Re: [PATCH v3 x86 1/2] fix page faults by nmiaction in nmi if kmemcheck is enabled

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

On Tue, Mar 06, 2012 at 06:09:43PM +0800, Li Zhong wrote:
> This patch tries to fix the problem of page fault exception caused by
> accessing nmiaction structure in nmi if kmemcheck is enabled. 
> If kmemcheck is enabled, the memory allocated through slab are in pages
> that are marked non-present, so that some checks could be done in the
> page fault handling code ( e.g. whether the memory is read before
> written to ). 
> As nmiaction is allocated in this way, so it resides in a non-present
> page. Then there is a page fault while the nmi code accessing the
> nmiaction structure, which would then cause a warning by
> WARN_ON_ONCE(in_nmi()) in kmemcheck_fault(), called by do_page_fault().
> v2: as Peter suggested, changed the nmiaction to use static storage.
> v3: as Peter suggested, use macro to shorten the codes. Also keep the
> original usage of register_nmi_handler, so users of this call doesn't
> need change. 

Thanks Li!  Looks fine to me.  I'll run some tests to make sure things
still work correctly.

To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at

[Site Home]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Tools]     [DDR & Rambus]     [Asterisk Internet PBX]     [Linux API]     [Monitors]

Add to Google