grub2/SOURCES/0125-Make-a-gdb-dprintf-that-tells-us-load-addresses.patch

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2021-02-12 08:18:34 +00:00
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Thu, 25 Jun 2015 15:11:36 -0400
Subject: [PATCH] Make a "gdb" dprintf that tells us load addresses.
This makes a grub_dprintf() call during platform init and during module
loading that tells us the virtual addresses of the .text and .data
sections of grub-core/kernel.exec and any modules it loads.
Specifically, it displays them in the gdb "add-symbol-file" syntax, with
the presumption that there's a variable $grubdir that reflects the path
to any such binaries.
Signed-off-by: Peter Jones <pjones@redhat.com>
---
grub-core/kern/dl.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++
grub-core/kern/efi/efi.c | 4 ++--
grub-core/kern/efi/init.c | 26 +++++++++++++++++++++++-
include/grub/efi/efi.h | 2 +-
4 files changed, 78 insertions(+), 4 deletions(-)
diff --git a/grub-core/kern/dl.c b/grub-core/kern/dl.c
index 5028d157c46..eb8b969cded 100644
--- a/grub-core/kern/dl.c
+++ b/grub-core/kern/dl.c
@@ -501,6 +501,23 @@ grub_dl_find_section (Elf_Ehdr *e, const char *name)
return s;
return NULL;
}
+static long
+grub_dl_find_section_index (Elf_Ehdr *e, const char *name)
+{
+ Elf_Shdr *s;
+ const char *str;
+ unsigned i;
+
+ s = (Elf_Shdr *) ((char *) e + e->e_shoff + e->e_shstrndx * e->e_shentsize);
+ str = (char *) e + s->sh_offset;
+
+ for (i = 0, s = (Elf_Shdr *) ((char *) e + e->e_shoff);
+ i < e->e_shnum;
+ i++, s = (Elf_Shdr *) ((char *) s + e->e_shentsize))
+ if (grub_strcmp (str + s->sh_name, name) == 0)
+ return (long)i;
+ return -1;
+}
/* Me, Vladimir Serbinenko, hereby I add this module check as per new
GNU module policy. Note that this license check is informative only.
@@ -644,6 +661,37 @@ grub_dl_relocate_symbols (grub_dl_t mod, void *ehdr)
return GRUB_ERR_NONE;
}
+static void
+grub_dl_print_gdb_info (grub_dl_t mod, Elf_Ehdr *e)
+{
+ void *text, *data = NULL;
+ long idx;
+
+ idx = grub_dl_find_section_index (e, ".text");
+ if (idx < 0)
+ return;
+
+ text = grub_dl_get_section_addr (mod, idx);
+ if (!text)
+ return;
+
+ idx = grub_dl_find_section_index (e, ".data");
+ if (idx >= 0)
+ data = grub_dl_get_section_addr (mod, idx);
+
+ if (data)
+ grub_qdprintf ("gdb", "add-symbol-file \\\n"
+ "/usr/lib/debug/usr/lib/grub/%s-%s/%s.debug "
+ "\\\n %p -s .data %p\n",
+ GRUB_TARGET_CPU, GRUB_PLATFORM,
+ mod->name, text, data);
+ else
+ grub_qdprintf ("gdb", "add-symbol-file \\\n"
+ "/usr/lib/debug/usr/lib/grub/%s-%s/%s.debug "
+ "\\\n%p\n",
+ GRUB_TARGET_CPU, GRUB_PLATFORM,
+ mod->name, text);
+}
/* Load a module from core memory. */
grub_dl_t
@@ -703,6 +751,8 @@ grub_dl_load_core_noinit (void *addr, grub_size_t size)
grub_dprintf ("modules", "module name: %s\n", mod->name);
grub_dprintf ("modules", "init function: %p\n", mod->init);
+ grub_dl_print_gdb_info (mod, e);
+
if (grub_dl_add (mod))
{
grub_dl_unload (mod);
diff --git a/grub-core/kern/efi/efi.c b/grub-core/kern/efi/efi.c
index bcae7f4699d..a2a732ffc0d 100644
--- a/grub-core/kern/efi/efi.c
+++ b/grub-core/kern/efi/efi.c
@@ -283,7 +283,7 @@ grub_efi_get_variable (const char *var, const grub_efi_guid_t *guid,
/* Search the mods section from the PE32/PE32+ image. This code uses
a PE32 header, but should work with PE32+ as well. */
grub_addr_t
-grub_efi_modules_addr (void)
+grub_efi_section_addr (const char *section_name)
{
grub_efi_loaded_image_t *image;
struct grub_pe32_header *header;
@@ -308,7 +308,7 @@ grub_efi_modules_addr (void)
i < coff_header->num_sections;
i++, section++)
{
- if (grub_strcmp (section->name, "mods") == 0)
+ if (grub_strcmp (section->name, section_name) == 0)
break;
}
diff --git a/grub-core/kern/efi/init.c b/grub-core/kern/efi/init.c
index 71d2279a0c1..e6183a4c44d 100644
--- a/grub-core/kern/efi/init.c
+++ b/grub-core/kern/efi/init.c
@@ -59,10 +59,33 @@ grub_efi_env_init (void)
grub_free (envblk_s.buf);
}
+static void
+grub_efi_print_gdb_info (void)
+{
+ grub_addr_t text;
+ grub_addr_t data;
+
+ text = grub_efi_section_addr (".text");
+ if (!text)
+ return;
+
+ data = grub_efi_section_addr (".data");
+ if (data)
+ grub_qdprintf ("gdb",
+ "add-symbol-file /usr/lib/debug/usr/lib/grub/%s-%s/"
+ "kernel.exec %p -s .data %p\n",
+ GRUB_TARGET_CPU, GRUB_PLATFORM, (void *)text, (void *)data);
+ else
+ grub_qdprintf ("gdb",
+ "add-symbol-file /usr/lib/debug/usr/lib/grub/%s-%s/"
+ "kernel.exec %p\n",
+ GRUB_TARGET_CPU, GRUB_PLATFORM, (void *)text);
+}
+
void
grub_efi_init (void)
{
- grub_modbase = grub_efi_modules_addr ();
+ grub_modbase = grub_efi_section_addr ("mods");
/* First of all, initialize the console so that GRUB can display
messages. */
grub_console_init ();
@@ -74,6 +97,7 @@ grub_efi_init (void)
0, 0, 0, NULL);
grub_efi_env_init ();
+ grub_efi_print_gdb_info ();
grub_efidisk_init ();
}
diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
index 09a18e56302..570a69361a5 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -132,7 +132,7 @@ grub_err_t grub_armxx_efi_linux_check_image(struct linux_armxx_kernel_header *lh
grub_err_t grub_armxx_efi_linux_boot_image(grub_addr_t addr, char *args);
#endif
-grub_addr_t grub_efi_modules_addr (void);
+grub_addr_t grub_efi_section_addr (const char *section);
void grub_efi_mm_init (void);
void grub_efi_mm_fini (void);