From: Paul Mackerras <[EMAIL PROTECTED]> Date: Sat, 12 Apr 2008 15:20:59 +1000
> There is a potential bug in __lmb_alloc_base where we subtract `size' > from the base address of a reserved region without checking whether > the subtraction could wrap around and produce a very large unsigned > value. In fact it probably isn't possible to hit the bug in practice > since it would only occur in the situation where we can't satisfy the > allocation request and there is a reserved region starting at 0. > > This fixes the potential bug by breaking out of the loop when we get > to the point where the base of the reserved region is less than the > size requested. This also restructures the loop to be a bit easier to > follow. > > The same logic got copied into lmb_alloc_nid_unreserved, so this makes > a similar change there. Here the bug is more likely to be hit because > the outer loop (in lmb_alloc_nid) goes through the memory regions in > increasing order rather than decreasing order as __lmb_alloc_base > does, and we are therefore more likely to hit the case where we are > testing against a reserved region with a base address of 0. > > Signed-off-by: Paul Mackerras <[EMAIL PROTECTED]> This looks great, thanks for doing this work Paul. I'll try to find some cycles to validate these changes alongside the pending sparc64 NUMA changes I have. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
