linuxdebug/include/linux/dynamic_debug.h

351 lines
11 KiB
C

/* 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_ANY \
(_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\
_DPRINTK_FLAGS_INCL_LINENO | _DPRINTK_FLAGS_INCL_TID)
#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;
};
#if defined(CONFIG_DYNAMIC_DEBUG_CORE)
int ddebug_add_module(struct _ddebug_info *dyndbg, const char *modname);
extern int ddebug_remove_module(const char *mod_name);
extern __printf(2, 3)
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
const char *modname);
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)
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);
/* 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_CORE */
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/printk.h>
static inline int ddebug_add_module(struct _ddebug_info *dinfo, const char *modname)
{
return 0;
}
static inline int ddebug_remove_module(const char *mod)
{
return 0;
}
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;
}
#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)
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 /* !CONFIG_DYNAMIC_DEBUG_CORE */
extern const struct kernel_param_ops param_ops_dyndbg_classes;
#endif