On Fri, 2015-01-30 at 19:08 +0700, Arseny Solokha wrote: > MMU_NO_CONTEXT is conditionally defined as 0 or (unsigned int)-1.
For nohash it is specifically -1. > However, in __flush_tlb_page() a corresponding variable is only tested > for open coded 0, which can cause NULL pointer dereference if `mm' > argument was legitimately passed as such. > > Bail out early in case the first argument is NULL, thus eliminate confusion > between different values of MMU_NO_CONTEXT and avoid disabling and then > re-enabling preemption unnecessarily. How did you notice this? Did you see an oops, or was it code inspection? I'm wondering what codepath gets here with mm == NULL. -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
