Re: [Crash-utility] [PATCH] arm64: fix backtraces of KASAN kernel dumpfile truncated

>>> We met "bt" cmd on KASAN kernel vmcore display truncated backtraces >>> like this: >>> >>> crash> bt >>> PID: 4131 TASK: ffff8001521df000 CPU: 3 COMMAND: "bash" >>> #0 [ffff2000224b0cb0] machine_kexec_prepare at ffff2000200bff4c >>> >> >> Can you help explain how to reproduce this issue? Or what's the >> critical configuration of the kernel? Can this issue be always >> reproduced? >> >> I tried to reproduce it on the latest kernel(commit bce9332220bd ) >> with the CONFIG_KASAN*=y, but can not reproduce this error. >> > > I can always reproduce the issue with openEuler-20.03-LTS-SP3. > I recompile openEuler kernel-4.19.90-xxx with CONFIG_KASAN=y, the gcc is > also from openEuler-20.03-LTS-SP3, version 7.3.0 > > I think it may be related to compiler, do you see the similar assembly > pattern when disassemble machine_kexec() or crash_save_cpu()? > Tried several times, the similar phenomenon can be observed on aarch64(built with the gcc-8.3.1) and this error can be reproduced. After applying this patch, the crash tool works well for now(with or without the current issue). And this change looks good to me. So: Ack