/* * lib/dynamic_debug.c * * make pr_debug()/dev_dbg() calls runtime configurable based upon their * source module. * * Copyright (C) 2008 Jason Baron <[email protected]> * By Greg Banks <[email protected]> * Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved. * Copyright (C) 2011 Bart Van Assche. All Rights Reserved. * Copyright (C) 2013 Du, Changbin <[email protected]> */ #define pr_fmt(fmt) … #include <linux/kernel.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/kallsyms.h> #include <linux/types.h> #include <linux/mutex.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/list.h> #include <linux/sysctl.h> #include <linux/ctype.h> #include <linux/string.h> #include <linux/parser.h> #include <linux/string_helpers.h> #include <linux/uaccess.h> #include <linux/dynamic_debug.h> #include <linux/debugfs.h> #include <linux/slab.h> #include <linux/jump_label.h> #include <linux/hardirq.h> #include <linux/sched.h> #include <linux/device.h> #include <linux/netdevice.h> #include <rdma/ib_verbs.h> extern struct _ddebug __start___dyndbg[]; extern struct _ddebug __stop___dyndbg[]; extern struct ddebug_class_map __start___dyndbg_classes[]; extern struct ddebug_class_map __stop___dyndbg_classes[]; struct ddebug_table { … }; struct ddebug_query { … }; struct ddebug_iter { … }; struct flag_settings { … }; static DEFINE_MUTEX(ddebug_lock); static LIST_HEAD(ddebug_tables); static int verbose; module_param(verbose, int, 0644); MODULE_PARM_DESC(…) …; /* Return the path relative to source root */ static inline const char *trim_prefix(const char *path) { … } static const struct { … } opt_array[] = …; struct flagsbuf { … }; /* format a string into buf[] which describes the _ddebug's flags */ static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb) { … } #define vnpr_info(lvl, fmt, ...) … #define vpr_info(fmt, ...) … #define v2pr_info(fmt, ...) … #define v3pr_info(fmt, ...) … #define v4pr_info(fmt, ...) … static void vpr_info_dq(const struct ddebug_query *query, const char *msg) { … } static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt, const char *class_string, int *class_id) { … } #define __outvar … /* * Search the tables for _ddebug's which match the given `query' and * apply the `flags' and `mask' to them. Returns number of matching * callsites, normally the same as number of changes. If verbose, * logs the changes. Takes ddebug_lock. */ static int ddebug_change(const struct ddebug_query *query, struct flag_settings *modifiers) { … } /* * Split the buffer `buf' into space-separated words. * Handles simple " and ' quoting, i.e. without nested, * embedded or escaped \". Return the number of words * or <0 on error. */ static int ddebug_tokenize(char *buf, char *words[], int maxwords) { … } /* * Parse a single line number. Note that the empty string "" * is treated as a special case and converted to zero, which * is later treated as a "don't care" value. */ static inline int parse_lineno(const char *str, unsigned int *val) { … } static int parse_linerange(struct ddebug_query *query, const char *first) { … } static int check_set(const char **dest, char *src, char *name) { … } /* * Parse words[] as a ddebug query specification, which is a series * of (keyword, value) pairs chosen from these possibilities: * * func <function-name> * file <full-pathname> * file <base-filename> * module <module-name> * format <escaped-string-to-find-in-format> * line <lineno> * line <first-lineno>-<last-lineno> // where either may be empty * * Only 1 of each type is allowed. * Returns 0 on success, <0 on error. */ static int ddebug_parse_query(char *words[], int nwords, struct ddebug_query *query, const char *modname) { … } /* * Parse `str' as a flags specification, format [-+=][p]+. * Sets up *maskp and *flagsp to be used when changing the * flags fields of matched _ddebug's. Returns 0 on success * or <0 on error. */ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers) { … } static int ddebug_exec_query(char *query_string, const char *modname) { … } /* handle multiple queries in query string, continue on error, return last error or number of matching callsites. Module name is either in param (for boot arg) or perhaps in query string. */ static int ddebug_exec_queries(char *query, const char *modname) { … } /* apply a new bitmap to the sys-knob's current bit-state */ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp, unsigned long *new_bits, unsigned long *old_bits) { … } /* stub to later conditionally add "$module." prefix where not already done */ #define KP_NAME(kp) … #define CLASSMAP_BITMASK(width) … /* accept comma-separated-list of [+-] classnames */ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp) { … } /** * param_set_dyndbg_classes - class FOO >control * @instr: string echo>d to sysfs, input depends on map_type * @kp: kp->arg has state: bits/lvl, map, map_type * * Enable/disable prdbgs by their class, as given in the arguments to * DECLARE_DYNDBG_CLASSMAP. For LEVEL map-types, enforce relative * levels by bitpos. * * Returns: 0 or <0 if error. */ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp) { … } EXPORT_SYMBOL(…); /** * param_get_dyndbg_classes - classes reader * @buffer: string description of controlled bits -> classes * @kp: kp->arg has state: bits, map * * Reads last written state, underlying prdbg state may have been * altered by direct >control. Displays 0x for DISJOINT, 0-N for * LEVEL Returns: #chars written or <0 on error */ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp) { … } EXPORT_SYMBOL(…); const struct kernel_param_ops param_ops_dyndbg_classes = …; EXPORT_SYMBOL(…); #define PREFIX_SIZE … static int remaining(int wrote) { … } static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf) { … } static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf) { … } void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...) { … } EXPORT_SYMBOL(…); void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev, const char *fmt, ...) { … } EXPORT_SYMBOL(…); #ifdef CONFIG_NET void __dynamic_netdev_dbg(struct _ddebug *descriptor, const struct net_device *dev, const char *fmt, ...) { … } EXPORT_SYMBOL(…); #endif #if IS_ENABLED(CONFIG_INFINIBAND) void __dynamic_ibdev_dbg(struct _ddebug *descriptor, const struct ib_device *ibdev, const char *fmt, ...) { … } EXPORT_SYMBOL(…); #endif /* * Install a noop handler to make dyndbg look like a normal kernel cli param. * This avoids warnings about dyndbg being an unknown cli param when supplied * by a user. */ static __init int dyndbg_setup(char *str) { … } __setup(…); /* * File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the * command text from userspace, parses and executes it. */ #define USER_BUF_PAGE … static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, size_t len, loff_t *offp) { … } /* * Set the iterator to point to the first _ddebug object * and return a pointer to that first object. Returns * NULL if there are no _ddebugs at all. */ static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter) { … } /* * Advance the iterator to point to the next _ddebug * object from the one the iterator currently points at, * and returns a pointer to the new _ddebug. Returns * NULL if the iterator has seen all the _ddebugs. */ static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter) { … } /* * Seq_ops start method. Called at the start of every * read() call from userspace. Takes the ddebug_lock and * seeks the seq_file's iterator to the given position. */ static void *ddebug_proc_start(struct seq_file *m, loff_t *pos) { … } /* * Seq_ops next method. Called several times within a read() * call from userspace, with ddebug_lock held. Walks to the * next _ddebug object with a special case for the header line. */ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) { … } #define class_in_range(class_id, map) … static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp) { … } /* * Seq_ops show method. Called several times within a read() * call from userspace, with ddebug_lock held. Formats the * current _ddebug as a single human-readable line, with a * special case for the header line. */ static int ddebug_proc_show(struct seq_file *m, void *p) { … } /* * Seq_ops stop method. Called at the end of each read() * call from userspace. Drops ddebug_lock. */ static void ddebug_proc_stop(struct seq_file *m, void *p) { … } static const struct seq_operations ddebug_proc_seqops = …; static int ddebug_proc_open(struct inode *inode, struct file *file) { … } static const struct file_operations ddebug_proc_fops = …; static const struct proc_ops proc_fops = …; static void ddebug_attach_module_classes(struct ddebug_table *dt, struct ddebug_class_map *classes, int num_classes) { … } /* * Allocate a new ddebug_table for the given module * and add it to the global list. */ static int ddebug_add_module(struct _ddebug_info *di, const char *modname) { … } /* helper for ddebug_dyndbg_(boot|module)_param_cb */ static int ddebug_dyndbg_param_cb(char *param, char *val, const char *modname, int on_err) { … } /* handle both dyndbg and $module.dyndbg params at boot */ static int ddebug_dyndbg_boot_param_cb(char *param, char *val, const char *unused, void *arg) { … } /* * modprobe foo finds foo.params in boot-args, strips "foo.", and * passes them to load_module(). This callback gets unknown params, * processes dyndbg params, rejects others. */ int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module) { … } static void ddebug_table_free(struct ddebug_table *dt) { … } #ifdef CONFIG_MODULES /* * Called in response to a module being unloaded. Removes * any ddebug_table's which point at the module. */ static int ddebug_remove_module(const char *mod_name) { … } static int ddebug_module_notify(struct notifier_block *self, unsigned long val, void *data) { … } static struct notifier_block ddebug_module_nb = …; #endif /* CONFIG_MODULES */ static void ddebug_remove_all_tables(void) { … } static __initdata int ddebug_init_success; static int __init dynamic_debug_init_control(void) { … } static int __init dynamic_debug_init(void) { … } /* Allow early initialization for boot messages via boot param */ early_initcall(dynamic_debug_init); /* Debugfs setup must be done later */ fs_initcall(dynamic_debug_init_control);
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