Just re-pinging on this ...
P.
On 1/4/19 7:53 AM, Prarit Bhargava wrote:
> Please be aware I am NOT subscribed to grub-devel.
>
> P.
>
> ---8<---
>
> Customers and users of the kernel are commenting that there is no way to
> update
> a grub variable without copy and pasting the existing data.
>
> For example,
>
> [10:57 AM root@intel-wildcatpass-07 grub-2.02]# ./grub-editenv list
> saved_entry=0
> next_entry=
> kernelopts=root=/dev/mapper/rhel_intel--wildcatpass--07-root ro
> crashkernel=auto resume=/dev/mapper/rhel_intel--wildcatpass--07-swap
> rd.lvm.lv=rhel_intel-wildcatpass-07/root
> rd.lvm.lv=rhel_intel-wildcatpass-07/swap console=ttyS0,115200n81
> ignore_loglevel
> [10:57 AM root@intel-wildcatpass-07 grub-2.02]# ./grub-editenv - set
> kernelopts="root=/dev/mapper/rhel_intel--wildcatpass--07-root ro
> crashkernel=auto resume=/dev/mapper/rhel_intel--wildcatpass--07-swap
> rd.lvm.lv=rhel_intel-wildcatpass-07/root
> rd.lvm.lv=rhel_intel-wildcatpass-07/swap console=ttyS0,115200n81
> ignore_loglevel newarg"
> [10:57 AM root@intel-wildcatpass-07 grub-2.02]# ./grub-editenv list
> saved_entry=0
> next_entry=
> kernelopts=root=/dev/mapper/rhel_intel--wildcatpass--07-root ro
> crashkernel=auto resume=/dev/mapper/rhel_intel--wildcatpass--07-swap
> rd.lvm.lv=rhel_intel-wildcatpass-07/root
> rd.lvm.lv=rhel_intel-wildcatpass-07/swap console=ttyS0,115200n81
> ignore_loglevel newarg
>
> which is cumbersome.
>
> Add functionality to add to an existing variable. For example,
>
> [10:58 AM root@intel-wildcatpass-07 grub-2.02]# ./grub-editenv list
> saved_entry=0
> next_entry=
> kernelopts=root=/dev/mapper/rhel_intel--wildcatpass--07-root ro
> crashkernel=auto resume=/dev/mapper/rhel_intel--wildcatpass--07-swap
> rd.lvm.lv=rhel_intel-wildcatpass-07/root
> rd.lvm.lv=rhel_intel-wildcatpass-07/swap console=ttyS0,115200n81
> ignore_loglevel
> [10:58 AM root@intel-wildcatpass-07 grub-2.02]# ./grub-editenv - set
> kernelopts+="newarg"
> [10:59 AM root@intel-wildcatpass-07 grub-2.02]# ./grub-editenv list
> saved_entry=0
> next_entry=
> kernelopts=root=/dev/mapper/rhel_intel--wildcatpass--07-root ro
> crashkernel=auto resume=/dev/mapper/rhel_intel--wildcatpass--07-swap
> rd.lvm.lv=rhel_intel-wildcatpass-07/root
> rd.lvm.lv=rhel_intel-wildcatpass-07/swap console=ttyS0,115200n81
> ignore_loglevel newarg
>
> Signed-off-by: Prarit Bhargava <pra...@redhat.com>
> Cc: mleit...@redhat.com
> Cc: pjo...@redhat.com
> Cc: javi...@redhat.com
> Cc: ar...@redhat.com
> ---
> grub-core/lib/envblk.c | 61 +++++++++++++++++++++++++++++++++++++++
> include/grub/lib/envblk.h | 1 +
> util/grub-editenv.c | 25 +++++++++++++++-
> 3 files changed, 86 insertions(+), 1 deletion(-)
>
> diff --git a/grub-core/lib/envblk.c b/grub-core/lib/envblk.c
> index 230e0e9d9abe..8ddbe2e8267e 100644
> --- a/grub-core/lib/envblk.c
> +++ b/grub-core/lib/envblk.c
> @@ -295,3 +295,64 @@ grub_envblk_iterate (grub_envblk_t envblk,
> p = find_next_line (p, pend);
> }
> }
> +
> +int
> +grub_envblk_add (grub_envblk_t envblk, const char *name, const char *add)
> +{
> + char *current, *new, *ostart, *pstart, *pend;
> + int newsize, ret = 1;
> +
> + /* get a copy of the existing entry */
> + pstart = envblk->buf + sizeof (GRUB_ENVBLK_SIGNATURE) - 1;
> + pstart = grub_strstr (pstart, name);
> + if (!pstart)
> + {
> + ret = -1; /* existing entry not found */
> + goto out;
> + }
> + pend = grub_strchr (pstart, '\n');
> + if (!pend || pend > (envblk->buf + envblk->size))
> + {
> + ret = -1; /* existing entry not found */
> + goto out;
> + }
> +
> + current = grub_zalloc (pend - pstart + 1);
> + if (!current)
> + {
> + ret = -2; /* out of memory */
> + goto out;
> + }
> + grub_strncpy (current, pstart, (int)(pend - pstart));
> +
> + ostart = grub_strchr (current, '=');
> + ostart++;
> +
> + /* create a buffer for the updated entry. */
> + newsize = grub_strlen (ostart) + grub_strlen (add) + 2;
> + new = grub_zalloc (newsize);
> + if (!new)
> + {
> + return -2; /* out of memory */
> + goto out;
> + }
> +
> + grub_strcpy (new, ostart);
> + grub_memcpy (new + grub_strlen (new), " ", 1);
> + grub_strcpy (new + grub_strlen (new), add);
> +
> + /* erase the current entry */
> + grub_envblk_delete (envblk, name);
> + /* add the updated entry */
> + if (!grub_envblk_set (envblk, name, new))
> + {
> + /* restore the original entry. This should always work */
> + grub_envblk_set (envblk, name, ostart);
> + ret = 0;
> + }
> +
> +out:
> + grub_free(new);
> + grub_free(current);
> + return ret;
> +}
> diff --git a/include/grub/lib/envblk.h b/include/grub/lib/envblk.h
> index c3e655921709..2a0f09e3435b 100644
> --- a/include/grub/lib/envblk.h
> +++ b/include/grub/lib/envblk.h
> @@ -37,6 +37,7 @@ void grub_envblk_delete (grub_envblk_t envblk, const char
> *name);
> void grub_envblk_iterate (grub_envblk_t envblk,
> void *hook_data,
> int hook (const char *name, const char *value,
> void *hook_data));
> +int grub_envblk_add(grub_envblk_t envblk, const char *name, const char *add);
> void grub_envblk_close (grub_envblk_t envblk);
>
> static inline char *
> diff --git a/util/grub-editenv.c b/util/grub-editenv.c
> index 118e89fe57fe..2df81a20b6bc 100644
> --- a/util/grub-editenv.c
> +++ b/util/grub-editenv.c
> @@ -210,15 +210,38 @@ set_variables (const char *name, int argc, char *argv[])
> while (argc)
> {
> char *p;
> + int add = 0;
>
> p = strchr (argv[0], '=');
> if (! p)
> grub_util_error (_("invalid parameter %s"), argv[0]);
>
> + if ( *(p - 1) == '+')
> + {
> + add = 1;
> + *(p - 1) = 0;
> + }
> *(p++) = 0;
>
> - if (! grub_envblk_set (envblk, argv[0], p))
> + if (!add && ! grub_envblk_set (envblk, argv[0], p))
> grub_util_error ("%s", _("environment block too small"));
> + else if (add) {
> + int ret;
> + ret = grub_envblk_add (envblk, argv[0], p);
> + switch (ret) {
> + case (0):
> + grub_util_error ("%s", _("environment block too small"));
> + break;
> + case (-1):
> + grub_util_error("%s", _("existing entry not found"));
> + break;
> + case (-2):
> + grub_util_error("%s", _("out of memory error"));
> + break;
> + default:
> + break;
> + }
> + }
>
> argc--;
> argv++;
>
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