diff --git a/src/arch/i386/image/elfboot.c b/src/arch/i386/image/elfboot.c index 3ff76203..dc356892 100644 --- a/src/arch/i386/image/elfboot.c +++ b/src/arch/i386/image/elfboot.c @@ -78,6 +78,27 @@ static int elfboot_exec ( struct image *image ) { return -ECANCELED; /* -EIMPOSSIBLE, anyone? */ } +/** + * 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 * @@ -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 533f94c1..5c2f9db2 100644 --- a/src/image/elf.c +++ b/src/image/elf.c @@ -40,27 +40,54 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include #include -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 ) { @@ -127,6 +141,55 @@ static int elf_load_segment ( struct image *image, Elf_Phdr *phdr, return 0; } +/** + * Process ELF segments + * + * @v image ELF file + * @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_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; + + /* Initialise maximum used address */ + *max = 0; + + /* Invalidate entry point */ + *entry = 0; + + /* 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_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 ) ); + return -ENOEXEC; + } + + return 0; +} + /** * Load ELF image into memory * @@ -144,9 +207,6 @@ int elf_load ( struct image *image, physaddr_t *entry, physaddr_t *max ) { [EI_CLASS] = ELFCLASS, }; Elf_Ehdr ehdr; - Elf_Phdr phdr; - Elf_Off phoff; - unsigned int phnum; int rc; /* Read ELF header */ @@ -157,33 +217,10 @@ int elf_load ( struct image *image, physaddr_t *entry, physaddr_t *max ) { 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-- ) { - 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 ) { - 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 ) ); - 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 e83a0cf1..033c3f7a 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 +#include #include +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 */