libsel4utils/src/elf.c - 3p/sel4/sel4_libs - Git at Google

 /*
  * Copyright 2014, NICTA
  *
  * This software may be distributed and modified according to the terms of
  * the BSD 2-Clause license. Note that NO WARRANTY is provided.
  * See "LICENSE_BSD2.txt" for details.
  *
  * @TAG(NICTA_BSD)
  */
 #include <autoconf.h>

 #if (defined CONFIG_LIB_SEL4_VKA && defined CONFIG_LIB_SEL4_VSPACE)

 #include <string.h>
 #include <sel4/sel4.h>
 #include <elf/elf.h>
 #include <cpio/cpio.h>
 #include <vka/capops.h>
 #include <sel4utils/thread.h>
 #include <sel4utils/util.h>
 #include <sel4utils/mapping.h>
 #include <sel4utils/elf.h>

 /* This library works with our cpio set up in the build system */
 extern char _cpio_archive[];

 /*
  * Convert ELF permissions into seL4 permissions.
  *
  * @param permissions elf permissions
  * @return seL4 permissions
  */
 static inline seL4_CapRights
 rights_from_elf(unsigned long permissions)
 {
     seL4_CapRights result = 0;

     if (permissions & PF_R || permissions & PF_X) {
         result |= seL4_CanRead;
     }

     if (permissions & PF_W) {
         result |= seL4_CanWrite;
     }

     return result;
 }

 static int
 load_segment(vspace_t *loadee_vspace, vspace_t *loader_vspace,
              vka_t *loadee_vka, vka_t *loader_vka,
              char *src, size_t segment_size, size_t file_size, uint32_t dst,
              reservation_t reservation)
 {
     int error = seL4_NoError;

     if (file_size > segment_size) {
         ZF_LOGE("Error, file_size %zu > segment_size %zu", file_size, segment_size);
         return seL4_InvalidArgument;
     }

     /* create a slot to map a page into the loader address space */
     seL4_CPtr loader_slot;
     cspacepath_t loader_frame_cap;

     error = vka_cspace_alloc(loader_vka, &loader_slot);
     if (error) {
         ZF_LOGE("Failed to allocate cslot by loader vka: %d", error);
         return error;
     }
     vka_cspace_make_path(loader_vka, loader_slot, &loader_frame_cap);

     /* We work a page at a time */
     unsigned int pos = 0;
     while (pos < segment_size && error == seL4_NoError) {
         void *loader_vaddr = 0;
         void *loadee_vaddr = (void *) ((seL4_Word)ROUND_DOWN(dst, PAGE_SIZE_4K));

         /* create and map the frame in the loadee address space */
         error = vspace_new_pages_at_vaddr(loadee_vspace, loadee_vaddr, 1, seL4_PageBits, reservation);
         if (error != seL4_NoError) {
             ZF_LOGE("ERROR: failed to allocate frame by loadee vka: %d", error);
             continue;
         }

         /* copy the frame cap to map into the loader address space */
         cspacepath_t loadee_frame_cap;

         vka_cspace_make_path(loadee_vka, vspace_get_cap(loadee_vspace, loadee_vaddr),
                              &loadee_frame_cap);
         error = vka_cnode_copy(&loader_frame_cap, &loadee_frame_cap, seL4_AllRights);
         if (error != seL4_NoError) {
             ZF_LOGE("ERROR: failed to copy frame cap into loader cspace: %d", error);
             continue;
         }

         /* map the frame into the loader address space */
         loader_vaddr = vspace_map_pages(loader_vspace, &loader_frame_cap.capPtr, NULL, seL4_AllRights,
                                         1, seL4_PageBits, 1);
         if (loader_vaddr == NULL) {
             ZF_LOGE("failed to map frame into loader vspace.");
             error = -1;
             continue;
         }

         /* finally copy the data */
         int nbytes = PAGE_SIZE_4K - (dst & PAGE_MASK_4K);
         if (pos < file_size) {
             memcpy(loader_vaddr + (dst % PAGE_SIZE_4K), (void*)src, MIN(nbytes, file_size - pos));
         }
         /* Note that we don't need to explicitly zero frames as seL4 gives us zero'd frames */

 #ifdef CONFIG_ARCH_ARM
         /* Flush the caches */
         seL4_ARM_Page_Unify_Instruction(loader_frame_cap.capPtr, 0, PAGE_SIZE_4K);
         seL4_ARM_Page_Unify_Instruction(loadee_frame_cap.capPtr, 0, PAGE_SIZE_4K);
 #endif /* CONFIG_ARCH_ARM */

         /* now unmap the page in the loader address space */
         vspace_unmap_pages(loader_vspace, (void *) loader_vaddr, 1, seL4_PageBits, VSPACE_PRESERVE);
         vka_cnode_delete(&loader_frame_cap);

         pos += nbytes;
         dst += nbytes;
         src += nbytes;
     }

     /* clear the cslot */
     vka_cspace_free(loader_vka, loader_frame_cap.capPtr);

     return error;
 }

 int
 sel4utils_elf_num_regions(char *image_name)
 {
     int i;
     unsigned long elf_size;
     char *elf_file;
     assert(image_name);
     elf_file = cpio_get_file(_cpio_archive, image_name, &elf_size);
     if (elf_file == NULL) {
         ZF_LOGE("ERROR: failed to load elf file %s", image_name);
         return 0;
     }

     int num_headers = elf_getNumProgramHeaders(elf_file);
     int loadable_headers = 0;

     for (i = 0; i < num_headers; i++) {
         /* Skip non-loadable segments (such as debugging data). */
         if (elf_getProgramHeaderType(elf_file, i) == PT_LOAD) {
             loadable_headers++;
         }
     }
     return loadable_headers;
 }

 static int
 make_region(vspace_t *loadee, unsigned long flags, unsigned long segment_size,
             unsigned long vaddr, sel4utils_elf_region_t *region, int anywhere)
 {
     region->cacheable = 1;
     region->rights = rights_from_elf(flags);
     region->elf_vstart = (void*)PAGE_ALIGN_4K(vaddr);
     region->size = PAGE_ALIGN_4K(vaddr + segment_size - 1) + PAGE_SIZE_4K - (uint32_t)((seL4_Word)region->elf_vstart);

     if (loadee) {
         if (anywhere) {
             region->reservation = vspace_reserve_range(loadee, region->size, region->rights, 1, (void**)&region->reservation_vstart);
         } else {
             region->reservation_vstart = region->elf_vstart;
             region->reservation = vspace_reserve_range_at(loadee,
                                                           region->elf_vstart,
                                                           region->size,
                                                           region->rights,
                                                           1);
         }
         return !region->reservation.res;
     }

     return 0;
 }

 void *
 sel4utils_elf_reserve(vspace_t *loadee, char *image_name, sel4utils_elf_region_t *regions)
 {
     unsigned long elf_size;
     char *elf_file = cpio_get_file(_cpio_archive, image_name, &elf_size);
     if (elf_file == NULL) {
         ZF_LOGE("ERROR: failed to load elf file %s", image_name);
         return NULL;
     }

     int num_headers = elf_getNumProgramHeaders(elf_file);
     int region = 0;

     for (int i = 0; i < num_headers; i++) {
         unsigned long flags, segment_size, vaddr;

         /* Skip non-loadable segments (such as debugging data). */
         if (elf_getProgramHeaderType(elf_file, i) == PT_LOAD) {
             /* Fetch information about this segment. */
             segment_size = elf_getProgramHeaderMemorySize(elf_file, i);
             vaddr = elf_getProgramHeaderVaddr(elf_file, i);
             flags = elf_getProgramHeaderFlags(elf_file, i);
             if (make_region(loadee, flags, segment_size, vaddr, &regions[region], 0)) {
                 for (region--; region >= 0; region--) {
                     vspace_free_reservation(loadee, regions[region].reservation);
                     regions[region].reservation.res = NULL;
                 }
                 ZF_LOGE("Failed to create reservation");
                 return NULL;
             }
             region++;
         }
     }

     uint64_t entry_point = elf_getEntryPoint(elf_file);
     if ((uint32_t) (entry_point >> 32) != 0) {
         ZF_LOGE("ERROR: this code hasn't been tested for 64bit!");
         return NULL;
     }
     assert(entry_point != 0);
     return (void*)(seL4_Word)entry_point;
 }

 void *
 sel4utils_elf_load_record_regions(vspace_t *loadee, vspace_t *loader, vka_t *loadee_vka, vka_t *loader_vka, char *image_name, sel4utils_elf_region_t *regions, int mapanywhere)
 {
     unsigned long elf_size;
     char *elf_file = cpio_get_file(_cpio_archive, image_name, &elf_size);
     if (elf_file == NULL) {
         ZF_LOGE("ERROR: failed to load elf file %s", image_name);
         return NULL;
     }

     int num_headers = elf_getNumProgramHeaders(elf_file);
     int error = seL4_NoError;
     int region_count = 0;

     uint64_t entry_point = elf_getEntryPoint(elf_file);
     if ((uint32_t) (entry_point >> 32) != 0) {
         ZF_LOGE("ERROR: this code hasn't been tested for 64bit!");
         return NULL;
     }
     assert(entry_point != 0);

     for (int i = 0; i < num_headers; i++) {
         char *source_addr;
         unsigned long flags, file_size, segment_size, vaddr;

         /* Skip non-loadable segments (such as debugging data). */
         if (elf_getProgramHeaderType(elf_file, i) == PT_LOAD) {
             /* Fetch information about this segment. */
             source_addr = elf_file + elf_getProgramHeaderOffset(elf_file, i);
             file_size = elf_getProgramHeaderFileSize(elf_file, i);
             segment_size = elf_getProgramHeaderMemorySize(elf_file, i);
             vaddr = elf_getProgramHeaderVaddr(elf_file, i);
             flags = elf_getProgramHeaderFlags(elf_file, i);
             /* make reservation */
             sel4utils_elf_region_t region;
             error = make_region(loadee, flags, segment_size, vaddr, &region, mapanywhere);
             if (error) {
                 ZF_LOGE("Failed to reserve region");
                 break;
             }
             unsigned long offset = vaddr - PAGE_ALIGN_4K(vaddr);
             /* Copy it across to the vspace */
             ZF_LOGI(" * Loading segment %08x-->%08x", (int)vaddr, (int)(vaddr + segment_size));
             error = load_segment(loadee, loader, loadee_vka, loader_vka, source_addr,
                                  segment_size, file_size, offset + (uint32_t)((seL4_Word)region.reservation_vstart), region.reservation);
             if (error) {
                 ZF_LOGE("Failed to load segment");
                 break;
             }
             /* record the region if requested */
             if (regions) {
                 regions[region_count] = region;
             } else {
                 vspace_free_reservation(loadee, region.reservation);
             }
             /* increment the count of the number of loaded regions */
             region_count++;
         }
     }

     return error == seL4_NoError ? (void*)(seL4_Word)entry_point : NULL;
 }

 uintptr_t sel4utils_elf_get_vsyscall(char *image_name)
 {
     unsigned long elf_size;
     char *elf_file = cpio_get_file(_cpio_archive, image_name, &elf_size);
     if (elf_file == NULL) {
         ZF_LOGE("ERROR: failed to lookup elf file %s", image_name);
         return 0;
     }
     /* See if we can find the __vsyscall section */
     void *addr = elf_getSectionNamed(elf_file, "__vsyscall");
     if (addr) {
         /* Hope everything is good and just dereference it */
         return *(uintptr_t*)addr;
     } else {
         return 0;
     }
 }

 void *
 sel4utils_elf_load(vspace_t *loadee, vspace_t *loader, vka_t *loadee_vka, vka_t *loader_vka, char *image_name)
 {
     return sel4utils_elf_load_record_regions(loadee, loader, loadee_vka, loader_vka, image_name, NULL, 0);
 }

 #endif /* (defined CONFIG_LIB_SEL4_VKA && defined CONFIG_LIB_SEL4_VSPACE) */
	/*
	* Copyright 2014, NICTA
	*
	* This software may be distributed and modified according to the terms of
	* the BSD 2-Clause license. Note that NO WARRANTY is provided.
	* See "LICENSE_BSD2.txt" for details.
	*
	* @TAG(NICTA_BSD)
	*/
	#include <autoconf.h>

	#if (defined CONFIG_LIB_SEL4_VKA && defined CONFIG_LIB_SEL4_VSPACE)

	#include <string.h>
	#include <sel4/sel4.h>
	#include <elf/elf.h>
	#include <cpio/cpio.h>
	#include <vka/capops.h>
	#include <sel4utils/thread.h>
	#include <sel4utils/util.h>
	#include <sel4utils/mapping.h>
	#include <sel4utils/elf.h>

	/* This library works with our cpio set up in the build system */
	extern char _cpio_archive[];

	/*
	* Convert ELF permissions into seL4 permissions.
	*
	* @param permissions elf permissions
	* @return seL4 permissions
	*/
	static inline seL4_CapRights
	rights_from_elf(unsigned long permissions)
	{
	seL4_CapRights result = 0;

	if (permissions & PF_R \|\| permissions & PF_X) {
	result \|= seL4_CanRead;
	}

	if (permissions & PF_W) {
	result \|= seL4_CanWrite;
	}

	return result;
	}

	static int
	load_segment(vspace_t loadee_vspace, vspace_t loader_vspace,
	vka_t loadee_vka, vka_t loader_vka,
	char *src, size_t segment_size, size_t file_size, uint32_t dst,
	reservation_t reservation)
	{
	int error = seL4_NoError;

	if (file_size > segment_size) {
	ZF_LOGE("Error, file_size %zu > segment_size %zu", file_size, segment_size);
	return seL4_InvalidArgument;
	}

	/* create a slot to map a page into the loader address space */
	seL4_CPtr loader_slot;
	cspacepath_t loader_frame_cap;

	error = vka_cspace_alloc(loader_vka, &loader_slot);
	if (error) {
	ZF_LOGE("Failed to allocate cslot by loader vka: %d", error);
	return error;
	}
	vka_cspace_make_path(loader_vka, loader_slot, &loader_frame_cap);

	/* We work a page at a time */
	unsigned int pos = 0;
	while (pos < segment_size && error == seL4_NoError) {
	void *loader_vaddr = 0;
	void loadee_vaddr = (void ) ((seL4_Word)ROUND_DOWN(dst, PAGE_SIZE_4K));

	/* create and map the frame in the loadee address space */
	error = vspace_new_pages_at_vaddr(loadee_vspace, loadee_vaddr, 1, seL4_PageBits, reservation);
	if (error != seL4_NoError) {
	ZF_LOGE("ERROR: failed to allocate frame by loadee vka: %d", error);
	continue;
	}

	/* copy the frame cap to map into the loader address space */
	cspacepath_t loadee_frame_cap;

	vka_cspace_make_path(loadee_vka, vspace_get_cap(loadee_vspace, loadee_vaddr),
	&loadee_frame_cap);
	error = vka_cnode_copy(&loader_frame_cap, &loadee_frame_cap, seL4_AllRights);
	if (error != seL4_NoError) {
	ZF_LOGE("ERROR: failed to copy frame cap into loader cspace: %d", error);
	continue;
	}

	/* map the frame into the loader address space */
	loader_vaddr = vspace_map_pages(loader_vspace, &loader_frame_cap.capPtr, NULL, seL4_AllRights,
	1, seL4_PageBits, 1);
	if (loader_vaddr == NULL) {
	ZF_LOGE("failed to map frame into loader vspace.");
	error = -1;
	continue;
	}

	/* finally copy the data */
	int nbytes = PAGE_SIZE_4K - (dst & PAGE_MASK_4K);
	if (pos < file_size) {
	memcpy(loader_vaddr + (dst % PAGE_SIZE_4K), (void*)src, MIN(nbytes, file_size - pos));
	}
	/* Note that we don't need to explicitly zero frames as seL4 gives us zero'd frames */

	#ifdef CONFIG_ARCH_ARM
	/* Flush the caches */
	seL4_ARM_Page_Unify_Instruction(loader_frame_cap.capPtr, 0, PAGE_SIZE_4K);
	seL4_ARM_Page_Unify_Instruction(loadee_frame_cap.capPtr, 0, PAGE_SIZE_4K);
	#endif /* CONFIG_ARCH_ARM */

	/* now unmap the page in the loader address space */
	vspace_unmap_pages(loader_vspace, (void *) loader_vaddr, 1, seL4_PageBits, VSPACE_PRESERVE);
	vka_cnode_delete(&loader_frame_cap);

	pos += nbytes;
	dst += nbytes;
	src += nbytes;
	}

	/* clear the cslot */
	vka_cspace_free(loader_vka, loader_frame_cap.capPtr);

	return error;
	}

	int
	sel4utils_elf_num_regions(char *image_name)
	{
	int i;
	unsigned long elf_size;
	char *elf_file;
	assert(image_name);
	elf_file = cpio_get_file(_cpio_archive, image_name, &elf_size);
	if (elf_file == NULL) {
	ZF_LOGE("ERROR: failed to load elf file %s", image_name);
	return 0;
	}

	int num_headers = elf_getNumProgramHeaders(elf_file);
	int loadable_headers = 0;

	for (i = 0; i < num_headers; i++) {
	/* Skip non-loadable segments (such as debugging data). */
	if (elf_getProgramHeaderType(elf_file, i) == PT_LOAD) {
	loadable_headers++;
	}
	}
	return loadable_headers;
	}

	static int
	make_region(vspace_t *loadee, unsigned long flags, unsigned long segment_size,
	unsigned long vaddr, sel4utils_elf_region_t *region, int anywhere)
	{
	region->cacheable = 1;
	region->rights = rights_from_elf(flags);
	region->elf_vstart = (void*)PAGE_ALIGN_4K(vaddr);
	region->size = PAGE_ALIGN_4K(vaddr + segment_size - 1) + PAGE_SIZE_4K - (uint32_t)((seL4_Word)region->elf_vstart);

	if (loadee) {
	if (anywhere) {
	region->reservation = vspace_reserve_range(loadee, region->size, region->rights, 1, (void**)&region->reservation_vstart);
	} else {
	region->reservation_vstart = region->elf_vstart;
	region->reservation = vspace_reserve_range_at(loadee,
	region->elf_vstart,
	region->size,
	region->rights,
	1);
	}
	return !region->reservation.res;
	}

	return 0;
	}

	void *
	sel4utils_elf_reserve(vspace_t loadee, char image_name, sel4utils_elf_region_t *regions)
	{
	unsigned long elf_size;
	char *elf_file = cpio_get_file(_cpio_archive, image_name, &elf_size);
	if (elf_file == NULL) {
	ZF_LOGE("ERROR: failed to load elf file %s", image_name);
	return NULL;
	}

	int num_headers = elf_getNumProgramHeaders(elf_file);
	int region = 0;

	for (int i = 0; i < num_headers; i++) {
	unsigned long flags, segment_size, vaddr;

	/* Skip non-loadable segments (such as debugging data). */
	if (elf_getProgramHeaderType(elf_file, i) == PT_LOAD) {
	/* Fetch information about this segment. */
	segment_size = elf_getProgramHeaderMemorySize(elf_file, i);
	vaddr = elf_getProgramHeaderVaddr(elf_file, i);
	flags = elf_getProgramHeaderFlags(elf_file, i);
	if (make_region(loadee, flags, segment_size, vaddr, &regions[region], 0)) {
	for (region--; region >= 0; region--) {
	vspace_free_reservation(loadee, regions[region].reservation);
	regions[region].reservation.res = NULL;
	}
	ZF_LOGE("Failed to create reservation");
	return NULL;
	}
	region++;
	}
	}

	uint64_t entry_point = elf_getEntryPoint(elf_file);
	if ((uint32_t) (entry_point >> 32) != 0) {
	ZF_LOGE("ERROR: this code hasn't been tested for 64bit!");
	return NULL;
	}
	assert(entry_point != 0);
	return (void*)(seL4_Word)entry_point;
	}

	void *
	sel4utils_elf_load_record_regions(vspace_t loadee, vspace_t loader, vka_t loadee_vka, vka_t loader_vka, char image_name, sel4utils_elf_region_t regions, int mapanywhere)
	{
	unsigned long elf_size;
	char *elf_file = cpio_get_file(_cpio_archive, image_name, &elf_size);
	if (elf_file == NULL) {
	ZF_LOGE("ERROR: failed to load elf file %s", image_name);
	return NULL;
	}

	int num_headers = elf_getNumProgramHeaders(elf_file);
	int error = seL4_NoError;
	int region_count = 0;

	uint64_t entry_point = elf_getEntryPoint(elf_file);
	if ((uint32_t) (entry_point >> 32) != 0) {
	ZF_LOGE("ERROR: this code hasn't been tested for 64bit!");
	return NULL;
	}
	assert(entry_point != 0);

	for (int i = 0; i < num_headers; i++) {
	char *source_addr;
	unsigned long flags, file_size, segment_size, vaddr;

	/* Skip non-loadable segments (such as debugging data). */
	if (elf_getProgramHeaderType(elf_file, i) == PT_LOAD) {
	/* Fetch information about this segment. */
	source_addr = elf_file + elf_getProgramHeaderOffset(elf_file, i);
	file_size = elf_getProgramHeaderFileSize(elf_file, i);
	segment_size = elf_getProgramHeaderMemorySize(elf_file, i);
	vaddr = elf_getProgramHeaderVaddr(elf_file, i);
	flags = elf_getProgramHeaderFlags(elf_file, i);
	/* make reservation */
	sel4utils_elf_region_t region;
	error = make_region(loadee, flags, segment_size, vaddr, &region, mapanywhere);
	if (error) {
	ZF_LOGE("Failed to reserve region");
	break;
	}
	unsigned long offset = vaddr - PAGE_ALIGN_4K(vaddr);
	/* Copy it across to the vspace */
	ZF_LOGI(" * Loading segment %08x-->%08x", (int)vaddr, (int)(vaddr + segment_size));
	error = load_segment(loadee, loader, loadee_vka, loader_vka, source_addr,
	segment_size, file_size, offset + (uint32_t)((seL4_Word)region.reservation_vstart), region.reservation);
	if (error) {
	ZF_LOGE("Failed to load segment");
	break;
	}
	/* record the region if requested */
	if (regions) {
	regions[region_count] = region;
	} else {
	vspace_free_reservation(loadee, region.reservation);
	}
	/* increment the count of the number of loaded regions */
	region_count++;
	}
	}

	return error == seL4_NoError ? (void*)(seL4_Word)entry_point : NULL;
	}

	uintptr_t sel4utils_elf_get_vsyscall(char *image_name)
	{
	unsigned long elf_size;
	char *elf_file = cpio_get_file(_cpio_archive, image_name, &elf_size);
	if (elf_file == NULL) {
	ZF_LOGE("ERROR: failed to lookup elf file %s", image_name);
	return 0;
	}
	/* See if we can find the __vsyscall section */
	void *addr = elf_getSectionNamed(elf_file, "__vsyscall");
	if (addr) {
	/* Hope everything is good and just dereference it */
	return (uintptr_t)addr;
	} else {
	return 0;
	}
	}

	void *
	sel4utils_elf_load(vspace_t loadee, vspace_t loader, vka_t loadee_vka, vka_t loader_vka, char *image_name)
	{
	return sel4utils_elf_load_record_regions(loadee, loader, loadee_vka, loader_vka, image_name, NULL, 0);
	}

	#endif /* (defined CONFIG_LIB_SEL4_VKA && defined CONFIG_LIB_SEL4_VSPACE) */