On Wed, 7 May 2014, Cyrill Gorcunov wrote: > On Tue, May 06, 2014 at 05:30:19PM -0400, Vince Weaver wrote: > > On Wed, 7 May 2014, Cyrill Gorcunov wrote: > > > > > > [ 67.872274] BUG: unable to handle kernel NULL pointer dereference at > > > > 00000004 > > > > [ 67.876146] IP: [<ffffffff81013df2>] > > > > p4_pmu_schedule_events+0xa5/0x331 > > > > > > This looks like > > > > > > p4_pmu_schedule_events: > > > ... > > > bind = p4_config_get_bind(hwc->config); > > > returned bind = NULL; > > > escr_idx = p4_get_escr_idx(bind->escr_msr[thread]); NULL deref > > > > > > If i'm right (btw it's possible to use addr2line helper?) > > > > Yes, the address maps to > > > > escr_idx = p4_get_escr_idx(bind->escr_msr[thread]); > > Great, now we knows the reason of the issue, only to figure out > why is left ;) > > > > then hwc->config > > > is corrupted and p4_config_get_bind returned nil simply because proper > > > event > > > was not found. And I don't understand how it could happen because before > > > configuration gets written into hwc->config it's validated once obtained > > > from user-space as a raw event. Weird... > > > > I'll try to get some sort of trace out if it to see what event is being > > tried. > > Yeah, this would help a lot.
sorry for the delay, I like to compile kernels locally and it takes a really long time to build a ftrace-enabled kernel on a pentium 4 it seems. Anyway I threw some printks in, and this is what I get: [ 447.572626] VMW: bind=NULL config=6b6b6b6b6b6b6b6b I have slab poisoning turned on. Use after free? Vince -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
