On Wed, Aug 16, 2017 at 5:57 AM, Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 16 Aug, at 12:03:22PM, Mark Rutland wrote: >> >> I'd expect we'd abort at a higher level, not taking any sample. i.e. >> we'd have the core overflow handler check in_funny_mm(), and if so, skip >> the sample, as with the skid case. > > FYI, this is my preferred solution for x86 too. One option for the "funny mm" flag would be literally the condition current->mm != current->active_mm. I *think* this gets all the cases right as long as efi_switch_mm is careful with its ordering and that the arch switch_mm() code can handle the resulting ordering. (x86's can now, I think, or at least will be able to in 4.14 -- not sure about other arches). That being said, there's a totally different solution: run EFI callbacks in a kernel thread. This has other benefits: we could run those callbacks in user mode some day, and doing *that* in a user thread seems like a mistake. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
