[PATCH 2/3] x86: add safe_smp_processor_id for x86_64

Vivek Goyal vgoyal at in.ibm.com
Wed Oct 24 02:31:41 EDT 2007


On Fri, Oct 19, 2007 at 06:23:02PM -0700, Hiroshi Shimamoto wrote:
> From: Hiroshi Shimamoto <h-shimamoto at ct.jp.nec.com>
> 
> Signed-off-by: Hiroshi Shimamoto <h-shimamoto at ct.jp.nec.com>
> ---
>  include/asm-x86/smp_64.h |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/include/asm-x86/smp_64.h b/include/asm-x86/smp_64.h
> index 6f0e027..ab612b0 100644
> --- a/include/asm-x86/smp_64.h
> +++ b/include/asm-x86/smp_64.h
> @@ -76,6 +76,8 @@ extern unsigned __cpuinitdata disabled_cpus;
> 
>  #endif /* CONFIG_SMP */
> 
> +#define safe_smp_processor_id()		smp_processor_id()
> +

Can you please implement a patch for safe_smp_processor_id() instead of
using smp_processor_id(). safe_smp_processor_id() was introduced to make
sure that we are not dependent on the stack of threads after kernel has
crashed instead read the apic id and convert it to cpu id with other
data structures. This helped in stack overflow case.

Hardcoding it to smp_processor_id() will give the false impression.

Thanks
Vivek



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