fs/proc/vmcore: replace vmcoredd_mutex by vmcore_mutex

Now that we have a mutex that synchronizes against opening of the vmcore,
let's use that one to replace vmcoredd_mutex: there is no need to have
two separate ones.

This is a preparation for properly preventing vmcore modifications
after the vmcore was opened.

Signed-off-by: David Hildenbrand <[email protected]>
Message-Id: <[email protected]>
Acked-by: Andrew Morton <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

Author: davidhildenbrand

fs/proc/vmcore.c

@@ -53,7 +53,6 @@ static struct proc_dir_entry *proc_vmcore;
 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
 /* Device Dump list and mutex to synchronize access to list */
 static LIST_HEAD(vmcoredd_list);
-static DEFINE_MUTEX(vmcoredd_mutex);
 
 static bool vmcoredd_disabled;
 core_param(novmcoredd, vmcoredd_disabled, bool, 0);
@@ -248,7 +247,7 @@ static int vmcoredd_copy_dumps(struct iov_iter *iter, u64 start, size_t size)
 	size_t tsz;
 	char *buf;
 
-	mutex_lock(&vmcoredd_mutex);
+	mutex_lock(&vmcore_mutex);
 	list_for_each_entry(dump, &vmcoredd_list, list) {
 		if (start < offset + dump->size) {
 			tsz = min(offset + (u64)dump->size - start, (u64)size);
@@ -269,7 +268,7 @@ static int vmcoredd_copy_dumps(struct iov_iter *iter, u64 start, size_t size)
 	}
 
 out_unlock:
-	mutex_unlock(&vmcoredd_mutex);
+	mutex_unlock(&vmcore_mutex);
 	return ret;
 }
 
@@ -283,7 +282,7 @@ static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst,
 	size_t tsz;
 	char *buf;
 
-	mutex_lock(&vmcoredd_mutex);
+	mutex_lock(&vmcore_mutex);
 	list_for_each_entry(dump, &vmcoredd_list, list) {
 		if (start < offset + dump->size) {
 			tsz = min(offset + (u64)dump->size - start, (u64)size);
@@ -306,7 +305,7 @@ static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst,
 	}
 
 out_unlock:
-	mutex_unlock(&vmcoredd_mutex);
+	mutex_unlock(&vmcore_mutex);
 	return ret;
 }
 #endif /* CONFIG_MMU */
@@ -1518,9 +1517,9 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
 	dump->size = data_size;
 
 	/* Add the dump to driver sysfs list */
-	mutex_lock(&vmcoredd_mutex);
+	mutex_lock(&vmcore_mutex);
 	list_add_tail(&dump->list, &vmcoredd_list);
-	mutex_unlock(&vmcoredd_mutex);
+	mutex_unlock(&vmcore_mutex);
 
 	vmcoredd_update_size(data_size);
 	return 0;
@@ -1538,7 +1537,7 @@ EXPORT_SYMBOL(vmcore_add_device_dump);
 static void vmcore_free_device_dumps(void)
 {
 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
-	mutex_lock(&vmcoredd_mutex);
+	mutex_lock(&vmcore_mutex);
 	while (!list_empty(&vmcoredd_list)) {
 		struct vmcoredd_node *dump;
 
@@ -1548,7 +1547,7 @@ static void vmcore_free_device_dumps(void)
 		vfree(dump->buf);
 		vfree(dump);
 	}
-	mutex_unlock(&vmcoredd_mutex);
+	mutex_unlock(&vmcore_mutex);
 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
 }