diff options
Diffstat (limited to 'fs/debugfs/file.c')
-rw-r--r-- | fs/debugfs/file.c | 119 |
1 files changed, 70 insertions, 49 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 2340f6978d6e..63146295153b 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -21,6 +21,7 @@ #include <linux/debugfs.h> #include <linux/io.h> #include <linux/slab.h> +#include <linux/atomic.h> static ssize_t default_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -403,6 +404,47 @@ struct dentry *debugfs_create_size_t(const char *name, umode_t mode, } EXPORT_SYMBOL_GPL(debugfs_create_size_t); +static int debugfs_atomic_t_set(void *data, u64 val) +{ + atomic_set((atomic_t *)data, val); + return 0; +} +static int debugfs_atomic_t_get(void *data, u64 *val) +{ + *val = atomic_read((atomic_t *)data); + return 0; +} +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get, + debugfs_atomic_t_set, "%lld\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%lld\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n"); + +/** + * debugfs_create_atomic_t - create a debugfs file that is used to read and + * write an atomic_t value + * @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 + * directory dentry if set. If this parameter is %NULL, then the + * file will be created in the root of the debugfs filesystem. + * @value: a pointer to the variable that the file should read to and write + * from. + */ +struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, + struct dentry *parent, atomic_t *value) +{ + /* if there are no write bits set, make read only */ + if (!(mode & S_IWUGO)) + return debugfs_create_file(name, mode, parent, value, + &fops_atomic_t_ro); + /* if there are no read bits set, make write only */ + if (!(mode & S_IRUGO)) + return debugfs_create_file(name, mode, parent, value, + &fops_atomic_t_wo); + + return debugfs_create_file(name, mode, parent, value, &fops_atomic_t); +} +EXPORT_SYMBOL_GPL(debugfs_create_atomic_t); static ssize_t read_file_bool(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) @@ -431,6 +473,7 @@ static ssize_t write_file_bool(struct file *file, const char __user *user_buf, if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; + buf[buf_size] = '\0'; if (strtobool(buf, &bv) == 0) *val = bv; @@ -526,73 +569,51 @@ struct array_data { u32 elements; }; -static int u32_array_open(struct inode *inode, struct file *file) -{ - file->private_data = NULL; - return nonseekable_open(inode, file); -} - -static size_t format_array(char *buf, size_t bufsize, const char *fmt, - u32 *array, u32 array_size) +static size_t u32_format_array(char *buf, size_t bufsize, + u32 *array, int array_size) { size_t ret = 0; - u32 i; - for (i = 0; i < array_size; i++) { + while (--array_size >= 0) { size_t len; + char term = array_size ? ' ' : '\n'; - len = snprintf(buf, bufsize, fmt, array[i]); - len++; /* ' ' or '\n' */ + len = snprintf(buf, bufsize, "%u%c", *array++, term); ret += len; - if (buf) { - buf += len; - bufsize -= len; - buf[-1] = (i == array_size-1) ? '\n' : ' '; - } + buf += len; + bufsize -= len; } - - ret++; /* \0 */ - if (buf) - *buf = '\0'; - return ret; } -static char *format_array_alloc(const char *fmt, u32 *array, - u32 array_size) +static int u32_array_open(struct inode *inode, struct file *file) { - size_t len = format_array(NULL, 0, fmt, array, array_size); - char *ret; - - ret = kmalloc(len, GFP_KERNEL); - if (ret == NULL) - return NULL; + struct array_data *data = inode->i_private; + int size, elements = data->elements; + char *buf; + + /* + * Max size: + * - 10 digits + ' '/'\n' = 11 bytes per number + * - terminating NUL character + */ + size = elements*11; + buf = kmalloc(size+1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + buf[size] = 0; + + file->private_data = buf; + u32_format_array(buf, size, data->array, data->elements); - format_array(ret, len, fmt, array, array_size); - return ret; + return nonseekable_open(inode, file); } static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len, loff_t *ppos) { - struct inode *inode = file->f_path.dentry->d_inode; - struct array_data *data = inode->i_private; - size_t size; - - if (*ppos == 0) { - if (file->private_data) { - kfree(file->private_data); - file->private_data = NULL; - } - - file->private_data = format_array_alloc("%u", data->array, - data->elements); - } - - size = 0; - if (file->private_data) - size = strlen(file->private_data); + size_t size = strlen(file->private_data); return simple_read_from_buffer(buf, len, ppos, file->private_data, size); |