Messages in this thread | | | From | Naresh Kamboju <> | Date | Fri, 24 Nov 2023 14:24:35 +0530 | Subject | Re: selftests: ftrace: WARNING: __list_del_entry_valid_or_report (lib/list_debug.c:62 (discriminator 1)) |
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Hi Mark,
On Thu, 23 Nov 2023 at 23:20, Mark Rutland <mark.rutland@arm.com> wrote: > > On Wed, Nov 22, 2023 at 10:12:51AM -0500, Steven Rostedt wrote: > > On Wed, 22 Nov 2023 19:49:43 +0530 > > Naresh Kamboju <naresh.kamboju@linaro.org> wrote: > > > > > Hi Steven, > > > > > > > > > > > > On Tue, 21 Nov 2023 at 02:06, Steven Rostedt <rostedt@goodmis.org> wrote: > > > > > > > > On Thu, 16 Nov 2023 18:00:16 +0530 > > > > Naresh Kamboju <naresh.kamboju@linaro.org> wrote: > > > [ 282.726999] Unexpected kernel BRK exception at EL1 > > > > What's a "BRK exception"? > > That's triggered by a BRK instruction (software breakpoint), we use it like UD2 > on x86. > > > > [ 282.731840] Internal error: BRK handler: 00000000f20003e8 [#1] PREEMPT SMP > > That lump of hex here means "this was triggered by a BRK #1000" instruction. > > That immediate (0x3e8 / 1000) is what GCC/Clang use for __builtin_trap(), which > is generated for a bunch of reasons, usually a sanitizer like UBSAN, or options > to trap on runtime issues.
The reported "Internal error: BRK handler:'' has been noticed several times on arm64 Juno-r2, Raspberry-pi-4 and qemu-arm64 in the past but the occurrence is very rare (1%) and hard to reproduce.
The old report links [1] [2] [3].
As you suspected, the following configs are enabled on this build.
CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL=y CONFIG_UBSAN=y CONFIG_UBSAN_TRAP=y CONFIG_CC_HAS_UBSAN_BOUNDS_STRICT=y CONFIG_UBSAN_BOUNDS=y CONFIG_UBSAN_BOUNDS_STRICT=y CONFIG_UBSAN_SHIFT=y # CONFIG_UBSAN_DIV_ZERO is not set # CONFIG_UBSAN_UNREACHABLE is not set CONFIG_UBSAN_BOOL=y CONFIG_UBSAN_ENUM=y CONFIG_UBSAN_SANITIZE_ALL=y # CONFIG_TEST_UBSAN is not set
> > Naresh, where can I find the config used for this run? I can try to reproduce > this and investigate.
The build artifacts are located in this link [4] and attached. - https://storage.tuxsuite.com/public/linaro/naresh/builds/2YTWTd3fPQdanNEe0Oz59XoRfa1/
May be useful links for the previous reports on this warning / internal error:
Following boot warnings and crashes noticed on arm64 Rpi4 device running Linux next-20230621 kernel. [1] - https://lore.kernel.org/all/CA+G9fYuifLivwhCh33kedtpU=6zUpTQ_uSkESyzdRKYp8WbTFQ@mail.gmail.com/
While running selftest clone3 test cases on qemu-arm64 the following kernel crash reported on Linux mainline kernel 6.4.0. [2] - https://lore.kernel.org/all/CA+G9fYsuc8D98BtW9rX0ahS9Rfqyn-5CALYWTy6fr_ypJqEErA@mail.gmail.com/
The kernel crash reported on arm64 juno-r2 device with kselftest-merge config while booting Linux next-20220513 kernel. [3] - https://lore.kernel.org/all/CA+G9fYtsp-1pi6d4J71BPYh-msjzbVt_-v3YrUu12dXPeyqTDg@mail.gmail.com/
> > Thanks, > Mark.
- Naresh [unhandled content-type:application/octet-stream] | |