diff options
-rw-r--r-- | src/arch/i386/image/elfboot.c | 33 | ||||
-rw-r--r-- | src/image/elf.c | 139 | ||||
-rw-r--r-- | src/include/ipxe/elf.h | 11 |
3 files changed, 131 insertions, 52 deletions
diff --git a/src/arch/i386/image/elfboot.c b/src/arch/i386/image/elfboot.c index 3ff7620..dc35689 100644 --- a/src/arch/i386/image/elfboot.c +++ b/src/arch/i386/image/elfboot.c @@ -79,6 +79,27 @@ static int elfboot_exec ( struct image *image ) { } /** + * Check that ELF segment uses flat physical addressing + * + * @v image ELF file + * @v phdr ELF program header + * @v dest Destination address + * @ret rc Return status code + */ +static int elfboot_check_segment ( struct image *image, Elf_Phdr *phdr, + physaddr_t dest ) { + + /* Check that ELF segment uses flat physical addressing */ + if ( phdr->p_vaddr != dest ) { + DBGC ( image, "ELF %p uses virtual addressing (phys %x, " + "virt %x)\n", image, phdr->p_paddr, phdr->p_vaddr ); + return -ENOEXEC; + } + + return 0; +} + +/** * Probe ELF image * * @v image ELF file @@ -95,14 +116,24 @@ static int elfboot_probe ( struct image *image ) { [EI_DATA] = ELFDATA2LSB, [EI_VERSION] = EV_CURRENT, }; + physaddr_t entry; + physaddr_t max; + int rc; /* Read ELF header */ copy_from_user ( &ehdr, image->data, 0, sizeof ( ehdr ) ); if ( memcmp ( ehdr.e_ident, e_ident, sizeof ( e_ident ) ) != 0 ) { - DBG ( "Invalid ELF identifier\n" ); + DBGC ( image, "Invalid ELF identifier\n" ); return -ENOEXEC; } + /* Check that this image uses flat physical addressing */ + if ( ( rc = elf_segments ( image, &ehdr, elfboot_check_segment, + &entry, &max ) ) != 0 ) { + DBGC ( image, "Unloadable ELF image\n" ); + return rc; + } + return 0; } diff --git a/src/image/elf.c b/src/image/elf.c index 533f94c..5c2f9db 100644 --- a/src/image/elf.c +++ b/src/image/elf.c @@ -40,27 +40,54 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include <ipxe/image.h> #include <ipxe/elf.h> -typedef Elf32_Ehdr Elf_Ehdr; -typedef Elf32_Phdr Elf_Phdr; -typedef Elf32_Off Elf_Off; -#define ELFCLASS ELFCLASS32 - /** * Load ELF segment into memory * * @v image ELF file * @v phdr ELF program header + * @v dest Destination address + * @ret rc Return status code + */ +static int elf_load_segment ( struct image *image, Elf_Phdr *phdr, + physaddr_t dest ) { + userptr_t buffer = phys_to_user ( dest ); + int rc; + + DBGC ( image, "ELF %p loading segment [%x,%x) to [%lx,%lx,%lx)\n", + image, phdr->p_offset, ( phdr->p_offset + phdr->p_filesz ), + dest, ( dest + phdr->p_filesz ), ( dest + phdr->p_memsz ) ); + + /* Verify and prepare segment */ + if ( ( rc = prep_segment ( buffer, phdr->p_filesz, + phdr->p_memsz ) ) != 0 ) { + DBGC ( image, "ELF %p could not prepare segment: %s\n", + image, strerror ( rc ) ); + return rc; + } + + /* Copy image to segment */ + memcpy_user ( buffer, 0, image->data, phdr->p_offset, phdr->p_filesz ); + + return 0; +} + +/** + * Process ELF segment + * + * @v image ELF file * @v ehdr ELF executable header + * @v phdr ELF program header + * @v process Segment processor * @ret entry Entry point, if found * @ret max Maximum used address * @ret rc Return status code */ -static int elf_load_segment ( struct image *image, Elf_Phdr *phdr, - Elf_Ehdr *ehdr, physaddr_t *entry, - physaddr_t *max ) { +static int elf_segment ( struct image *image, Elf_Ehdr *ehdr, Elf_Phdr *phdr, + int ( * process ) ( struct image *image, + Elf_Phdr *phdr, physaddr_t dest ), + physaddr_t *entry, physaddr_t *max ) { physaddr_t dest; physaddr_t end; - userptr_t buffer; unsigned long e_offset; int rc; @@ -86,28 +113,15 @@ static int elf_load_segment ( struct image *image, Elf_Phdr *phdr, image ); return -ENOEXEC; } - buffer = phys_to_user ( dest ); end = ( dest + phdr->p_memsz ); - DBGC ( image, "ELF %p loading segment [%x,%x) to [%x,%x,%x)\n", image, - phdr->p_offset, ( phdr->p_offset + phdr->p_filesz ), - phdr->p_paddr, ( phdr->p_paddr + phdr->p_filesz ), - ( phdr->p_paddr + phdr->p_memsz ) ); - - /* Verify and prepare segment */ - if ( ( rc = prep_segment ( buffer, phdr->p_filesz, - phdr->p_memsz ) ) != 0 ) { - DBGC ( image, "ELF %p could not prepare segment: %s\n", - image, strerror ( rc ) ); - return rc; - } - /* Update maximum used address, if applicable */ if ( end > *max ) *max = end; - /* Copy image to segment */ - memcpy_user ( buffer, 0, image->data, phdr->p_offset, phdr->p_filesz ); + /* Process segment */ + if ( ( rc = process ( image, phdr, dest ) ) != 0 ) + return rc; /* Set execution address, if it lies within this segment */ if ( ( e_offset = ( ehdr->e_entry - dest ) ) < phdr->p_filesz ) { @@ -128,62 +142,85 @@ static int elf_load_segment ( struct image *image, Elf_Phdr *phdr, } /** - * Load ELF image into memory + * Process ELF segments * * @v image ELF file - * @ret entry Entry point + * @v ehdr ELF executable header + * @v process Segment processor + * @ret entry Entry point, if found * @ret max Maximum used address * @ret rc Return status code */ -int elf_load ( struct image *image, physaddr_t *entry, physaddr_t *max ) { - static const uint8_t e_ident[] = { - [EI_MAG0] = ELFMAG0, - [EI_MAG1] = ELFMAG1, - [EI_MAG2] = ELFMAG2, - [EI_MAG3] = ELFMAG3, - [EI_CLASS] = ELFCLASS, - }; - Elf_Ehdr ehdr; +int elf_segments ( struct image *image, Elf_Ehdr *ehdr, + int ( * process ) ( struct image *image, Elf_Phdr *phdr, + physaddr_t dest ), + physaddr_t *entry, physaddr_t *max ) { Elf_Phdr phdr; Elf_Off phoff; unsigned int phnum; int rc; - /* Read ELF header */ - copy_from_user ( &ehdr, image->data, 0, sizeof ( ehdr ) ); - if ( memcmp ( &ehdr.e_ident[EI_MAG0], e_ident, - sizeof ( e_ident ) ) != 0 ) { - DBGC ( image, "ELF %p has invalid signature\n", image ); - return -ENOEXEC; - } - /* Initialise maximum used address */ *max = 0; /* Invalidate entry point */ *entry = 0; - /* Read ELF program headers */ - for ( phoff = ehdr.e_phoff , phnum = ehdr.e_phnum ; phnum ; - phoff += ehdr.e_phentsize, phnum-- ) { + /* Read and process ELF program headers */ + for ( phoff = ehdr->e_phoff , phnum = ehdr->e_phnum ; phnum ; + phoff += ehdr->e_phentsize, phnum-- ) { if ( phoff > image->len ) { DBGC ( image, "ELF %p program header %d outside " "image\n", image, phnum ); return -ENOEXEC; } copy_from_user ( &phdr, image->data, phoff, sizeof ( phdr ) ); - if ( ( rc = elf_load_segment ( image, &phdr, &ehdr, - entry, max ) ) != 0 ) { + if ( ( rc = elf_segment ( image, ehdr, &phdr, process, + entry, max ) ) != 0 ) return rc; - } } /* Check for a valid execution address */ if ( ! *entry ) { DBGC ( image, "ELF %p entry point %lx outside image\n", - image, ( ( unsigned long ) ehdr.e_entry ) ); + image, ( ( unsigned long ) ehdr->e_entry ) ); + return -ENOEXEC; + } + + return 0; +} + +/** + * Load ELF image into memory + * + * @v image ELF file + * @ret entry Entry point + * @ret max Maximum used address + * @ret rc Return status code + */ +int elf_load ( struct image *image, physaddr_t *entry, physaddr_t *max ) { + static const uint8_t e_ident[] = { + [EI_MAG0] = ELFMAG0, + [EI_MAG1] = ELFMAG1, + [EI_MAG2] = ELFMAG2, + [EI_MAG3] = ELFMAG3, + [EI_CLASS] = ELFCLASS, + }; + Elf_Ehdr ehdr; + int rc; + + /* Read ELF header */ + copy_from_user ( &ehdr, image->data, 0, sizeof ( ehdr ) ); + if ( memcmp ( &ehdr.e_ident[EI_MAG0], e_ident, + sizeof ( e_ident ) ) != 0 ) { + DBGC ( image, "ELF %p has invalid signature\n", image ); return -ENOEXEC; } + /* Load ELF segments into memory */ + if ( ( rc = elf_segments ( image, &ehdr, elf_load_segment, + entry, max ) ) != 0 ) + return rc; + return 0; } diff --git a/src/include/ipxe/elf.h b/src/include/ipxe/elf.h index e83a0cf..033c3f7 100644 --- a/src/include/ipxe/elf.h +++ b/src/include/ipxe/elf.h @@ -10,8 +10,19 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); +#include <stdint.h> +#include <ipxe/image.h> #include <elf.h> +typedef Elf32_Ehdr Elf_Ehdr; +typedef Elf32_Phdr Elf_Phdr; +typedef Elf32_Off Elf_Off; +#define ELFCLASS ELFCLASS32 + +extern int elf_segments ( struct image *image, Elf_Ehdr *ehdr, + int ( * process ) ( struct image *image, + Elf_Phdr *phdr, physaddr_t dest ), + physaddr_t *entry, physaddr_t *max ); extern int elf_load ( struct image *image, physaddr_t *entry, physaddr_t *max ); #endif /* _IPXE_ELF_H */ |