[PATCH v2 0/4] EFI envblk

[PATCH v2 0/4] EFI envblk

[Glenn Washburn]

Update v2:
 * Rebase onto current master. This really did not change the contents of
   the patch though

This patch series (for me) was motivated by the "gdb: Add more support for
debugging on EFI platforms" patch series, which allowed printing in early
EFI init of the GDB command for properly loading symbols. That approach of
having the functionality be included at compile time was ultimately
rejected. During the discussion of that series, Robbie suggested[1] using
patches by Peter and in the Redhat downstream repo which uses an EFI
variable to store a GRUB env block. Using this, a user could store a
variable in the env block stored in the EFI variable and then have GRUB
load that env block in early init as a way to enable the printing of the
GDB command.

I've taken the original patches by Peter, made more suitable for including
in GRUB, fixed some bugs, and added a minor feature. The first patch, adds
env block loading in early EFI init from the GRUB_ENV EFI variable. The
second patch is included to provide tools for GRUB to set this EFI env
block itself, as opposed to needing to use the method suggested by
Robbie[1], which requires GNU/Linux and the user-space grub2-editenv
utility. Of course, if GRUB is crashing before one can run the
efi-export-env command, then other ways of creating and setting the EFI
envblk variable are necessary. The third patch adds a test which checks the
usability of the commands and the early init loading. And the last patch,
whichvmotivated this series, prints the GDB command string if the GRUB
variable named "enable_earlyinit_gdbinfo" is present and is set to "1", after
the env block is loaded from the GRUB_ENV EFI variable. We might want a
different name for the GRUB variable, I don't really have a preference.

Glenn

[1] https://mail.gnu.org/archive/html/grub-devel/2023-03/msg00072.html

Glenn Washburn (2):
  tests: Add efienv_test for testing efi-export-env and efi-load-env
  efi: Print GDB command for loading symbols if variable exists

Peter Jones (2):
  efi: Load env block from GRUB_ENV EFI variable in early init
  efi: Add efi-export-env and efi-load-env commands

 Makefile.util.def            |   6 ++
 docs/grub.texi               |  24 +++++
 grub-core/Makefile.core.def  |   7 ++
 grub-core/commands/efi/env.c | 182 +++++++++++++++++++++++++++++++++++
 grub-core/kern/efi/efi.c     |   3 +
 grub-core/kern/efi/init.c    |  37 +++++++
 grub-core/lib/envblk.c       |  43 +++++++++
 include/grub/efi/efi.h       |   5 +
 include/grub/lib/envblk.h    |   3 +
 tests/efienv_test.in         |  57 +++++++++++
 10 files changed, 367 insertions(+)
 create mode 100644 grub-core/commands/efi/env.c
 create mode 100644 tests/efienv_test.in

Range-diff against v1:
1:  15a9c7112eae ! 1:  d2ad090d7486 efi: Load env block from GRUB_ENV EFI variable in early init
    @@ grub-core/kern/efi/init.c
      #ifdef GRUB_STACK_PROTECTOR
      
      static grub_efi_char16_t stack_chk_fail_msg[] =
    -@@ grub-core/kern/efi/init.c: stack_protector_init (void)
    +@@ grub-core/kern/efi/init.c: grub_stack_protector_init (void)
      
      grub_addr_t grub_modbase;
      
2:  d000cdbd0468 = 2:  456f4245ef76 efi: Add efi-export-env and efi-load-env commands
3:  3966eba4a32b = 3:  04072bccc2c7 tests: Add efienv_test for testing efi-export-env and efi-load-env
4:  b65e7a8bac40 = 4:  a23667d25f40 efi: Print GDB command for loading symbols if variable exists
-- 
2.34.1


_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel

[PATCH v2 1/4] efi: Load env block from GRUB_ENV EFI variable in early init

[Glenn Washburn]

From: Peter Jones <pjones@redhat.com>

This allows setting GRUB variables before any user interaction or GRUB
script can run. It is primarily intended to be used to turn on early
debugging.

Signed-off-by: Peter Jones <pjones@redhat.com>
Replace grub_efi_guid_t -> grub_guid_t
Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 grub-core/Makefile.core.def |  1 +
 grub-core/kern/efi/init.c   | 31 +++++++++++++++++++++++++++++++
 include/grub/efi/efi.h      |  5 +++++
 3 files changed, 37 insertions(+)

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 063ef5dd7801..5699736dad20 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -219,6 +219,7 @@ kernel = {
   efi = kern/efi/acpi.c;
   efi = kern/efi/sb.c;
   efi = kern/lockdown.c;
+  efi = lib/envblk.c;
   i386_coreboot = kern/i386/pc/acpi.c;
   i386_multiboot = kern/i386/pc/acpi.c;
   i386_coreboot = kern/acpi.c;
diff --git a/grub-core/kern/efi/init.c b/grub-core/kern/efi/init.c
index 1637077e1e96..2da6036129a1 100644
--- a/grub-core/kern/efi/init.c
+++ b/grub-core/kern/efi/init.c
@@ -28,8 +28,11 @@
 #include <grub/env.h>
 #include <grub/mm.h>
 #include <grub/kernel.h>
+
 #include <grub/stack_protector.h>
 
+#include <grub/lib/envblk.h>
+
 #ifdef GRUB_STACK_PROTECTOR
 
 static grub_efi_char16_t stack_chk_fail_msg[] =
@@ -94,6 +97,31 @@ grub_stack_protector_init (void)
 
 grub_addr_t grub_modbase;
 
+/* Helper for grub_efi_env_init */
+static int
+set_var (const char *name, const char *value,
+	 void *whitelist __attribute__((__unused__)))
+{
+  grub_env_set (name, value);
+  return 0;
+}
+
+static void
+grub_efi_env_init (void)
+{
+  grub_guid_t efi_grub_guid = GRUB_EFI_GRUB_VARIABLE_GUID;
+  struct grub_envblk envblk_s = { NULL, 0 };
+  grub_envblk_t envblk = &envblk_s;
+
+  grub_efi_get_variable ("GRUB_ENV", &efi_grub_guid, &envblk_s.size,
+                         (void **) &envblk_s.buf);
+  if (envblk_s.buf == NULL || envblk_s.size < 1)
+    return;
+
+  grub_envblk_iterate (envblk, NULL, set_var);
+  grub_free (envblk_s.buf);
+}
+
 void
 grub_efi_init (void)
 {
@@ -105,6 +133,9 @@ grub_efi_init (void)
   /* Initialize the memory management system.  */
   grub_efi_mm_init ();
 
+  /* Populate environment with variables from EFI envblk, if it exists.  */
+  grub_efi_env_init ();
+
   /*
    * Lockdown the GRUB and register the shim_lock verifier
    * if the UEFI Secure Boot is enabled.
diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
index a5cd99e5afa9..3edf44dbda49 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -25,6 +25,11 @@
 #include <grub/efi/api.h>
 #include <grub/efi/pe32.h>
 
+#define GRUB_EFI_GRUB_VARIABLE_GUID \
+  { 0x91376aff, 0xcba6, 0x42be, \
+    { 0x94, 0x9d, 0x06, 0xfd, 0xe8, 0x11, 0x28, 0xe8 } \
+  }
+
 #define GRUB_LINUX_ARM_MAGIC_SIGNATURE 0x016f2818
 
 struct linux_arch_kernel_header {
-- 
2.34.1


_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel

[PATCH v2 2/4] efi: Add efi-export-env and efi-load-env commands

[Glenn Washburn]

From: Peter Jones <pjones@redhat.com>

This adds "efi-export-env VARIABLES" and "efi-load-env", which manipulate
the environment block stored in the EFI variable
GRUB_ENV-91376aff-cba6-42be-949d-06fde81128e8.

Signed-off-by: Peter Jones <pjones@redhat.com>
Fix rebase, cherry-pick issues, grub_efi_guid_t -> grub_guid_t,
  module name bug, missing return bug, memory leaks, formatting
Add support for specifying multiple variables at once for efi-export-env.
Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 docs/grub.texi               |  24 +++++
 grub-core/Makefile.core.def  |   6 ++
 grub-core/commands/efi/env.c | 182 +++++++++++++++++++++++++++++++++++
 grub-core/kern/efi/efi.c     |   3 +
 grub-core/lib/envblk.c       |  43 +++++++++
 include/grub/lib/envblk.h    |   3 +
 6 files changed, 261 insertions(+)
 create mode 100644 grub-core/commands/efi/env.c

diff --git a/docs/grub.texi b/docs/grub.texi
index 2ea6c56d100e..4d53777dce14 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -6391,6 +6391,8 @@ you forget a command, you can run the command @command{help}
 * distrust::                    Remove a pubkey from trusted keys
 * drivemap::                    Map a drive to another
 * echo::                        Display a line of text
+* efi-export-env::              Export environment variable to UEFI
+* efi-load-env::                Load the grub environment from UEFI
 * efitextmode::                 Set/Get text output mode resolution
 * eval::                        Evaluate agruments as GRUB commands
 * export::                      Export an environment variable
@@ -6860,6 +6862,28 @@ character will print that character.
 @end deffn
 
 
+@node efi-export-env
+@subsection efi-export-env
+
+@deffn Command efi-export-env varname [varname @dots{}]
+Export the given GRUB variables to the GRUB_ENV UEFI variable as a GRUB
+environment block. The contents of an existing environment block in GRUB_ENV
+will be merged. So variables existing in GRUB_ENV but not given as arguements
+will be unaffected by this command.
+@end deffn
+
+
+@node efi-load-env
+@subsection efi-load-env
+
+@deffn Command efi-load-env
+Load the grub environment from the GRUB_ENV UEFI variable. This will overwrite
+existing variables if they exist in the environment block present in the UEFI
+variable. Other existing GRUB variables will be unchanged. This can allow for
+the persistence of state across boots.
+@end deffn
+
+
 @node efitextmode
 @subsection efitextmode
 
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 5699736dad20..640f9176d306 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -829,6 +829,12 @@ module = {
   enable = efi;
 };
 
+module = {
+  name = efienv;
+  common = commands/efi/env.c;
+  enable = efi;
+};
+
 module = {
   name = efifwsetup;
   efi = commands/efi/efifwsetup.c;
diff --git a/grub-core/commands/efi/env.c b/grub-core/commands/efi/env.c
new file mode 100644
index 000000000000..b5775bcbd4bc
--- /dev/null
+++ b/grub-core/commands/efi/env.c
@@ -0,0 +1,182 @@
+/* env.c - commands to load/export environment block to EFI variable */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2023  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <grub/dl.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+#include <grub/types.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+#include <grub/efi/api.h>
+#include <grub/efi/efi.h>
+#include <grub/env.h>
+#include <grub/lib/envblk.h>
+#include <grub/command.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static const grub_guid_t grub_env_guid = GRUB_EFI_GRUB_VARIABLE_GUID;
+
+static grub_err_t
+grub_efi_export_env (grub_command_t cmd __attribute__ ((unused)),
+		     int argc, char *argv[])
+{
+  const char *value;
+  char *old_value;
+  struct grub_envblk envblk_s = { NULL, 0 };
+  grub_envblk_t envblk = &envblk_s;
+  grub_err_t err = GRUB_ERR_NONE;
+  int i, changed = 1;
+  grub_efi_status_t status;
+
+  grub_dprintf ("efienv", "argc:%d\n", argc);
+  for (i = 0; i < argc; i++)
+    grub_dprintf ("efienv", "argv[%d]: %s\n", i, argv[i]);
+
+  if (argc < 1)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("variable names expected"));
+
+  status = grub_efi_get_variable ("GRUB_ENV", &grub_env_guid, &envblk_s.size,
+				  (void **) &envblk_s.buf);
+  if (envblk_s.buf == NULL || envblk_s.size < 1 || status != GRUB_EFI_SUCCESS)
+    {
+      char *buf = grub_malloc (DEFAULT_ENVBLK_SIZE + 1);
+      if (!buf)
+        return grub_errno;
+
+      grub_memcpy (buf, GRUB_ENVBLK_SIGNATURE, sizeof (GRUB_ENVBLK_SIGNATURE) - 1);
+      grub_memset (buf + sizeof (GRUB_ENVBLK_SIGNATURE) - 1, '#',
+	      DEFAULT_ENVBLK_SIZE - sizeof (GRUB_ENVBLK_SIGNATURE) + 1);
+      buf[DEFAULT_ENVBLK_SIZE] = '\0';
+
+      envblk_s.buf = buf;
+      envblk_s.size = DEFAULT_ENVBLK_SIZE;
+    }
+  else
+    {
+      char *buf = grub_realloc (envblk_s.buf, envblk_s.size + 1);
+      if (buf == NULL)
+	{
+	  err = grub_errno;
+	  goto cleanup;
+	}
+
+      envblk_s.buf = buf;
+      envblk_s.buf[envblk_s.size] = '\0';
+    }
+
+  for (i = 0; i < argc; i++)
+    {
+      err = grub_envblk_get (envblk, argv[i], &old_value);
+      if (err != GRUB_ERR_NONE)
+	{
+	  grub_dprintf ("efienv", "grub_envblk_get returned %d\n", err);
+	  goto cleanup;
+	}
+
+      value = grub_env_get (argv[i]);
+      if ((value == NULL && old_value == NULL) ||
+	  (value && old_value && !grub_strcmp (old_value, value)))
+	changed = 0;
+
+      if (old_value != NULL)
+	grub_free (old_value);
+
+      if (changed == 0)
+	{
+	  grub_dprintf ("efienv", "No changes necessary for \"%s\"\n", argv[i]);
+	  continue;
+	}
+
+      if (value != NULL)
+	{
+	  grub_dprintf ("efienv", "setting \"%s\" to \"%s\"\n", argv[i], value);
+	  grub_envblk_set (envblk, argv[i], value);
+	}
+      else
+	{
+	  grub_dprintf ("efienv", "deleting \"%s\" from envblk\n", argv[i]);
+	  grub_envblk_delete (envblk, argv[0]);
+	}
+
+      grub_dprintf ("efienv", "envblk is %" PRIuGRUB_SIZE " bytes:\n\"%s\"\n",
+		    envblk_s.size, envblk_s.buf);
+    }
+
+  grub_dprintf ("efienv", "removing GRUB_ENV\n");
+  status = grub_efi_set_variable ("GRUB_ENV", &grub_env_guid, NULL, 0);
+  if (status != GRUB_EFI_SUCCESS)
+    grub_dprintf ("efienv", "removal returned 0x%" PRIxGRUB_EFI_UINTN_T "\n", status);
+
+  grub_dprintf ("efienv", "setting GRUB_ENV\n");
+  status = grub_efi_set_variable ("GRUB_ENV", &grub_env_guid,
+				  envblk_s.buf, envblk_s.size);
+  if (status != GRUB_EFI_SUCCESS)
+    grub_dprintf ("efienv", "setting GRUB_ENV returned %" PRIxGRUB_EFI_UINTN_T "\n", status);
+
+ cleanup:
+  grub_free (envblk_s.buf);
+
+  return err;
+}
+
+static int
+set_var (const char *name, const char *value,
+	 void *whitelist __attribute__((__unused__)))
+{
+  grub_env_set (name, value);
+  return 0;
+}
+
+static grub_err_t
+grub_efi_load_env (grub_command_t cmd __attribute__ ((unused)),
+		   int argc, char *argv[] __attribute__((__unused__)))
+{
+  struct grub_envblk envblk_s = { NULL, 0 };
+  grub_envblk_t envblk = &envblk_s;
+
+  if (argc > 0)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("unexpected argument"));
+
+  grub_efi_get_variable ("GRUB_ENV", &grub_env_guid, &envblk_s.size,
+                         (void **) &envblk_s.buf);
+  if (envblk_s.buf == NULL || envblk_s.size < 1)
+    return 0;
+
+  grub_envblk_iterate (envblk, NULL, set_var);
+  grub_free (envblk_s.buf);
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_command_t export_cmd, loadenv_cmd;
+
+GRUB_MOD_INIT(efienv)
+{
+  export_cmd = grub_register_command ("efi-export-env", grub_efi_export_env,
+	    N_("VARIABLE_NAME [VARIABLE_NAME ...]"),
+	    N_("Export environment variable to UEFI."));
+  loadenv_cmd = grub_register_command ("efi-load-env", grub_efi_load_env,
+	    NULL, N_("Load the grub environment from UEFI."));
+}
+
+GRUB_MOD_FINI(efienv)
+{
+  grub_unregister_command (export_cmd);
+  grub_unregister_command (loadenv_cmd);
+}
diff --git a/grub-core/kern/efi/efi.c b/grub-core/kern/efi/efi.c
index b93ae3aba12d..38e508ff6c28 100644
--- a/grub-core/kern/efi/efi.c
+++ b/grub-core/kern/efi/efi.c
@@ -222,6 +222,9 @@ grub_efi_set_variable_with_attributes (const char *var, const grub_guid_t *guid,
   if (status == GRUB_EFI_SUCCESS)
     return GRUB_ERR_NONE;
 
+  if (status == GRUB_EFI_NOT_FOUND && datasize == 0)
+    return GRUB_ERR_NONE;
+
   return grub_error (GRUB_ERR_IO, "could not set EFI variable `%s'", var);
 }
 
diff --git a/grub-core/lib/envblk.c b/grub-core/lib/envblk.c
index 2e4e78b132d4..ed7eb258e1c7 100644
--- a/grub-core/lib/envblk.c
+++ b/grub-core/lib/envblk.c
@@ -223,6 +223,49 @@ grub_envblk_delete (grub_envblk_t envblk, const char *name)
     }
 }
 
+struct get_var_state {
+  const char * const name;
+  char * value;
+  int found;
+};
+
+static int
+get_var (const char * const name, const char * const value, void *statep)
+{
+  struct get_var_state *state = (struct get_var_state *) statep;
+
+  if (!grub_strcmp (state->name, name))
+    {
+      state->found = 1;
+      state->value = grub_strdup (value);
+      if (state->value == NULL)
+	grub_errno = grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
+
+      return 1;
+    }
+
+  return 0;
+}
+
+grub_err_t
+grub_envblk_get (grub_envblk_t envblk, const char * const name, char ** const value)
+{
+  struct get_var_state state = {
+      .name = name,
+      .value = NULL,
+      .found = 0,
+  };
+
+  grub_envblk_iterate (envblk, (void *) &state, get_var);
+
+  *value = state.value;
+
+  if (state.found && state.value == NULL)
+    return grub_errno;
+
+  return GRUB_ERR_NONE;
+}
+
 void
 grub_envblk_iterate (grub_envblk_t envblk,
                      void *hook_data,
diff --git a/include/grub/lib/envblk.h b/include/grub/lib/envblk.h
index c3e655921709..ab969af24612 100644
--- a/include/grub/lib/envblk.h
+++ b/include/grub/lib/envblk.h
@@ -22,6 +22,8 @@
 #define GRUB_ENVBLK_SIGNATURE	"# GRUB Environment Block\n"
 #define GRUB_ENVBLK_DEFCFG	"grubenv"
 
+#define DEFAULT_ENVBLK_SIZE	1024
+
 #ifndef ASM_FILE
 
 struct grub_envblk
@@ -33,6 +35,7 @@ typedef struct grub_envblk *grub_envblk_t;
 
 grub_envblk_t grub_envblk_open (char *buf, grub_size_t size);
 int grub_envblk_set (grub_envblk_t envblk, const char *name, const char *value);
+grub_err_t grub_envblk_get (grub_envblk_t envblk, const char * const name, char ** const value);
 void grub_envblk_delete (grub_envblk_t envblk, const char *name);
 void grub_envblk_iterate (grub_envblk_t envblk,
                           void *hook_data,
-- 
2.34.1


_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel

[PATCH v2 3/4] tests: Add efienv_test for testing efi-export-env and efi-load-env

[Glenn Washburn]

Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 Makefile.util.def    |  6 +++++
 tests/efienv_test.in | 57 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)
 create mode 100644 tests/efienv_test.in

diff --git a/Makefile.util.def b/Makefile.util.def
index 0f74a1680f13..539f8c4edd9a 100644
--- a/Makefile.util.def
+++ b/Makefile.util.def
@@ -1185,6 +1185,12 @@ script = {
   common = tests/help_test.in;
 };
 
+script = {
+  testcase = nonnative;
+  name = efienv_test;
+  common = tests/efienv_test.in;
+};
+
 script = {
   testcase = nonnative;
   name = grub_script_gettext;
diff --git a/tests/efienv_test.in b/tests/efienv_test.in
new file mode 100644
index 000000000000..8ae8c2893d53
--- /dev/null
+++ b/tests/efienv_test.in
@@ -0,0 +1,57 @@
+#! @BUILD_SHEBANG@
+# Copyright (C) 2023  Free Software Foundation, Inc.
+#
+# GRUB is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# GRUB is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+
+set -e
+grubshell=@builddir@/grub-shell
+
+. "@builddir@/grub-core/modinfo.sh"
+
+case "${grub_modinfo_target_cpu}-${grub_modinfo_platform}" in
+    *-efi)
+	;;
+    # Skip Non-EFI platforms, as this test does not apply
+    *)
+	exit 77;;
+esac
+
+test_script() {
+  cat <<'EOF'
+  efienv_test_var_val="#1 some \\$test value."
+
+  if [ "$efienv_test_var" == "$efienv_test_var_val" ]; then
+    echo TEST PASSED
+  else
+    efienv_test_var="XXX${efienv_test_var_val}"
+    efi-export-env efienv_test_var
+    efienv_test_var=erased
+    efi-load-env
+
+    if [ "$efienv_test_var" != "XXX${efienv_test_var_val}" ]; then
+      echo TEST FAILED
+      halt
+    fi
+
+    efienv_test_var="${efienv_test_var_val}"
+    efi-export-env efienv_test_var
+    reboot
+  fi
+EOF
+}
+
+output=$(test_script | "${grubshell}" --modules="efienv,halt" | tail -n1)
+if [ "$output" != "TEST PASSED" ]; then
+   exit 1
+fi
-- 
2.34.1


_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel

[PATCH v2 4/4] efi: Print GDB command for loading symbols if variable exists

[Glenn Washburn]

If the variable "enable_earlyinit_gdbinfo" exists, print the GDB command
needed to properly load symbols in an attached GDB session. This variable
must come from the environment block stored in the GRUB_ENV EFI variable,
which allows this to get printed as early as possible.

Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 grub-core/kern/efi/init.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/grub-core/kern/efi/init.c b/grub-core/kern/efi/init.c
index 2da6036129a1..bdc65fb72ef3 100644
--- a/grub-core/kern/efi/init.c
+++ b/grub-core/kern/efi/init.c
@@ -125,6 +125,8 @@ grub_efi_env_init (void)
 void
 grub_efi_init (void)
 {
+  const char *value;
+
   grub_modbase = grub_efi_section_addr ("mods");
   /* First of all, initialize the console so that GRUB can display
      messages.  */
@@ -136,6 +138,10 @@ grub_efi_init (void)
   /* Populate environment with variables from EFI envblk, if it exists.  */
   grub_efi_env_init ();
 
+  value = grub_env_get ("enable_earlyinit_gdbinfo");
+  if (value != NULL && !grub_strcmp (value, "1"))
+    grub_efi_print_gdb_info ();
+
   /*
    * Lockdown the GRUB and register the shim_lock verifier
    * if the UEFI Secure Boot is enabled.
-- 
2.34.1


_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel

Re: [PATCH v2 0/4] EFI envblk

[Glenn Washburn]

Daniel,

Is this still in the to be reviewed queue? Despite how long its been, I
believe this patch series still applies cleanly to master.

Glenn

On Mon, 23 Sep 2024 01:04:54 -0500
Glenn Washburn <development@efficientek.com> wrote:

> Update v2:
>  * Rebase onto current master. This really did not change the contents of
>    the patch though
> 
> This patch series (for me) was motivated by the "gdb: Add more support for
> debugging on EFI platforms" patch series, which allowed printing in early
> EFI init of the GDB command for properly loading symbols. That approach of
> having the functionality be included at compile time was ultimately
> rejected. During the discussion of that series, Robbie suggested[1] using
> patches by Peter and in the Redhat downstream repo which uses an EFI
> variable to store a GRUB env block. Using this, a user could store a
> variable in the env block stored in the EFI variable and then have GRUB
> load that env block in early init as a way to enable the printing of the
> GDB command.
> 
> I've taken the original patches by Peter, made more suitable for including
> in GRUB, fixed some bugs, and added a minor feature. The first patch, adds
> env block loading in early EFI init from the GRUB_ENV EFI variable. The
> second patch is included to provide tools for GRUB to set this EFI env
> block itself, as opposed to needing to use the method suggested by
> Robbie[1], which requires GNU/Linux and the user-space grub2-editenv
> utility. Of course, if GRUB is crashing before one can run the
> efi-export-env command, then other ways of creating and setting the EFI
> envblk variable are necessary. The third patch adds a test which checks the
> usability of the commands and the early init loading. And the last patch,
> whichvmotivated this series, prints the GDB command string if the GRUB
> variable named "enable_earlyinit_gdbinfo" is present and is set to "1", after
> the env block is loaded from the GRUB_ENV EFI variable. We might want a
> different name for the GRUB variable, I don't really have a preference.
> 
> Glenn
> 
> [1] https://mail.gnu.org/archive/html/grub-devel/2023-03/msg00072.html
> 
> Glenn Washburn (2):
>   tests: Add efienv_test for testing efi-export-env and efi-load-env
>   efi: Print GDB command for loading symbols if variable exists
> 
> Peter Jones (2):
>   efi: Load env block from GRUB_ENV EFI variable in early init
>   efi: Add efi-export-env and efi-load-env commands
> 
>  Makefile.util.def            |   6 ++
>  docs/grub.texi               |  24 +++++
>  grub-core/Makefile.core.def  |   7 ++
>  grub-core/commands/efi/env.c | 182 +++++++++++++++++++++++++++++++++++
>  grub-core/kern/efi/efi.c     |   3 +
>  grub-core/kern/efi/init.c    |  37 +++++++
>  grub-core/lib/envblk.c       |  43 +++++++++
>  include/grub/efi/efi.h       |   5 +
>  include/grub/lib/envblk.h    |   3 +
>  tests/efienv_test.in         |  57 +++++++++++
>  10 files changed, 367 insertions(+)
>  create mode 100644 grub-core/commands/efi/env.c
>  create mode 100644 tests/efienv_test.in
> 
> Range-diff against v1:
> 1:  15a9c7112eae ! 1:  d2ad090d7486 efi: Load env block from GRUB_ENV EFI variable in early init
>     @@ grub-core/kern/efi/init.c
>       #ifdef GRUB_STACK_PROTECTOR
>       
>       static grub_efi_char16_t stack_chk_fail_msg[] =
>     -@@ grub-core/kern/efi/init.c: stack_protector_init (void)
>     +@@ grub-core/kern/efi/init.c: grub_stack_protector_init (void)
>       
>       grub_addr_t grub_modbase;
>       
> 2:  d000cdbd0468 = 2:  456f4245ef76 efi: Add efi-export-env and efi-load-env commands
> 3:  3966eba4a32b = 3:  04072bccc2c7 tests: Add efienv_test for testing efi-export-env and efi-load-env
> 4:  b65e7a8bac40 = 4:  a23667d25f40 efi: Print GDB command for loading symbols if variable exists

_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel