techpack: audio: aw88261: Load calibration file through firmware class

Direct access to filesystem is insane and hits a neverallow, load it
through the firmware class instead.

Co-authored-by: Michael Bestas <mkbestas@lineageos.org>
Change-Id: Ic522644c73d63a36430526736257d635deb08f6a

techpack/audio/asoc/codecs/aw88261/aw_calib.c

@@ -20,6 +20,7 @@
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/device.h>
+#include <linux/firmware.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <sound/core.h>
@@ -47,20 +48,12 @@ static unsigned int g_cali_status = false;
 static struct miscdevice *g_misc_dev = NULL;
 static DEFINE_MUTEX(g_cali_lock);
 
-#ifdef AW_CALI_STORE_EXAMPLE
+#define AWINIC_CALI_FILE  "aw_cali.bin"
- /*write cali to persist file example*/
-#define AWINIC_CALI_FILE  "/mnt/vendor/persist/factory/audio/aw_cali.bin"
 #define AW_INT_DEC_DIGIT 10
 
-static void aw_fs_read(struct file *file, char *buf, size_t count, loff_t *pos)
+#ifdef AW_CALI_STORE_EXAMPLE
-{
+/*write cali to persist file example*/
-#ifdef AW_KERNEL_VER_OVER_5_4_0
+#define AWINIC_CALI_PERSIST_FILE  "/mnt/vendor/persist/factory/audio/aw_cali.bin"
-	kernel_read(file, buf, count, pos);
-#else
-	vfs_read(file, buf, count, pos);
-#endif
-}
-
 static void aw_fs_write(struct file *file, char *buf, size_t count, loff_t *pos)
 {
 #ifdef AW_KERNEL_VER_OVER_5_4_0
@@ -77,7 +70,7 @@ static int aw_cali_write_cali_re_to_file(int32_t cali_re, int channel)
 	loff_t pos = 0;
 	mm_segment_t fs;
 
-	fp = filp_open(AWINIC_CALI_FILE, O_RDWR | O_CREAT, 0644);
+	fp = filp_open(AWINIC_CALI_PERSIST_FILE, O_RDWR | O_CREAT, 0644);
 	if (IS_ERR(fp)) {
 		pr_err("%s:channel:%d open %s failed!\n",
 		__func__, channel, AWINIC_CALI_FILE);
@@ -101,60 +94,49 @@ static int aw_cali_write_cali_re_to_file(int32_t cali_re, int channel)
 	filp_close(fp, NULL);
 	return 0;
 }
+#endif
 
-static int aw_cali_get_read_cali_re(int32_t *cali_re, int channel)
+static int aw_cali_get_read_cali_re(struct aw_device *aw_dev, int32_t *cali_re, int channel)
 {
-	struct file *fp = NULL;
+	int rc = -EINVAL;
-	/*struct inode *node;*/
-	int f_size;
-	char *buf = NULL;
 	int32_t int_cali_re = 0;
 	loff_t pos = 0;
-	mm_segment_t fs;
+	const struct firmware *fw = NULL;
 
-	fp = filp_open(AWINIC_CALI_FILE, O_RDONLY, 0);
+	/* open cali file */
-	if (IS_ERR(fp)) {
+	if (request_firmware(&fw, AWINIC_CALI_FILE, aw_dev->dev)) {
 		pr_err("%s:channel:%d open %s failed!\n",
 			__func__, channel, AWINIC_CALI_FILE);
-		return -EINVAL;
+		return rc;
+	}
+
+	if (!fw || !fw->data || !fw->size) {
+		pr_err("%s: invalid firmware", __func__);
+		goto error;
+	}
+
+	if (fw->size < AW_INT_DEC_DIGIT || fw->size > AW_INT_DEC_DIGIT * 2) {
+		pr_err("%s: invalid firmware size\n", __func__);
+		goto error;
 	}
 
 	pos = AW_INT_DEC_DIGIT * channel;
 
-	/*node = fp->f_dentry->d_inode;*/
+	if (sscanf(fw->data + pos, "%d", &int_cali_re) == 1)
-	/*f_size = node->i_size;*/
-	f_size = AW_INT_DEC_DIGIT;
-
-	buf = kzalloc(f_size + 1, GFP_ATOMIC);
-	if (!buf) {
-		pr_err("%s: channel:%d malloc mem %d failed!\n",
-			 __func__, channel, f_size);
-		filp_close(fp, NULL);
-		return -EINVAL;
-	}
-
-	fs = get_fs();
-	set_fs(KERNEL_DS);
-
-	aw_fs_read(fp, buf, f_size, &pos);
-
-	set_fs(fs);
-
-	if (sscanf(buf, "%d", &int_cali_re) == 1)
 		*cali_re = int_cali_re;
 	else
 		*cali_re = AW_ERRO_CALI_VALUE;
 
-	pr_info("%s: channel:%d buf:%s int_cali_re: %d\n",
+	pr_info("%s: channel:%d int_cali_re: %d\n",
-		__func__, channel, buf, int_cali_re);
+		__func__, channel, int_cali_re);
 
-	kfree(buf);
+	rc = 0;
-	buf = NULL;
-	filp_close(fp, NULL);
 
-	return  0;
+error:
+	/* close file */
+	release_firmware(fw);
+	return rc;
 }
-#endif
 
 /*custom need add to set/get cali_re form/to nv*/
 int aw_cali_write_re_to_nvram(int32_t cali_re, int32_t channel)
@@ -170,18 +152,14 @@ int aw_cali_write_re_to_nvram(int32_t cali_re, int32_t channel)
 #endif
 }
 
-int aw_cali_read_re_from_nvram(int32_t *cali_re, int32_t channel)
+int aw_cali_read_re_from_nvram(struct aw_device *aw_dev, int32_t *cali_re, int32_t channel)
 {
 	/*custom add, if success return value is 0 , else -1*/
-#ifdef AW_CALI_STORE_EXAMPLE
 	if (channel >= AW_DEV_CH_MAX) {
 		pr_err("%s: unsupported channel [%d] \n", __func__, channel);
 		return -EINVAL;
 	}
-	return aw_cali_get_read_cali_re(cali_re, channel);
+	return aw_cali_get_read_cali_re(aw_dev, cali_re, channel);
-#else
-	return 0;
-#endif
 }
 
 int aw_cali_store_cali_re(struct aw_device *aw_dev, int32_t re)

techpack/audio/asoc/codecs/aw88261/aw_calib.h

@@ -1,8 +1,6 @@
 #ifndef __AWINIC_CALIBRATION_H__
 #define __AWINIC_CALIBRATION_H__
 
-#define AW_CALI_STORE_EXAMPLE
-
 #define AW_CALI_READ_TIMES (3)
 #define AW_ERRO_CALI_VALUE (0)
 #define AW_CALI_RE_DEFAULT_TIMER	(3000)
@@ -136,7 +134,7 @@ struct aw_cali_desc {
 int aw_cali_init(struct aw_cali_desc *cali_desc);
 void aw_cali_deinit(struct aw_cali_desc *cali_desc);
 int aw_cali_svc_get_cali_status(void);
-int aw_cali_read_re_from_nvram(int32_t *cali_re, int32_t ch_index);
+int aw_cali_read_re_from_nvram(struct aw_device *aw_dev, int32_t *cali_re, int32_t ch_index);
 
 
 #endif

techpack/audio/asoc/codecs/aw88261/aw_device.c

@@ -1509,7 +1509,7 @@ int aw_dev_init_cali_re(struct aw_device *aw_dev)
 
 	if (aw_dev->cali_desc.mode) {
 		if (aw_dev->cali_desc.cali_re == AW_ERRO_CALI_VALUE) {
-			ret = aw_cali_read_re_from_nvram(&aw_dev->cali_desc.cali_re, aw_dev->channel);
+			ret = aw_cali_read_re_from_nvram(aw_dev, &aw_dev->cali_desc.cali_re, aw_dev->channel);
 			if (ret) {
 				aw_dev_info(aw_dev->dev, "read nvram cali failed, use default Re");
 				aw_dev->cali_desc.cali_re = AW_ERRO_CALI_VALUE;