diff options
Diffstat (limited to 'include/linux/dynamic_debug.h')
| -rw-r--r-- | include/linux/dynamic_debug.h | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h new file mode 100644 index 000000000..4fcbf4d4f --- /dev/null +++ b/include/linux/dynamic_debug.h @@ -0,0 +1,354 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _DYNAMIC_DEBUG_H +#define _DYNAMIC_DEBUG_H + +#if defined(CONFIG_JUMP_LABEL) +#include <linux/jump_label.h> +#endif + +#include <linux/build_bug.h> + +/* + * An instance of this structure is created in a special + * ELF section at every dynamic debug callsite. At runtime, + * the special section is treated as an array of these. + */ +struct _ddebug { + /* + * These fields are used to drive the user interface + * for selecting and displaying debug callsites. + */ + const char *modname; + const char *function; + const char *filename; + const char *format; + unsigned int lineno:18; +#define CLS_BITS 6 + unsigned int class_id:CLS_BITS; +#define _DPRINTK_CLASS_DFLT ((1 << CLS_BITS) - 1) + /* + * The flags field controls the behaviour at the callsite. + * The bits here are changed dynamically when the user + * writes commands to <debugfs>/dynamic_debug/control + */ +#define _DPRINTK_FLAGS_NONE 0 +#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */ +#define _DPRINTK_FLAGS_INCL_MODNAME (1<<1) +#define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2) +#define _DPRINTK_FLAGS_INCL_LINENO (1<<3) +#define _DPRINTK_FLAGS_INCL_TID (1<<4) +#define _DPRINTK_FLAGS_INCL_SOURCENAME (1<<5) + +#define _DPRINTK_FLAGS_INCL_ANY \ + (_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\ + _DPRINTK_FLAGS_INCL_LINENO | _DPRINTK_FLAGS_INCL_TID |\ + _DPRINTK_FLAGS_INCL_SOURCENAME) + +#if defined DEBUG +#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT +#else +#define _DPRINTK_FLAGS_DEFAULT 0 +#endif + unsigned int flags:8; +#ifdef CONFIG_JUMP_LABEL + union { + struct static_key_true dd_key_true; + struct static_key_false dd_key_false; + } key; +#endif +} __attribute__((aligned(8))); + +enum class_map_type { + DD_CLASS_TYPE_DISJOINT_BITS, + /** + * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit. + * expecting hex input. Built for drm.debug, basis for other types. + */ + DD_CLASS_TYPE_LEVEL_NUM, + /** + * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N. + * N turns on just bits N-1 .. 0, so N=0 turns all bits off. + */ + DD_CLASS_TYPE_DISJOINT_NAMES, + /** + * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES, + * classes are independent, like _DISJOINT_BITS. + */ + DD_CLASS_TYPE_LEVEL_NAMES, + /** + * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES, + * intended for names like: INFO,DEBUG,TRACE, with a module prefix + * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug + */ +}; + +struct ddebug_class_map { + struct list_head link; + struct module *mod; + const char *mod_name; /* needed for builtins */ + const char **class_names; + const int length; + const int base; /* index of 1st .class_id, allows split/shared space */ + enum class_map_type map_type; +}; + +/** + * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module + * @_var: a struct ddebug_class_map, passed to module_param_cb + * @_type: enum class_map_type, chooses bits/verbose, numeric/symbolic + * @_base: offset of 1st class-name. splits .class_id space + * @classes: class-names used to control class'd prdbgs + */ +#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \ + static const char *_var##_classnames[] = { __VA_ARGS__ }; \ + static struct ddebug_class_map __aligned(8) __used \ + __section("__dyndbg_classes") _var = { \ + .mod = THIS_MODULE, \ + .mod_name = KBUILD_MODNAME, \ + .base = _base, \ + .map_type = _maptype, \ + .length = NUM_TYPE_ARGS(char*, __VA_ARGS__), \ + .class_names = _var##_classnames, \ + } +#define NUM_TYPE_ARGS(eltype, ...) \ + (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype)) + +/* encapsulate linker provided built-in (or module) dyndbg data */ +struct _ddebug_info { + struct _ddebug *descs; + struct ddebug_class_map *classes; + unsigned int num_descs; + unsigned int num_classes; +}; + +struct ddebug_class_param { + union { + unsigned long *bits; + unsigned int *lvl; + }; + char flags[8]; + const struct ddebug_class_map *map; +}; + +/* + * pr_debug() and friends are globally enabled or modules have selectively + * enabled them. + */ +#if defined(CONFIG_DYNAMIC_DEBUG) || \ + (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) + +extern __printf(2, 3) +void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...); + +struct device; + +extern __printf(3, 4) +void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev, + const char *fmt, ...); + +struct net_device; + +extern __printf(3, 4) +void __dynamic_netdev_dbg(struct _ddebug *descriptor, + const struct net_device *dev, + const char *fmt, ...); + +struct ib_device; + +extern __printf(3, 4) +void __dynamic_ibdev_dbg(struct _ddebug *descriptor, + const struct ib_device *ibdev, + const char *fmt, ...); + +#define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \ + static struct _ddebug __aligned(8) \ + __section("__dyndbg") name = { \ + .modname = KBUILD_MODNAME, \ + .function = __func__, \ + .filename = __FILE__, \ + .format = (fmt), \ + .lineno = __LINE__, \ + .flags = _DPRINTK_FLAGS_DEFAULT, \ + .class_id = cls, \ + _DPRINTK_KEY_INIT \ + }; \ + BUILD_BUG_ON_MSG(cls > _DPRINTK_CLASS_DFLT, \ + "classid value overflow") + +#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \ + DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, _DPRINTK_CLASS_DFLT, fmt) + +#ifdef CONFIG_JUMP_LABEL + +#ifdef DEBUG + +#define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT) + +#define DYNAMIC_DEBUG_BRANCH(descriptor) \ + static_branch_likely(&descriptor.key.dd_key_true) +#else +#define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT) + +#define DYNAMIC_DEBUG_BRANCH(descriptor) \ + static_branch_unlikely(&descriptor.key.dd_key_false) +#endif + +#else /* !CONFIG_JUMP_LABEL */ + +#define _DPRINTK_KEY_INIT + +#ifdef DEBUG +#define DYNAMIC_DEBUG_BRANCH(descriptor) \ + likely(descriptor.flags & _DPRINTK_FLAGS_PRINT) +#else +#define DYNAMIC_DEBUG_BRANCH(descriptor) \ + unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) +#endif + +#endif /* CONFIG_JUMP_LABEL */ + +/* + * Factory macros: ($prefix)dynamic_func_call($suffix) + * + * Lower layer (with __ prefix) gets the callsite metadata, and wraps + * the func inside a debug-branch/static-key construct. Upper layer + * (with _ prefix) does the UNIQUE_ID once, so that lower can ref the + * name/label multiple times, and tie the elements together. + * Multiple flavors: + * (|_cls): adds in _DPRINT_CLASS_DFLT as needed + * (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs) + */ +#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \ + DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \ + if (DYNAMIC_DEBUG_BRANCH(id)) \ + func(&id, ##__VA_ARGS__); \ +} while (0) +#define __dynamic_func_call(id, fmt, func, ...) \ + __dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt, \ + func, ##__VA_ARGS__) + +#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do { \ + DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \ + if (DYNAMIC_DEBUG_BRANCH(id)) \ + func(__VA_ARGS__); \ +} while (0) +#define __dynamic_func_call_no_desc(id, fmt, func, ...) \ + __dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT, \ + fmt, func, ##__VA_ARGS__) + +/* + * "Factory macro" for generating a call to func, guarded by a + * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be + * initialized using the fmt argument. The function will be called with + * the address of the descriptor as first argument, followed by all + * the varargs. Note that fmt is repeated in invocations of this + * macro. + */ +#define _dynamic_func_call_cls(cls, fmt, func, ...) \ + __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__) +#define _dynamic_func_call(fmt, func, ...) \ + _dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__) + +/* + * A variant that does the same, except that the descriptor is not + * passed as the first argument to the function; it is only called + * with precisely the macro's varargs. + */ +#define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...) \ + __dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt, \ + func, ##__VA_ARGS__) +#define _dynamic_func_call_no_desc(fmt, func, ...) \ + _dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt, \ + func, ##__VA_ARGS__) + +#define dynamic_pr_debug_cls(cls, fmt, ...) \ + _dynamic_func_call_cls(cls, fmt, __dynamic_pr_debug, \ + pr_fmt(fmt), ##__VA_ARGS__) + +#define dynamic_pr_debug(fmt, ...) \ + _dynamic_func_call(fmt, __dynamic_pr_debug, \ + pr_fmt(fmt), ##__VA_ARGS__) + +#define dynamic_dev_dbg(dev, fmt, ...) \ + _dynamic_func_call(fmt, __dynamic_dev_dbg, \ + dev, fmt, ##__VA_ARGS__) + +#define dynamic_netdev_dbg(dev, fmt, ...) \ + _dynamic_func_call(fmt, __dynamic_netdev_dbg, \ + dev, fmt, ##__VA_ARGS__) + +#define dynamic_ibdev_dbg(dev, fmt, ...) \ + _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \ + dev, fmt, ##__VA_ARGS__) + +#define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \ + groupsize, buf, len, ascii) \ + _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \ + print_hex_dump, \ + KERN_DEBUG, prefix_str, prefix_type, \ + rowsize, groupsize, buf, len, ascii) + +/* for test only, generally expect drm.debug style macro wrappers */ +#define __pr_debug_cls(cls, fmt, ...) do { \ + BUILD_BUG_ON_MSG(!__builtin_constant_p(cls), \ + "expecting constant class int/enum"); \ + dynamic_pr_debug_cls(cls, fmt, ##__VA_ARGS__); \ + } while (0) + +#else /* !(CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE)) */ + +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/printk.h> + +#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) +#define DYNAMIC_DEBUG_BRANCH(descriptor) false + +#define dynamic_pr_debug(fmt, ...) \ + do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0) +#define dynamic_dev_dbg(dev, fmt, ...) \ + do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0) +#define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \ + groupsize, buf, len, ascii) \ + do { if (0) \ + print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \ + rowsize, groupsize, buf, len, ascii); \ + } while (0) + +#endif /* CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE) */ + + +#ifdef CONFIG_DYNAMIC_DEBUG_CORE + +extern int ddebug_dyndbg_module_param_cb(char *param, char *val, + const char *modname); +struct kernel_param; +int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp); +int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp); + +#else + +static inline int ddebug_dyndbg_module_param_cb(char *param, char *val, + const char *modname) +{ + if (!strcmp(param, "dyndbg")) { + /* avoid pr_warn(), which wants pr_fmt() fully defined */ + printk(KERN_WARNING "dyndbg param is supported only in " + "CONFIG_DYNAMIC_DEBUG builds\n"); + return 0; /* allow and ignore */ + } + return -EINVAL; +} + +struct kernel_param; +static inline int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp) +{ return 0; } +static inline int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp) +{ return 0; } + +#endif + + +extern const struct kernel_param_ops param_ops_dyndbg_classes; + +#endif /* _DYNAMIC_DEBUG_H */ |