[U-Boot] [RFC v3 09/10] efi_loader: rework bootmgr/bootefi using load_image API

AKASHI Takahiro takahiro.akashi at linaro.org
Thu Apr 18 00:13:52 UTC 2019


On Tue, Apr 16, 2019 at 12:56:32PM +0200, Heinrich Schuchardt wrote:
> On 4/16/19 6:24 AM, AKASHI Takahiro wrote:
> >In the current implementation, bootefi command and EFI boot manager
> >don't use load_image API, instead, use more primitive and internal
> >functions. This will introduce duplicated code and potentially
> >unknown bugs as well as inconsistent behaviours.
> >
> >With this patch, do_efibootmgr() and do_boot_efi() are completely
> >overhauled and re-implemented using load_image API.
> >
> >Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> >---
> >  cmd/bootefi.c                 | 197 +++++++++++++++++++---------------
> >  include/efi_loader.h          |   5 +-
> >  lib/efi_loader/efi_bootmgr.c  |  43 ++++----
> >  lib/efi_loader/efi_boottime.c |   2 +
> >  4 files changed, 134 insertions(+), 113 deletions(-)
> >
> >diff --git a/cmd/bootefi.c b/cmd/bootefi.c
> >index f14966961b23..97d49a53a44b 100644
> >--- a/cmd/bootefi.c
> >+++ b/cmd/bootefi.c
> >@@ -222,88 +222,39 @@ static efi_status_t efi_install_fdt(const char *fdt_opt)
> >  /**
> >   * do_bootefi_exec() - execute EFI binary
> >   *
> >- * @efi:		address of the binary
> >- * @device_path:	path of the device from which the binary was loaded
> >- * @image_path:		device path of the binary
> >+ * @handle:		handle of loaded image
> >   * Return:		status code
> >   *
> >   * Load the EFI binary into a newly assigned memory unwinding the relocation
> >   * information, install the loaded image protocol, and call the binary.
> >   */
> >-static efi_status_t do_bootefi_exec(void *efi,
> >-				    struct efi_device_path *device_path,
> >-				    struct efi_device_path *image_path)
> >+static efi_status_t do_bootefi_exec(efi_handle_t handle)
> >  {
> >-	efi_handle_t mem_handle = NULL;
> >-	struct efi_device_path *memdp = NULL;
> >-	efi_status_t ret;
> >-	struct efi_loaded_image_obj *image_obj = NULL;
> >  	struct efi_loaded_image *loaded_image_info = NULL;
> >-
> >-	/*
> >-	 * Special case for efi payload not loaded from disk, such as
> >-	 * 'bootefi hello' or for example payload loaded directly into
> >-	 * memory via JTAG, etc:
> >-	 */
> >-	if (!device_path && !image_path) {
> >-		printf("WARNING: using memory device/image path, this may confuse some payloads!\n");
> >-		/* actual addresses filled in after efi_load_pe() */
> >-		memdp = efi_dp_from_mem(EFI_RESERVED_MEMORY_TYPE, 0, 0);
> >-		device_path = image_path = memdp;
> >-		/*
> >-		 * Grub expects that the device path of the loaded image is
> >-		 * installed on a handle.
> >-		 */
> >-		ret = efi_create_handle(&mem_handle);
> >-		if (ret != EFI_SUCCESS)
> >-			return ret; /* TODO: leaks device_path */
> >-		ret = efi_add_protocol(mem_handle, &efi_guid_device_path,
> >-				       device_path);
> >-		if (ret != EFI_SUCCESS)
> >-			goto err_add_protocol;
> >-	} else {
> >-		assert(device_path && image_path);
> >-	}
> >-
> >-	ret = efi_setup_loaded_image(device_path, image_path, &image_obj,
> >-				     &loaded_image_info);
> >-	if (ret)
> >-		goto err_prepare;
> >+	efi_status_t ret;
> >
> >  	/* Transfer environment variable as load options */
> >-	set_load_options(loaded_image_info, "bootargs");
> 
> In set_load_options() an error could occur (out of memory). So I think
> it should return a status.

I didn't change anything in set_load_options(), but I will follow
your comment.

> >-
> >-	/* Load the EFI payload */
> >-	ret = efi_load_pe(image_obj, efi, loaded_image_info);
> >+	ret = EFI_CALL(systab.boottime->open_protocol(
> >+					handle,
> >+					&efi_guid_loaded_image,
> >+					(void **)&loaded_image_info,
> >+					NULL, NULL,
> >+					EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL));
> 
> Shouldn't we move this to set_load_options()?

No. This line has nothing to do with "load options."

> >  	if (ret != EFI_SUCCESS)
> >-		goto err_prepare;
> >-
> >-	if (memdp) {
> >-		struct efi_device_path_memory *mdp = (void *)memdp;
> >-		mdp->memory_type = loaded_image_info->image_code_type;
> >-		mdp->start_address = (uintptr_t)loaded_image_info->image_base;
> >-		mdp->end_address = mdp->start_address +
> >-				loaded_image_info->image_size;
> >-	}
> >+		goto err;
> >+	set_load_options(loaded_image_info, "bootargs");
> >
> >  	/* we don't support much: */
> >  	env_set("efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_OsIndicationsSupported",
> >  		"{ro,boot}(blob)0000000000000000");
> 
> Shouldn't this move to efi_setup.c? Probably we should also set
> OsIndications. I would prefer using efi_set_variable(). I think moving
> this could be done in a preparatory patch.

Yeah, I am aware of this issue.
Will fix in a separate patch.

> >
> >  	/* Call our payload! */
> >-	debug("%s: Jumping to 0x%p\n", __func__, image_obj->entry);
> >-	ret = EFI_CALL(efi_start_image(&image_obj->header, NULL, NULL));
> >+	ret = EFI_CALL(efi_start_image(handle, NULL, NULL));
> >
> >-err_prepare:
> >-	/* image has returned, loaded-image obj goes *poof*: */
> >  	efi_restore_gd();
> >  	free(loaded_image_info->load_options);
> >-	efi_delete_handle(&image_obj->header);
> >-
> >-err_add_protocol:
> >-	if (mem_handle)
> >-		efi_delete_handle(mem_handle);
> >
> >+err:
> >  	return ret;
> >  }
> >
> >@@ -317,8 +268,7 @@ err_add_protocol:
> >   */
> >  static int do_efibootmgr(const char *fdt_opt)
> >  {
> >-	struct efi_device_path *device_path, *file_path;
> >-	void *addr;
> >+	efi_handle_t handle;
> >  	efi_status_t ret;
> >
> >  	/* Allow unaligned memory access */
> >@@ -340,19 +290,19 @@ static int do_efibootmgr(const char *fdt_opt)
> >  	else if (ret != EFI_SUCCESS)
> >  		return CMD_RET_FAILURE;
> >
> >-	addr = efi_bootmgr_load(&device_path, &file_path);
> >-	if (!addr)
> >-		return 1;
> >+	ret = efi_bootmgr_load(&handle);
> >+	if (ret != EFI_SUCCESS) {
> >+		printf("EFI boot manager: Cannot load any image\n");
> >+		return CMD_RET_FAILURE;
> >+	}
> >
> >-	printf("## Starting EFI application at %p ...\n", addr);
> >-	ret = do_bootefi_exec(addr, device_path, file_path);
> >-	printf("## Application terminated, r = %lu\n",
> >-	       ret & ~EFI_ERROR_MASK);
> >+	ret = do_bootefi_exec(handle);
> >+	printf("## Application terminated, r = %lu\n", ret & ~EFI_ERROR_MASK);
> >
> >  	if (ret != EFI_SUCCESS)
> >-		return 1;
> >+		return CMD_RET_FAILURE;
> >
> >-	return 0;
> >+	return CMD_RET_SUCCESS;
> >  }
> >
> >  /*
> >@@ -367,10 +317,14 @@ static int do_efibootmgr(const char *fdt_opt)
> >   */
> >  static int do_boot_efi(const char *image_opt, const char *fdt_opt)
> >  {
> >-	unsigned long addr;
> >-	char *saddr;
> >+	void *image_buf;
> >+	struct efi_device_path *device_path, *image_path;
> >+	struct efi_device_path *memdp = NULL, *file_path = NULL;
> >+	const char *saddr;
> >+	unsigned long addr, size;
> >+	const char *size_str;
> >+	efi_handle_t mem_handle = NULL, handle;
> >  	efi_status_t ret;
> >-	unsigned long fdt_addr;
> >
> >  	/* Allow unaligned memory access */
> >  	allow_unaligned();
> >@@ -392,36 +346,94 @@ static int do_boot_efi(const char *image_opt, const char *fdt_opt)
> >  		return CMD_RET_FAILURE;
> >
> >  #ifdef CONFIG_CMD_BOOTEFI_HELLO
> >-	if (!strcmp(argv[1], "hello")) {
> >-		ulong size = __efi_helloworld_end - __efi_helloworld_begin;
> >-
> >+	if (!strcmp(image_opt, "hello")) {
> >  		saddr = env_get("loadaddr");
> >+		size = __efi_helloworld_end - __efi_helloworld_begin;
> >+
> >  		if (saddr)
> >  			addr = simple_strtoul(saddr, NULL, 16);
> >  		else
> >  			addr = CONFIG_SYS_LOAD_ADDR;
> >-		memcpy(map_sysmem(addr, size), __efi_helloworld_begin, size);
> >+
> >+		image_buf = map_sysmem(addr, size);
> >+		memcpy(image_buf, __efi_helloworld_begin, size);
> >+
> >+		device_path = NULL;
> >+		image_path = NULL;
> >  	} else
> >  #endif
> >  	{
> >-		saddr = argv[1];
> >+		saddr = image_opt;
> >+		size_str = env_get("filesize");
> >+		if (size_str)
> >+			size = simple_strtoul(size_str, NULL, 16);
> >+		else
> >+			size = 0;
> >
> >  		addr = simple_strtoul(saddr, NULL, 16);
> >  		/* Check that a numeric value was passed */
> >  		if (!addr && *saddr != '0')
> >  			return CMD_RET_USAGE;
> >+
> >+		image_buf = map_sysmem(addr, size);
> >+
> >+		device_path = bootefi_device_path;
> >+		image_path = bootefi_image_path;
> >  	}
> >
> >-	printf("## Starting EFI application at %08lx ...\n", addr);
> >-	ret = do_bootefi_exec(map_sysmem(addr, 0), bootefi_device_path,
> >-			      bootefi_image_path);
> >-	printf("## Application terminated, r = %lu\n",
> >-	       ret & ~EFI_ERROR_MASK);
> >+	if (!device_path && !image_path) {
> >+		/*
> >+		 * Special case for efi payload not loaded from disk,
> >+		 * such as 'bootefi hello' or for example payload
> >+		 * loaded directly into memory via JTAG, etc:
> >+		 */
> >+		printf("WARNING: using memory device/image path, this may confuse some payloads!\n");
> 
> The EFI spec says that either of SourceBuffer or DevicePath may be NULL
> when calling LoadImage().

So are you suggesting we should remove this message?

> >+
> >+		/* actual addresses filled in after efi_load_image() */
> >+		memdp = efi_dp_from_mem(EFI_RESERVED_MEMORY_TYPE,
> >+					(uint64_t)image_buf, size);
> >+		file_path = memdp; /* append(memdp, NULL) */
> >+
> >+		/*
> >+		 * Make sure that device for device_path exist
> >+		 * in load_image(). Otherwise, shell and grub will fail.
> 
> GRUB will fail anyway because it cannot determine the disk from which it
> was loaded. So why are we doing this?

I will comment on another reply.

> >+		 */
> >+		ret = efi_create_handle(&mem_handle);
> >+		if (ret != EFI_SUCCESS)
> >+			/* TODO: leaks device_path */
> >+			goto err_add_protocol;
> >+
> >+		ret = efi_add_protocol(mem_handle, &efi_guid_device_path,
> >+				       memdp);
> 
> Couldn't we as well use the device path of the root node as "file_path"?

I don't get you point very well, but
it will depend on how we should fix a grub issue mentioned above.

> >+		if (ret != EFI_SUCCESS)
> >+			goto err_add_protocol;
> >+	} else {
> >+		assert(device_path && image_path);
> >+		file_path = efi_dp_append(device_path, image_path);
> 
> Where is file_path freed?

In this function. Will fix.

> >+	}
> >+
> >+	ret = EFI_CALL(efi_load_image(false, efi_root,
> >+				      file_path, image_buf, size, &handle));
> >+	if (ret != EFI_SUCCESS)
> >+		goto err_prepare;
> >+
> >+	ret = do_bootefi_exec(handle);
> >+	printf("## Application terminated, r = %lu\n", ret & ~EFI_ERROR_MASK);
> >+
> >+err_prepare:
> >+	if (device_path)
> >+		efi_free_pool(file_path);
> >+
> >+err_add_protocol:
> >+	if (mem_handle)
> >+		efi_delete_handle(mem_handle);
> >+	if (memdp)
> >+		efi_free_pool(memdp);
> >
> >  	if (ret != EFI_SUCCESS)
> >  		return CMD_RET_FAILURE;
> >-	else
> >-		return CMD_RET_SUCCESS;
> >+
> >+	return CMD_RET_SUCCESS;
> >  }
> >
> >  #ifdef CONFIG_CMD_BOOTEFI_SELFTEST
> >@@ -581,7 +593,7 @@ static char bootefi_help_text[] =
> >  	"    Use environment variable efi_selftest to select a single test.\n"
> >  	"    Use 'setenv efi_selftest list' to enumerate all tests.\n"
> >  #endif
> >-	"bootefi bootmgr [fdt addr]\n"
> >+	"bootefi bootmgr [fdt address]\n"
> >  	"  - load and boot EFI payload based on BootOrder/BootXXXX variables.\n"
> >  	"\n"
> >  	"    If specified, the device tree located at <fdt address> gets\n"
> >@@ -606,6 +618,13 @@ void efi_set_bootdev(const char *dev, const char *devnr, const char *path)
> >  	ret = efi_dp_from_name(dev, devnr, path, &device, &image);
> >  	if (ret == EFI_SUCCESS) {
> >  		bootefi_device_path = device;
> >+		if (image) {
> >+			/* FIXME: image should not contain device */
> >+			struct efi_device_path *image_tmp = image;
> >+
> >+			efi_dp_split_file_path(image, &device, &image);
> >+			efi_free_pool(image_tmp);
> >+		}
> >  		bootefi_image_path = image;
> >  	} else {
> >  		bootefi_device_path = NULL;
> >diff --git a/include/efi_loader.h b/include/efi_loader.h
> >index d524dc7e24c1..c3eda2bb05d7 100644
> >--- a/include/efi_loader.h
> >+++ b/include/efi_loader.h
> >@@ -408,8 +408,6 @@ efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
> >  				    struct efi_device_path *file_path,
> >  				    struct efi_loaded_image_obj **handle_ptr,
> >  				    struct efi_loaded_image **info_ptr);
> >-efi_status_t efi_load_image_from_path(struct efi_device_path *file_path,
> >-				      void **buffer, efi_uintn_t *size);
> >  /* Print information about all loaded images */
> >  void efi_print_image_infos(void *pc);
> >
> >@@ -563,8 +561,7 @@ struct efi_load_option {
> >
> >  void efi_deserialize_load_option(struct efi_load_option *lo, u8 *data);
> >  unsigned long efi_serialize_load_option(struct efi_load_option *lo, u8 **data);
> >-void *efi_bootmgr_load(struct efi_device_path **device_path,
> >-		       struct efi_device_path **file_path);
> >+efi_status_t efi_bootmgr_load(efi_handle_t *handle);
> >
> >  #else /* CONFIG_IS_ENABLED(EFI_LOADER) */
> >
> >diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> >index 4fccadc5483d..13ec79b2098b 100644
> >--- a/lib/efi_loader/efi_bootmgr.c
> >+++ b/lib/efi_loader/efi_bootmgr.c
> >@@ -120,14 +120,14 @@ static void *get_var(u16 *name, const efi_guid_t *vendor,
> >   * if successful.  This checks that the EFI_LOAD_OPTION is active (enabled)
> >   * and that the specified file to boot exists.
> >   */
> >-static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
> >-			    struct efi_device_path **file_path)
> >+static efi_status_t try_load_entry(u16 n, efi_handle_t *handle)
> >  {
> >  	struct efi_load_option lo;
> >  	u16 varname[] = L"Boot0000";
> >  	u16 hexmap[] = L"0123456789ABCDEF";
> >-	void *load_option, *image = NULL;
> >+	void *load_option;
> >  	efi_uintn_t size;
> >+	efi_status_t ret;
> >
> >  	varname[4] = hexmap[(n & 0xf000) >> 12];
> >  	varname[5] = hexmap[(n & 0x0f00) >> 8];
> >@@ -136,19 +136,19 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
> >
> >  	load_option = get_var(varname, &efi_global_variable_guid, &size);
> >  	if (!load_option)
> >-		return NULL;
> >+		return EFI_LOAD_ERROR;
> >
> >  	efi_deserialize_load_option(&lo, load_option);
> >
> >  	if (lo.attributes & LOAD_OPTION_ACTIVE) {
> >  		u32 attributes;
> >-		efi_status_t ret;
> >
> >  		debug("%s: trying to load \"%ls\" from %pD\n",
> >  		      __func__, lo.label, lo.file_path);
> >
> >-		ret = efi_load_image_from_path(lo.file_path, &image, &size);
> >-
> >+		ret = EFI_CALL(efi_load_image(false, (void *)0x1 /* FIXME */,
> >+					      lo.file_path, NULL, 0,
> >+					      handle));
> >  		if (ret != EFI_SUCCESS)
> >  			goto error;
> >
> >@@ -159,17 +159,22 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
> >  				L"BootCurrent",
> >  				(efi_guid_t *)&efi_global_variable_guid,
> >  				attributes, size, &n));
> >-		if (ret != EFI_SUCCESS)
> >+		if (ret != EFI_SUCCESS) {
> >+			if (EFI_CALL(efi_unload_image(*handle))
> >+			    != EFI_SUCCESS)
> >+				printf("Unloading image failed\n");
> >  			goto error;
> >+		}
> >
> >  		printf("Booting: %ls\n", lo.label);
> >-		efi_dp_split_file_path(lo.file_path, device_path, file_path);
> >+	} else {
> >+		ret = EFI_LOAD_ERROR;
> >  	}
> >
> >  error:
> >  	free(load_option);
> >
> >-	return image;
> >+	return ret;
> >  }
> >
> >  /*
> >@@ -177,12 +182,10 @@ error:
> >   * EFI variable, the available load-options, finding and returning
> >   * the first one that can be loaded successfully.
> >   */
> >-void *efi_bootmgr_load(struct efi_device_path **device_path,
> >-		       struct efi_device_path **file_path)
> >+efi_status_t efi_bootmgr_load(efi_handle_t *handle)
> >  {
> >  	u16 bootnext, *bootorder;
> >  	efi_uintn_t size;
> >-	void *image = NULL;
> >  	int i, num;
> >  	efi_status_t ret;
> >
> >@@ -209,10 +212,9 @@ void *efi_bootmgr_load(struct efi_device_path **device_path,
> >  		/* load BootNext */
> >  		if (ret == EFI_SUCCESS) {
> >  			if (size == sizeof(u16)) {
> >-				image = try_load_entry(bootnext, device_path,
> >-						       file_path);
> >-				if (image)
> >-					return image;
> >+				ret = try_load_entry(bootnext, handle);
> >+				if (ret == EFI_SUCCESS)
> >+					return ret;
> >  			}
> >  		} else {
> >  			printf("Deleting BootNext failed\n");
> >@@ -223,19 +225,20 @@ void *efi_bootmgr_load(struct efi_device_path **device_path,
> >  	bootorder = get_var(L"BootOrder", &efi_global_variable_guid, &size);
> >  	if (!bootorder) {
> >  		printf("BootOrder not defined\n");
> >+		ret = EFI_NOT_FOUND;
> >  		goto error;
> >  	}
> >
> >  	num = size / sizeof(uint16_t);
> >  	for (i = 0; i < num; i++) {
> >  		debug("%s: trying to load Boot%04X\n", __func__, bootorder[i]);
> >-		image = try_load_entry(bootorder[i], device_path, file_path);
> >-		if (image)
> >+		ret = try_load_entry(bootorder[i], handle);
> >+		if (ret == EFI_SUCCESS)
> >  			break;
> >  	}
> >
> >  	free(bootorder);
> >
> >  error:
> >-	return image;
> >+	return ret;
> >  }
> >diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> >index b215bd7723da..65425fabc08f 100644
> >--- a/lib/efi_loader/efi_boottime.c
> >+++ b/lib/efi_loader/efi_boottime.c
> >@@ -1611,6 +1611,7 @@ failure:
> >   * @size:	size of the loaded image
> >   * Return:	status code
> >   */
> >+static
> >  efi_status_t efi_load_image_from_path(struct efi_device_path *file_path,
> >  				      void **buffer, efi_uintn_t *size)
> >  {
> >@@ -2684,6 +2685,7 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
> >  	}
> >
> >  	current_image = image_handle;
> >+	debug("EFI: Jumping into 0x%p\n", image_obj->entry);
> 
> Please, use EFI_PRINT() here.

Basically I agree, but there are lots of debug()'s in this file.
We should replace them all at once later.

Thanks,
-Takahiro Akashi

> Best regards
> 
> Heinrich
> 
> >  	ret = EFI_CALL(image_obj->entry(image_handle, &systab));
> >
> >  	/*
> >
> 


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