Re: [PATCH 2/2] Make editenv chase symlinks including those across devices.

[Daniel Kiper]

On Fri, Oct 18, 2019 at 02:42:21PM +0200, Javier Martinez Canillas wrote:
> From: Peter Jones <address@hidden>
>
> This lets us make /boot/grub2/grubenv a symlink to

Who or what creates that link?

> /boot/efi/EFI/fedora/grubenv even though they're different mount points,
> which allows /usr/bin/grub2-editenv to be the same across platforms
> (i.e. UEFI vs BIOS).
>
> Signed-off-by: Peter Jones <address@hidden>
> Reviewed-by: Adam Jackson <address@hidden>
> Signed-off-by: Javier Martinez Canillas <address@hidden>
> ---
>
>  Makefile.util.def | 11 +++++++++++
>  util/editenv.c    | 46 ++++++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 55 insertions(+), 2 deletions(-)
>
> diff --git a/Makefile.util.def b/Makefile.util.def
> index 969d32f0097..733a397cb2b 100644
> --- a/Makefile.util.def
> +++ b/Makefile.util.def
> @@ -240,8 +240,19 @@ program = {
>
>    common = util/grub-editenv.c;
>    common = util/editenv.c;
> +  common = util/grub-install-common.c;
>    common = grub-core/osdep/init.c;
> +  common = grub-core/osdep/compress.c;
> +  extra_dist = grub-core/osdep/unix/compress.c;
> +  extra_dist = grub-core/osdep/basic/compress.c;
> +  common = util/mkimage.c;
> +  common = util/grub-mkimage32.c;
> +  common = util/grub-mkimage64.c;
> +  common = grub-core/osdep/config.c;
> +  common = util/config.c;
> +  common = util/resolve.c;
>
> +  ldadd = '$(LIBLZMA)';

Hmmm... Why do we need that change? Does not it belong to different patch?

>    ldadd = libgrubmods.a;
>    ldadd = libgrubgcry.a;
>    ldadd = libgrubkern.a;
> diff --git a/util/editenv.c b/util/editenv.c
> index eb2d0c03a98..e61dc1283a4 100644
> --- a/util/editenv.c
> +++ b/util/editenv.c
> @@ -37,6 +37,7 @@ grub_util_create_envblk_file (const char *name)
>    FILE *fp;
>    char *buf;
>    char *namenew;
> +  char *rename_target = xstrdup(name);
>
>    buf = xmalloc (DEFAULT_ENVBLK_SIZE);
>
> @@ -60,7 +61,48 @@ grub_util_create_envblk_file (const char *name)
>    free (buf);
>    fclose (fp);
>
> -  if (grub_util_rename (namenew, name) < 0)
> -    grub_util_error (_("cannot rename the file %s to %s"), namenew, name);
> +  ssize_t size = 1;

I do not like variables declarations mixed with the code in that way.
Please move it to the beginning of the function.

> +  while (1)
> +    {
> +      char *linkbuf;
> +      ssize_t retsize;

...but I am OK with that... Hmmm... And it seems to me that size
can be moved here.

> +
> +      linkbuf = xmalloc(size+1);

linkbuf = xmalloc (size + 1); Missing spaces...

> +      retsize = grub_util_readlink (rename_target, linkbuf, size);
> +      if (retsize < 0 && (errno == ENOENT || errno == EINVAL))
> +     {
> +       free (linkbuf);
> +       break;
> +     }
> +      else if (retsize < 0)
> +     {
> +       grub_util_error (_("cannot rename the file %s to %s: %m"), namenew, 
> name);
> +       free (linkbuf);
> +       free (namenew);
> +       return;
> +     }
> +      else if (retsize == size)
> +     {
> +       free(linkbuf);

free (linkbuf);

> +       size += 128;
> +       continue;
> +     }
> +
> +      free (rename_target);
> +      linkbuf[retsize] = '\0';
> +      rename_target = linkbuf;
> +    }
> +
> +  int rc = grub_util_rename (namenew, rename_target);

Please move this variable declaration to the beginning of function.

Daniel