[RFC PATCH] perf/arm64: Add BRBE support for bpf_get_branch_snapshot()

[Leo Yan]

Hi,

On Fri, Jan 02, 2026 at 09:51:15PM +0000, Puranjay Mohan wrote:
> Hi Catalin, Will, Mark, and Rob.
> 
> I don't have access to BRBE enabled hardware and Qemu doesn't support
> this as well therefore I just sent the compile tested version.
> 
> Can you help me with testing this:
> 
> The relevant bpf self test is:
> 
> ./test_progs -t get_branch_snapshot
> #132     get_branch_snapshot:SKIP
> Summary: 1/0 PASSED, 1 SKIPPED, 0 FAILED
> 
> skipped for my setup as it is not supported.

eBPF selftest build is quite heavy (many dependencies), finally I built
it cleanly.

I did a test on FVP RevC, the test hit NULL pointer deference and kernel
panic in armv8pmu_sched_task().  See https://termbin.com/peg4, the
backtrace should can give you hints for the issue.

Thanks,
Leo

P.s. some logs are duplicate, this might be caused by two cores both hit
the NULL pointer issue ?