From: Ard Biesheuvel ardb@kernel.org
[ 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@kernel.org Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Link: https://lore.kernel.org/r/20230807162720.545787-21-ardb@kernel.org Signed-off-by: Ard Biesheuvel ardb@kernel.org --- arch/x86/boot/compressed/misc.c | 29 ++++++++++++++++---- arch/x86/include/asm/boot.h | 8 ++++++ 2 files changed, 32 insertions(+), 5 deletions(-)
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index e4e3e49fcc37..fb55ac18af6f 100644 --- 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_len; */ 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_kernel(void *rmode, unsigned char *output) #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); diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h index 215d37f7dde8..b3a7cfb0d99e 100644 --- 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 */