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Re: [PATCH 3/3] scandir: fix wrong assumption about errno [BZ #17804]
On 12/21/2017 02:54 PM, Aurelien Jarno wrote:
> malloc and realloc may set errno to ENOMEM even if they are successful.
> The scandir code wrongly assume that they do not change errno, this
> causes scandir to fail with ENOMEM even if malloc succeed.
>
> The code already handles that readdir might set errno by calling
> __set_errno (0) to clear the error. Move that part at the end of the
> loop to also take malloc and realloc into account.
>
> Changelog:
> [BZ #17804]
> * dirent/scandir-tail.c (SCANDIR_TAIL): Move __set_errno (0) at the
> end of the loop.
OK with changes below.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> ---
> ChangeLog | 6 ++++++
> dirent/scandir-tail.c | 7 +++++--
> 2 files changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/ChangeLog b/ChangeLog
> index 7bf30d27ef..31fddf5794 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,9 @@
> +2017-12-21 Aurelien Jarno <aurelien@aurel32.net>
> +
> + [BZ #17804]
> + * dirent/scandir-tail.c (SCANDIR_TAIL): Move __set_errno (0) at the
> + end of the loop.
> +
> 2017-12-21 Aurelien Jarno <aurelien@aurel32.net>
>
> [BZ #22615]
> diff --git a/dirent/scandir-tail.c b/dirent/scandir-tail.c
> index 068c644c4e..00fe9ef030 100644
> --- a/dirent/scandir-tail.c
> +++ b/dirent/scandir-tail.c
> @@ -61,8 +61,6 @@ SCANDIR_TAIL (DIR *dp,
> if (!selected)
> continue;
> }
> - else
> - __set_errno (0);
OK.
>
> if (__glibc_unlikely (c.cnt == vsize))
> {
> @@ -81,6 +79,11 @@ SCANDIR_TAIL (DIR *dp,
> if (vnew == NULL)
> break;
> v[c.cnt++] = (DIRENT_TYPE *) memcpy (vnew, d, dsize);
> +
> + /* Ignore errors from readdir, malloc or realloc. These functions
> + might have changed errno. It was zero before and it need to be
> + again to make the latter tests work. */
Suggest:
/* Ignore error from readdir, malloc, or realloc. These functions
might have set errno to non-zero on success. It was zero before
and it needs to be again to make the later tests work. */
Please also change the wording of the matching comment on line 56.
> + __set_errno (0);
> }
>
> if (__glibc_likely (errno == 0))
>
--
Cheers,
Carlos.