linux-kernel - [PATCH v2 10/23] firmware: add helper to copy built-in data to pre-alloc buffer

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Date:   Mon, 20 Nov 2017 10:23:56 -0800
From:   "Luis R. Rodriguez" <mcgrof@...nel.org>
To:     gregkh@...uxfoundation.org
Cc:     akpm@...ux-foundation.org, keescook@...omium.org,
        mfuzzey@...keon.com, zohar@...ux.vnet.ibm.com, dhowells@...hat.com,
        pali.rohar@...il.com, tiwai@...e.de, arend.vanspriel@...adcom.com,
        zajec5@...il.com, nbroeking@...com, markivx@...eaurora.org,
        stephen.boyd@...aro.org, broonie@...nel.org,
        dmitry.torokhov@...il.com, dwmw2@...radead.org,
        torvalds@...ux-foundation.org, Abhay_Salunke@...l.com,
        bjorn.andersson@...aro.org, jewalt@...innovations.com,
        linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        "Luis R. Rodriguez" <mcgrof@...nel.org>
Subject: [PATCH v2 10/23] firmware: add helper to copy built-in data to pre-alloc buffer

This makes it clearer that the parameters passed are only used for
the preallocated buffer option, ie, when a caller uses:

	request_firmware_into_buf()

Otherwise this code won't run. We flip the logic just so the actual
prellocated buf code is not indented.

Signed-off-by: Luis R. Rodriguez <mcgrof@...nel.org>
---
 drivers/base/firmware_class.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 4f64410fe7e6..aba3f2cbe2f4 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -146,6 +146,14 @@ static struct firmware_cache fw_cache;
 extern struct builtin_fw __start_builtin_fw[];
 extern struct builtin_fw __end_builtin_fw[];
 
+static void fw_copy_to_prealloc_buf(struct firmware *fw,
+				    void *buf, size_t size)
+{
+	if (!buf || size < fw->size)
+		return;
+	memcpy(buf, fw->data, fw->size);
+}
+
 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
 				    void *buf, size_t size)
 {
@@ -155,9 +163,8 @@ static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
 		if (strcmp(name, b_fw->name) == 0) {
 			fw->size = b_fw->size;
 			fw->data = b_fw->data;
+			fw_copy_to_prealloc_buf(fw, buf, size);
 
-			if (buf && fw->size <= size)
-				memcpy(buf, fw->data, fw->size);
 			return true;
 		}
 	}
-- 
2.15.0