Messages in this thread | | | From | Puranjay Mohan <> | Date | Mon, 3 Jul 2023 11:36:53 +0200 | Subject | Re: next: Rpi4: Unexpected kernel BRK exception at EL1 |
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Hi Naresh,
On Mon, Jun 26, 2023 at 11:04 AM Puranjay Mohan <puranjay12@gmail.com> wrote: > > Hi Naresh, > > On Thu, Jun 22, 2023 at 2:35 PM Naresh Kamboju > <naresh.kamboju@linaro.org> wrote: > > > > Hi Mark, > > > > On Thu, 22 Jun 2023 at 15:12, Mark Rutland <mark.rutland@arm.com> wrote: > > > > > > On Wed, Jun 21, 2023 at 01:57:21PM +0100, Mark Rutland wrote: > > > > On Wed, Jun 21, 2023 at 06:06:51PM +0530, Naresh Kamboju wrote: > > > > > Following boot warnings and crashes noticed on arm64 Rpi4 device running > > > > > Linux next-20230621 kernel. > > > > > > > > > > Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> > > > > > > > > > > boot log: > > > > > > > > > > [ 22.331748] Kernel text patching generated an invalid instruction > > > > > at 0xffff8000835d6580! > > > > > [ 22.340579] Unexpected kernel BRK exception at EL1 > > > > > [ 22.346141] Internal error: BRK handler: 00000000f2000100 [#1] PREEMPT SMP > > > > > > > > This indicates execution of AARCH64_BREAK_FAULT. > > > > > > > > That could be from dodgy arguments to aarch64_insn_gen_*(), or elsewhere, and > > > > given this is in the networking code I suspect this'll be related to BPF. > > > > > > > > Looking at next-20230621 I see commit: > > > > > > > > 49703aa2adfaff28 ("bpf, arm64: use bpf_jit_binary_pack_alloc") > > > > > > > > ... which changed the way BPF allocates memory, and has code that pads memory > > > > with a bunch of AARCH64_BREAK_FAULT, so it looks like that *might* be related. > > > > > > For the benefit of those just looknig at this thread, there has been some > > > discussion in the original thread for this commit. Summary and links below. > > > > > > We identified a potential issue with missing cache maintenance: > > > > > > https://lore.kernel.org/linux-arm-kernel/ZJMXqTffB22LSOkd@FVFF77S0Q05N/ > > > > > > Puranjay verified that was causing the problem seen here: > > > > > > https://lore.kernel.org/linux-arm-kernel/CANk7y0h5ucxmMz4K8sGx7qogFyx6PRxYxmFtwTRO7=0Y=B4ugw@mail.gmail.com/ > > > > > > Alexei has dropped this commit for now: > > > > > > https://lore.kernel.org/linux-arm-kernel/CAADnVQJqDOMABEx8JuU6r_Dehyf=SkDfRNChx1oNfqPoo7pSrw@mail.gmail.com/ > > > > Thanks for the detailed information. > > I am happy to test any proposed fix patches. > > I have sent the v4 of the patch series: > https://lore.kernel.org/bpf/20230626085811.3192402-1-puranjay12@gmail.com/T/#t > This works on my raspberry pi 4 setup. If possible can you test this > on the similar setup where it was failing earlier?
I think my previous email was missed. Can you test the V4 series in the same setup? This is still not applied to the bpf-next tree.
Thanks, Puranjay.
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