On Sat, Aug 04, 2018 at 08:05:24AM -0500, Kyle Evans wrote: > On Sat, Aug 4, 2018 at 3:37 AM, Konstantin Belousov <kostikbel_at_gmail.com> wrote: > > On Fri, Aug 03, 2018 at 11:27:02PM -0500, Kyle Evans wrote: > >> > >> This seems odd- pmap lock is acquired at [1], then asserted shortly > >> later at [2]... I avoid some of this stuff as well as I can, but is it > >> actually possible for PCPU_GET(...) acquired curpmap to not match > >> curthread->td_proc->p_vmspace->vm_pmap in this context? > >> > >> [1] https://svnweb.freebsd.org/base/head/sys/dev/efidev/efirt.c?view=markup#l260 > >> [2] https://svnweb.freebsd.org/base/head/sys/amd64/amd64/efirt_machdep.c?view=markup#l254 > > There could be that curpcpu not yet synced with proc0 pmap. It could be > > fixed. > > > > But it is not clear to me why efi_arch_enter() is called there. I see > > the check for GetTime belonging to the range described by a map descriptor. > > I do not see why do you need an enter into the EFI context for comparing > > integers. > > This probably could have been documented better, but efi_runtime > pointer may (always?) point into runtime service memory that isn't > valid/available at that point, so we get a fault and panic when > dereferencing it to grab rt_gettime address. We ran into this wall > when adding the check originally. Wouldn't it be enough to access it by translating physical address into DMAP ?Received on Sat Aug 04 2018 - 11:14:03 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:41:17 UTC