Commit 4f894483 authored by Eric Biggers's avatar Eric Biggers Committed by Danilo Krummrich
Browse files

firmware_loader: use SHA-256 library API instead of crypto_shash API 



This user of SHA-256 does not support any other algorithm, so the
crypto_shash abstraction provides no value.  Just use the SHA-256
library API instead, which is much simpler and easier to use.

Also take advantage of printk's built-in hex conversion using %*phN.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250428190909.852705-1-ebiggers@kernel.org


Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent e99efa8a

drivers/base/firmware_loader/Kconfig

+1 −3
Original line number Diff line number Diff line
@@ -3,8 +3,7 @@ menu "Firmware loader" 


config FW_LOADER

	tristate "Firmware loading facility" if EXPERT

	select CRYPTO_HASH if FW_LOADER_DEBUG

	select CRYPTO_SHA256 if FW_LOADER_DEBUG

	select CRYPTO_LIB_SHA256 if FW_LOADER_DEBUG

	default y

	help

	  This enables the firmware loading facility in the kernel. The kernel
@@ -28,7 +27,6 @@ config FW_LOADER 


config FW_LOADER_DEBUG

	bool "Log filenames and checksums for loaded firmware"

	depends on CRYPTO = FW_LOADER || CRYPTO=y

	depends on DYNAMIC_DEBUG

	depends on FW_LOADER

	default FW_LOADER

drivers/base/firmware_loader/main.c

+4 −30
Original line number Diff line number Diff line
@@ -806,41 +806,15 @@ static void fw_abort_batch_reqs(struct firmware *fw) 
}



#if defined(CONFIG_FW_LOADER_DEBUG)

#include <crypto/hash.h>

#include <crypto/sha2.h>



static void fw_log_firmware_info(const struct firmware *fw, const char *name, struct device *device)

{

	struct shash_desc *shash;

	struct crypto_shash *alg;

	u8 *sha256buf;

	char *outbuf;

	u8 digest[SHA256_DIGEST_SIZE];



	alg = crypto_alloc_shash("sha256", 0, 0);

	if (IS_ERR(alg))

		return;



	sha256buf = kmalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);

	outbuf = kmalloc(SHA256_BLOCK_SIZE + 1, GFP_KERNEL);

	shash = kmalloc(sizeof(*shash) + crypto_shash_descsize(alg), GFP_KERNEL);

	if (!sha256buf || !outbuf || !shash)

		goto out_free;



	shash->tfm = alg;



	if (crypto_shash_digest(shash, fw->data, fw->size, sha256buf) < 0)

		goto out_free;



	for (int i = 0; i < SHA256_DIGEST_SIZE; i++)

		sprintf(&outbuf[i * 2], "%02x", sha256buf[i]);

	outbuf[SHA256_BLOCK_SIZE] = 0;

	dev_dbg(device, "Loaded FW: %s, sha256: %s\n", name, outbuf);



out_free:

	kfree(shash);

	kfree(outbuf);

	kfree(sha256buf);

	crypto_free_shash(alg);

	sha256(fw->data, fw->size, digest);

	dev_dbg(device, "Loaded FW: %s, sha256: %*phN\n",

		name, SHA256_DIGEST_SIZE, digest);

}

#else

static void fw_log_firmware_info(const struct firmware *fw, const char *name,