soc: qcom: socinfo: Protect current_image using semaphore lock.

Variable current_image can be modified by multiple threads.
This change will protect current_image getting modified
by multiple threads.

Change-Id: I33df463311b24f73b1ba124d388731a72bd13263
CRs-Fixed: 2016485
Signed-off-by: Swetha Chikkaboraiah <schikk@codeaurora.org>

1 files changed, 34 insertions, 4 deletions

diff --git a/drivers/soc/qcom/socinfo.c b/drivers/soc/qcom/socinfo.c
index dd3e545eb7da..353a3cb66ba8 100644
--- a/drivers/soc/qcom/socinfo.c
+++ b/drivers/soc/qcom/socinfo.c
@@ -46,6 +46,7 @@
 #define SMEM_IMAGE_VERSION_OEM_OFFSET 95
 #define SMEM_IMAGE_VERSION_PARTITION_APPS 10
 
+static DECLARE_RWSEM(current_image_rwsem);
 enum {
 	HW_PLATFORM_UNKNOWN = 0,
 	HW_PLATFORM_SURF    = 1,
@@ -899,7 +900,9 @@ msm_get_image_version(struct device *dev,
 		pr_err("Failed to get image version base address");
 		return snprintf(buf, SMEM_IMAGE_VERSION_NAME_SIZE, "Unknown");
 	}
+	down_read(&current_image_rwsem);
 	string_address += current_image * SMEM_IMAGE_VERSION_SINGLE_BLOCK_SIZE;
+	up_read(&current_image_rwsem);
 	return snprintf(buf, SMEM_IMAGE_VERSION_NAME_SIZE, "%-.75s\n",
 			string_address);
 }
@@ -912,14 +915,19 @@ msm_set_image_version(struct device *dev,
 {
 	char *store_address;
 
-	if (current_image != SMEM_IMAGE_VERSION_PARTITION_APPS)
+	down_read(&current_image_rwsem);
+	if (current_image != SMEM_IMAGE_VERSION_PARTITION_APPS) {
+		up_read(&current_image_rwsem);
 		return count;
+	}
 	store_address = socinfo_get_image_version_base_address();
 	if (IS_ERR_OR_NULL(store_address)) {
 		pr_err("Failed to get image version base address");
+		up_read(&current_image_rwsem);
 		return count;
 	}
 	store_address += current_image * SMEM_IMAGE_VERSION_SINGLE_BLOCK_SIZE;
+	up_read(&current_image_rwsem);
 	snprintf(store_address, SMEM_IMAGE_VERSION_NAME_SIZE, "%-.75s", buf);
 	return count;
 }
@@ -937,7 +945,9 @@ msm_get_image_variant(struct device *dev,
 		return snprintf(buf, SMEM_IMAGE_VERSION_VARIANT_SIZE,
 		"Unknown");
 	}
+	down_read(&current_image_rwsem);
 	string_address += current_image * SMEM_IMAGE_VERSION_SINGLE_BLOCK_SIZE;
+	up_read(&current_image_rwsem);
 	string_address += SMEM_IMAGE_VERSION_VARIANT_OFFSET;
 	return snprintf(buf, SMEM_IMAGE_VERSION_VARIANT_SIZE, "%-.20s\n",
 			string_address);
@@ -951,14 +961,19 @@ msm_set_image_variant(struct device *dev,
 {
 	char *store_address;
 
-	if (current_image != SMEM_IMAGE_VERSION_PARTITION_APPS)
+	down_read(&current_image_rwsem);
+	if (current_image != SMEM_IMAGE_VERSION_PARTITION_APPS) {
+		up_read(&current_image_rwsem);
 		return count;
+	}
 	store_address = socinfo_get_image_version_base_address();
 	if (IS_ERR_OR_NULL(store_address)) {
 		pr_err("Failed to get image version base address");
+		up_read(&current_image_rwsem);
 		return count;
 	}
 	store_address += current_image * SMEM_IMAGE_VERSION_SINGLE_BLOCK_SIZE;
+	up_read(&current_image_rwsem);
 	store_address += SMEM_IMAGE_VERSION_VARIANT_OFFSET;
 	snprintf(store_address, SMEM_IMAGE_VERSION_VARIANT_SIZE, "%-.20s", buf);
 	return count;
@@ -976,7 +991,9 @@ msm_get_image_crm_version(struct device *dev,
 		pr_err("Failed to get image version base address");
 		return snprintf(buf, SMEM_IMAGE_VERSION_OEM_SIZE, "Unknown");
 	}
+	down_read(&current_image_rwsem);
 	string_address += current_image * SMEM_IMAGE_VERSION_SINGLE_BLOCK_SIZE;
+	up_read(&current_image_rwsem);
 	string_address += SMEM_IMAGE_VERSION_OEM_OFFSET;
 	return snprintf(buf, SMEM_IMAGE_VERSION_OEM_SIZE, "%-.33s\n",
 			string_address);
@@ -990,14 +1007,19 @@ msm_set_image_crm_version(struct device *dev,
 {
 	char *store_address;
 
-	if (current_image != SMEM_IMAGE_VERSION_PARTITION_APPS)
+	down_read(&current_image_rwsem);
+	if (current_image != SMEM_IMAGE_VERSION_PARTITION_APPS) {
+		up_read(&current_image_rwsem);
 		return count;
+	}
 	store_address = socinfo_get_image_version_base_address();
 	if (IS_ERR_OR_NULL(store_address)) {
 		pr_err("Failed to get image version base address");
+		up_read(&current_image_rwsem);
 		return count;
 	}
 	store_address += current_image * SMEM_IMAGE_VERSION_SINGLE_BLOCK_SIZE;
+	up_read(&current_image_rwsem);
 	store_address += SMEM_IMAGE_VERSION_OEM_OFFSET;
 	snprintf(store_address, SMEM_IMAGE_VERSION_OEM_SIZE, "%-.33s", buf);
 	return count;
@@ -1008,8 +1030,14 @@ msm_get_image_number(struct device *dev,
 			struct device_attribute *attr,
 			char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n",
+	int ret;
+
+	down_read(&current_image_rwsem);
+	ret = snprintf(buf, PAGE_SIZE, "%d\n",
 			current_image);
+	up_read(&current_image_rwsem);
+	return ret;
+
 }
 
 static ssize_t
@@ -1021,10 +1049,12 @@ msm_select_image(struct device *dev, struct device_attribute *attr,
 	ret = kstrtoint(buf, 10, &digit);
 	if (ret)
 		return ret;
+	down_write(&current_image_rwsem);
 	if (0 <= digit && digit < SMEM_IMAGE_VERSION_BLOCKS_COUNT)
 		current_image = digit;
 	else
 		current_image = 0;
+	up_write(&current_image_rwsem);
 	return count;
 }