Re: [PATCH] selftests/mm: Fix memleak in migration benchmark

[Lorenzo Stoakes <ljs@kernel.org>]

On Wed, Jul 08, 2026 at 06:37:05PM +0800, Hongfu Li wrote:
> Several early return paths in run_migration_benchmark() skip
> hmm_buffer_free(), leaking the buffer. Replace with a single cleanup
> label.
>
> Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>

LGTM. With the Fixes tag added as requested by David, feel free to add:

Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>

> ---
>  tools/testing/selftests/mm/hmm-tests.c | 19 +++++++++++--------
>  1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c
> index e4c49699f3f7..e8046675a0c3 100644
> --- a/tools/testing/selftests/mm/hmm-tests.c
> +++ b/tools/testing/selftests/mm/hmm-tests.c
> @@ -2828,8 +2828,10 @@ static inline int run_migration_benchmark(int fd, int use_thp, size_t buffer_siz
>  	buffer->ptr = mmap(NULL, buffer_size, PROT_READ | PROT_WRITE,
>  			  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
>
> -	if (buffer->ptr == MAP_FAILED)
> -		return -1;
> +	if (buffer->ptr == MAP_FAILED) {
> +		ret = -1;
> +		goto cleanup;
> +	}
>
>  	/* Apply THP hint if requested */
>  	if (use_thp)
> @@ -2838,7 +2840,7 @@ static inline int run_migration_benchmark(int fd, int use_thp, size_t buffer_siz
>  		ret = madvise(buffer->ptr, buffer_size, MADV_NOHUGEPAGE);
>
>  	if (ret)
> -		return ret;
> +		goto cleanup;
>
>  	/* Initialize memory to make sure pages are allocated */
>  	ptr = (int *)buffer->ptr;
> @@ -2848,11 +2850,11 @@ static inline int run_migration_benchmark(int fd, int use_thp, size_t buffer_siz
>  	/* Warmup iteration */
>  	ret = hmm_migrate_sys_to_dev(fd, buffer, npages);
>  	if (ret)
> -		return ret;
> +		goto cleanup;
>
>  	ret = hmm_migrate_dev_to_sys(fd, buffer, npages);
>  	if (ret)
> -		return ret;
> +		goto cleanup;
>
>  	/* Benchmark iterations */
>  	for (i = 0; i < iterations; i++) {
> @@ -2861,7 +2863,7 @@ static inline int run_migration_benchmark(int fd, int use_thp, size_t buffer_siz
>
>  		ret = hmm_migrate_sys_to_dev(fd, buffer, npages);
>  		if (ret)
> -			return ret;
> +			goto cleanup;
>
>  		end = get_time_ms();
>  		s2d_total += (end - start);
> @@ -2871,7 +2873,7 @@ static inline int run_migration_benchmark(int fd, int use_thp, size_t buffer_siz
>
>  		ret = hmm_migrate_dev_to_sys(fd, buffer, npages);
>  		if (ret)
> -			return ret;
> +			goto cleanup;
>
>  		end = get_time_ms();
>  		d2s_total += (end - start);
> @@ -2886,8 +2888,9 @@ static inline int run_migration_benchmark(int fd, int use_thp, size_t buffer_siz
>  				 (results->dev_to_sys_time / 1000.0);
>
>  	/* Cleanup */
> +cleanup:
>  	hmm_buffer_free(buffer);
> -	return 0;
> +	return ret;
>  }
>
>  /*
> --
> 2.25.1
>

Cheers, Lorenzo