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Shutemov" , Linus Torvalds Subject: [PATCH v3 17/21] x86/decompressor: Factor out kernel decompression and relocation Date: Mon, 22 May 2023 09:14:11 +0200 Message-Id: <20230522071415.501717-18-ardb@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230522071415.501717-1-ardb@kernel.org> References: <20230522071415.501717-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2968; i=ardb@kernel.org; h=from:subject; bh=U1WWTB8Ed6jF5PagzQzhXVR5oyHC5bjwVmmRHfA2IP0=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JISVbzInp2qXX4X8a2I+/eyMtFH7p1BEGxr2LvH6UaC27O y/lfuHXjlIWBjEOBlkxRRaB2X/f7Tw9UarWeZYszBxWJpAhDFycAjCRtOkM/+s0DRi736y1lWna uO3hvhy7XN5lpWtPqb3582tOtcwBoxcM/2v/zm2ZMdt7s6f9XN93Af9dVy39UvvofmyPo2eSzcL wFHYA X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 --- arch/x86/boot/compressed/misc.c | 28 ++++++++++++++++---- arch/x86/include/asm/boot.h | 8 ++++++ 2 files changed, 31 insertions(+), 5 deletions(-) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/mis= c.c index ad7a2297c9e186df..831485a66300319e 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; } =20 +const unsigned long kernel_total_size =3D VO__end - VO__text; + static u8 boot_heap[BOOT_HEAP_SIZE] __aligned(4); =20 extern unsigned char input_data[]; extern unsigned int input_len, output_len; =20 +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 =3D (unsigned long)boot_heap; + free_mem_end_ptr =3D (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 =3D 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 *outp= ut) { - const unsigned long kernel_total_size =3D VO__end - VO__text; unsigned long virt_addr =3D LOAD_PHYSICAL_ADDR; memptr heap =3D (memptr)boot_heap; unsigned long needed_size; @@ -464,10 +485,7 @@ asmlinkage __visible void *extract_kernel(void *rmode,= unsigned char *output) accept_memory(__pa(output), __pa(output) + needed_size); } =20 - __decompress(input_data, input_len, NULL, NULL, output, output_len, - NULL, error); - entry_offset =3D parse_elf(output); - handle_relocations(output, output_len, virt_addr); + entry_offset =3D decompress_kernel(output, virt_addr, error); =20 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 9191280d9ea3160d..4ae14339cb8cc72d 100644 --- a/arch/x86/include/asm/boot.h +++ b/arch/x86/include/asm/boot.h @@ -62,4 +62,12 @@ # define BOOT_STACK_SIZE 0x1000 #endif =20 +#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 */ --=20 2.39.2