Arnd Bergmann wrote: > On Monday 26 November 2007, Jan Kratochvil wrote: >> Hi, >> >> this testcase: >> http://people.redhat.com/jkratoch/dabr-lost.c >> >> reproduces a PPC DABR kernel bug. The variable `variable' should not get >> modified as the thread modifying it should be caught by its DABR: >> >> $ ./dabr-lost >> TID 30914: DABR 0x10012a77 NIP 0x80f6ebb318 >> TID 30915: DABR 0x10012a77 NIP 0x80f6ebb318 >> TID 30916: DABR 0x10012a77 NIP 0x80f6ebb318 >> TID 30914: hitting the variable >> TID 30915: hitting the variable >> TID 30916: hitting the variable >> variable found = 30916, caught TID = 30914 >> TID 30916: DABR 0x10012a77 >> Variable got modified by a thread which has DABR still set! >> > > This sounds like a bug recently reported by Uli Weigand. BenH > said he'd take a look, but it probably fell under the table. > The problem found by Uli is that on certain processors (Cell/B.E. > in his case), the DABRX register needs to be set in order for > the DABR to take effect.
Just as a note, the PS3's lv1_set_dabr(), which we used for ppc_md.set_dabr sets up both the DABRX and DABR registers. -Geoff _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
