Messages in this thread | | | From | David Mosberger <> | Date | Mon, 11 Aug 2003 11:43:08 -0700 | Subject | Re: [PATCH][2.6] WARN_ON_STACK_VAR aka fighting variable lifetime bugs |
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>>>>> On Sat, 9 Aug 2003 15:29:41 -0400 (EDT), Zwane Mwaikambo <zwane@arm.linux.org.uk> said:
Zwane> --- linux-2.6.0-test2-irq/include/asm-ia64/bug.h 30 Jul 2003 00:06:30 -0000 1.1.1.1 Zwane> +++ linux-2.6.0-test2-irq/include/asm-ia64/bug.h 9 Aug 2003 19:14:09 -0000 Zwane> +#define WARN_ON_STACK_VAR(ptr) do { \ Zwane> + unsigned long __ti = (unsigned long)current_thread_info(); \ Zwane> + WARN_ON((__ti & (unsigned long)(ptr)) == __ti); \ Zwane> +} while (0)
Note that on ia64 we don't use bit-masking to calculate the task-pointer. Instead, thread-info follows the task structure. This is done such that the task-structure, thread-info, and kernel stack can be mapped by a single (pinned) TLB entry.
The correct check for a variable being on the stack of the current task would be something like this:
((unsigned long)(ptr) - (unsigned long) current) < IA64_STK_OFFSET
(IA64_STK_OFFSET is declared by <asm/ptrace.h>).
Thanks,
--david - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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