wrote:
> From: "David A. Long" <dave.l...@linaro.org>
> +/**
> + * regs_within_kernel_stack() - check the address in the stack
> + * @regs: pt_regs which contains kernel stack pointer.
> + * @addr: address which is checked.
> + *
> + * regs_within_kernel_stack() checks @addr is within the kernel stack
> page(s).
> + * If @addr is within the kernel stack, it returns true. If not, returns
> false.
> + */
> +bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
> +{
> + return ((addr & ~(THREAD_SIZE - 1)) ==
> + (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) ||
> + on_irq_stack(addr, raw_smp_processor_id());
> +}
> +
> +/**
> + * regs_get_kernel_stack_nth() - get Nth entry of the stack
> + * @regs: pt_regs which contains kernel stack pointer.
> + * @n: stack entry number.
> + *
> + * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
> + * is specified by @regs. If the @n th entry is NOT in the kernel stack,
> + * this returns 0.
> + */
> +unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
> +{
> + unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
> +
> + addr += n;
> + if (regs_within_kernel_stack(regs, (unsigned long)addr))
If the @addr fall in the interrupt stack, the regs_within_kernel_stack()
will return true. But Is it what we want?
thanks
Huang Shijie
