grub2/0006-Follow-the-device-where-blscfg-is-discovered.patch

From 6523d493b0772316a3fbb249eb070ada5d266a98 Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Wed, 28 Jun 2023 14:32:40 +0800
Subject: [PATCH 6/9] Follow the device where blscfg is discovered

Previously, the code assumed that GRUB_BOOT_DEVICE "($root)" was always
the correct device for the discovered bls menu. However, this assumption
could lead to inaccuracies when attempting to load bls for devices other
than $root.

This patch introduces a more robust approach by utilizing the `struct
find_entry_info *info->devid` parameter, representing the device used to
discover the bls directory. This change ensures consistency in
subsequent translations to native GRUB commands, eliminating potential
discrepancies in device identification during the blscfg process.

Signed-off-by: Michael Chang <mchang@suse.com>
---
 grub-core/commands/blscfg.c | 40 +++++++++++++++++++++++++------------
 include/grub/menu.h         |  1 +
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/grub-core/commands/blscfg.c b/grub-core/commands/blscfg.c
index 6495891b9..c872bcef0 100644
--- a/grub-core/commands/blscfg.c
+++ b/grub-core/commands/blscfg.c
@@ -55,15 +55,18 @@ struct keyval
 
 static struct bls_entry *entries = NULL;
 
-/* Cache probing in frob_boot_device().  Used for linux entry also.
- * Always true in non-emu, meaning to prefix things with GRUB_BOOT_DEVICE. */
-static int separate_boot = -1;
-
 #define FOR_BLS_ENTRIES(var) FOR_LIST_ELEMENTS (var, entries)
 
 /* BLS appears to make paths relative to the filesystem that snippets are
  * on, not /.  Attempt to cope. */
-static char *frob_boot_device(char *tmp)
+#ifdef GRUB_MACHINE_EMU
+/* Cache probing in frob_boot_device().  Used for linux entry also.
+ * Unused in non-emu, meaning to prefix things with device of parent blsdir. */
+static int separate_boot = -1;
+static char *frob_boot_device(char *tmp, const char *bootdev UNUSED)
+#else
+static char *frob_boot_device(char *tmp, const char *bootdev)
+#endif
 {
 #ifdef GRUB_MACHINE_EMU
   grub_file_t f;
@@ -94,9 +97,11 @@ static char *frob_boot_device(char *tmp)
  probed:
   if (!separate_boot)
     return grub_stpcpy (tmp, " ");
-#endif
-
   return grub_stpcpy (tmp, " " GRUB_BOOT_DEVICE);
+#else
+  tmp = grub_stpcpy (tmp, " ");
+  return grub_stpcpy (tmp, bootdev);
+#endif
 }
 
 static int bls_add_keyval(struct bls_entry *entry, char *key, char *val)
@@ -568,6 +573,9 @@ static int read_entry (
       if (rc < 0)
 	break;
     }
+  
+    if (info->devid)
+      entry->devid = grub_strdup(info->devid);
 
     if (!rc)
       bls_add_entry(entry);
@@ -772,6 +780,7 @@ static void create_entry (struct bls_entry *entry)
   char *id = entry->filename;
   char *dotconf = id;
   char *hotkey = NULL;
+  char *bootdev = entry->devid ? grub_xasprintf("(%s)", entry->devid) : grub_strdup (GRUB_BOOT_DEVICE);
 
   char *users = NULL;
   char **classes = NULL;
@@ -865,12 +874,12 @@ static void create_entry (struct bls_entry *entry)
       char *tmp;
 
       for (i = 0; early_initrds != NULL && early_initrds[i] != NULL; i++)
-	initrd_size += sizeof (" " GRUB_BOOT_DEVICE) \
+	initrd_size += sizeof (" ") + grub_strlen (bootdev) \
 		       + grub_strlen(initrd_prefix)  \
 		       + grub_strlen (early_initrds[i]) + 1;
 
       for (i = 0; initrds != NULL && initrds[i] != NULL; i++)
-	initrd_size += sizeof (" " GRUB_BOOT_DEVICE) \
+	initrd_size += sizeof (" ") + grub_strlen (bootdev) \
 		       + grub_strlen (initrds[i]) + 1;
       initrd_size += 1;
 
@@ -885,7 +894,7 @@ static void create_entry (struct bls_entry *entry)
       for (i = 0; early_initrds != NULL && early_initrds[i] != NULL; i++)
 	{
 	  grub_dprintf ("blscfg", "adding early initrd %s\n", early_initrds[i]);
-	  tmp = frob_boot_device (tmp);
+	  tmp = frob_boot_device (tmp, bootdev);
 	  tmp = grub_stpcpy (tmp, initrd_prefix);
 	  tmp = grub_stpcpy (tmp, early_initrds[i]);
 	  grub_free(early_initrds[i]);
@@ -894,7 +903,7 @@ static void create_entry (struct bls_entry *entry)
       for (i = 0; initrds != NULL && initrds[i] != NULL; i++)
 	{
 	  grub_dprintf ("blscfg", "adding initrd %s\n", initrds[i]);
-	  tmp = frob_boot_device (tmp);
+	  tmp = frob_boot_device (tmp, bootdev);
 	  tmp = grub_stpcpy (tmp, initrds[i]);
 	}
       tmp = grub_stpcpy (tmp, "\n");
@@ -916,7 +925,7 @@ static void create_entry (struct bls_entry *entry)
 	    }
 	}
 
-      dt_size = sizeof("devicetree " GRUB_BOOT_DEVICE) + grub_strlen(devicetree) + 1;
+      dt_size = sizeof("devicetree ") + grub_strlen(bootdev) + grub_strlen(devicetree) + 1;
 
       if (add_dt_prefix)
 	{
@@ -931,7 +940,7 @@ static void create_entry (struct bls_entry *entry)
         }
       char *tmp = dt;
       tmp = grub_stpcpy (dt, "devicetree");
-      tmp = frob_boot_device (tmp);
+      tmp = frob_boot_device (tmp, bootdev);
       if (add_dt_prefix)
         tmp = grub_stpcpy (tmp, prefix);
       tmp = grub_stpcpy (tmp, devicetree);
@@ -950,7 +959,11 @@ static void create_entry (struct bls_entry *entry)
 			"linux %s%s%s%s\n"
 			"%s%s",
 			savedefault ? "savedefault\n" : "",
+#ifdef GRUB_MACHINE_EMU
 			separate_boot ? GRUB_BOOT_DEVICE : "",
+#else
+			bootdev,
+#endif
 			clinux, options ? " " : "", options ? options : "",
 			initrd ? initrd : "", dt ? dt : "");
 
@@ -969,6 +982,7 @@ finish:
   grub_free (args);
   grub_free (argv);
   grub_free (src);
+  grub_free (bootdev);
 }
 
 struct find_entry_info {
diff --git a/include/grub/menu.h b/include/grub/menu.h
index 43080828c..76b191c33 100644
--- a/include/grub/menu.h
+++ b/include/grub/menu.h
@@ -28,6 +28,7 @@ struct bls_entry
   int nkeyvals;
   char *filename;
   int visible;
+  const char *devid;
 };
 
 struct grub_menu_entry_class
-- 
2.44.0