All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ard Biesheuvel <ardb@kernel.org>
To: linux-efi@vger.kernel.org
Cc: loongarch@lists.linux.dev, Ard Biesheuvel <ardb@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	Ilias Apalodimas <ilias.apalodimas@linaro.org>,
	Huacai Chen <chenhuacai@loongson.cn>,
	Xi Ruoyao <xry111@xry111.site>
Subject: [PATCH v2 6/8] efi: libstub: remove DT dependency from generic stub
Date: Tue, 20 Sep 2022 20:35:52 +0200	[thread overview]
Message-ID: <20220920183554.3870247-7-ardb@kernel.org> (raw)
In-Reply-To: <20220920183554.3870247-1-ardb@kernel.org>

Refactor the generic EFI stub entry code so that all the dependencies on
device tree are abstracted and hidden behind a generic efi_boot_kernel()
routine that can also be implemented in other ways. This allows users of
the generic stub to avoid using FDT for passing information to the core
kernel.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/libstub/efi-stub.c | 53 +----------------
 drivers/firmware/efi/libstub/efistub.h  |  7 +--
 drivers/firmware/efi/libstub/fdt.c      | 61 ++++++++++++++++++--
 3 files changed, 60 insertions(+), 61 deletions(-)

diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 7d53528613ce..e6179a89430b 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -10,7 +10,6 @@
  */
 
 #include <linux/efi.h>
-#include <linux/libfdt.h>
 #include <asm/efi.h>
 
 #include "efistub.h"
@@ -132,14 +131,11 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	unsigned long image_addr;
 	unsigned long image_size = 0;
 	/* addr/point and size pairs for memory management*/
-	unsigned long fdt_addr = 0;  /* Original DTB */
-	unsigned long fdt_size = 0;
 	char *cmdline_ptr = NULL;
 	int cmdline_size = 0;
 	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
 	unsigned long reserve_addr = 0;
 	unsigned long reserve_size = 0;
-	enum efi_secureboot_mode secure_boot;
 	struct screen_info *si;
 	efi_properties_table_t *prop_tbl;
 
@@ -215,38 +211,6 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	/* Ask the firmware to clear memory on unclean shutdown */
 	efi_enable_reset_attack_mitigation();
 
-	secure_boot = efi_get_secureboot();
-
-	/*
-	 * Unauthenticated device tree data is a security hazard, so ignore
-	 * 'dtb=' unless UEFI Secure Boot is disabled.  We assume that secure
-	 * boot is enabled if we can't determine its state.
-	 */
-	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
-	     secure_boot != efi_secureboot_mode_disabled) {
-		if (strstr(cmdline_ptr, "dtb="))
-			efi_err("Ignoring DTB from command line.\n");
-	} else {
-		status = efi_load_dtb(image, &fdt_addr, &fdt_size);
-
-		if (status != EFI_SUCCESS) {
-			efi_err("Failed to load device tree!\n");
-			goto fail_free_image;
-		}
-	}
-
-	if (fdt_addr) {
-		efi_info("Using DTB from command line\n");
-	} else {
-		/* Look for a device tree configuration table entry. */
-		fdt_addr = (uintptr_t)get_fdt(&fdt_size);
-		if (fdt_addr)
-			efi_info("Using DTB from configuration table\n");
-	}
-
-	if (!fdt_addr)
-		efi_info("Generating empty DTB\n");
-
 	efi_load_initrd(image, ULONG_MAX,
 			efi_get_max_initrd_addr(image_addr));
 
@@ -290,23 +254,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 
 	install_memreserve_table();
 
-	status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr, cmdline_ptr,
-						fdt_addr, fdt_size);
-	if (status != EFI_SUCCESS)
-		goto fail_free_fdt;
-
-	if (IS_ENABLED(CONFIG_ARM))
-		efi_handle_post_ebs_state();
-
-	efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
-	/* not reached */
-
-fail_free_fdt:
-	efi_err("Failed to update FDT and exit boot services\n");
-
-	efi_free(fdt_size, fdt_addr);
+	status = efi_boot_kernel(handle, image, image_addr, cmdline_ptr);
 
-fail_free_image:
 	efi_free(image_size, image_addr);
 	efi_free(reserve_size, reserve_addr);
 fail_free_screeninfo:
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 84d3d4e25d46..e26f8625a2b5 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -844,11 +844,8 @@ typedef efi_status_t (*efi_exit_boot_map_processing)(
 efi_status_t efi_exit_boot_services(void *handle, void *priv,
 				    efi_exit_boot_map_processing priv_func);
 
-efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
-					    unsigned long *new_fdt_addr,
-					    char *cmdline_ptr,
-					    unsigned long fdt_addr,
-					    unsigned long fdt_size);
+efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image,
+			     unsigned long kernel_addr, char *cmdline_ptr);
 
 void *get_fdt(unsigned long *fdt_size);
 
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index 3c252346a425..dbea887b9956 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -220,17 +220,18 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv)
  * exit_boot_services() call, so the exiting of boot services is very tightly
  * tied to the creation of the FDT with the final memory map in it.
  */
-
+static
 efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
+					    efi_loaded_image_t *image,
 					    unsigned long *new_fdt_addr,
-					    char *cmdline_ptr,
-					    unsigned long fdt_addr,
-					    unsigned long fdt_size)
+					    char *cmdline_ptr)
 {
 	unsigned long desc_size;
 	u32 desc_ver;
 	efi_status_t status;
 	struct exit_boot_struct priv;
+	unsigned long fdt_addr = 0;
+	unsigned long fdt_size = 0;
 
 	if (!efi_novamap) {
 		status = efi_alloc_virtmap(&priv.runtime_map, &desc_size,
@@ -241,6 +242,36 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
 		}
 	}
 
+	/*
+	 * Unauthenticated device tree data is a security hazard, so ignore
+	 * 'dtb=' unless UEFI Secure Boot is disabled.  We assume that secure
+	 * boot is enabled if we can't determine its state.
+	 */
+	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
+	    efi_get_secureboot() != efi_secureboot_mode_disabled) {
+		if (strstr(cmdline_ptr, "dtb="))
+			efi_err("Ignoring DTB from command line.\n");
+	} else {
+		status = efi_load_dtb(image, &fdt_addr, &fdt_size);
+
+		if (status != EFI_SUCCESS) {
+			efi_err("Failed to load device tree!\n");
+			goto fail;
+		}
+	}
+
+	if (fdt_addr) {
+		efi_info("Using DTB from command line\n");
+	} else {
+		/* Look for a device tree configuration table entry. */
+		fdt_addr = (uintptr_t)get_fdt(&fdt_size);
+		if (fdt_addr)
+			efi_info("Using DTB from configuration table\n");
+	}
+
+	if (!fdt_addr)
+		efi_info("Generating empty DTB\n");
+
 	efi_info("Exiting boot services...\n");
 
 	status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX);
@@ -304,11 +335,33 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
 	efi_free(MAX_FDT_SIZE, *new_fdt_addr);
 
 fail:
+	efi_free(fdt_size, fdt_addr);
+
 	efi_bs_call(free_pool, priv.runtime_map);
 
 	return EFI_LOAD_ERROR;
 }
 
+efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image,
+			     unsigned long kernel_addr, char *cmdline_ptr)
+{
+	unsigned long fdt_addr;
+	efi_status_t status;
+
+	status = allocate_new_fdt_and_exit_boot(handle, image, &fdt_addr,
+						cmdline_ptr);
+	if (status != EFI_SUCCESS) {
+		efi_err("Failed to update FDT and exit boot services\n");
+		return status;
+	}
+
+	if (IS_ENABLED(CONFIG_ARM))
+		efi_handle_post_ebs_state();
+
+	efi_enter_kernel(kernel_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
+	/* not reached */
+}
+
 void *get_fdt(unsigned long *fdt_size)
 {
 	void *fdt;
-- 
2.35.1


  parent reply	other threads:[~2022-09-20 18:36 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-20 18:35 [PATCH v2 0/8] efi: disentangle the generic EFI stub from FDT Ard Biesheuvel
2022-09-20 18:35 ` [PATCH v2 1/8] efi: libstub: drop pointless get_memory_map() call Ard Biesheuvel
2022-09-20 18:35 ` [PATCH v2 2/8] efi: libstub: avoid efi_get_memory_map() for allocating the virt map Ard Biesheuvel
2022-09-20 18:35 ` [PATCH v2 3/8] efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmap Ard Biesheuvel
2022-09-20 18:35 ` [PATCH v2 4/8] efi: libstub: remove pointless goto kludge Ard Biesheuvel
2022-09-20 18:35 ` [PATCH v2 5/8] efi: libstub: unify initrd loading between architectures Ard Biesheuvel
2022-09-20 18:35 ` Ard Biesheuvel [this message]
2022-09-20 18:35 ` [PATCH v2 7/8] efi: libstub: install boot-time memory map as config table Ard Biesheuvel
2022-09-20 18:35 ` [PATCH v2 8/8] efi/loongarch: libstub: remove dependency on flattened DT Ard Biesheuvel
2022-09-21  4:00   ` Huacai Chen
2022-09-21  8:14     ` Ard Biesheuvel
2022-09-22  2:15       ` Huacai Chen
2022-09-22  7:12         ` Ard Biesheuvel
2022-09-22  7:21           ` Huacai Chen
2022-09-22  7:24             ` Ard Biesheuvel
2022-09-22  7:41               ` Huacai Chen
2022-09-22  8:59                 ` Ard Biesheuvel
2022-09-22 12:07                   ` Huacai Chen
2022-09-22 12:50                     ` Ard Biesheuvel
2022-09-22 12:57                       ` Ard Biesheuvel
2022-09-22 13:08                       ` Huacai Chen
2022-09-22 13:10                         ` Ard Biesheuvel
2022-09-22 13:12                           ` Huacai Chen
2022-09-22 13:18                             ` Ard Biesheuvel
2022-09-22 13:19                               ` Ard Biesheuvel
2022-09-22 13:51                                 ` Ard Biesheuvel
2022-09-22 14:48                                   ` Huacai Chen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220920183554.3870247-7-ardb@kernel.org \
    --to=ardb@kernel.org \
    --cc=arnd@arndb.de \
    --cc=chenhuacai@loongson.cn \
    --cc=ilias.apalodimas@linaro.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=loongarch@lists.linux.dev \
    --cc=xry111@xry111.site \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.