diff options
| -rw-r--r-- | CREDITS | 1 | ||||
| -rw-r--r-- | Documentation/devices.txt | 86 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/base/Makefile | 2 | ||||
| -rw-r--r-- | drivers/base/devcoredump.c | 83 | ||||
| -rw-r--r-- | drivers/firmware/qemu_fw_cfg.c | 4 | ||||
| -rw-r--r-- | drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c | 4 | ||||
| -rw-r--r-- | fs/char_dev.c | 4 | ||||
| -rw-r--r-- | fs/debugfs/file.c | 436 | ||||
| -rw-r--r-- | fs/debugfs/inode.c | 108 | ||||
| -rw-r--r-- | fs/debugfs/internal.h | 26 | ||||
| -rw-r--r-- | fs/kernfs/dir.c | 8 | ||||
| -rw-r--r-- | fs/kernfs/inode.c | 15 | ||||
| -rw-r--r-- | include/linux/debugfs.h | 49 | ||||
| -rw-r--r-- | include/linux/devcoredump.h | 86 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 | ||||
| -rw-r--r-- | include/linux/isa.h | 2 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 1 | ||||
| -rw-r--r-- | scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci | 67 |
19 files changed, 811 insertions, 179 deletions
@@ -768,6 +768,7 @@ D: Z85230 driver D: Former security contact point (please use vendor-sec@lst.de) D: ex 2.2 maintainer D: 2.1.x modular sound +D: Assigned major/minor numbers maintainer at lanana.org S: c/o Red Hat UK Ltd S: Alexandra House S: Alexandra Terrace diff --git a/Documentation/devices.txt b/Documentation/devices.txt index 87b4c5e82d39..4035eca87144 100644 --- a/Documentation/devices.txt +++ b/Documentation/devices.txt @@ -1,20 +1,17 @@ - LINUX ALLOCATED DEVICES (2.6+ version) - - Maintained by Alan Cox <device@lanana.org> - - Last revised: 6th April 2009 + LINUX ALLOCATED DEVICES (4.x+ version) This list is the Linux Device List, the official registry of allocated device numbers and /dev directory nodes for the Linux operating system. -The latest version of this list is available from -http://www.lanana.org/docs/device-list/ or -ftp://ftp.kernel.org/pub/linux/docs/device-list/. This version may be -newer than the one distributed with the Linux kernel. - -The LaTeX version of this document is no longer maintained. +The LaTeX version of this document is no longer maintained, nor is +the document that used to reside at lanana.org. This version in the +mainline Linux kernel is the master document. Updates shall be sent +as patches to the kernel maintainers (see the SubmittingPatches document). +Specifically explore the sections titled "CHAR and MISC DRIVERS", and +"BLOCK LAYER" in the MAINTAINERS file to find the right maintainers +to involve for character and block devices. This document is included by reference into the Filesystem Hierarchy Standard (FHS). The FHS is available from http://www.pathname.com/fhs/. @@ -23,60 +20,33 @@ Allocations marked (68k/Amiga) apply to Linux/68k on the Amiga platform only. Allocations marked (68k/Atari) apply to Linux/68k on the Atari platform only. -The symbol {2.6} means the allocation is obsolete and scheduled for -removal once kernel version 2.6 (or equivalent) is released. Some of these -allocations have already been removed. - -This document is in the public domain. The author requests, however, +This document is in the public domain. The authors requests, however, that semantically altered versions are not distributed without -permission of the author, assuming the author can be contacted without +permission of the authors, assuming the authors can be contacted without an unreasonable effort. -In particular, please don't sent patches for this list to Linus, at -least not without contacting me first. - -I do not have any information about these devices beyond what appears -on this list. Any such information requests will be deleted without -reply. - **** DEVICE DRIVERS AUTHORS PLEASE READ THIS **** -To have a major number allocated, or a minor number in situations -where that applies (e.g. busmice), please contact me with the -appropriate device information. Also, if you have additional -information regarding any of the devices listed below, or if I have -made a mistake, I would greatly appreciate a note. - -I do, however, make a few requests about the nature of your report. -This is necessary for me to be able to keep this list up to date and -correct in a timely manner. First of all, *please* send it to the -correct address... <device@lanana.org>. I receive hundreds of email -messages a day, so mail sent to other addresses may very well get lost -in the avalanche. Please put in a descriptive subject, so I can find -your mail again should I need to. Too many people send me email -saying just "device number request" in the subject. - -Second, please include a description of the device *in the same format -as this list*. The reason for this is that it is the only way I have -found to ensure I have all the requisite information to publish your -device and avoid conflicts. +Linux now has extensive support for dynamic allocation of device numbering +and can use sysfs and udev (systemd) to handle the naming needs. There are +still some exceptions in the serial and boot device area. Before asking +for a device number make sure you actually need one. -Third, please don't assume that the distributed version of the list is -up to date. Due to the number of registrations I have to maintain it -in "batch mode", so there is likely additional registrations that -haven't been listed yet. +To have a major number allocated, or a minor number in situations +where that applies (e.g. busmice), please submit a patch and send to +the authors as indicated above. -Fourth, remember that Linux now has extensive support for dynamic allocation -of device numbering and can use sysfs and udev to handle the naming needs. -There are still some exceptions in the serial and boot device area. Before -asking for a device number make sure you actually need one. +Keep the description of the device *in the same format +as this list*. The reason for this is that it is the only way we have +found to ensure we have all the requisite information to publish your +device and avoid conflicts. -Finally, sometimes I have to play "namespace police." Please don't be -offended. I often get submissions for /dev names that would be bound -to cause conflicts down the road. I am trying to avoid getting in a +Finally, sometimes we have to play "namespace police." Please don't be +offended. We often get submissions for /dev names that would be bound +to cause conflicts down the road. We are trying to avoid getting in a situation where we would have to suffer an incompatible forward -change. Therefore, please consult with me *before* you make your +change. Therefore, please consult with us *before* you make your device names and numbers in any way public, at least to the point where it would be at all difficult to get them changed. @@ -3099,9 +3069,9 @@ Your cooperation is appreciated. 129 = /dev/ipath_sma Device used by Subnet Management Agent 130 = /dev/ipath_diag Device used by diagnostics programs -234-239 UNASSIGNED - -240-254 char LOCAL/EXPERIMENTAL USE +234-254 char RESERVED FOR DYNAMIC ASSIGNMENT + Character devices that request a dynamic allocation of major number will + take numbers starting from 254 and downward. 240-254 block LOCAL/EXPERIMENTAL USE Allocated for local/experimental use. For devices not diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2dc18605831f..a5977986f38b 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2472,10 +2472,16 @@ config ISA_DMA_API Enables ISA-style DMA support for devices requiring such controllers. If unsure, say Y. +config ISA_BUS + bool "ISA bus support" + help + Enables ISA bus support for devices requiring such controllers. + if X86_32 config ISA bool "ISA support" + depends on ISA_BUS ---help--- Find out whether you have ISA slots on your motherboard. ISA is the name of a bus system, i.e. the way the CPU talks to the other stuff diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 6b2a84e7f2be..4ebfb81cc7e9 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -10,7 +10,7 @@ obj-$(CONFIG_DMA_CMA) += dma-contiguous.o obj-y += power/ obj-$(CONFIG_HAS_DMA) += dma-mapping.o obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o -obj-$(CONFIG_ISA) += isa.o +obj-$(CONFIG_ISA_BUS) += isa.o obj-$(CONFIG_FW_LOADER) += firmware_class.o obj-$(CONFIG_NUMA) += node.o obj-$(CONFIG_MEMORY_HOTPLUG_SPARSE) += memory.o diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c index 1bd120a0b084..240374fd1838 100644 --- a/drivers/base/devcoredump.c +++ b/drivers/base/devcoredump.c @@ -4,6 +4,7 @@ * GPL LICENSE SUMMARY * * Copyright(c) 2014 Intel Mobile Communications GmbH + * Copyright(c) 2015 Intel Deutschland GmbH * * This program is free software; you can redistribute it and/or modify * it under the terms of version 2 of the GNU General Public License as @@ -41,12 +42,12 @@ static bool devcd_disabled; struct devcd_entry { struct device devcd_dev; - const void *data; + void *data; size_t datalen; struct module *owner; ssize_t (*read)(char *buffer, loff_t offset, size_t count, - const void *data, size_t datalen); - void (*free)(const void *data); + void *data, size_t datalen); + void (*free)(void *data); struct delayed_work del_wk; struct device *failing_dev; }; @@ -174,7 +175,7 @@ static struct class devcd_class = { }; static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count, - const void *data, size_t datalen) + void *data, size_t datalen) { if (offset > datalen) return -EINVAL; @@ -188,6 +189,11 @@ static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count, return count; } +static void devcd_freev(void *data) +{ + vfree(data); +} + /** * dev_coredumpv - create device coredump with vmalloc data * @dev: the struct device for the crashed device @@ -198,10 +204,10 @@ static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count, * This function takes ownership of the vmalloc'ed data and will free * it when it is no longer used. See dev_coredumpm() for more information. */ -void dev_coredumpv(struct device *dev, const void *data, size_t datalen, +void dev_coredumpv(struct device *dev, void *data, size_t datalen, gfp_t gfp) { - dev_coredumpm(dev, NULL, data, datalen, gfp, devcd_readv, vfree); + dev_coredumpm(dev, NULL, data, datalen, gfp, devcd_readv, devcd_freev); } EXPORT_SYMBOL_GPL(dev_coredumpv); @@ -213,6 +219,44 @@ static int devcd_match_failing(struct device *dev, const void *failing) } /** + * devcd_free_sgtable - free all the memory of the given scatterlist table + * (i.e. both pages and scatterlist instances) + * NOTE: if two tables allocated with devcd_alloc_sgtable and then chained + * using the sg_chain function then that function should be called only once + * on the chained table + * @table: pointer to sg_table to free + */ +static void devcd_free_sgtable(void *data) +{ + _devcd_free_sgtable(data); +} + +/** + * devcd_read_from_table - copy data from sg_table to a given buffer + * and return the number of bytes read + * @buffer: the buffer to copy the data to it + * @buf_len: the length of the buffer + * @data: the scatterlist table to copy from + * @offset: start copy from @offset@ bytes from the head of the data + * in the given scatterlist + * @data_len: the length of the data in the sg_table + */ +static ssize_t devcd_read_from_sgtable(char *buffer, loff_t offset, + size_t buf_len, void *data, + size_t data_len) +{ + struct scatterlist *table = data; + + if (offset > data_len) + return -EINVAL; + + if (offset + buf_len > data_len) + buf_len = data_len - offset; + return sg_pcopy_to_buffer(table, sg_nents(table), buffer, buf_len, + offset); +} + +/** * dev_coredumpm - create device coredump with read/free methods * @dev: the struct device for the crashed device * @owner: the module that contains the read/free functions, use %THIS_MODULE @@ -228,10 +272,10 @@ static int devcd_match_failing(struct device *dev, const void *failing) * function will be called to free the data. */ void dev_coredumpm(struct device *dev, struct module *owner, - const void *data, size_t datalen, gfp_t gfp, + void *data, size_t datalen, gfp_t gfp, ssize_t (*read)(char *buffer, loff_t offset, size_t count, - const void *data, size_t datalen), - void (*free)(const void *data)) + void *data, size_t datalen), + void (*free)(void *data)) { static atomic_t devcd_count = ATOMIC_INIT(0); struct devcd_entry *devcd; @@ -291,6 +335,27 @@ void dev_coredumpm(struct device *dev, struct module *owner, } EXPORT_SYMBOL_GPL(dev_coredumpm); +/** + * dev_coredumpmsg - create device coredump that uses scatterlist as data + * parameter + * @dev: the struct device for the crashed device + * @table: the dump data + * @datalen: length of the data + * @gfp: allocation flags + * + * Creates a new device coredump for the given device. If a previous one hasn't + * been read yet, the new coredump is discarded. The data lifetime is determined + * by the device coredump framework and when it is no longer needed + * it will free the data. + */ +void dev_coredumpsg(struct device *dev, struct scatterlist *table, + size_t datalen, gfp_t gfp) +{ + dev_coredumpm(dev, NULL, table, datalen, gfp, devcd_read_from_sgtable, + devcd_free_sgtable); +} +EXPORT_SYMBOL_GPL(dev_coredumpsg); + static int __init devcoredump_init(void) { return class_register(&devcd_class); diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c index 815c4a5cae54..d999fe3b1de6 100644 --- a/drivers/firmware/qemu_fw_cfg.c +++ b/drivers/firmware/qemu_fw_cfg.c @@ -125,9 +125,7 @@ static void fw_cfg_io_cleanup(void) # define FW_CFG_CTRL_OFF 0x00 # define FW_CFG_DATA_OFF 0x01 # else -# warning "QEMU FW_CFG may not be available on this architecture!" -# define FW_CFG_CTRL_OFF 0x00 -# define FW_CFG_DATA_OFF 0x01 +# error "QEMU FW_CFG not available on this architecture!" # endif #endif diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c index 4856eac120f6..a4b0581d2275 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c @@ -71,7 +71,7 @@ #include "iwl-csr.h" static ssize_t iwl_mvm_read_coredump(char *buffer, loff_t offset, size_t count, - const void *data, size_t datalen) + void *data, size_t datalen) { const struct iwl_mvm_dump_ptrs *dump_ptrs = data; ssize_t bytes_read; @@ -104,7 +104,7 @@ static ssize_t iwl_mvm_read_coredump(char *buffer, loff_t offset, size_t count, return bytes_read + bytes_read_trans; } -static void iwl_mvm_free_coredump(const void *data) +static void iwl_mvm_free_coredump(void *data) { const struct iwl_mvm_dump_ptrs *fw_error_dump = data; diff --git a/fs/char_dev.c b/fs/char_dev.c index 24b142569ca9..687471dc04a0 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -91,6 +91,10 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor, break; } + if (i < CHRDEV_MAJOR_DYN_END) + pr_warn("CHRDEV \"%s\" major number %d goes below the dynamic allocation range", + name, i); + if (i == 0) { ret = -EBUSY; goto out; diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index d2ba12e23ed9..9c1c9a01b7e5 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -22,6 +22,12 @@ #include <linux/slab.h> #include <linux/atomic.h> #include <linux/device.h> +#include <linux/srcu.h> +#include <asm/poll.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) @@ -35,27 +41,293 @@ static ssize_t default_write_file(struct file *file, const char __user *buf, return count; } -const struct file_operations debugfs_file_operations = { +const struct file_operations debugfs_noop_file_operations = { .read = default_read_file, .write = default_write_file, .open = simple_open, .llseek = noop_llseek, }; -static struct dentry *debugfs_create_mode(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) +/** + * debugfs_use_file_start - mark the beginning of file data access + * @dentry: the dentry object whose data is being accessed. + * @srcu_idx: a pointer to some memory to store a SRCU index in. + * + * Up to a matching call to debugfs_use_file_finish(), 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_use_file_start() 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. + * + * Regardless of the return code, any call to + * debugfs_use_file_start() must be followed by a matching call + * to debugfs_use_file_finish(). + */ +int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx) + __acquires(&debugfs_srcu) +{ + *srcu_idx = srcu_read_lock(&debugfs_srcu); + barrier(); + if (d_unlinked(dentry)) + return -EIO; + return 0; +} +EXPORT_SYMBOL_GPL(debugfs_use_file_start); + +/** + * debugfs_use_file_finish - mark the end of file data access + * @srcu_idx: the SRCU index "created" by a former call to + * debugfs_use_file_start(). + * + * Allow any ongoing concurrent call into debugfs_remove() or + * debugfs_remove_recursive() blocked by a former call to + * debugfs_use_file_start() to proceed and return to its caller. + */ +void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu) +{ + srcu_read_unlock(&debugfs_srcu, srcu_idx); +} +EXPORT_SYMBOL_GPL(debugfs_use_file_finish); + +#define F_DENTRY(filp) ((filp)->f_path.dentry) + +#define REAL_FOPS_DEREF(dentry) \ + ((const struct file_operations *)(dentry)->d_fsdata) + +static int open_proxy_open(struct inode *inode, struct file *filp) +{ + const struct dentry *dentry = F_DENTRY(filp); + const struct file_operations *real_fops = NULL; + int srcu_idx, r; + + r = debugfs_use_file_start(dentry, &srcu_idx); + if (r) { + r = -ENOENT; + goto out; + } + + real_fops = REAL_FOPS_DEREF(dentry); + 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: + fops_put(real_fops); + debugfs_use_file_finish(srcu_idx); + 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) \ +{ \ + const struct dentry *dentry = F_DENTRY(filp); \ + const struct file_operations *real_fops = \ + REAL_FOPS_DEREF(dentry); \ + int srcu_idx; \ + ret_type r; \ + \ + r = debugfs_use_file_start(dentry, &srcu_idx); \ + if (likely(!r)) \ + r = real_fops->name(args); \ + debugfs_use_file_finish(srcu_idx); \ + 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 unsigned int full_proxy_poll(struct file *filp, + struct poll_table_struct *wait) +{ + const struct dentry *dentry = F_DENTRY(filp); + const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry); + int srcu_idx; + unsigned int r = 0; + + if (debugfs_use_file_start(dentry, &srcu_idx)) { + debugfs_use_file_finish(srcu_idx); + return POLLHUP; + } + + r = real_fops->poll(filp, wait); + debugfs_use_file_finish(srcu_idx); + 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 = REAL_FOPS_DEREF(dentry); + 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 0; +} + +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) +{ + const struct dentry *dentry = F_DENTRY(filp); + const struct file_operations *real_fops = NULL; + struct file_operations *proxy_fops = NULL; + int srcu_idx, r; + + r = debugfs_use_file_start(dentry, &srcu_idx); + if (r) { + r = -ENOENT; + goto out; + } + + real_fops = REAL_FOPS_DEREF(dentry); + 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 (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_use_file_finish(srcu_idx); + 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) +{ + ssize_t ret; + int srcu_idx; + + ret = debugfs_use_file_start(F_DENTRY(file), &srcu_idx); + if (likely(!ret)) + ret = simple_attr_read(file, buf, len, ppos); + debugfs_use_file_finish(srcu_idx); + 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) +{ + ssize_t ret; + int srcu_idx; + + ret = debugfs_use_file_start(F_DENTRY(file), &srcu_idx); + if (likely(!ret)) + ret = simple_attr_write(file, buf, len, ppos); + debugfs_use_file_finish(srcu_idx); + 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(name, mode, parent, value, fops_ro); + 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(name, mode, parent, value, fops_wo); + return debugfs_create_file_unsafe(name, mode, parent, value, + fops_wo); - return debugfs_create_file(name, mode, parent, value, fops); + return debugfs_create_file_unsafe(name, mode, parent, value, fops); } static int debugfs_u8_set(void *data, u64 val) @@ -68,9 +340,9 @@ 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"); +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 @@ -99,7 +371,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); struct dentry *debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, u8 *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_u8, + return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8, &fops_u8_ro, &fops_u8_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u8); @@ -114,9 +386,9 @@ 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"); +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 @@ -145,7 +417,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); struct dentry *debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, u16 *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_u16, + return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16, &fops_u16_ro, &fops_u16_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u16); @@ -160,9 +432,9 @@ 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"); +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 @@ -191,7 +463,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); struct dentry *debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, u32 *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_u32, + return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32, &fops_u32_ro, &fops_u32_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u32); @@ -207,9 +479,9 @@ 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"); +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 @@ -238,7 +510,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n"); struct dentry *debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, u64 *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_u64, + return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64, &fops_u64_ro, &fops_u64_wo); } EXPORT_SYMBOL_GPL(debugfs_create_u64); @@ -254,9 +526,10 @@ static int debugfs_ulong_get(void *data, u64 *val) *val = *(unsigned long *)data; return 0; } -DEFINE_SIMPLE_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set, "%llu\n"); -DEFINE_SIMPLE_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n"); -DEFINE_SIMPLE_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n"); +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 @@ -286,26 +559,30 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n"); struct dentry *debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, unsigned long *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_ulong, - &fops_ulong_ro, &fops_ulong_wo); + return debugfs_create_mode_unsafe(name, mode, parent, value, + &fops_ulong, &fops_ulong_ro, + &fops_ulong_wo); } EXPORT_SYMBOL_GPL(debugfs_create_ulong); -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_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_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_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_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_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_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n"); -DEFINE_SIMPLE_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n"); -DEFINE_SIMPLE_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\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 @@ -328,7 +605,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n"); struct dentry *debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, u8 *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_x8, + return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8, &fops_x8_ro, &fops_x8_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x8); @@ -346,7 +623,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_x8); struct dentry *debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, u16 *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_x16, + return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16, &fops_x16_ro, &fops_x16_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x16); @@ -364,7 +641,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_x16); struct dentry *debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, u32 *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_x32, + return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32, &fops_x32_ro, &fops_x32_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x32); @@ -382,7 +659,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_x32); struct dentry *debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, u64 *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_x64, + return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64, &fops_x64_ro, &fops_x64_wo); } EXPORT_SYMBOL_GPL(debugfs_create_x64); @@ -398,10 +675,10 @@ 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 */ -DEFINE_SIMPLE_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n"); -DEFINE_SIMPLE_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n"); +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 @@ -416,8 +693,9 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n"); struct dentry *debugfs_create_size_t(const char *name, umode_t mode, struct dentry *parent, size_t *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_size_t, - &fops_size_t_ro, &fops_size_t_wo); + 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); @@ -431,10 +709,12 @@ 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, +DEFINE_DEBUGFS_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"); +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 @@ -450,8 +730,9 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n"); struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, struct dentry *parent, atomic_t *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_atomic_t, - &fops_atomic_t_ro, &fops_atomic_t_wo); + 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); @@ -459,9 +740,17 @@ ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { char buf[3]; - bool *val = file->private_data; + bool val; + int r, srcu_idx; - if (*val) + r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx); + if (likely(!r)) + val = *(bool *)file->private_data; + debugfs_use_file_finish(srcu_idx); + if (r) + return r; + + if (val) buf[0] = 'Y'; else buf[0] = 'N'; @@ -477,6 +766,7 @@ ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, char buf[32]; size_t buf_size; bool bv; + int r, srcu_idx; bool *val = file->private_data; buf_size = min(count, (sizeof(buf)-1)); @@ -484,8 +774,14 @@ ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, return -EFAULT; buf[buf_size] = '\0'; - if (strtobool(buf, &bv) == 0) - *val = bv; + if (strtobool(buf, &bv) == 0) { + r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx); + if (likely(!r)) + *val = bv; + debugfs_use_file_finish(srcu_idx); + if (r) + return r; + } return count; } @@ -537,7 +833,7 @@ static const struct file_operations fops_bool_wo = { struct dentry *debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, bool *value) { - return debugfs_create_mode(name, mode, parent, value, &fops_bool, + return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool, &fops_bool_ro, &fops_bool_wo); } EXPORT_SYMBOL_GPL(debugfs_create_bool); @@ -546,8 +842,15 @@ 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); + ssize_t r; + int srcu_idx; + + r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx); + if (likely(!r)) + r = simple_read_from_buffer(user_buf, count, ppos, blob->data, + blob->size); + debugfs_use_file_finish(srcu_idx); + return r; } static const struct file_operations fops_blob = { @@ -584,7 +887,7 @@ 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); + return debugfs_create_file_unsafe(name, mode, parent, blob, &fops_blob); } EXPORT_SYMBOL_GPL(debugfs_create_blob); @@ -689,7 +992,8 @@ struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, data->array = array; data->elements = elements; - return debugfs_create_file(name, mode, parent, data, &u32_array_fops); + return debugfs_create_file_unsafe(name, mode, parent, data, + &u32_array_fops); } EXPORT_SYMBOL_GPL(debugfs_create_u32_array); diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 8580831ed237..4bc1f68243c1 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -27,9 +27,14 @@ #include <linux/parser.h> #include <linux/magic.h> #include <linux/slab.h> +#include <linux/srcu.h> + +#include "internal.h" #define DEBUGFS_DEFAULT_MODE 0700 +DEFINE_SRCU(debugfs_srcu); + static struct vfsmount *debugfs_mount; static int debugfs_mount_count; static bool debugfs_registered; @@ -39,7 +44,8 @@ static struct inode *debugfs_get_inode(struct super_block *sb) struct inode *inode = new_inode(sb); if (inode) { inode->i_ino = get_next_ino(); - inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + inode->i_atime = inode->i_mtime = + inode->i_ctime = current_fs_time(sb); } return inode; } @@ -294,6 +300,37 @@ static struct dentry *end_creating(struct dentry *dentry) return dentry; } +static struct dentry *__debugfs_create_file(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *proxy_fops, + const struct file_operations *real_fops) +{ + struct dentry *dentry; + struct inode *inode; + + if (!(mode & S_IFMT)) + mode |= S_IFREG; + BUG_ON(!S_ISREG(mode)); + dentry = start_creating(name, parent); + + if (IS_ERR(dentry)) + return NULL; + + inode = debugfs_get_inode(dentry->d_sb); + if (unlikely(!inode)) + return failed_creating(dentry); + + inode->i_mode = mode; + inode->i_private = data; + + inode->i_fop = proxy_fops; + dentry->d_fsdata = (void *)real_fops; + + d_instantiate(dentry, inode); + fsnotify_create(d_inode(dentry->d_parent), dentry); + return end_creating(dentry); +} + /** * debugfs_create_file - create a file in the debugfs filesystem * @name: a pointer to a string containing the name of the file to create. @@ -324,29 +361,52 @@ struct dentry *debugfs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops) { - struct dentry *dentry; - struct inode *inode; - if (!(mode & S_IFMT)) - mode |= S_IFREG; - BUG_ON(!S_ISREG(mode)); - dentry = start_creating(name, parent); - - if (IS_ERR(dentry)) - return NULL; + return __debugfs_create_file(name, mode, parent, data, + fops ? &debugfs_full_proxy_file_operations : + &debugfs_noop_file_operations, + fops); +} +EXPORT_SYMBOL_GPL(debugfs_create_file); - inode = debugfs_get_inode(dentry->d_sb); - if (unlikely(!inode)) - return failed_creating(dentry); +/** + * debugfs_create_file_unsafe - create a file in the debugfs filesystem + * @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. + * @data: a pointer to something that the caller will want to get to later + * on. The inode.i_private pointer will point to this value on + * the open() call. + * @fops: a pointer to a struct file_operations that should be used for + * this file. + * + * debugfs_create_file_unsafe() is completely analogous to + * debugfs_create_file(), the only difference being that the fops + * handed it will not get protected against file removals by the + * debugfs core. + * + * It is your responsibility to protect your struct file_operation + * methods against file removals by means of debugfs_use_file_start() + * and debugfs_use_file_finish(). ->open() is still protected by + * debugfs though. + * + * Any struct file_operations defined by means of + * DEFINE_DEBUGFS_ATTRIBUTE() is protected against file removals and + * thus, may be used here. + */ +struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fops) +{ - inode->i_mode = mode; - inode->i_fop = fops ? fops : &debugfs_file_operations; - inode->i_private = data; - d_instantiate(dentry, inode); - fsnotify_create(d_inode(dentry->d_parent), dentry); - return end_creating(dentry); + return __debugfs_create_file(name, mode, parent, data, + fops ? &debugfs_open_proxy_file_operations : + &debugfs_noop_file_operations, + fops); } -EXPORT_SYMBOL_GPL(debugfs_create_file); +EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe); /** * debugfs_create_file_size - create a file in the debugfs filesystem @@ -461,7 +521,11 @@ struct dentry *debugfs_create_automount(const char *name, inode->i_flags |= S_AUTOMOUNT; inode->i_private = data; dentry->d_fsdata = (void *)f; + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inc_nlink(inode); d_instantiate(dentry, inode); + inc_nlink(d_inode(dentry->d_parent)); + fsnotify_mkdir(d_inode(dentry->d_parent), dentry); return end_creating(dentry); } EXPORT_SYMBOL(debugfs_create_automount); @@ -565,6 +629,8 @@ void debugfs_remove(struct dentry *dentry) inode_unlock(d_inode(parent)); if (!ret) simple_release_fs(&debugfs_mount, &debugfs_mount_count); + + synchronize_srcu(&debugfs_srcu); } EXPORT_SYMBOL_GPL(debugfs_remove); @@ -642,6 +708,8 @@ void debugfs_remove_recursive(struct dentry *dentry) if (!__debugfs_remove(child, parent)) simple_release_fs(&debugfs_mount, &debugfs_mount_count); inode_unlock(d_inode(parent)); + + synchronize_srcu(&debugfs_srcu); } EXPORT_SYMBOL_GPL(debugfs_remove_recursive); diff --git a/fs/debugfs/internal.h b/fs/debugfs/internal.h new file mode 100644 index 000000000000..bba52634b995 --- /dev/null +++ b/fs/debugfs/internal.h @@ -0,0 +1,26 @@ +/* + * internal.h - declarations internal to debugfs + * + * Copyright (C) 2016 Nicolai Stange <nicstange@gmail.com> + * + * 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. + * + */ + +#ifndef _DEBUGFS_INTERNAL_H_ +#define _DEBUGFS_INTERNAL_H_ + +struct file_operations; + +/* declared over in file.c */ +extern const struct file_operations debugfs_noop_file_operations; +extern const struct file_operations debugfs_open_proxy_file_operations; +extern const struct file_operations debugfs_full_proxy_file_operations; + +struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fops); + +#endif /* _DEBUGFS_INTERNAL_H_ */ diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 03b688d19f69..eb2c58732bcf 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -753,7 +753,8 @@ int kernfs_add_one(struct kernfs_node *kn) ps_iattr = parent->iattr; if (ps_iattr) { struct iattr *ps_iattrs = &ps_iattr->ia_iattr; - ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; + ktime_get_real_ts(&ps_iattrs->ia_ctime); + ps_iattrs->ia_mtime = ps_iattrs->ia_ctime; } mutex_unlock(&kernfs_mutex); @@ -1279,8 +1280,9 @@ static void __kernfs_remove(struct kernfs_node *kn) /* update timestamps on the parent */ if (ps_iattr) { - ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; - ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; + ktime_get_real_ts(&ps_iattr->ia_iattr.ia_ctime); + ps_iattr->ia_iattr.ia_mtime = + ps_iattr->ia_iattr.ia_ctime; } kernfs_put(pos); diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c index 16405ae88d2d..1ac1dbae5aba 100644 --- a/fs/kernfs/inode.c +++ b/fs/kernfs/inode.c @@ -54,7 +54,10 @@ static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn) iattrs->ia_mode = kn->mode; iattrs->ia_uid = GLOBAL_ROOT_UID; iattrs->ia_gid = GLOBAL_ROOT_GID; - iattrs->ia_atime = iattrs->ia_mtime = iattrs->ia_ctime = CURRENT_TIME; + + ktime_get_real_ts(&iattrs->ia_atime); + iattrs->ia_mtime = iattrs->ia_atime; + iattrs->ia_ctime = iattrs->ia_atime; simple_xattrs_init(&kn->iattr->xattrs); out_unlock: @@ -236,16 +239,18 @@ ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size) static inline void set_default_inode_attr(struct inode *inode, umode_t mode) { inode->i_mode = mode; - inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + inode->i_atime = inode->i_mtime = + inode->i_ctime = current_fs_time(inode->i_sb); } static inline void set_inode_attr(struct inode *inode, struct iattr *iattr) { + struct super_block *sb = inode->i_sb; inode->i_uid = iattr->ia_uid; inode->i_gid = iattr->ia_gid; - inode->i_atime = iattr->ia_atime; - inode->i_mtime = iattr->ia_mtime; - inode->i_ctime = iattr->ia_ctime; + inode->i_atime = timespec_trunc(iattr->ia_atime, sb->s_time_gran); + inode->i_mtime = timespec_trunc(iattr->ia_mtime, sb->s_time_gran); + inode->i_ctime = timespec_trunc(iattr->ia_ctime, sb->s_time_gran); } static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode) diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index 981e53ab84e8..1438e2322d5c 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -19,9 +19,11 @@ #include <linux/seq_file.h> #include <linux/types.h> +#include <linux/compiler.h> struct device; struct file_operations; +struct srcu_struct; struct debugfs_blob_wrapper { void *data; @@ -41,14 +43,16 @@ struct debugfs_regset32 { extern struct dentry *arch_debugfs_dir; -#if defined(CONFIG_DEBUG_FS) +extern struct srcu_struct debugfs_srcu; -/* declared over in file.c */ -extern const struct file_operations debugfs_file_operations; +#if defined(CONFIG_DEBUG_FS) struct dentry *debugfs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops); +struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fops); struct dentry *debugfs_create_file_size(const char *name, umode_t mode, struct dentry *parent, void *data, @@ -68,6 +72,31 @@ struct dentry *debugfs_create_automount(const char *name, void debugfs_remove(struct dentry *dentry); void debugfs_remove_recursive(struct dentry *dentry); +int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx) + __acquires(&debugfs_srcu); + +void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu); + +ssize_t debugfs_attr_read(struct file *file, char __user *buf, + size_t len, loff_t *ppos); +ssize_t debugfs_attr_write(struct file *file, const char __user *buf, + size_t len, loff_t *ppos); + +#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ +static int __fops ## _open(struct inode *inode, struct file *file) \ +{ \ + __simple_attr_check_format(__fmt, 0ull); \ + return simple_attr_open(inode, file, __get, __set, __fmt); \ +} \ +static const struct file_operations __fops = { \ + .owner = THIS_MODULE, \ + .open = __fops ## _open, \ + .release = simple_attr_release, \ + .read = debugfs_attr_read, \ + .write = debugfs_attr_write, \ + .llseek = generic_file_llseek, \ +} + struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, struct dentry *new_dir, const char *new_name); @@ -176,6 +205,20 @@ static inline void debugfs_remove(struct dentry *dentry) static inline void debugfs_remove_recursive(struct dentry *dentry) { } +static inline int debugfs_use_file_start(const struct dentry *dentry, + int *srcu_idx) + __acquires(&debugfs_srcu) +{ + return 0; +} + +static inline void debugfs_use_file_finish(int srcu_idx) + __releases(&debugfs_srcu) +{ } + +#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ + static const struct file_operations __fops = { 0 } + static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, struct dentry *new_dir, char *new_name) { diff --git a/include/linux/devcoredump.h b/include/linux/devcoredump.h index c0a360e99f64..269521f143ac 100644 --- a/include/linux/devcoredump.h +++ b/include/linux/devcoredump.h @@ -1,3 +1,22 @@ +/* + * This file is provided under the GPLv2 license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2015 Intel Deutschland GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * The full GNU General Public License is included in this distribution + * in the file called COPYING. + */ #ifndef __DEVCOREDUMP_H #define __DEVCOREDUMP_H @@ -5,17 +24,62 @@ #include <linux/module.h> #include <linux/vmalloc.h> +#include <linux/scatterlist.h> +#include <linux/slab.h> + +/* + * _devcd_free_sgtable - free all the memory of the given scatterlist table + * (i.e. both pages and scatterlist instances) + * NOTE: if two tables allocated and chained using the sg_chain function then + * this function should be called only once on the first table + * @table: pointer to sg_table to free + */ +static inline void _devcd_free_sgtable(struct scatterlist *table) +{ + int i; + struct page *page; + struct scatterlist *iter; + struct scatterlist *delete_iter; + + /* free pages */ + iter = table; + for_each_sg(table, iter, sg_nents(table), i) { + page = sg_page(iter); + if (page) + __free_page(page); + } + + /* then free all chained tables */ + iter = table; + delete_iter = table; /* always points on a head of a table */ + while (!sg_is_last(iter)) { + iter++; + if (sg_is_chain(iter)) { + iter = sg_chain_ptr(iter); + kfree(delete_iter); + delete_iter = iter; + } + } + + /* free the last table */ + kfree(delete_iter); +} + + #ifdef CONFIG_DEV_COREDUMP -void dev_coredumpv(struct device *dev, const void *data, size_t datalen, +void dev_coredumpv(struct device *dev, void *data, size_t datalen, gfp_t gfp); void dev_coredumpm(struct device *dev, struct module *owner, - const void *data, size_t datalen, gfp_t gfp, + void *data, size_t datalen, gfp_t gfp, ssize_t (*read)(char *buffer, loff_t offset, size_t count, - const void *data, size_t datalen), - void (*free)(const void *data)); + void *data, size_t datalen), + void (*free)(void *data)); + +void dev_coredumpsg(struct device *dev, struct scatterlist *table, + size_t datalen, gfp_t gfp); #else -static inline void dev_coredumpv(struct device *dev, const void *data, +static inline void dev_coredumpv(struct device *dev, void *data, size_t datalen, gfp_t gfp) { vfree(data); @@ -23,13 +87,19 @@ static inline void dev_coredumpv(struct device *dev, const void *data, static inline void dev_coredumpm(struct device *dev, struct module *owner, - const void *data, size_t datalen, gfp_t gfp, + void *data, size_t datalen, gfp_t gfp, ssize_t (*read)(char *buffer, loff_t offset, size_t count, - const void *data, size_t datalen), - void (*free)(const void *data)) + void *data, size_t datalen), + void (*free)(void *data)) { free(data); } + +static inline void dev_coredumpsg(struct device *dev, struct scatterlist *table, + size_t datalen, gfp_t gfp) +{ + _devcd_free_sgtable(table); +} #endif /* CONFIG_DEV_COREDUMP */ #endif /* __DEVCOREDUMP_H */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 70e61b58baaf..ff7178348ff7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2395,6 +2395,8 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev, /* fs/char_dev.c */ #define CHRDEV_MAJOR_HASH_SIZE 255 +/* Marks the bottom of the first segment of free char majors */ +#define CHRDEV_MAJOR_DYN_END 234 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *); extern int register_chrdev_region(dev_t, unsigned, const char *); extern int __register_chrdev(unsigned int major, unsigned int baseminor, diff --git a/include/linux/isa.h b/include/linux/isa.h index b0270e3814c8..2a02862775eb 100644 --- a/include/linux/isa.h +++ b/include/linux/isa.h @@ -22,7 +22,7 @@ struct isa_driver { #define to_isa_driver(x) container_of((x), struct isa_driver, driver) -#ifdef CONFIG_ISA +#ifdef CONFIG_ISA_BUS int isa_register_driver(struct isa_driver *, unsigned int); void isa_unregister_driver(struct isa_driver *); #else diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1e9a607534ca..ddb0e8337aae 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -257,6 +257,7 @@ config PAGE_OWNER config DEBUG_FS bool "Debug Filesystem" + select SRCU help debugfs is a virtual file system that kernel developers use to put debugging files into. Enable this option to be able to read and diff --git a/scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci b/scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci new file mode 100644 index 000000000000..85cf5408d378 --- /dev/null +++ b/scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci @@ -0,0 +1,67 @@ +/// Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE +/// for debugfs files. +/// +//# Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file() +//# imposes some significant overhead as compared to +//# DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe(). +// +// Copyright (C): 2016 Nicolai Stange +// Options: --no-includes +// + +virtual context +virtual patch +virtual org +virtual report + +@dsa@ +declarer name DEFINE_SIMPLE_ATTRIBUTE; +identifier dsa_fops; +expression dsa_get, dsa_set, dsa_fmt; +position p; +@@ +DEFINE_SIMPLE_ATTRIBUTE@p(dsa_fops, dsa_get, dsa_set, dsa_fmt); + +@dcf@ +expression name, mode, parent, data; +identifier dsa.dsa_fops; +@@ +debugfs_create_file(name, mode, parent, data, &dsa_fops) + + +@context_dsa depends on context && dcf@ +declarer name DEFINE_DEBUGFS_ATTRIBUTE; +identifier dsa.dsa_fops; +expression dsa.dsa_get, dsa.dsa_set, dsa.dsa_fmt; +@@ +* DEFINE_SIMPLE_ATTRIBUTE(dsa_fops, dsa_get, dsa_set, dsa_fmt); + + +@patch_dcf depends on patch expression@ +expression name, mode, parent, data; +identifier dsa.dsa_fops; +@@ +- debugfs_create_file(name, mode, parent, data, &dsa_fops) ++ debugfs_create_file_unsafe(name, mode, parent, data, &dsa_fops) + +@patch_dsa depends on patch_dcf && patch@ +identifier dsa.dsa_fops; +expression dsa.dsa_get, dsa.dsa_set, dsa.dsa_fmt; +@@ +- DEFINE_SIMPLE_ATTRIBUTE(dsa_fops, dsa_get, dsa_set, dsa_fmt); ++ DEFINE_DEBUGFS_ATTRIBUTE(dsa_fops, dsa_get, dsa_set, dsa_fmt); + + +@script:python depends on org && dcf@ +fops << dsa.dsa_fops; +p << dsa.p; +@@ +msg="%s should be defined with DEFINE_DEBUGFS_ATTRIBUTE" % (fops) +coccilib.org.print_todo(p[0], msg) + +@script:python depends on report && dcf@ +fops << dsa.dsa_fops; +p << dsa.p; +@@ +msg="WARNING: %s should be defined with DEFINE_DEBUGFS_ATTRIBUTE" % (fops) +coccilib.report.print_report(p[0], msg) |