3 files changed, 75 insertions, 7 deletions

diff --git a/drivers/base/firmware_loader/Kconfig b/drivers/base/firmware_loader/Kconfig
index 5166b323a0f8..5ca00e02fe82 100644
--- a/drivers/base/firmware_loader/Kconfig
+++ b/drivers/base/firmware_loader/Kconfig
@@ -3,6 +3,8 @@ 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
 	default y
 	help
 	  This enables the firmware loading facility in the kernel. The kernel
@@ -24,6 +26,17 @@ config FW_LOADER
 	  You also want to be sure to enable this built-in if you are going to
 	  enable built-in firmware (CONFIG_EXTRA_FIRMWARE).
 
+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
+	help
+	  Select this option to use dynamic debug to log firmware filenames and
+	  SHA256 checksums to the kernel log for each firmware file that is
+	  loaded.
+
 if FW_LOADER
 
 config FW_LOADER_PAGED_BUF
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 017c4cdb219e..9d79d5ad9102 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -493,9 +493,9 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
 					     const void *in_buffer))
 {
 	size_t size;
-	int i, len;
+	int i, len, maxlen = 0;
 	int rc = -ENOENT;
-	char *path;
+	char *path, *nt = NULL;
 	size_t msize = INT_MAX;
 	void *buffer = NULL;
 
@@ -518,8 +518,17 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
 		if (!fw_path[i][0])
 			continue;
 
-		len = snprintf(path, PATH_MAX, "%s/%s%s",
-			       fw_path[i], fw_priv->fw_name, suffix);
+		/* strip off \n from customized path */
+		maxlen = strlen(fw_path[i]);
+		if (i == 0) {
+			nt = strchr(fw_path[i], '\n');
+			if (nt)
+				maxlen = nt - fw_path[i];
+		}
+
+		len = snprintf(path, PATH_MAX, "%.*s/%s%s",
+			       maxlen, fw_path[i],
+			       fw_priv->fw_name, suffix);
 		if (len >= PATH_MAX) {
 			rc = -ENAMETOOLONG;
 			break;
@@ -791,6 +800,50 @@ static void fw_abort_batch_reqs(struct firmware *fw)
 	mutex_unlock(&fw_lock);
 }
 
+#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;
+
+	alg = crypto_alloc_shash("sha256", 0, 0);
+	if (!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_shash;
+
+	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_shash:
+	crypto_free_shash(alg);
+out_free:
+	kfree(shash);
+	kfree(outbuf);
+	kfree(sha256buf);
+}
+#else
+static void fw_log_firmware_info(const struct firmware *fw, const char *name,
+				 struct device *device)
+{}
+#endif
+
 /* called from request_firmware() and request_firmware_work_func() */
 static int
 _request_firmware(const struct firmware **firmware_p, const char *name,
@@ -861,11 +914,13 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
 	revert_creds(old_cred);
 	put_cred(kern_cred);
 
- out:
+out:
 	if (ret < 0) {
 		fw_abort_batch_reqs(fw);
 		release_firmware(fw);
 		fw = NULL;
+	} else {
+		fw_log_firmware_info(fw, name, device);
 	}
 
 	*firmware_p = fw;
diff --git a/drivers/base/firmware_loader/sysfs.c b/drivers/base/firmware_loader/sysfs.c
index 56911d75b90a..c9c93b47d9a5 100644
--- a/drivers/base/firmware_loader/sysfs.c
+++ b/drivers/base/firmware_loader/sysfs.c
@@ -25,7 +25,7 @@ void __fw_load_abort(struct fw_priv *fw_priv)
 }
 
 #ifdef CONFIG_FW_LOADER_USER_HELPER
-static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
+static ssize_t timeout_show(const struct class *class, const struct class_attribute *attr,
 			    char *buf)
 {
 	return sysfs_emit(buf, "%d\n", __firmware_loading_timeout());
@@ -44,7 +44,7 @@ static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
  *
  *	Note: zero means 'wait forever'.
  **/
-static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
+static ssize_t timeout_store(const struct class *class, const struct class_attribute *attr,
 			     const char *buf, size_t count)
 {
 	int tmp_loading_timeout = simple_strtol(buf, NULL, 10);