[PATCH v2 1/9] lib: elf: Move the generic elf loading/validating functions to lib
Lokesh Vutla
lokeshvutla at ti.com
Fri Jan 17 05:27:02 CET 2020
Simon,
On 13/01/20 11:24 AM, Keerthy wrote:
> Move the generic elf loading/validating functions to lib/
> so that they can be re-used and accessed by code existing
> outside cmd.
>
> Signed-off-by: Keerthy <j-keerthy at ti.com>
> Suggested-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
Are you okay with this patch? If yes, Ill apply to u-boot-ti along with other
patches in this series.
Thanks and regards,
Lokesh
> ---
> Changes in v2:
>
> * Factored out all the generic elf handling functions under lib/elf.c
>
> cmd/Kconfig | 1 +
> cmd/elf.c | 229 --------------------------------------------
> include/elf.h | 4 +
> lib/Kconfig | 3 +
> lib/Makefile | 1 +
> lib/elf.c | 256 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 6 files changed, 265 insertions(+), 229 deletions(-)
> create mode 100644 lib/elf.c
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index 298feae24d..6f4f08d02a 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -375,6 +375,7 @@ config CMD_ADTIMG
> config CMD_ELF
> bool "bootelf, bootvx"
> default y
> + select ELF
> help
> Boot an ELF/vxWorks image from the memory.
>
> diff --git a/cmd/elf.c b/cmd/elf.c
> index 32f12a72b9..23cc17aebc 100644
> --- a/cmd/elf.c
> +++ b/cmd/elf.c
> @@ -26,211 +26,6 @@
> #include <linux/linkage.h>
> #endif
>
> -/*
> - * A very simple ELF64 loader, assumes the image is valid, returns the
> - * entry point address.
> - *
> - * Note if U-Boot is 32-bit, the loader assumes the to segment's
> - * physical address and size is within the lower 32-bit address space.
> - */
> -static unsigned long load_elf64_image_phdr(unsigned long addr)
> -{
> - Elf64_Ehdr *ehdr; /* Elf header structure pointer */
> - Elf64_Phdr *phdr; /* Program header structure pointer */
> - int i;
> -
> - ehdr = (Elf64_Ehdr *)addr;
> - phdr = (Elf64_Phdr *)(addr + (ulong)ehdr->e_phoff);
> -
> - /* Load each program header */
> - for (i = 0; i < ehdr->e_phnum; ++i) {
> - void *dst = (void *)(ulong)phdr->p_paddr;
> - void *src = (void *)addr + phdr->p_offset;
> -
> - debug("Loading phdr %i to 0x%p (%lu bytes)\n",
> - i, dst, (ulong)phdr->p_filesz);
> - if (phdr->p_filesz)
> - memcpy(dst, src, phdr->p_filesz);
> - if (phdr->p_filesz != phdr->p_memsz)
> - memset(dst + phdr->p_filesz, 0x00,
> - phdr->p_memsz - phdr->p_filesz);
> - flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
> - roundup(phdr->p_memsz, ARCH_DMA_MINALIGN));
> - ++phdr;
> - }
> -
> - if (ehdr->e_machine == EM_PPC64 && (ehdr->e_flags &
> - EF_PPC64_ELFV1_ABI)) {
> - /*
> - * For the 64-bit PowerPC ELF V1 ABI, e_entry is a function
> - * descriptor pointer with the first double word being the
> - * address of the entry point of the function.
> - */
> - uintptr_t addr = ehdr->e_entry;
> -
> - return *(Elf64_Addr *)addr;
> - }
> -
> - return ehdr->e_entry;
> -}
> -
> -static unsigned long load_elf64_image_shdr(unsigned long addr)
> -{
> - Elf64_Ehdr *ehdr; /* Elf header structure pointer */
> - Elf64_Shdr *shdr; /* Section header structure pointer */
> - unsigned char *strtab = 0; /* String table pointer */
> - unsigned char *image; /* Binary image pointer */
> - int i; /* Loop counter */
> -
> - ehdr = (Elf64_Ehdr *)addr;
> -
> - /* Find the section header string table for output info */
> - shdr = (Elf64_Shdr *)(addr + (ulong)ehdr->e_shoff +
> - (ehdr->e_shstrndx * sizeof(Elf64_Shdr)));
> -
> - if (shdr->sh_type == SHT_STRTAB)
> - strtab = (unsigned char *)(addr + (ulong)shdr->sh_offset);
> -
> - /* Load each appropriate section */
> - for (i = 0; i < ehdr->e_shnum; ++i) {
> - shdr = (Elf64_Shdr *)(addr + (ulong)ehdr->e_shoff +
> - (i * sizeof(Elf64_Shdr)));
> -
> - if (!(shdr->sh_flags & SHF_ALLOC) ||
> - shdr->sh_addr == 0 || shdr->sh_size == 0) {
> - continue;
> - }
> -
> - if (strtab) {
> - debug("%sing %s @ 0x%08lx (%ld bytes)\n",
> - (shdr->sh_type == SHT_NOBITS) ? "Clear" : "Load",
> - &strtab[shdr->sh_name],
> - (unsigned long)shdr->sh_addr,
> - (long)shdr->sh_size);
> - }
> -
> - if (shdr->sh_type == SHT_NOBITS) {
> - memset((void *)(uintptr_t)shdr->sh_addr, 0,
> - shdr->sh_size);
> - } else {
> - image = (unsigned char *)addr + (ulong)shdr->sh_offset;
> - memcpy((void *)(uintptr_t)shdr->sh_addr,
> - (const void *)image, shdr->sh_size);
> - }
> - flush_cache(rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN),
> - roundup((shdr->sh_addr + shdr->sh_size),
> - ARCH_DMA_MINALIGN) -
> - rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN));
> - }
> -
> - if (ehdr->e_machine == EM_PPC64 && (ehdr->e_flags &
> - EF_PPC64_ELFV1_ABI)) {
> - /*
> - * For the 64-bit PowerPC ELF V1 ABI, e_entry is a function
> - * descriptor pointer with the first double word being the
> - * address of the entry point of the function.
> - */
> - uintptr_t addr = ehdr->e_entry;
> -
> - return *(Elf64_Addr *)addr;
> - }
> -
> - return ehdr->e_entry;
> -}
> -
> -/*
> - * A very simple ELF loader, assumes the image is valid, returns the
> - * entry point address.
> - *
> - * The loader firstly reads the EFI class to see if it's a 64-bit image.
> - * If yes, call the ELF64 loader. Otherwise continue with the ELF32 loader.
> - */
> -static unsigned long load_elf_image_phdr(unsigned long addr)
> -{
> - Elf32_Ehdr *ehdr; /* Elf header structure pointer */
> - Elf32_Phdr *phdr; /* Program header structure pointer */
> - int i;
> -
> - ehdr = (Elf32_Ehdr *)addr;
> - if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
> - return load_elf64_image_phdr(addr);
> -
> - phdr = (Elf32_Phdr *)(addr + ehdr->e_phoff);
> -
> - /* Load each program header */
> - for (i = 0; i < ehdr->e_phnum; ++i) {
> - void *dst = (void *)(uintptr_t)phdr->p_paddr;
> - void *src = (void *)addr + phdr->p_offset;
> -
> - debug("Loading phdr %i to 0x%p (%i bytes)\n",
> - i, dst, phdr->p_filesz);
> - if (phdr->p_filesz)
> - memcpy(dst, src, phdr->p_filesz);
> - if (phdr->p_filesz != phdr->p_memsz)
> - memset(dst + phdr->p_filesz, 0x00,
> - phdr->p_memsz - phdr->p_filesz);
> - flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
> - roundup(phdr->p_memsz, ARCH_DMA_MINALIGN));
> - ++phdr;
> - }
> -
> - return ehdr->e_entry;
> -}
> -
> -static unsigned long load_elf_image_shdr(unsigned long addr)
> -{
> - Elf32_Ehdr *ehdr; /* Elf header structure pointer */
> - Elf32_Shdr *shdr; /* Section header structure pointer */
> - unsigned char *strtab = 0; /* String table pointer */
> - unsigned char *image; /* Binary image pointer */
> - int i; /* Loop counter */
> -
> - ehdr = (Elf32_Ehdr *)addr;
> - if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
> - return load_elf64_image_shdr(addr);
> -
> - /* Find the section header string table for output info */
> - shdr = (Elf32_Shdr *)(addr + ehdr->e_shoff +
> - (ehdr->e_shstrndx * sizeof(Elf32_Shdr)));
> -
> - if (shdr->sh_type == SHT_STRTAB)
> - strtab = (unsigned char *)(addr + shdr->sh_offset);
> -
> - /* Load each appropriate section */
> - for (i = 0; i < ehdr->e_shnum; ++i) {
> - shdr = (Elf32_Shdr *)(addr + ehdr->e_shoff +
> - (i * sizeof(Elf32_Shdr)));
> -
> - if (!(shdr->sh_flags & SHF_ALLOC) ||
> - shdr->sh_addr == 0 || shdr->sh_size == 0) {
> - continue;
> - }
> -
> - if (strtab) {
> - debug("%sing %s @ 0x%08lx (%ld bytes)\n",
> - (shdr->sh_type == SHT_NOBITS) ? "Clear" : "Load",
> - &strtab[shdr->sh_name],
> - (unsigned long)shdr->sh_addr,
> - (long)shdr->sh_size);
> - }
> -
> - if (shdr->sh_type == SHT_NOBITS) {
> - memset((void *)(uintptr_t)shdr->sh_addr, 0,
> - shdr->sh_size);
> - } else {
> - image = (unsigned char *)addr + shdr->sh_offset;
> - memcpy((void *)(uintptr_t)shdr->sh_addr,
> - (const void *)image, shdr->sh_size);
> - }
> - flush_cache(rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN),
> - roundup((shdr->sh_addr + shdr->sh_size),
> - ARCH_DMA_MINALIGN) -
> - rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN));
> - }
> -
> - return ehdr->e_entry;
> -}
> -
> /* Allow ports to override the default behavior */
> static unsigned long do_bootelf_exec(ulong (*entry)(int, char * const[]),
> int argc, char * const argv[])
> @@ -246,30 +41,6 @@ static unsigned long do_bootelf_exec(ulong (*entry)(int, char * const[]),
> return ret;
> }
>
> -/*
> - * Determine if a valid ELF image exists at the given memory location.
> - * First look at the ELF header magic field, then make sure that it is
> - * executable.
> - */
> -int valid_elf_image(unsigned long addr)
> -{
> - Elf32_Ehdr *ehdr; /* Elf header structure pointer */
> -
> - ehdr = (Elf32_Ehdr *)addr;
> -
> - if (!IS_ELF(*ehdr)) {
> - printf("## No elf image at address 0x%08lx\n", addr);
> - return 0;
> - }
> -
> - if (ehdr->e_type != ET_EXEC) {
> - printf("## Not a 32-bit elf image at address 0x%08lx\n", addr);
> - return 0;
> - }
> -
> - return 1;
> -}
> -
> /* Interpreter command to boot an arbitrary ELF image from memory */
> int do_bootelf(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> {
> diff --git a/include/elf.h b/include/elf.h
> index 81f40191d7..e7c51986df 100644
> --- a/include/elf.h
> +++ b/include/elf.h
> @@ -692,6 +692,10 @@ unsigned long elf_hash(const unsigned char *name);
>
> #ifndef __ASSEMBLER__
> int valid_elf_image(unsigned long addr);
> +unsigned long load_elf64_image_phdr(unsigned long addr);
> +unsigned long load_elf64_image_shdr(unsigned long addr);
> +unsigned long load_elf_image_phdr(unsigned long addr);
> +unsigned long load_elf_image_shdr(unsigned long addr);
> #endif
>
> #endif /* _ELF_H */
> diff --git a/lib/Kconfig b/lib/Kconfig
> index d040a87d26..b155ced4b2 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -601,4 +601,7 @@ config TEST_FDTDEC
> config LIB_DATE
> bool
>
> +config ELF
> + bool "enable basic elf loading/validating functions"
> +
> endmenu
> diff --git a/lib/Makefile b/lib/Makefile
> index 6b7b9ce85c..93f22d210e 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -121,6 +121,7 @@ obj-y += vsprintf.o strto.o
> endif
>
> obj-y += date.o
> +obj-$(CONFIG_ELF) += elf.o
>
> #
> # Build a fast OID lookup registry from include/linux/oid_registry.h
> diff --git a/lib/elf.c b/lib/elf.c
> new file mode 100644
> index 0000000000..54ac4ee502
> --- /dev/null
> +++ b/lib/elf.c
> @@ -0,0 +1,256 @@
> +/*
> + * Copyright (c) 2001 William L. Pitts
> + * All rights reserved.
> + *
> + * Redistribution and use in source and binary forms are freely
> + * permitted provided that the above copyright notice and this
> + * paragraph and the following disclaimer are duplicated in all
> + * such forms.
> + *
> + * This software is provided "AS IS" and without any express or
> + * implied warranties, including, without limitation, the implied
> + * warranties of merchantability and fitness for a particular
> + * purpose.
> + */
> +
> +#include <common.h>
> +#include <command.h>
> +#include <cpu_func.h>
> +#include <elf.h>
> +#include <env.h>
> +#include <net.h>
> +#include <vxworks.h>
> +#ifdef CONFIG_X86
> +#include <vbe.h>
> +#include <asm/e820.h>
> +#include <linux/linkage.h>
> +#endif
> +
> +/*
> + * A very simple ELF64 loader, assumes the image is valid, returns the
> + * entry point address.
> + *
> + * Note if U-Boot is 32-bit, the loader assumes the to segment's
> + * physical address and size is within the lower 32-bit address space.
> + */
> +unsigned long load_elf64_image_phdr(unsigned long addr)
> +{
> + Elf64_Ehdr *ehdr; /* Elf header structure pointer */
> + Elf64_Phdr *phdr; /* Program header structure pointer */
> + int i;
> +
> + ehdr = (Elf64_Ehdr *)addr;
> + phdr = (Elf64_Phdr *)(addr + (ulong)ehdr->e_phoff);
> +
> + /* Load each program header */
> + for (i = 0; i < ehdr->e_phnum; ++i) {
> + void *dst = (void *)(ulong)phdr->p_paddr;
> + void *src = (void *)addr + phdr->p_offset;
> +
> + debug("Loading phdr %i to 0x%p (%lu bytes)\n",
> + i, dst, (ulong)phdr->p_filesz);
> + if (phdr->p_filesz)
> + memcpy(dst, src, phdr->p_filesz);
> + if (phdr->p_filesz != phdr->p_memsz)
> + memset(dst + phdr->p_filesz, 0x00,
> + phdr->p_memsz - phdr->p_filesz);
> + flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
> + roundup(phdr->p_memsz, ARCH_DMA_MINALIGN));
> + ++phdr;
> + }
> +
> + if (ehdr->e_machine == EM_PPC64 && (ehdr->e_flags &
> + EF_PPC64_ELFV1_ABI)) {
> + /*
> + * For the 64-bit PowerPC ELF V1 ABI, e_entry is a function
> + * descriptor pointer with the first double word being the
> + * address of the entry point of the function.
> + */
> + uintptr_t addr = ehdr->e_entry;
> +
> + return *(Elf64_Addr *)addr;
> + }
> +
> + return ehdr->e_entry;
> +}
> +
> +unsigned long load_elf64_image_shdr(unsigned long addr)
> +{
> + Elf64_Ehdr *ehdr; /* Elf header structure pointer */
> + Elf64_Shdr *shdr; /* Section header structure pointer */
> + unsigned char *strtab = 0; /* String table pointer */
> + unsigned char *image; /* Binary image pointer */
> + int i; /* Loop counter */
> +
> + ehdr = (Elf64_Ehdr *)addr;
> +
> + /* Find the section header string table for output info */
> + shdr = (Elf64_Shdr *)(addr + (ulong)ehdr->e_shoff +
> + (ehdr->e_shstrndx * sizeof(Elf64_Shdr)));
> +
> + if (shdr->sh_type == SHT_STRTAB)
> + strtab = (unsigned char *)(addr + (ulong)shdr->sh_offset);
> +
> + /* Load each appropriate section */
> + for (i = 0; i < ehdr->e_shnum; ++i) {
> + shdr = (Elf64_Shdr *)(addr + (ulong)ehdr->e_shoff +
> + (i * sizeof(Elf64_Shdr)));
> +
> + if (!(shdr->sh_flags & SHF_ALLOC) ||
> + shdr->sh_addr == 0 || shdr->sh_size == 0) {
> + continue;
> + }
> +
> + if (strtab) {
> + debug("%sing %s @ 0x%08lx (%ld bytes)\n",
> + (shdr->sh_type == SHT_NOBITS) ? "Clear" : "Load",
> + &strtab[shdr->sh_name],
> + (unsigned long)shdr->sh_addr,
> + (long)shdr->sh_size);
> + }
> +
> + if (shdr->sh_type == SHT_NOBITS) {
> + memset((void *)(uintptr_t)shdr->sh_addr, 0,
> + shdr->sh_size);
> + } else {
> + image = (unsigned char *)addr + (ulong)shdr->sh_offset;
> + memcpy((void *)(uintptr_t)shdr->sh_addr,
> + (const void *)image, shdr->sh_size);
> + }
> + flush_cache(rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN),
> + roundup((shdr->sh_addr + shdr->sh_size),
> + ARCH_DMA_MINALIGN) -
> + rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN));
> + }
> +
> + if (ehdr->e_machine == EM_PPC64 && (ehdr->e_flags &
> + EF_PPC64_ELFV1_ABI)) {
> + /*
> + * For the 64-bit PowerPC ELF V1 ABI, e_entry is a function
> + * descriptor pointer with the first double word being the
> + * address of the entry point of the function.
> + */
> + uintptr_t addr = ehdr->e_entry;
> +
> + return *(Elf64_Addr *)addr;
> + }
> +
> + return ehdr->e_entry;
> +}
> +
> +/*
> + * A very simple ELF loader, assumes the image is valid, returns the
> + * entry point address.
> + *
> + * The loader firstly reads the EFI class to see if it's a 64-bit image.
> + * If yes, call the ELF64 loader. Otherwise continue with the ELF32 loader.
> + */
> +unsigned long load_elf_image_phdr(unsigned long addr)
> +{
> + Elf32_Ehdr *ehdr; /* Elf header structure pointer */
> + Elf32_Phdr *phdr; /* Program header structure pointer */
> + int i;
> +
> + ehdr = (Elf32_Ehdr *)addr;
> + if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
> + return load_elf64_image_phdr(addr);
> +
> + phdr = (Elf32_Phdr *)(addr + ehdr->e_phoff);
> +
> + /* Load each program header */
> + for (i = 0; i < ehdr->e_phnum; ++i) {
> + void *dst = (void *)(uintptr_t)phdr->p_paddr;
> + void *src = (void *)addr + phdr->p_offset;
> +
> + debug("Loading phdr %i to 0x%p (%i bytes)\n",
> + i, dst, phdr->p_filesz);
> + if (phdr->p_filesz)
> + memcpy(dst, src, phdr->p_filesz);
> + if (phdr->p_filesz != phdr->p_memsz)
> + memset(dst + phdr->p_filesz, 0x00,
> + phdr->p_memsz - phdr->p_filesz);
> + flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
> + roundup(phdr->p_memsz, ARCH_DMA_MINALIGN));
> + ++phdr;
> + }
> +
> + return ehdr->e_entry;
> +}
> +
> +unsigned long load_elf_image_shdr(unsigned long addr)
> +{
> + Elf32_Ehdr *ehdr; /* Elf header structure pointer */
> + Elf32_Shdr *shdr; /* Section header structure pointer */
> + unsigned char *strtab = 0; /* String table pointer */
> + unsigned char *image; /* Binary image pointer */
> + int i; /* Loop counter */
> +
> + ehdr = (Elf32_Ehdr *)addr;
> + if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
> + return load_elf64_image_shdr(addr);
> +
> + /* Find the section header string table for output info */
> + shdr = (Elf32_Shdr *)(addr + ehdr->e_shoff +
> + (ehdr->e_shstrndx * sizeof(Elf32_Shdr)));
> +
> + if (shdr->sh_type == SHT_STRTAB)
> + strtab = (unsigned char *)(addr + shdr->sh_offset);
> +
> + /* Load each appropriate section */
> + for (i = 0; i < ehdr->e_shnum; ++i) {
> + shdr = (Elf32_Shdr *)(addr + ehdr->e_shoff +
> + (i * sizeof(Elf32_Shdr)));
> +
> + if (!(shdr->sh_flags & SHF_ALLOC) ||
> + shdr->sh_addr == 0 || shdr->sh_size == 0) {
> + continue;
> + }
> +
> + if (strtab) {
> + debug("%sing %s @ 0x%08lx (%ld bytes)\n",
> + (shdr->sh_type == SHT_NOBITS) ? "Clear" : "Load",
> + &strtab[shdr->sh_name],
> + (unsigned long)shdr->sh_addr,
> + (long)shdr->sh_size);
> + }
> +
> + if (shdr->sh_type == SHT_NOBITS) {
> + memset((void *)(uintptr_t)shdr->sh_addr, 0,
> + shdr->sh_size);
> + } else {
> + image = (unsigned char *)addr + shdr->sh_offset;
> + memcpy((void *)(uintptr_t)shdr->sh_addr,
> + (const void *)image, shdr->sh_size);
> + }
> + flush_cache(rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN),
> + roundup((shdr->sh_addr + shdr->sh_size),
> + ARCH_DMA_MINALIGN) -
> + rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN));
> + }
> +
> + return ehdr->e_entry;
> +}
> +
> +/*
> + * Determine if a valid ELF image exists at the given memory location.
> + * First look at the ELF header magic field, then make sure that it is
> + * executable.
> + */
> +int valid_elf_image(unsigned long addr)
> +{
> + Elf32_Ehdr *ehdr; /* Elf header structure pointer */
> +
> + ehdr = (Elf32_Ehdr *)addr;
> +
> + if (!IS_ELF(*ehdr)) {
> + printf("## No elf image at address 0x%08lx\n", addr);
> + return 0;
> + }
> +
> + if (ehdr->e_type != ET_EXEC) {
> + printf("## Not a 32-bit elf image at address 0x%08lx\n", addr);
> + return 0;
> + }
> +
> + return 1;
> +}
>
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