Re: [PATCH] perf intel-bts: Free the old snapshot reference array after growing it

[James Clark]

On 04/11/2026 02:20, lirongqing wrote:
> From: Li RongQing <lirongqing@xxxxxxxxx>
>
> The snapshot reference array grows when a mapping index exceeds its
> capacity. Its old entries are copied into a new allocation, but the old
> array is abandoned when snapshot_refs is replaced.
>
> Release the old array after copying it so expanding past sixteen
> mappings does not leak it.
>
> Fixes: d0170af7004d ("perf tools: Add Intel BTS support")
> Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
> ---
>   tools/perf/arch/x86/util/intel-bts.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/tools/perf/arch/x86/util/intel-bts.c b/tools/perf/arch/x86/util/intel-bts.c
> index d44d568..9403681 100644
> --- a/tools/perf/arch/x86/util/intel-bts.c
> +++ b/tools/perf/arch/x86/util/intel-bts.c
> @@ -299,6 +299,7 @@ static int intel_bts_alloc_snapshot_refs(struct intel_bts_recording *btsr,
>   
>   	memcpy(refs, btsr->snapshot_refs, cnt * sz);
>   
> +	free(btsr->snapshot_refs);
>   	btsr->snapshot_refs = refs;
>   	btsr->snapshot_ref_cnt = new_cnt;
>   

I made the same fix here [1] as well as turning BTS snapshots into the 
generic one. But that doesn't have a fixes tag, so maybe this patch is 
still useful.

Reviewed-by: James Clark <james.clark@xxxxxxxxxx>

[1]: 
https://lore.kernel.org/all/20261102-james-cs-unformatted-per-thread-fix-v3-10-dbcb0c281b9b@xxxxxxxxxx/