On Tue, 19 Jun 2012 22:35:08 +0000 "Pearson, Greg" <greg.pearson@xxxxxx> wrote: > On 06/19/2012 04:14 PM, Andrew Morton wrote: > > On Mon, 18 Jun 2012 17:47:58 -0600 > > Greg Pearson <greg.pearson@xxxxxx> wrote: > > > >> The __alloc_memory_core_early() routine will ask memblock for a range > >> of memory then try to reserve it. If the reserved region array lacks > >> space for the new range, memblock_double_array() is called to allocate > >> more space for the array. If memblock is used to allocate memory for > >> the new array it can end up using a range that overlaps with the range > >> originally allocated in __alloc_memory_core_early(), leading to possible > >> data corruption. > > OK, but we have no information about whether it *does* lead to data > > corruption. Are there workloads which trigger this? End users who are > > experiencing problems? > > > > See, I (and others) need to work out whether this patch should be > > included in 3.5 or even earlier kernels. To do that we often need the > > developer to tell us what the impact of the bug is upon users. Please > > always include this info when fixing bugs. > > Andrew, > > I'm currently working on a prototype system that exhibits the data > corruption problem when doubling the reserved array while booting the > system. This system will be a released product in the future. OK. I guess we can slip this fix into 3.5. Do you think it should be backported? I guess "yes", as you will probably want to run 3.4 or earlier kernels on that machine. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>