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Commit d2078d5a authored by Linn Crosetto's avatar Linn Crosetto Committed by Matt Fleming
Browse files

x86: EFI stub support for large memory maps 



This patch fixes a problem with EFI memory maps larger than 128 entries
when booting using the EFI stub, which results in overflowing e820_map
in boot_params and an eventual halt when checking the map size in
sanitize_e820_map().

If the number of map entries is greater than what can fit in e820_map,
add the extra entries to the setup_data list using type SETUP_E820_EXT.
These extra entries are then picked up when the setup_data list is
parsed in parse_e820_ext().

Signed-off-by: default avatarLinn Crosetto <linn@hp.com>
Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
parent 3203209d

arch/x86/boot/compressed/eboot.c

+161 −61
Original line number Diff line number Diff line
@@ -519,71 +519,47 @@ fail: 
	return NULL;

}



static efi_status_t exit_boot(struct boot_params *boot_params,

			      void *handle)

static void add_e820ext(struct boot_params *params,

			struct setup_data *e820ext, u32 nr_entries)

{

	struct efi_info *efi = &boot_params->efi_info;

	struct e820entry *e820_map = &boot_params->e820_map[0];

	struct e820entry *prev = NULL;

	unsigned long size, key, desc_size, _size;

	efi_memory_desc_t *mem_map;

	struct setup_data *data;

	efi_status_t status;

	__u32 desc_version;

	bool called_exit = false;

	u8 nr_entries;

	int i;



get_map:

	status = efi_get_memory_map(sys_table, &mem_map, &size, &desc_size,

				    &desc_version, &key);



	if (status != EFI_SUCCESS)

		return status;

	unsigned long size;



	memcpy(&efi->efi_loader_signature, EFI_LOADER_SIGNATURE, sizeof(__u32));

	efi->efi_systab = (unsigned long)sys_table;

	efi->efi_memdesc_size = desc_size;

	efi->efi_memdesc_version = desc_version;

	efi->efi_memmap = (unsigned long)mem_map;

	efi->efi_memmap_size = size;

	e820ext->type = SETUP_E820_EXT;

	e820ext->len = nr_entries * sizeof(struct e820entry);

	e820ext->next = 0;



#ifdef CONFIG_X86_64

	efi->efi_systab_hi = (unsigned long)sys_table >> 32;

	efi->efi_memmap_hi = (unsigned long)mem_map >> 32;

#endif

	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;



	/* Might as well exit boot services now */

	status = efi_call_phys2(sys_table->boottime->exit_boot_services,

				handle, key);

	if (status != EFI_SUCCESS) {

		/*

		 * ExitBootServices() will fail if any of the event

		 * handlers change the memory map. In which case, we

		 * must be prepared to retry, but only once so that

		 * we're guaranteed to exit on repeated failures instead

		 * of spinning forever.

		 */

		if (called_exit)

			goto free_mem_map;

	while (data && data->next)

		data = (struct setup_data *)(unsigned long)data->next;



		called_exit = true;

		efi_call_phys1(sys_table->boottime->free_pool, mem_map);

		goto get_map;

	if (data)

		data->next = (unsigned long)e820ext;

	else

		params->hdr.setup_data = (unsigned long)e820ext;

}



	/* Historic? */

	boot_params->alt_mem_k = 32 * 1024;

static efi_status_t setup_e820(struct boot_params *params,

			       struct setup_data *e820ext, u32 e820ext_size)

{

	struct e820entry *e820_map = &params->e820_map[0];

	struct efi_info *efi = &params->efi_info;

	struct e820entry *prev = NULL;

	u32 nr_entries;

	u32 nr_desc;

	int i;



	/*

	 * Convert the EFI memory map to E820.

	 */

	nr_entries = 0;

	for (i = 0; i < size / desc_size; i++) {

	nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;



	for (i = 0; i < nr_desc; i++) {

		efi_memory_desc_t *d;

		unsigned int e820_type = 0;

		unsigned long m = (unsigned long)mem_map;

		unsigned long m = efi->efi_memmap;



		d = (efi_memory_desc_t *)(m + (i * desc_size));

		d = (efi_memory_desc_t *)(m + (i * efi->efi_memdesc_size));

		switch (d->type) {

		case EFI_RESERVED_TYPE:

		case EFI_RUNTIME_SERVICES_CODE:
@@ -620,18 +596,142 @@ get_map: 


		/* Merge adjacent mappings */

		if (prev && prev->type == e820_type &&

		    (prev->addr + prev->size) == d->phys_addr)

		    (prev->addr + prev->size) == d->phys_addr) {

			prev->size += d->num_pages << 12;

		else {

			continue;

		}



		if (nr_entries == ARRAY_SIZE(params->e820_map)) {

			u32 need = (nr_desc - i) * sizeof(struct e820entry) +

				   sizeof(struct setup_data);



			if (!e820ext || e820ext_size < need)

				return EFI_BUFFER_TOO_SMALL;



			/* boot_params map full, switch to e820 extended */

			e820_map = (struct e820entry *)e820ext->data;

		}



		e820_map->addr = d->phys_addr;

			e820_map->size = d->num_pages << 12;

		e820_map->size = d->num_pages << PAGE_SHIFT;

		e820_map->type = e820_type;

		prev = e820_map++;

		nr_entries++;

	}



	if (nr_entries > ARRAY_SIZE(params->e820_map)) {

		u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_map);



		add_e820ext(params, e820ext, nr_e820ext);

		nr_entries -= nr_e820ext;

	}



	params->e820_entries = (u8)nr_entries;



	return EFI_SUCCESS;

}



static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,

				  u32 *e820ext_size)

{

	efi_status_t status;

	unsigned long size;



	size = sizeof(struct setup_data) +

		sizeof(struct e820entry) * nr_desc;



	if (*e820ext) {

		efi_call_phys1(sys_table->boottime->free_pool, *e820ext);

		*e820ext = NULL;

		*e820ext_size = 0;

	}



	status = efi_call_phys3(sys_table->boottime->allocate_pool,

				EFI_LOADER_DATA, size, e820ext);



	if (status == EFI_SUCCESS)

		*e820ext_size = size;



	return status;

}



static efi_status_t exit_boot(struct boot_params *boot_params,

			      void *handle)

{

	struct efi_info *efi = &boot_params->efi_info;

	unsigned long map_sz, key, desc_size;

	efi_memory_desc_t *mem_map;

	struct setup_data *e820ext;

	__u32 e820ext_size;

	__u32 nr_desc, prev_nr_desc;

	efi_status_t status;

	__u32 desc_version;

	bool called_exit = false;

	u8 nr_entries;

	int i;



	nr_desc = 0;

	e820ext = NULL;

	e820ext_size = 0;



get_map:

	status = efi_get_memory_map(sys_table, &mem_map, &map_sz, &desc_size,

				    &desc_version, &key);



	if (status != EFI_SUCCESS)

		return status;



	prev_nr_desc = nr_desc;

	nr_desc = map_sz / desc_size;

	if (nr_desc > prev_nr_desc &&

	    nr_desc > ARRAY_SIZE(boot_params->e820_map)) {

		u32 nr_e820ext = nr_desc - ARRAY_SIZE(boot_params->e820_map);



		status = alloc_e820ext(nr_e820ext, &e820ext, &e820ext_size);

		if (status != EFI_SUCCESS)

			goto free_mem_map;



		efi_call_phys1(sys_table->boottime->free_pool, mem_map);

		goto get_map; /* Allocated memory, get map again */

	}



	boot_params->e820_entries = nr_entries;

	memcpy(&efi->efi_loader_signature, EFI_LOADER_SIGNATURE, sizeof(__u32));

	efi->efi_systab = (unsigned long)sys_table;

	efi->efi_memdesc_size = desc_size;

	efi->efi_memdesc_version = desc_version;

	efi->efi_memmap = (unsigned long)mem_map;

	efi->efi_memmap_size = map_sz;



#ifdef CONFIG_X86_64

	efi->efi_systab_hi = (unsigned long)sys_table >> 32;

	efi->efi_memmap_hi = (unsigned long)mem_map >> 32;

#endif



	/* Might as well exit boot services now */

	status = efi_call_phys2(sys_table->boottime->exit_boot_services,

				handle, key);

	if (status != EFI_SUCCESS) {

		/*

		 * ExitBootServices() will fail if any of the event

		 * handlers change the memory map. In which case, we

		 * must be prepared to retry, but only once so that

		 * we're guaranteed to exit on repeated failures instead

		 * of spinning forever.

		 */

		if (called_exit)

			goto free_mem_map;



		called_exit = true;

		efi_call_phys1(sys_table->boottime->free_pool, mem_map);

		goto get_map;

	}



	/* Historic? */

	boot_params->alt_mem_k = 32 * 1024;



	status = setup_e820(boot_params, e820ext, e820ext_size);

	if (status != EFI_SUCCESS)

		return status;



	return EFI_SUCCESS;