From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Marta Lewandowska <mlewando@redhat.com>

Date: Mon, 9 Oct 2023 08:53:18 +0200

Subject: [PATCH] add flag to only search root dev

fixes bz#2223437

Signed-off-by: Marta Lewandowska <mlewando@redhat.com>

---

 grub-core/commands/search.c      | 36 ++++++++++++++++++++++++++++++++++++

 grub-core/commands/search_wrap.c |  5 +++++

 grub-core/kern/misc.c            | 30 ++++++++++++++++++++++++++++++

 include/grub/misc.h              |  1 +

 include/grub/search.h            |  3 ++-

 5 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/grub-core/commands/search.c b/grub-core/commands/search.c

index 57d26ced8a8e..819231751c38 100644

--- a/grub-core/commands/search.c

+++ b/grub-core/commands/search.c

@@ -85,6 +85,42 @@ iterate_device (const char *name, void *data)

       grub_device_close (dev);

     }

+  /* Skip it if it's not the root device when requested. */

+  if (ctx->flags & SEARCH_FLAGS_ROOTDEV_ONLY)

+    {

+      const char *root_dev;

+      root_dev = grub_env_get ("root");

+      if (root_dev != NULL && *root_dev != '\0')

+      {

+        char *root_disk = grub_malloc (grub_strlen(root_dev) + 1);

+        char *name_disk = grub_malloc (grub_strlen(name) + 1);

+        char *rem_1 = grub_malloc(grub_strlen(root_dev) + 1);

+        char *rem_2 = grub_malloc(grub_strlen(name) + 1);

+

+	if (root_disk != NULL && name_disk != NULL && 

+	    rem_1 != NULL && rem_2 != NULL)

+  	  {

+            /* get just the disk name; partitions will be different. */

+            grub_str_sep (root_dev, root_disk, ',', rem_1);

+            grub_str_sep (name, name_disk, ',', rem_2);

+            if (root_disk != NULL && *root_disk != '\0' &&

+    	        name_disk != NULL && *name_disk != '\0')

+              if (grub_strcmp(root_disk, name_disk) != 0)

+                {

+                  grub_free (root_disk);

+                  grub_free (name_disk);

+                  grub_free (rem_1);

+                  grub_free (rem_2);

+                  return 0;

+                }

+	  }

+        grub_free (root_disk);

+        grub_free (name_disk);

+        grub_free (rem_1);

+        grub_free (rem_2);

+      }

+    }

+

 #ifdef DO_SEARCH_FS_UUID

 #define compare_fn grub_strcasecmp

 #else

diff --git a/grub-core/commands/search_wrap.c b/grub-core/commands/search_wrap.c

index 0b62acf85359..06b5f51eefb5 100644

--- a/grub-core/commands/search_wrap.c

+++ b/grub-core/commands/search_wrap.c

@@ -41,6 +41,7 @@ static const struct grub_arg_option options[] =

      ARG_TYPE_STRING},

     {"no-floppy",	'n', 0, N_("Do not probe any floppy drive."), 0, 0},

     {"efidisk-only",	0, 0, N_("Only probe EFI disks."), 0, 0},

+    {"root-dev-only",  'r', 0, N_("Only probe root device."), 0, 0},

     {"hint",	        'h', GRUB_ARG_OPTION_REPEATABLE,

      N_("First try the device HINT. If HINT ends in comma, "

 	"also try subpartitions"), N_("HINT"), ARG_TYPE_STRING},

@@ -75,6 +76,7 @@ enum options

     SEARCH_SET,

     SEARCH_NO_FLOPPY,

     SEARCH_EFIDISK_ONLY,

+    SEARCH_ROOTDEV_ONLY,

     SEARCH_HINT,

     SEARCH_HINT_IEEE1275,

     SEARCH_HINT_BIOS,

@@ -189,6 +191,9 @@ grub_cmd_search (grub_extcmd_context_t ctxt, int argc, char **args)

   if (state[SEARCH_EFIDISK_ONLY].set)

     flags |= SEARCH_FLAGS_EFIDISK_ONLY;

+  if (state[SEARCH_ROOTDEV_ONLY].set)

+    flags |= SEARCH_FLAGS_ROOTDEV_ONLY;

+

   if (state[SEARCH_LABEL].set)

     grub_search_label (id, var, flags, hints, nhints);

   else if (state[SEARCH_FS_UUID].set)

diff --git a/grub-core/kern/misc.c b/grub-core/kern/misc.c

index cb454614022f..c0ac7fee6cc2 100644

--- a/grub-core/kern/misc.c

+++ b/grub-core/kern/misc.c

@@ -619,6 +619,36 @@ grub_reverse (char *str)

     }

 }

+/* Separate string into two parts, broken up by delimiter delim. */

+void

+grub_str_sep (const char *s, char *p, char delim, char *r)

+{

+  char* t = grub_strndup(s, grub_strlen(s));

+

+  if (t != NULL && *t != '\0')

+  {

+    char* tmp = t;

+  

+    while (((*p = *t) != '\0') && ((*p = *t) != delim))

+    {

+      p++;

+      t++;

+    }

+    *p = '\0';

+  

+    if (*t != '\0')

+    {

+      t++;

+      while ((*r++ = *t++) != '\0')

+        ;

+      *r = '\0';

+    }

+    grub_free (tmp);

+  }

+  else

+    grub_free (t);

+}

+

 /* Divide N by D, return the quotient, and store the remainder in *R.  */

 grub_uint64_t

 grub_divmod64 (grub_uint64_t n, grub_uint64_t d, grub_uint64_t *r)

diff --git a/include/grub/misc.h b/include/grub/misc.h

index faae0ae8606c..981526644d29 100644

--- a/include/grub/misc.h

+++ b/include/grub/misc.h

@@ -314,6 +314,7 @@ void *EXPORT_FUNC(grub_memset) (void *s, int c, grub_size_t n);

 grub_size_t EXPORT_FUNC(grub_strlen) (const char *s) WARN_UNUSED_RESULT;

 int EXPORT_FUNC(grub_printf) (const char *fmt, ...) __attribute__ ((format (GNU_PRINTF, 1, 2)));

 int EXPORT_FUNC(grub_printf_) (const char *fmt, ...) __attribute__ ((format (GNU_PRINTF, 1, 2)));

+void EXPORT_FUNC(grub_str_sep) (const char *s, char *p, char delim, char *r);

 /* Replace all `ch' characters of `input' with `with' and copy the

    result into `output'; return EOS address of `output'. */

diff --git a/include/grub/search.h b/include/grub/search.h

index 4190aeb2cbf5..321d1400e451 100644

--- a/include/grub/search.h

+++ b/include/grub/search.h

@@ -22,7 +22,8 @@

 enum search_flags

   {

     SEARCH_FLAGS_NO_FLOPPY	= 1,

-    SEARCH_FLAGS_EFIDISK_ONLY	= 2

+    SEARCH_FLAGS_EFIDISK_ONLY	= 2,

+    SEARCH_FLAGS_ROOTDEV_ONLY	= 4

   };

 void grub_search_fs_file (const char *key, const char *var,