Re: [PATCH 6/8] perf machine: Reset errno before strtol in guest kernel map creation

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [Low] Missing explicit POSIX header inclusions for <stdio.h> and <limits.h>.
--

--- Patch [6]: [PATCH 6/8] perf machine: Reset errno before strtol in guest kernel map creation ---
commit 8cf9920f21a3b72d2b6dbb2087000cbeceb43bbb
Author: Arnaldo Carvalho de Melo <acme@redhat.com>

perf machine: Reset errno before strtol in guest kernel map creation

This commit resets errno to 0 before calling strtol() in
machines__create_guest_kernel_maps(). This prevents a stale ERANGE from
earlier library calls from causing valid directory names to be skipped.

> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 83d38637afe34..1700130adedb3 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c

[Severity: Low]
This is a pre-existing issue, but is this file missing explicit POSIX header
inclusions for <stdio.h> and <limits.h>?

Looking at the include block at the top of tools/perf/util/machine.c:

// SPDX-License-Identifier: GPL-2.0
#include <dirent.h>
#include <errno.h>
#include <inttypes.h>
#include <regex.h>
#include <stdlib.h>
#include <string.h>
#include "callchain.h"

The code relies on PATH_MAX and snprintf() further down in
machines__create_guest_kernel_maps(). Relying on implicit header inclusions
works for glibc, but does it cause build failures under musl libc environments?

Could <stdio.h> and <limits.h> be explicitly included to ensure strict musl
compatibility?

> @@ -1258,6 +1258,7 @@ int machines__create_guest_kernel_maps(struct machines *machines)
>  				/* Filter out . and .. */
>  				continue;
>  			}
> +			errno = 0;
>  			pid = (pid_t)strtol(namelist[i]->d_name, &endp, 10);
>  			if ((*endp != '\0') ||
>  			    (endp == namelist[i]->d_name) ||

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260726234014.63111-1-acme@kernel.org?part=6