[tip:,x86/boot] x86/boot: Drop PE/COFF .reloc section
Commit Message
The following commit has been merged into the x86/boot branch of tip:
Commit-ID: fa5750521e0a4efbc1af05223da9c4bbd6c21c83
Gitweb: https://git.kernel.org/tip/fa5750521e0a4efbc1af05223da9c4bbd6c21c83
Author: Ard Biesheuvel <ardb@kernel.org>
AuthorDate: Fri, 15 Sep 2023 17:16:30
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Sun, 17 Sep 2023 19:48:43 +02:00
x86/boot: Drop PE/COFF .reloc section
Ancient buggy EFI loaders may have required a .reloc section to be
present at some point in time, but this has not been true for a long
time so the .reloc section can just be dropped.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915171623.655440-16-ardb@google.com
---
arch/x86/boot/header.S | 20 --------------------
arch/x86/boot/setup.ld | 4 ++--
arch/x86/boot/tools/build.c | 34 +++++-----------------------------
3 files changed, 7 insertions(+), 51 deletions(-)
@@ -155,26 +155,6 @@ section_table:
IMAGE_SCN_MEM_READ | \
IMAGE_SCN_MEM_EXECUTE # Characteristics
- #
- # The EFI application loader requires a relocation section
- # because EFI applications must be relocatable. The .reloc
- # offset & size fields are filled in by build.c.
- #
- .ascii ".reloc"
- .byte 0
- .byte 0
- .long 0
- .long 0
- .long 0 # SizeOfRawData
- .long 0 # PointerToRawData
- .long 0 # PointerToRelocations
- .long 0 # PointerToLineNumbers
- .word 0 # NumberOfRelocations
- .word 0 # NumberOfLineNumbers
- .long IMAGE_SCN_CNT_INITIALIZED_DATA | \
- IMAGE_SCN_MEM_READ | \
- IMAGE_SCN_MEM_DISCARDABLE # Characteristics
-
#ifdef CONFIG_EFI_MIXED
#
# The offset & size fields are filled in by build.c.
@@ -40,8 +40,8 @@ SECTIONS
setup_sig = .;
LONG(0x5a5aaa55)
- /* Reserve some extra space for the reloc and compat sections */
- setup_size = ALIGN(ABSOLUTE(.) + 64, 512);
+ /* Reserve some extra space for the compat section */
+ setup_size = ALIGN(ABSOLUTE(.) + 32, 512);
setup_sects = ABSOLUTE(setup_size / 512);
}
@@ -47,7 +47,6 @@ typedef unsigned int u32;
/* This must be large enough to hold the entire setup */
u8 buf[SETUP_SECT_MAX*512];
-#define PECOFF_RELOC_RESERVE 0x20
#define PECOFF_COMPAT_RESERVE 0x20
static unsigned long efi32_pe_entry;
@@ -180,24 +179,13 @@ static void update_pecoff_section_header(char *section_name, u32 offset, u32 siz
update_pecoff_section_header_fields(section_name, offset, size, size, offset);
}
-static void update_pecoff_setup_and_reloc(unsigned int size)
+static void update_pecoff_setup(unsigned int size)
{
u32 setup_offset = 0x200;
- u32 reloc_offset = size - PECOFF_RELOC_RESERVE - PECOFF_COMPAT_RESERVE;
-#ifdef CONFIG_EFI_MIXED
- u32 compat_offset = reloc_offset + PECOFF_RELOC_RESERVE;
-#endif
- u32 setup_size = reloc_offset - setup_offset;
+ u32 compat_offset = size - PECOFF_COMPAT_RESERVE;
+ u32 setup_size = compat_offset - setup_offset;
update_pecoff_section_header(".setup", setup_offset, setup_size);
- update_pecoff_section_header(".reloc", reloc_offset, PECOFF_RELOC_RESERVE);
-
- /*
- * Modify .reloc section contents with a single entry. The
- * relocation is applied to offset 10 of the relocation section.
- */
- put_unaligned_le32(reloc_offset + 10, &buf[reloc_offset]);
- put_unaligned_le32(10, &buf[reloc_offset + 4]);
#ifdef CONFIG_EFI_MIXED
update_pecoff_section_header(".compat", compat_offset, PECOFF_COMPAT_RESERVE);
@@ -214,21 +202,10 @@ static void update_pecoff_setup_and_reloc(unsigned int size)
#endif
}
-static int reserve_pecoff_reloc_section(int c)
-{
- /* Reserve 0x20 bytes for .reloc section */
- memset(buf+c, 0, PECOFF_RELOC_RESERVE);
- return PECOFF_RELOC_RESERVE;
-}
-
#else
-static inline void update_pecoff_setup_and_reloc(unsigned int size) {}
+static inline void update_pecoff_setup(unsigned int size) {}
-static inline int reserve_pecoff_reloc_section(int c)
-{
- return 0;
-}
#endif /* CONFIG_EFI_STUB */
static int reserve_pecoff_compat_section(int c)
@@ -307,7 +284,6 @@ int main(int argc, char ** argv)
fclose(file);
c += reserve_pecoff_compat_section(c);
- c += reserve_pecoff_reloc_section(c);
/* Pad unused space with zeros */
setup_sectors = (c + 511) / 512;
@@ -316,7 +292,7 @@ int main(int argc, char ** argv)
i = setup_sectors*512;
memset(buf+c, 0, i-c);
- update_pecoff_setup_and_reloc(i);
+ update_pecoff_setup(i);
/* Open and stat the kernel file */
fd = open(argv[2], O_RDONLY);