This is a note to let you know that I've just added the patch titled
x86/decompressor: Factor out kernel decompression and relocation
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-decompressor-factor-out-kernel-decompression-and-relocation.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable+bounces-25903-greg=kroah.com@xxxxxxxxxxxxxxx Mon Mar 4 12:21:02 2024
From: Ard Biesheuvel <ardb+git@xxxxxxxxxx>
Date: Mon, 4 Mar 2024 12:19:48 +0100
Subject: x86/decompressor: Factor out kernel decompression and relocation
To: stable@xxxxxxxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx, Ard Biesheuvel <ardb@xxxxxxxxxx>, Borislav Petkov <bp@xxxxxxxxx>
Message-ID: <20240304111937.2556102-30-ardb+git@xxxxxxxxxx>
From: Ard Biesheuvel <ardb+git@xxxxxxxxxx>
From: Ard Biesheuvel <ardb@xxxxxxxxxx>
[ Commit 83381519352d6b5b3e429bf72aaab907480cb6b6 upstream ]
Factor out the decompressor sequence that invokes the decompressor,
parses the ELF and applies the relocations so that it can be called
directly from the EFI stub.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230807162720.545787-21-ardb@xxxxxxxxxx
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/boot/compressed/misc.c | 29 ++++++++++++++++++++++++-----
arch/x86/include/asm/boot.h | 8 ++++++++
2 files changed, 32 insertions(+), 5 deletions(-)
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -330,11 +330,33 @@ static size_t parse_elf(void *output)
return ehdr.e_entry - LOAD_PHYSICAL_ADDR;
}
+const unsigned long kernel_total_size = VO__end - VO__text;
+
static u8 boot_heap[BOOT_HEAP_SIZE] __aligned(4);
extern unsigned char input_data[];
extern unsigned int input_len, output_len;
+unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr,
+ void (*error)(char *x))
+{
+ unsigned long entry;
+
+ if (!free_mem_ptr) {
+ free_mem_ptr = (unsigned long)boot_heap;
+ free_mem_end_ptr = (unsigned long)boot_heap + sizeof(boot_heap);
+ }
+
+ if (__decompress(input_data, input_len, NULL, NULL, outbuf, output_len,
+ NULL, error) < 0)
+ return ULONG_MAX;
+
+ entry = parse_elf(outbuf);
+ handle_relocations(outbuf, output_len, virt_addr);
+
+ return entry;
+}
+
/*
* The compressed kernel image (ZO), has been moved so that its position
* is against the end of the buffer used to hold the uncompressed kernel
@@ -354,7 +376,6 @@ extern unsigned int input_len, output_le
*/
asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output)
{
- const unsigned long kernel_total_size = VO__end - VO__text;
unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
memptr heap = (memptr)boot_heap;
unsigned long needed_size;
@@ -457,10 +478,8 @@ asmlinkage __visible void *extract_kerne
#endif
debug_putstr("\nDecompressing Linux... ");
- __decompress(input_data, input_len, NULL, NULL, output, output_len,
- NULL, error);
- entry_offset = parse_elf(output);
- handle_relocations(output, output_len, virt_addr);
+
+ entry_offset = decompress_kernel(output, virt_addr, error);
debug_putstr("done.\nBooting the kernel (entry_offset: 0x");
debug_puthex(entry_offset);
--- a/arch/x86/include/asm/boot.h
+++ b/arch/x86/include/asm/boot.h
@@ -79,4 +79,12 @@
# define BOOT_STACK_SIZE 0x1000
#endif
+#ifndef __ASSEMBLY__
+extern unsigned int output_len;
+extern const unsigned long kernel_total_size;
+
+unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr,
+ void (*error)(char *x));
+#endif
+
#endif /* _ASM_X86_BOOT_H */
Patches currently in stable-queue which might be from kroah.com@xxxxxxxxxxxxxxx are
queue-6.1/x86-decompressor-avoid-magic-offsets-for-efi-handover-entrypoint.patch
queue-6.1/x86-efistub-avoid-placing-the-kernel-below-load_physical_addr.patch
queue-6.1/x86-efistub-avoid-legacy-decompressor-when-doing-efi-boot.patch
queue-6.1/x86-efistub-perform-4-5-level-paging-switch-from-the-stub.patch
queue-6.1/x86-boot-rename-conflicting-boot_params-pointer-to-boot_params_ptr.patch
queue-6.1/x86-efistub-perform-snp-feature-test-while-running-in-the-firmware.patch
queue-6.1/x86-efistub-simplify-and-clean-up-handover-entry-code.patch
queue-6.1/efi-libstub-add-memory-attribute-protocol-definitions.patch
queue-6.1/efi-libstub-add-limit-argument-to-efi_random_alloc.patch
queue-6.1/efi-x86-fix-the-missing-kaslr_flag-bit-in-boot_params-hdr.loadflags.patch
queue-6.1/arm64-efi-limit-allocations-to-48-bit-addressable-physical-region.patch
queue-6.1/x86-efistub-prefer-efi-memory-attributes-protocol-over-dxe-services.patch
queue-6.1/efi-efivars-prevent-double-registration.patch
queue-6.1/x86-boot-efistub-assign-global-boot_params-variable.patch
queue-6.1/x86-efistub-clear-bss-in-efi-handover-protocol-entrypoint.patch
queue-6.1/x86-decompressor-factor-out-kernel-decompression-and-relocation.patch
queue-6.1/efi-x86-avoid-physical-kaslr-on-older-dell-systems.patch
