kernel-aes67/fs/debugfs/file.c
Linus Torvalds e05e279e6f debugfs: fix u32_array race in format_array_alloc
The format_array_alloc() function is fundamentally racy, in that it
prints the array twice: once to figure out how much space to allocate
for the buffer, and the second time to actually print out the data.

If any of the array contents changes in between, the allocation size may
be wrong, and the end result may be truncated in odd ways.

Just don't do it.  Allocate a maximum-sized array up-front, and just
format the array contents once.  The only user of the u32_array
interfaces is the Xen spinlock statistics code, and it has 31 entries in
the arrays, so the maximum size really isn't that big, and the end
result is much simpler code without the bug.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-21 11:48:05 -07:00

721 lines
26 KiB
C

/*
* file.c - part of debugfs, a tiny little debug file system
*
* Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004 IBM Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* debugfs is for people to use instead of /proc or /sys.
* See Documentation/DocBook/filesystems for more details.
*
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/namei.h>
#include <linux/debugfs.h>
#include <linux/io.h>
#include <linux/slab.h>
static ssize_t default_read_file(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
return 0;
}
static ssize_t default_write_file(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return count;
}
const struct file_operations debugfs_file_operations = {
.read = default_read_file,
.write = default_write_file,
.open = simple_open,
.llseek = noop_llseek,
};
static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
nd_set_link(nd, dentry->d_inode->i_private);
return NULL;
}
const struct inode_operations debugfs_link_operations = {
.readlink = generic_readlink,
.follow_link = debugfs_follow_link,
};
static int debugfs_u8_set(void *data, u64 val)
{
*(u8 *)data = val;
return 0;
}
static int debugfs_u8_get(void *data, u64 *val)
{
*val = *(u8 *)data;
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
* @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.
*
* This function creates a file in debugfs with the given name that
* contains the value of the variable @value. If the @mode variable is so
* set, it can be read from, and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, %NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u8(const char *name, umode_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);
static int debugfs_u16_set(void *data, u64 val)
{
*(u16 *)data = val;
return 0;
}
static int debugfs_u16_get(void *data, u64 *val)
{
*val = *(u16 *)data;
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
* @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.
*
* This function creates a file in debugfs with the given name that
* contains the value of the variable @value. If the @mode variable is so
* set, it can be read from, and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, %NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u16(const char *name, umode_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);
static int debugfs_u32_set(void *data, u64 val)
{
*(u32 *)data = val;
return 0;
}
static int debugfs_u32_get(void *data, u64 *val)
{
*val = *(u32 *)data;
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
* @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.
*
* This function creates a file in debugfs with the given name that
* contains the value of the variable @value. If the @mode variable is so
* set, it can be read from, and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, %NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u32(const char *name, umode_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);
static int debugfs_u64_set(void *data, u64 val)
{
*(u64 *)data = val;
return 0;
}
static int debugfs_u64_get(void *data, u64 *val)
{
*val = *(u64 *)data;
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
* @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.
*
* This function creates a file in debugfs with the given name that
* contains the value of the variable @value. If the @mode variable is so
* set, it can be read from, and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, %NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u64(const char *name, umode_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");
DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n");
/*
* debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value
*
* These functions are exactly the same as the above functions (but use a hex
* output for the decimal challenged). For details look at the above unsigned
* decimal functions.
*/
/**
* debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit 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_x8(const char *name, umode_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);
/**
* debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit 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_x16(const char *name, umode_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);
/**
* debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit 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_x32(const char *name, umode_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);
/**
* debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit 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_x64(const char *name, umode_t mode,
struct dentry *parent, u64 *value)
{
return debugfs_create_file(name, mode, parent, value, &fops_x64);
}
EXPORT_SYMBOL_GPL(debugfs_create_x64);
static int debugfs_size_t_set(void *data, u64 val)
{
*(size_t *)data = val;
return 0;
}
static int debugfs_size_t_get(void *data, u64 *val)
{
*val = *(size_t *)data;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
"%llu\n"); /* %llu and %zu are more or less the same */
/**
* debugfs_create_size_t - create a debugfs file that is used to read and write an size_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_size_t(const char *name, umode_t mode,
struct dentry *parent, size_t *value)
{
return debugfs_create_file(name, mode, parent, value, &fops_size_t);
}
EXPORT_SYMBOL_GPL(debugfs_create_size_t);
static ssize_t read_file_bool(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
char buf[3];
u32 *val = file->private_data;
if (*val)
buf[0] = 'Y';
else
buf[0] = 'N';
buf[1] = '\n';
buf[2] = 0x00;
return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
}
static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
size_t count, loff_t *ppos)
{
char buf[32];
size_t buf_size;
bool bv;
u32 *val = file->private_data;
buf_size = min(count, (sizeof(buf)-1));
if (copy_from_user(buf, user_buf, buf_size))
return -EFAULT;
if (strtobool(buf, &bv) == 0)
*val = bv;
return count;
}
static const struct file_operations fops_bool = {
.read = read_file_bool,
.write = write_file_bool,
.open = simple_open,
.llseek = default_llseek,
};
/**
* debugfs_create_bool - create a debugfs file that is used to read and write a boolean 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.
*
* This function creates a file in debugfs with the given name that
* contains the value of the variable @value. If the @mode variable is so
* set, it can be read from, and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, %NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_bool(const char *name, umode_t mode,
struct dentry *parent, u32 *value)
{
return debugfs_create_file(name, mode, parent, value, &fops_bool);
}
EXPORT_SYMBOL_GPL(debugfs_create_bool);
static ssize_t read_file_blob(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct debugfs_blob_wrapper *blob = file->private_data;
return simple_read_from_buffer(user_buf, count, ppos, blob->data,
blob->size);
}
static const struct file_operations fops_blob = {
.read = read_file_blob,
.open = simple_open,
.llseek = default_llseek,
};
/**
* 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
* directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the debugfs filesystem.
* @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
* to the blob data and the size of the data.
*
* This function creates a file in debugfs with the given name that exports
* @blob->data as a binary blob. If the @mode variable is so set it can be
* read from. Writing is not supported.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, %NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_blob(const char *name, umode_t mode,
struct dentry *parent,
struct debugfs_blob_wrapper *blob)
{
return debugfs_create_file(name, mode, parent, blob, &fops_blob);
}
EXPORT_SYMBOL_GPL(debugfs_create_blob);
struct array_data {
void *array;
u32 elements;
};
static size_t u32_format_array(char *buf, size_t bufsize,
u32 *array, int array_size)
{
size_t ret = 0;
while (--array_size >= 0) {
size_t len;
char term = array_size ? ' ' : '\n';
len = snprintf(buf, bufsize, "%u%c", *array++, term);
ret += len;
buf += len;
bufsize -= len;
}
return ret;
}
static int u32_array_open(struct inode *inode, struct file *file)
{
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);
return nonseekable_open(inode, file);
}
static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
loff_t *ppos)
{
size_t size = strlen(file->private_data);
return simple_read_from_buffer(buf, len, ppos,
file->private_data, size);
}
static int u32_array_release(struct inode *inode, struct file *file)
{
kfree(file->private_data);
return 0;
}
static const struct file_operations u32_array_fops = {
.owner = THIS_MODULE,
.open = u32_array_open,
.release = u32_array_release,
.read = u32_array_read,
.llseek = no_llseek,
};
/**
* debugfs_create_u32_array - create a debugfs file that is used to read u32
* array.
* @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.
* @array: u32 array that provides data.
* @elements: total number of elements in the array.
*
* This function creates a file in debugfs with the given name that exports
* @array as data. If the @mode variable is so set it can be read from.
* Writing is not supported. Seek within the file is also not supported.
* Once array is created its size can not be changed.
*
* The function returns a pointer to dentry on success. If debugfs is not
* enabled in the kernel, the value -%ENODEV will be returned.
*/
struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
struct dentry *parent,
u32 *array, u32 elements)
{
struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
if (data == NULL)
return NULL;
data->array = array;
data->elements = elements;
return debugfs_create_file(name, mode, parent, data, &u32_array_fops);
}
EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
#ifdef CONFIG_HAS_IOMEM
/*
* The regset32 stuff is used to print 32-bit registers using the
* seq_file utilities. We offer printing a register set in an already-opened
* sequential file or create a debugfs file that only prints a regset32.
*/
/**
* debugfs_print_regs32 - use seq_print to describe a set of registers
* @s: the seq_file structure being used to generate output
* @regs: an array if struct debugfs_reg32 structures
* @nregs: the length of the above array
* @base: the base address to be used in reading the registers
* @prefix: a string to be prefixed to every output line
*
* This function outputs a text block describing the current values of
* some 32-bit hardware registers. It is meant to be used within debugfs
* files based on seq_file that need to show registers, intermixed with other
* information. The prefix argument may be used to specify a leading string,
* because some peripherals have several blocks of identical registers,
* for example configuration of dma channels
*/
int debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
int nregs, void __iomem *base, char *prefix)
{
int i, ret = 0;
for (i = 0; i < nregs; i++, regs++) {
if (prefix)
ret += seq_printf(s, "%s", prefix);
ret += seq_printf(s, "%s = 0x%08x\n", regs->name,
readl(base + regs->offset));
}
return ret;
}
EXPORT_SYMBOL_GPL(debugfs_print_regs32);
static int debugfs_show_regset32(struct seq_file *s, void *data)
{
struct debugfs_regset32 *regset = s->private;
debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
return 0;
}
static int debugfs_open_regset32(struct inode *inode, struct file *file)
{
return single_open(file, debugfs_show_regset32, inode->i_private);
}
static const struct file_operations fops_regset32 = {
.open = debugfs_open_regset32,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
/**
* debugfs_create_regset32 - create a debugfs file that returns register values
* @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.
* @regset: a pointer to a struct debugfs_regset32, which contains a pointer
* to an array of register definitions, the array size and the base
* address where the register bank is to be found.
*
* This function creates a file in debugfs with the given name that reports
* the names and values of a set of 32-bit registers. If the @mode variable
* is so set it can be read from. Writing is not supported.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, %NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
struct dentry *parent,
struct debugfs_regset32 *regset)
{
return debugfs_create_file(name, mode, parent, regset, &fops_regset32);
}
EXPORT_SYMBOL_GPL(debugfs_create_regset32);
#endif /* CONFIG_HAS_IOMEM */