grub2/0231-Make-linux_arm_kernel_header.hdr_offset-be-at-the-ri.patch
Peter Jones bed013f094 Fix arm32 off-by-one error on reading the PE header.
Signed-off-by: Peter Jones <pjones@redhat.com>
2018-08-16 13:55:16 -04:00

113 lines
4.3 KiB
Diff

From 2d9fe8142b8d470ffe63a23f7788e1c2530401d2 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Thu, 16 Aug 2018 11:08:11 -0400
Subject: [PATCH] Make linux_arm_kernel_header.hdr_offset be at the right place
The kernel in front of me (slightly edited to make objdump work) looks like:
00000000 4d 5a 10 13 4d 5a 10 13 4d 5a 10 13 4d 5a 10 13 |MZ..MZ..MZ..MZ..|
00000010 4d 5a 10 13 4d 5a 10 13 4d 5a 10 13 00 00 a0 e1 |MZ..MZ..MZ......|
00000020 f6 03 00 ea 18 28 6f 01 00 00 00 00 00 32 74 00 |.....(o......2t.|
00000030 01 02 03 04 45 45 45 45 74 a2 00 00 40 00 00 00 |....EEEEt...@...|
00000040 50 45 00 00 4c 01 04 00 00 00 00 00 00 00 00 00 |PE..L...........|
00000050 00 00 00 00 90 00 06 03 0b 01 02 14 00 20 74 00 |............. t.|
00000060 00 14 00 00 00 00 00 00 b4 19 00 00 00 10 00 00 |................|
00000070 00 30 74 00 00 00 00 00 00 10 00 00 00 02 00 00 |.0t.............|
00000080 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000090 00 44 74 00 00 10 00 00 00 00 00 00 0a 00 00 00 |.Dt.............|
000000a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000b0 00 00 00 00 06 00 00 00 00 00 00 00 00 00 00 00 |................|
000000c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
(I don't know why the MZ header is there 7 times, but the offsets work out, so
it's merely a surprising distraction.)
If linux_arm_kernel_header.reserved2 is 16 bytes, that means hdr_offset is
here:
00000030 01 02 03 04 45 45 45 45 74 a2 00 00 40 00 00 00 |....EEEEt...@...|
00000040 50 45 00 00 4c 01 04 00 00 00 00 00 00 00 00 00 |PE..L...........|
^^^^^^^^^^^
But it's supposed to be 4 bytes before that.
This patch makes the reserved field be 3*32 instead of 4*32, and that means we
can find the PE header correcrtly at 0x40 by reading the value at 0x3c.
Signed-off-by: Peter Jones <pjones@redhat.com>
---
grub-core/kern/dl.c | 5 +++++
grub-core/loader/efi/linux.c | 3 +++
include/grub/arm/linux.h | 2 +-
3 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/grub-core/kern/dl.c b/grub-core/kern/dl.c
index 91105bc4677..3625bd656aa 100644
--- a/grub-core/kern/dl.c
+++ b/grub-core/kern/dl.c
@@ -701,6 +701,7 @@ grub_dl_load_core_noinit (void *addr, grub_size_t size)
Elf_Ehdr *e;
grub_dl_t mod;
+ grub_env_set ("debug", "linux,modules,gdb,secureboot");
grub_dprintf ("modules", "module at %p, size 0x%lx\n", addr,
(unsigned long) size);
e = addr;
@@ -768,6 +769,7 @@ grub_dl_load_core (void *addr, grub_size_t size)
{
grub_dl_t mod;
+ grub_env_set ("debug", "linux,modules,gdb,secureboot");
grub_boot_time ("Parsing module");
mod = grub_dl_load_core_noinit (addr, size);
@@ -791,6 +793,7 @@ grub_dl_load_file (const char *filename)
void *core = 0;
grub_dl_t mod = 0;
+ grub_env_set ("debug", "linux,modules,gdb,secureboot");
#ifdef GRUB_MACHINE_EFI
if (grub_efi_secure_boot ())
{
@@ -850,6 +853,8 @@ grub_dl_load (const char *name)
grub_dl_t mod;
const char *grub_dl_dir = grub_env_get ("prefix");
+ grub_env_set ("debug", "linux,modules,gdb,secureboot");
+
mod = grub_dl_get (name);
if (mod)
return mod;
diff --git a/grub-core/loader/efi/linux.c b/grub-core/loader/efi/linux.c
index 0622dfa48d4..b56ea0bc041 100644
--- a/grub-core/loader/efi/linux.c
+++ b/grub-core/loader/efi/linux.c
@@ -79,7 +79,10 @@ grub_efi_linux_boot (void *kernel_addr, grub_off_t handover_offset,
offset = 512;
#endif
+ grub_dprintf ("linux", "kernel_addr: %p handover_offset: %p params: %p\n",
+ kernel_addr, (void *)(grub_efi_uintn_t)handover_offset, kernel_params);
hf = (handover_func)((char *)kernel_addr + handover_offset + offset);
+ grub_dprintf ("linux", "handover_func() = %p\n", hf);
hf (grub_efi_image_handle, grub_efi_system_table, kernel_params);
return GRUB_ERR_BUG;
diff --git a/include/grub/arm/linux.h b/include/grub/arm/linux.h
index 5900fc8a40c..bed308f22cb 100644
--- a/include/grub/arm/linux.h
+++ b/include/grub/arm/linux.h
@@ -31,7 +31,7 @@ struct linux_arm_kernel_header {
grub_uint32_t magic;
grub_uint32_t start; /* _start */
grub_uint32_t end; /* _edata */
- grub_uint32_t reserved2[4];
+ grub_uint32_t reserved2[3];
grub_uint32_t hdr_offset;
};
--
2.17.1