On Fri, Apr 8, 2016 at 4:31 AM, Avery Pennarun <apenwarr@xxxxxxxxx> wrote: > On Fri, Apr 8, 2016 at 3:15 AM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: >> On Fri, 2016-04-08 at 09:01 +0200, Johannes Berg wrote: >>> On Fri, 2016-04-08 at 08:56 +0200, Johannes Berg wrote: >>> > On Thu, 2016-04-07 at 21:32 -0400, Avery Pennarun wrote: >>> > > Yes. Here it is: >>> > > http://apenwarr.ca/tmp/mac80211-agg-status-crash.ko >>> > > >>> > Unfortunately there are no debug symbols in this file, so it >>> > doesn't >>> > help me much. I can't even seem to get objdump to disassemble it >>> > correctly: looks like the file is in thumb, going from things >>> > like R_ARM_THM_CALL relocations, but even -Mforce-thumb doesn't >>> > seem >>> > to DRT; sta_agg_status_read+0xeb isn't even a valid instruction >>> > offset in regular ARM mode. >>> > >>> It *seems* that it most likely crashes on the first access to tid_tx, >>> which is consistent with the story of disabling TX aggregation >>> timeouts >>> reducing the chances. >>> >>> So I guess we have to look for some TX aggregation teardown RCU >>> pointer problem? >> >> Can't find anything. The only other thing I saw now is that the TID >> appears to be 7 (in r7), might be worth looking for whether that's a >> common thing or not? > > Just to be clear, this crash is only from *reading* the agg_status > files. I don't know if the crashiness reduces when disabling the > aggregation timeouts, since that's a separate bug (in which the queue > gets stuck and the 'pending' column of this file just keeps > increasing). > > I'll try twiddling some options again tomorrow and see if I can get > one with proper debug symbols. For what it's worth, this platform is > "ARMv7 Processor rev 1 (v7l)" and the gcc build is made for Cortex A9. > You can find an x86 build of our toolchain in the git repo at > https://gfiber.googlesource.com/toolchains/mindspeed. Updated .ko file that definitely has debug symbols this time: http://apenwarr.ca/tmp/mac80211-agg-status-crash-debugsyms.ko a gdb compiled for x86-64 that can definitely read the above .ko file: http://apenwarr.ca/tmp/arm-gdb Thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
