1 files changed, 64 insertions, 1 deletions

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 33a90120f6ad..4d74fc72c195 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -67,6 +67,8 @@ static int debugfs_u8_get(void *data, u64 *val)
         return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
 
 /**
  * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
@@ -95,6 +97,13 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
 struct dentry *debugfs_create_u8(const char *name, mode_t mode,
                                  struct dentry *parent, u8 *value)
 {
+        /* if there are no write bits set, make read only */
+        if (!(mode & S_IWUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_u8_ro);
+        /* if there are no read bits set, make write only */
+        if (!(mode & S_IRUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_u8_wo);
+
         return debugfs_create_file(name, mode, parent, value, &fops_u8);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_u8);
@@ -110,6 +119,8 @@ static int debugfs_u16_get(void *data, u64 *val)
         return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
 
 /**
  * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
@@ -138,6 +149,13 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
 struct dentry *debugfs_create_u16(const char *name, mode_t mode,
                                   struct dentry *parent, u16 *value)
 {
+        /* if there are no write bits set, make read only */
+        if (!(mode & S_IWUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_u16_ro);
+        /* if there are no read bits set, make write only */
+        if (!(mode & S_IRUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_u16_wo);
+
         return debugfs_create_file(name, mode, parent, value, &fops_u16);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_u16);
@@ -153,6 +171,8 @@ static int debugfs_u32_get(void *data, u64 *val)
         return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
 
 /**
  * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
@@ -181,6 +201,13 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
 struct dentry *debugfs_create_u32(const char *name, mode_t mode,
                                  struct dentry *parent, u32 *value)
 {
+        /* if there are no write bits set, make read only */
+        if (!(mode & S_IWUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_u32_ro);
+        /* if there are no read bits set, make write only */
+        if (!(mode & S_IRUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_u32_wo);
+
         return debugfs_create_file(name, mode, parent, value, &fops_u32);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_u32);
@@ -197,6 +224,8 @@ static int debugfs_u64_get(void *data, u64 *val)
         return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
 
 /**
  * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
@@ -225,15 +254,28 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
 struct dentry *debugfs_create_u64(const char *name, mode_t mode,
                                  struct dentry *parent, u64 *value)
 {
+        /* if there are no write bits set, make read only */
+        if (!(mode & S_IWUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_u64_ro);
+        /* if there are no read bits set, make write only */
+        if (!(mode & S_IRUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_u64_wo);
+
         return debugfs_create_file(name, mode, parent, value, &fops_u64);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_u64);
 
 DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
 
 DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
 
 DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
 
 /*
  * debugfs_create_x{8,16,32} - create a debugfs file that is used to read and write an unsigned {8,16,32}-bit value
@@ -256,6 +298,13 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n"
 struct dentry *debugfs_create_x8(const char *name, mode_t mode,
                                  struct dentry *parent, u8 *value)
 {
+        /* if there are no write bits set, make read only */
+        if (!(mode & S_IWUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_x8_ro);
+        /* if there are no read bits set, make write only */
+        if (!(mode & S_IRUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_x8_wo);
+
         return debugfs_create_file(name, mode, parent, value, &fops_x8);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_x8);
@@ -273,6 +322,13 @@ EXPORT_SYMBOL_GPL(debugfs_create_x8);
 struct dentry *debugfs_create_x16(const char *name, mode_t mode,
                                  struct dentry *parent, u16 *value)
 {
+        /* if there are no write bits set, make read only */
+        if (!(mode & S_IWUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_x16_ro);
+        /* if there are no read bits set, make write only */
+        if (!(mode & S_IRUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_x16_wo);
+
         return debugfs_create_file(name, mode, parent, value, &fops_x16);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_x16);
@@ -290,6 +346,13 @@ EXPORT_SYMBOL_GPL(debugfs_create_x16);
 struct dentry *debugfs_create_x32(const char *name, mode_t mode,
                                  struct dentry *parent, u32 *value)
 {
+        /* if there are no write bits set, make read only */
+        if (!(mode & S_IWUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_x32_ro);
+        /* if there are no read bits set, make write only */
+        if (!(mode & S_IRUGO))
+                return debugfs_create_file(name, mode, parent, value, &fops_x32_wo);
+
         return debugfs_create_file(name, mode, parent, value, &fops_x32);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_x32);
@@ -419,7 +482,7 @@ static const struct file_operations fops_blob = {
 };
 
 /**
- * debugfs_create_blob - create a debugfs file that is used to read and write a binary blob
+ * debugfs_create_blob - create a debugfs file that is used to read a binary blob
  * @name: a pointer to a string containing the name of the file to create.
  * @mode: the permission that the file should have
  * @parent: a pointer to the parent dentry for this file.  This should be a