// SPDX-License-Identifier: GPL-2.0
/*
* 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.
*
* debugfs is for people to use instead of /proc or /sys.
* See Documentation/filesystems/ for more details.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/debugfs.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/atomic.h>
#include <linux/device.h>
#include <linux/poll.h>
#include <linux/security.h>
#include "internal.h"
struct poll_table_struct;
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_noop_file_operations = {
.read = default_read_file,
.write = default_write_file,
.open = simple_open,
.llseek = noop_llseek,
};
#define F_DENTRY(filp) ((filp)->f_path.dentry)
const struct file_operations *debugfs_real_fops(const struct file *filp)
{
struct debugfs_fsdata *fsd = F_DENTRY(filp)->d_fsdata;
if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) {
/*
* Urgh, we've been called w/o a protecting
* debugfs_file_get().
*/
WARN_ON(1);
return NULL;
}
return fsd->real_fops;
}
EXPORT_SYMBOL_GPL(debugfs_real_fops);
/**
* debugfs_file_get - mark the beginning of file data access
* @dentry: the dentry object whose data is being accessed.
*
* Up to a matching call to debugfs_file_put(), any successive call
* into the file removing functions debugfs_remove() and
* debugfs_remove_recursive() will block. Since associated private
* file data may only get freed after a successful return of any of
* the removal functions, you may safely access it after a successful
* call to debugfs_file_get() without worrying about lifetime issues.
*
* If -%EIO is returned, the file has already been removed and thus,
* it is not safe to access any of its data. If, on the other hand,
* it is allowed to access the file data, zero is returned.
*/
int debugfs_file_get(struct dentry *dentry)
{
struct debugfs_fsdata *fsd;
void *d_fsd;
d_fsd = READ_ONCE(dentry->d_fsdata);
if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) {
fsd = d_fsd;
} else {
fsd = kmalloc(sizeof(*fsd), GFP_KERNEL);
if (!fsd)
return -ENOMEM;
fsd->real_fops = (void *)((unsigned long)d_fsd &
~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
refcount_set(&fsd->active_users, 1);
init_completion(&fsd->active_users_drained);
if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) {
kfree(fsd);
fsd = READ_ONCE(dentry->d_fsdata);
}
}
/*
* In case of a successful cmpxchg() above, this check is
* strictly necessary and must follow it, see the comment in
* __debugfs_remove_file().
* OTOH, if the cmpxchg() hasn't been executed or wasn't
* successful, this serves the purpose of not starving
* removers.
*/
if (d_unlinked(dentry))
return -EIO;
if (!refcount_inc_not_zero(&fsd->active_users))
return -EIO;
return 0;
}
EXPORT_SYMBOL_GPL(debugfs_file_get);
/**
* debugfs_file_put - mark the end of file data access
* @dentry: the dentry object formerly passed to
* debugfs_file_get().
*
* Allow any ongoing concurrent call into debugfs_remove() or
* debugfs_remove_recursive() blocked by a former call to
* debugfs_file_get() to proceed and return to its caller.
*/
void debugfs_file_put(struct dentry *dentry)
{
struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata);
if (refcount_dec_and_test(&fsd->active_users))
complete(&fsd->active_users_drained);
}
EXPORT_SYMBOL_GPL(debugfs_file_put);
/*
* Only permit access to world-readable files when the kernel is locked down.
* We also need to exclude any file that has ways to write or alter it as root
* can bypass the permissions check.
*/
static bool debugfs_is_locked_down(struct inode *inode,
struct file *filp,
const struct file_operations *real_fops)
{
if ((inode->i_mode & 07777) == 0444 &&
!(filp->f_mode & FMODE_WRITE) &&
!real_fops->unlocked_ioctl &&
!real_fops->compat_ioctl &&
!real_fops->mmap)
return false;
return security_locked_down(LOCKDOWN_DEBUGFS);
}
static int open_proxy_open(struct inode *inode, struct file *filp)
{
struct dentry *dentry = F_DENTRY(filp);
const struct file_operations *real_fops = NULL;
int r;
r = debugfs_file_get(dentry);
if (r)
return r == -EIO ? -ENOENT : r;
real_fops = debugfs_real_fops(filp);
r = debugfs_is_locked_down(inode, filp, real_fops);
if (r)
goto out;
real_fops = fops_get(real_fops);
if (!real_fops) {
/* Huh? Module did not clean up after itself at exit? */
WARN(1, "debugfs file owner did not clean up at exit: %pd",
dentry);
r = -ENXIO;
goto out;
}
replace_fops(filp, real_fops);
if (real_fops->open)
r = real_fops->open(inode, filp);
out:
debugfs_file_put(dentry);
return r;
}
const struct file_operations debugfs_open_proxy_file_operations = {
.open = open_proxy_open,
};
#define PROTO(args...) args
#define ARGS(args...) args
#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \
static ret_type full_proxy_ ## name(proto) \
{ \
struct dentry *dentry = F_DENTRY(filp); \
const struct file_operations *real_fops; \
ret_type r; \
\
r = debugfs_file_get(dentry); \
if (unlikely(r)) \
return r; \
real_fops = debugfs_real_fops(filp); \
r = real_fops->name(args); \
debugfs_file_put(dentry); \
return r; \
}
FULL_PROXY_FUNC(llseek, loff_t, filp,
PROTO(struct file *filp, loff_t offset, int whence),
ARGS(filp, offset, whence));
FULL_PROXY_FUNC(read, ssize_t, filp,
PROTO(struct file *filp, char __user *buf, size_t size,
loff_t *ppos),
ARGS(filp, buf, size, ppos));
FULL_PROXY_FUNC(write, ssize_t, filp,
PROTO(struct file *filp, const char __user *buf, size_t size,
loff_t *ppos),
ARGS(filp, buf, size, ppos));
FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
ARGS(filp, cmd, arg));
static __poll_t full_proxy_poll(struct file *filp,
struct poll_table_struct *wait)
{
struct dentry *dentry = F_DENTRY(filp);
__poll_t r = 0;
const struct file_operations *real_fops;
if (debugfs_file_get(dentry))
return EPOLLHUP;
real_fops = debugfs_real_fops(filp);
r = real_fops->poll(filp, wait);
debugfs_file_put(dentry);
return r;
}
static int full_proxy_release(struct inode *inode, struct file *filp)
{
const struct dentry *dentry = F_DENTRY(filp);
const struct file_operations *real_fops = debugfs_real_fops(filp);
const struct file_operations *proxy_fops = filp->f_op;
int r = 0;
/*
* We must not protect this against removal races here: the
* original releaser should be called unconditionally in order
* not to leak any resources. Releasers must not assume that
* ->i_private is still being meaningful here.
*/
if (real_fops->release)
r = real_fops->release(inode, filp);
replace_fops(filp, d_inode(dentry)->i_fop);
kfree((void *)proxy_fops);
fops_put(real_fops);
return r;
}
static void __full_proxy_fops_init(struct file_operations *proxy_fops,
const struct file_operations *real_fops)
{
proxy_fops->release = full_proxy_release;
if (real_fops->llseek)
proxy_fops->llseek = full_proxy_llseek;
if (real_fops->read)
proxy_fops->read = full_proxy_read;
if (real_fops->write)
proxy_fops->write = full_proxy_write;
if (real_fops->poll)
proxy_fops->poll = full_proxy_poll;
if (real_fops->unlocked_ioctl)
proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl;
}
static int full_proxy_open(struct inode *inode, struct file *filp)
{
struct dentry *dentry = F_DENTRY(filp);
const struct file_operations *real_fops = NULL;
struct file_operations *proxy_fops = NULL;
int r;
r = debugfs_file_get(dentry);
if (r)
return r == -EIO ? -ENOENT : r;
real_fops = debugfs_real_fops(filp);
r = debugfs_is_locked_down(inode, filp, real_fops);
if (r)
goto out;
real_fops = fops_get(real_fops);
if (!real_fops) {
/* Huh? Module did not cleanup after itself at exit? */
WARN(1, "debugfs file owner did not clean up at exit: %pd",
dentry);
r = -ENXIO;
goto out;
}
proxy_fops = kzalloc(sizeof(*proxy_fops), GFP_KERNEL);
if (!proxy_fops) {
r = -ENOMEM;
goto free_proxy;
}
__full_proxy_fops_init(proxy_fops, real_fops);
replace_fops(filp, proxy_fops);
if (real_fops->open) {
r = real_fops->open(inode, filp);
if (r) {
replace_fops(filp, d_inode(dentry)->i_fop);
goto free_proxy;
} else if (filp->f_op != proxy_fops) {
/* No protection against file removal anymore. */
WARN(1, "debugfs file owner replaced proxy fops: %pd",
dentry);
goto free_proxy;
}
}
goto out;
free_proxy:
kfree(proxy_fops);
fops_put(real_fops);
out:
debugfs_file_put(dentry);
return r;
}
const struct file_operations debugfs_full_proxy_file_operations = {
.open = full_proxy_open,
};
ssize_t debugfs_attr_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos)
{
struct dentry *dentry = F_DENTRY(file);
ssize_t ret;
ret = debugfs_file_get(dentry);
if (unlikely(ret))
return ret;
ret = simple_attr_read(file, buf, len, ppos);
debugfs_file_put(dentry);
return ret;
}
EXPORT_SYMBOL_GPL(debugfs_attr_read);
ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
struct dentry *dentry = F_DENTRY(file);
ssize_t ret;
ret = debugfs_file_get(dentry);
if (unlikely(ret))
return ret;
ret = simple_attr_write(file, buf, len, ppos);
debugfs_file_put(dentry);
return ret;
}
EXPORT_SYMBOL_GPL(debugfs_attr_write);
static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode,
struct dentry *parent, void *value,
const struct file_operations *fops,
const struct file_operations *fops_ro,
const struct file_operations *fops_wo)
{
/* if there are no write bits set, make read only */
if (!(mode & S_IWUGO))
return debugfs_create_file_unsafe(name, mode, parent, value,
fops_ro);
/* if there are no read bits set, make write only */
if (!(mode & S_IRUGO))
return debugfs_create_file_unsafe(name, mode, parent, value,
fops_wo);
return debugfs_create_file_unsafe(name, mode, parent, value, fops);
}
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_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
DEFINE_DEBUGFS_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, %ERR_PTR(-ERROR) will be
* returned.
*
* If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
* be returned.
*/
struct dentry *debugfs_create_u8(const char *name, umode_t mode,
struct dentry *parent, u8 *value)
{
return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8,
&fops_u8_ro, &fops_u8_wo);
}
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_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
DEFINE_DEBUGFS_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, %ERR_PTR(-ERROR) will be
* returned.
*
* If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
* be returned.
*/
struct dentry *debugfs_create_u16(const char *name, umode_t mode,
struct dentry *parent, u16 *value)
{
return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16,
&fops_u16_ro, &fops_u16_wo);
}
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_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
DEFINE_DEBUGFS_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, %ERR_PTR(-ERROR) will be
* returned.
*
* If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
* be returned.
*/
struct dentry *debugfs_create_u32(const char *name, umode_t mode,
struct dentry *parent, u32 *value)
{
return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32,
&fops_u32_ro, &fops_u32_wo);
}
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_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
DEFINE_DEBUGFS_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, %ERR_PTR(-ERROR) will be
* returned.
*
* If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
* be returned.
*/
struct dentry *debugfs_create_u64(const char *name, umode_t mode,
struct dentry *parent, u64 *value)
{
return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64,
&fops_u64_ro, &fops_u64_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_u64);
static int debugfs_ulong_set(void *data, u64 val)
{
*(unsigned long *)data = val;
return 0;
}
static int debugfs_ulong_get(void *data, u64 *val)
{
*val = *(unsigned long *)data;
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set,
"%llu\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
/**
* debugfs_create_ulong - create a debugfs file that is used to read and write
* an unsigned long 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, %ERR_PTR(-ERROR) will be
* returned.
*
* If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
* be returned.
*/
struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
struct dentry *parent, unsigned long *value)
{
return debugfs_create_mode_unsafe(name, mode, parent, value,
&fops_ulong, &fops_ulong_ro,
&fops_ulong_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_ulong);
DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set,
"0x%04llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set,
"0x%08llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set,
"0x%016llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, 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)
{
return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8,
&fops_x8_ro, &fops_x8_wo);
}
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)
{
return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16,
&fops_x16_ro, &fops_x16_wo);
}
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)
{
return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32,
&fops_x32_ro, &fops_x32_wo);
}
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_mode_unsafe(name, mode, parent, value, &fops_x64,
&fops_x64_ro, &fops_x64_wo);
}
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_DEBUGFS_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
"%llu\n"); /* %llu and %zu are more or less the same */
DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n");
/**
* 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_mode_unsafe(name, mode, parent, value,
&fops_size_t, &fops_size_t_ro,
&fops_size_t_wo);
}
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_DEBUGFS_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
debugfs_atomic_t_set, "%lld\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
"%lld\n");
DEFINE_DEBUGFS_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)
{
return debugfs_create_mode_unsafe(name, mode, parent, value,
&fops_atomic_t, &fops_atomic_t_ro,
&fops_atomic_t_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
char buf[3];
bool val;
int r;
struct dentry *dentry = F_DENTRY(file);
r = debugfs_file_get(dentry);
if (unlikely(r))
return r;
val = *(bool *)file->private_data;
debugfs_file_put(dentry);
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);
}
EXPORT_SYMBOL_GPL(debugfs_read_file_bool);
ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
size_t count, loff_t *ppos)
{
bool bv;
int r;
bool *val = file->private_data;
struct dentry *dentry = F_DENTRY(file);
r = kstrtobool_from_user(user_buf, count, &bv);
if (!r) {
r = debugfs_file_get(dentry);
if (unlikely(r))
return r;
*val = bv;
debugfs_file_put(dentry);
}
return count;
}
EXPORT_SYMBOL_GPL(debugfs_write_file_bool);
static const struct file_operations fops_bool = {
.read = debugfs_read_file_bool,
.write = debugfs_write_file_bool,
.open = simple_open,
.llseek = default_llseek,
};
static const struct file_operations fops_bool_ro = {
.read = debugfs_read_file_bool,
.open = simple_open,
.llseek = default_llseek,
};
static const struct file_operations fops_bool_wo = {
.write = debugfs_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, %ERR_PTR(-ERROR) will be
* returned.
*
* If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
* be returned.
*/
struct dentry *debugfs_create_bool(const char *name, umode_t mode,
struct dentry *parent, bool *value)
{
return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool,
&fops_bool_ro, &fops_bool_wo);
}
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;
struct dentry *dentry = F_DENTRY(file);
ssize_t r;
r = debugfs_file_get(dentry);
if (unlikely(r))
return r;
r = simple_read_from_buffer(user_buf, count, ppos, blob->data,
blob->size);
debugfs_file_put(dentry);
return r;
}
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, %ERR_PTR(-ERROR) will be
* returned.
*
* If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
* be returned.
*/
struct dentry *debugfs_create_blob(const char *name, umode_t mode,
struct dentry *parent,
struct debugfs_blob_wrapper *blob)
{
return debugfs_create_file_unsafe(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.
*/
void 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;
data->array = array;
data->elements = elements;
debugfs_create_file_unsafe(name, mode, parent, data, &u32_array_fops);
}
EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
#ifdef [31mCONFIG_HAS_IOMEM[0m
/*
* 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
*/
void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
int nregs, void __iomem *base, char *prefix)
{
int i;
for (i = 0; i < nregs; i++, regs++) {
if (prefix)
seq_printf(s, "%s", prefix);
seq_printf(s, "%s = 0x%08x\n", regs->name,
readl(base + regs->offset));
if (seq_has_overflowed(s))
break;
}
}
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, %ERR_PTR(-ERROR) will be
* returned.
*
* If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
* be returned.
*/
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 */
struct debugfs_devm_entry {
int (*read)(struct seq_file *seq, void *data);
struct device *dev;
};
static int debugfs_devm_entry_open(struct inode *inode, struct file *f)
{
struct debugfs_devm_entry *entry = inode->i_private;
return single_open(f, entry->read, entry->dev);
}
static const struct file_operations debugfs_devm_entry_ops = {
.owner = THIS_MODULE,
.open = debugfs_devm_entry_open,
.release = single_release,
.read = seq_read,
.llseek = seq_lseek
};
/**
* debugfs_create_devm_seqfile - create a debugfs file that is bound to device.
*
* @dev: device related to this debugfs file.
* @name: name of the debugfs file.
* @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.
* @read_fn: function pointer called to print the seq_file content.
*/
struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
struct dentry *parent,
int (*read_fn)(struct seq_file *s,
void *data))
{
struct debugfs_devm_entry *entry;
if (IS_ERR(parent))
return ERR_PTR(-ENOENT);
entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL);
if (!entry)
return ERR_PTR(-ENOMEM);
entry->read = read_fn;
entry->dev = dev;
return debugfs_create_file(name, S_IRUGO, parent, entry,
&debugfs_devm_entry_ops);
}
EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);