Re: [PATCH v8 14/15] perf annotate-arm64: Support per-cpu variable access tracking

[sashiko-bot@kernel.org]

> Extend update_insn_state_arm64() to handle per-cpu variable addressing.
> 
> On arm64, per-cpu variables are accessed by adding a per-cpu offset
> (typically from the '__per_cpu_offset' array) to the address of a global
> variable or a structure field with '__percpu' modifier (e.g.,
> 's32 __percpu *counters' in struct percpu_counter). This results in
> instruction patterns like:
> 
>   ldr   x0, [x6, x5]   // Pattern A: direct load per-cpu instance
>   add   x0, x6, x5     // Pattern B: compute per-cpu address
> 
> where x6 holds the per-cpu offset retrieved from:
> 
>   adrp  x4, <page>
>   add   x4, x4, #offset          // x4 = &__per_cpu_offset
> [ ... ]
>   found by insn track: 0(reg5, reg2) type-offset=0
>   final result:  type='int' size=0x4
> 
> Reviewed-by: Namhyung Kim <namhyung@kernel.org>
> Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>

Sashiko has reviewed this patch and found no issues.

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