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dynamic_debug.c
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dynamic_debug.c
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/*
* 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) "dyndbg: " 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 list_head link, maps;
const char *mod_name;
unsigned int num_ddebugs;
struct _ddebug *ddebugs;
};
struct ddebug_query {
const char *filename;
const char *module;
const char *function;
const char *format;
const char *class_string;
unsigned int first_lineno, last_lineno;
};
struct ddebug_iter {
struct ddebug_table *table;
int idx;
};
struct flag_settings {
unsigned int flags;
unsigned int mask;
};
static DEFINE_MUTEX(ddebug_lock);
static LIST_HEAD(ddebug_tables);
static int verbose;
module_param(verbose, int, 0644);
MODULE_PARM_DESC(verbose, " dynamic_debug/control processing "
"( 0 = off (default), 1 = module add/rm, 2 = >control summary, 3 = parsing, 4 = per-site changes)");
/* Return the path relative to source root */
static inline const char *trim_prefix(const char *path)
{
int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
if (strncmp(path, __FILE__, skip))
skip = 0; /* prefix mismatch, don't skip */
return path + skip;
}
static struct { unsigned flag:8; char opt_char; } opt_array[] = {
{ _DPRINTK_FLAGS_PRINT, 'p' },
{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
{ _DPRINTK_FLAGS_INCL_LINENO, 'l' },
{ _DPRINTK_FLAGS_INCL_TID, 't' },
{ _DPRINTK_FLAGS_NONE, '_' },
};
struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; };
/* format a string into buf[] which describes the _ddebug's flags */
static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb)
{
char *p = fb->buf;
int i;
for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
if (flags & opt_array[i].flag)
*p++ = opt_array[i].opt_char;
if (p == fb->buf)
*p++ = '_';
*p = '\0';
return fb->buf;
}
#define vnpr_info(lvl, fmt, ...) \
do { \
if (verbose >= lvl) \
pr_info(fmt, ##__VA_ARGS__); \
} while (0)
#define vpr_info(fmt, ...) vnpr_info(1, fmt, ##__VA_ARGS__)
#define v2pr_info(fmt, ...) vnpr_info(2, fmt, ##__VA_ARGS__)
#define v3pr_info(fmt, ...) vnpr_info(3, fmt, ##__VA_ARGS__)
#define v4pr_info(fmt, ...) vnpr_info(4, fmt, ##__VA_ARGS__)
static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
{
/* trim any trailing newlines */
int fmtlen = 0;
if (query->format) {
fmtlen = strlen(query->format);
while (fmtlen && query->format[fmtlen - 1] == '\n')
fmtlen--;
}
v3pr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u class=%s\n",
msg,
query->function ?: "",
query->filename ?: "",
query->module ?: "",
fmtlen, query->format ?: "",
query->first_lineno, query->last_lineno, query->class_string);
}
static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
const char *class_string, int *class_id)
{
struct ddebug_class_map *map;
int idx;
list_for_each_entry(map, &dt->maps, link) {
idx = match_string(map->class_names, map->length, class_string);
if (idx >= 0) {
*class_id = idx + map->base;
return map;
}
}
*class_id = -ENOENT;
return NULL;
}
#define __outvar /* filled by callee */
/*
* 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)
{
int i;
struct ddebug_table *dt;
unsigned int newflags;
unsigned int nfound = 0;
struct flagsbuf fbuf, nbuf;
struct ddebug_class_map *map = NULL;
int __outvar valid_class;
/* search for matching ddebugs */
mutex_lock(&ddebug_lock);
list_for_each_entry(dt, &ddebug_tables, link) {
/* match against the module name */
if (query->module &&
!match_wildcard(query->module, dt->mod_name))
continue;
if (query->class_string) {
map = ddebug_find_valid_class(dt, query->class_string, &valid_class);
if (!map)
continue;
} else {
/* constrain query, do not touch class'd callsites */
valid_class = _DPRINTK_CLASS_DFLT;
}
for (i = 0; i < dt->num_ddebugs; i++) {
struct _ddebug *dp = &dt->ddebugs[i];
/* match site against query-class */
if (dp->class_id != valid_class)
continue;
/* match against the source filename */
if (query->filename &&
!match_wildcard(query->filename, dp->filename) &&
!match_wildcard(query->filename,
kbasename(dp->filename)) &&
!match_wildcard(query->filename,
trim_prefix(dp->filename)))
continue;
/* match against the function */
if (query->function &&
!match_wildcard(query->function, dp->function))
continue;
/* match against the format */
if (query->format) {
if (*query->format == '^') {
char *p;
/* anchored search. match must be at beginning */
p = strstr(dp->format, query->format+1);
if (p != dp->format)
continue;
} else if (!strstr(dp->format, query->format))
continue;
}
/* match against the line number range */
if (query->first_lineno &&
dp->lineno < query->first_lineno)
continue;
if (query->last_lineno &&
dp->lineno > query->last_lineno)
continue;
nfound++;
newflags = (dp->flags & modifiers->mask) | modifiers->flags;
if (newflags == dp->flags)
continue;
#ifdef CONFIG_JUMP_LABEL
if (dp->flags & _DPRINTK_FLAGS_PRINT) {
if (!(newflags & _DPRINTK_FLAGS_PRINT))
static_branch_disable(&dp->key.dd_key_true);
} else if (newflags & _DPRINTK_FLAGS_PRINT) {
static_branch_enable(&dp->key.dd_key_true);
}
#endif
v4pr_info("changed %s:%d [%s]%s %s => %s\n",
trim_prefix(dp->filename), dp->lineno,
dt->mod_name, dp->function,
ddebug_describe_flags(dp->flags, &fbuf),
ddebug_describe_flags(newflags, &nbuf));
dp->flags = newflags;
}
}
mutex_unlock(&ddebug_lock);
if (!nfound && verbose)
pr_info("no matches for query\n");
return nfound;
}
/*
* 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)
{
int nwords = 0;
while (*buf) {
char *end;
/* Skip leading whitespace */
buf = skip_spaces(buf);
if (!*buf)
break; /* oh, it was trailing whitespace */
if (*buf == '#')
break; /* token starts comment, skip rest of line */
/* find `end' of word, whitespace separated or quoted */
if (*buf == '"' || *buf == '\'') {
int quote = *buf++;
for (end = buf; *end && *end != quote; end++)
;
if (!*end) {
pr_err("unclosed quote: %s\n", buf);
return -EINVAL; /* unclosed quote */
}
} else {
for (end = buf; *end && !isspace(*end); end++)
;
BUG_ON(end == buf);
}
/* `buf' is start of word, `end' is one past its end */
if (nwords == maxwords) {
pr_err("too many words, legal max <=%d\n", maxwords);
return -EINVAL; /* ran out of words[] before bytes */
}
if (*end)
*end++ = '\0'; /* terminate the word */
words[nwords++] = buf;
buf = end;
}
if (verbose >= 3) {
int i;
pr_info("split into words:");
for (i = 0; i < nwords; i++)
pr_cont(" \"%s\"", words[i]);
pr_cont("\n");
}
return nwords;
}
/*
* 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)
{
BUG_ON(str == NULL);
if (*str == '\0') {
*val = 0;
return 0;
}
if (kstrtouint(str, 10, val) < 0) {
pr_err("bad line-number: %s\n", str);
return -EINVAL;
}
return 0;
}
static int parse_linerange(struct ddebug_query *query, const char *first)
{
char *last = strchr(first, '-');
if (query->first_lineno || query->last_lineno) {
pr_err("match-spec: line used 2x\n");
return -EINVAL;
}
if (last)
*last++ = '\0';
if (parse_lineno(first, &query->first_lineno) < 0)
return -EINVAL;
if (last) {
/* range <first>-<last> */
if (parse_lineno(last, &query->last_lineno) < 0)
return -EINVAL;
/* special case for last lineno not specified */
if (query->last_lineno == 0)
query->last_lineno = UINT_MAX;
if (query->last_lineno < query->first_lineno) {
pr_err("last-line:%d < 1st-line:%d\n",
query->last_lineno,
query->first_lineno);
return -EINVAL;
}
} else {
query->last_lineno = query->first_lineno;
}
v3pr_info("parsed line %d-%d\n", query->first_lineno,
query->last_lineno);
return 0;
}
static int check_set(const char **dest, char *src, char *name)
{
int rc = 0;
if (*dest) {
rc = -EINVAL;
pr_err("match-spec:%s val:%s overridden by %s\n",
name, *dest, src);
}
*dest = src;
return rc;
}
/*
* 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)
{
unsigned int i;
int rc = 0;
char *fline;
/* check we have an even number of words */
if (nwords % 2 != 0) {
pr_err("expecting pairs of match-spec <value>\n");
return -EINVAL;
}
for (i = 0; i < nwords; i += 2) {
char *keyword = words[i];
char *arg = words[i+1];
if (!strcmp(keyword, "func")) {
rc = check_set(&query->function, arg, "func");
} else if (!strcmp(keyword, "file")) {
if (check_set(&query->filename, arg, "file"))
return -EINVAL;
/* tail :$info is function or line-range */
fline = strchr(query->filename, ':');
if (!fline)
continue;
*fline++ = '\0';
if (isalpha(*fline) || *fline == '*' || *fline == '?') {
/* take as function name */
if (check_set(&query->function, fline, "func"))
return -EINVAL;
} else {
if (parse_linerange(query, fline))
return -EINVAL;
}
} else if (!strcmp(keyword, "module")) {
rc = check_set(&query->module, arg, "module");
} else if (!strcmp(keyword, "format")) {
string_unescape_inplace(arg, UNESCAPE_SPACE |
UNESCAPE_OCTAL |
UNESCAPE_SPECIAL);
rc = check_set(&query->format, arg, "format");
} else if (!strcmp(keyword, "line")) {
if (parse_linerange(query, arg))
return -EINVAL;
} else if (!strcmp(keyword, "class")) {
rc = check_set(&query->class_string, arg, "class");
} else {
pr_err("unknown keyword \"%s\"\n", keyword);
return -EINVAL;
}
if (rc)
return rc;
}
if (!query->module && modname)
/*
* support $modname.dyndbg=<multiple queries>, when
* not given in the query itself
*/
query->module = modname;
vpr_info_dq(query, "parsed");
return 0;
}
/*
* 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)
{
int op, i;
switch (*str) {
case '+':
case '-':
case '=':
op = *str++;
break;
default:
pr_err("bad flag-op %c, at start of %s\n", *str, str);
return -EINVAL;
}
v3pr_info("op='%c'\n", op);
for (; *str ; ++str) {
for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
if (*str == opt_array[i].opt_char) {
modifiers->flags |= opt_array[i].flag;
break;
}
}
if (i < 0) {
pr_err("unknown flag '%c'\n", *str);
return -EINVAL;
}
}
v3pr_info("flags=0x%x\n", modifiers->flags);
/* calculate final flags, mask based upon op */
switch (op) {
case '=':
/* modifiers->flags already set */
modifiers->mask = 0;
break;
case '+':
modifiers->mask = ~0U;
break;
case '-':
modifiers->mask = ~modifiers->flags;
modifiers->flags = 0;
break;
}
v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
return 0;
}
static int ddebug_exec_query(char *query_string, const char *modname)
{
struct flag_settings modifiers = {};
struct ddebug_query query = {};
#define MAXWORDS 9
int nwords, nfound;
char *words[MAXWORDS];
nwords = ddebug_tokenize(query_string, words, MAXWORDS);
if (nwords <= 0) {
pr_err("tokenize failed\n");
return -EINVAL;
}
/* check flags 1st (last arg) so query is pairs of spec,val */
if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
pr_err("flags parse failed\n");
return -EINVAL;
}
if (ddebug_parse_query(words, nwords-1, &query, modname)) {
pr_err("query parse failed\n");
return -EINVAL;
}
/* actually go and implement the change */
nfound = ddebug_change(&query, &modifiers);
vpr_info_dq(&query, nfound ? "applied" : "no-match");
return nfound;
}
/* 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)
{
char *split;
int i, errs = 0, exitcode = 0, rc, nfound = 0;
for (i = 0; query; query = split) {
split = strpbrk(query, ";\n");
if (split)
*split++ = '\0';
query = skip_spaces(query);
if (!query || !*query || *query == '#')
continue;
vpr_info("query %d: \"%s\" mod:%s\n", i, query, modname ?: "*");
rc = ddebug_exec_query(query, modname);
if (rc < 0) {
errs++;
exitcode = rc;
} else {
nfound += rc;
}
i++;
}
if (i)
v2pr_info("processed %d queries, with %d matches, %d errs\n",
i, nfound, errs);
if (exitcode)
return exitcode;
return nfound;
}
/* 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)
{
#define QUERY_SIZE 128
char query[QUERY_SIZE];
const struct ddebug_class_map *map = dcp->map;
int matches = 0;
int bi, ct;
v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
for (bi = 0; bi < map->length; bi++) {
if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
continue;
snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
ct = ddebug_exec_queries(query, NULL);
matches += ct;
v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
ct, map->class_names[bi], *new_bits);
}
return matches;
}
/* stub to later conditionally add "$module." prefix where not already done */
#define KP_NAME(kp) kp->name
#define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
/* accept comma-separated-list of [+-] classnames */
static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
{
const struct ddebug_class_param *dcp = kp->arg;
const struct ddebug_class_map *map = dcp->map;
unsigned long curr_bits, old_bits;
char *cl_str, *p, *tmp;
int cls_id, totct = 0;
bool wanted;
cl_str = tmp = kstrdup(instr, GFP_KERNEL);
p = strchr(cl_str, '\n');
if (p)
*p = '\0';
/* start with previously set state-bits, then modify */
curr_bits = old_bits = *dcp->bits;
vpr_info("\"%s\" > %s:0x%lx\n", cl_str, KP_NAME(kp), curr_bits);
for (; cl_str; cl_str = p) {
p = strchr(cl_str, ',');
if (p)
*p++ = '\0';
if (*cl_str == '-') {
wanted = false;
cl_str++;
} else {
wanted = true;
if (*cl_str == '+')
cl_str++;
}
cls_id = match_string(map->class_names, map->length, cl_str);
if (cls_id < 0) {
pr_err("%s unknown to %s\n", cl_str, KP_NAME(kp));
continue;
}
/* have one or more valid class_ids of one *_NAMES type */
switch (map->map_type) {
case DD_CLASS_TYPE_DISJOINT_NAMES:
/* the +/- pertains to a single bit */
if (test_bit(cls_id, &curr_bits) == wanted) {
v3pr_info("no change on %s\n", cl_str);
continue;
}
curr_bits ^= BIT(cls_id);
totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
*dcp->bits = curr_bits;
v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
map->class_names[cls_id]);
break;
case DD_CLASS_TYPE_LEVEL_NAMES:
/* cls_id = N in 0..max. wanted +/- determines N or N-1 */
old_bits = CLASSMAP_BITMASK(*dcp->lvl);
curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
*dcp->lvl = (cls_id + (wanted ? 1 : 0));
v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
map->class_names[cls_id], old_bits, curr_bits);
break;
default:
pr_err("illegal map-type value %d\n", map->map_type);
}
}
kfree(tmp);
vpr_info("total matches: %d\n", totct);
return 0;
}
/**
* 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)
{
const struct ddebug_class_param *dcp = kp->arg;
const struct ddebug_class_map *map = dcp->map;
unsigned long inrep, new_bits, old_bits;
int rc, totct = 0;
switch (map->map_type) {
case DD_CLASS_TYPE_DISJOINT_NAMES:
case DD_CLASS_TYPE_LEVEL_NAMES:
/* handle [+-]classnames list separately, we are done here */
return param_set_dyndbg_classnames(instr, kp);
case DD_CLASS_TYPE_DISJOINT_BITS:
case DD_CLASS_TYPE_LEVEL_NUM:
/* numeric input, accept and fall-thru */
rc = kstrtoul(instr, 0, &inrep);
if (rc) {
pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
return -EINVAL;
}
break;
default:
pr_err("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
return -EINVAL;
}
/* only _BITS,_NUM (numeric) map-types get here */
switch (map->map_type) {
case DD_CLASS_TYPE_DISJOINT_BITS:
/* expect bits. mask and warn if too many */
if (inrep & ~CLASSMAP_BITMASK(map->length)) {
pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
inrep &= CLASSMAP_BITMASK(map->length);
}
v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
*dcp->bits = inrep;
break;
case DD_CLASS_TYPE_LEVEL_NUM:
/* input is bitpos, of highest verbosity to be enabled */
if (inrep > map->length) {
pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
KP_NAME(kp), inrep, map->length);
inrep = map->length;
}
old_bits = CLASSMAP_BITMASK(*dcp->lvl);
new_bits = CLASSMAP_BITMASK(inrep);
v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
*dcp->lvl = inrep;
break;
default:
pr_warn("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
}
vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
return 0;
}
EXPORT_SYMBOL(param_set_dyndbg_classes);
/**
* 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)
{
const struct ddebug_class_param *dcp = kp->arg;
const struct ddebug_class_map *map = dcp->map;
switch (map->map_type) {
case DD_CLASS_TYPE_DISJOINT_NAMES:
case DD_CLASS_TYPE_DISJOINT_BITS:
return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
case DD_CLASS_TYPE_LEVEL_NAMES:
case DD_CLASS_TYPE_LEVEL_NUM:
return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
default:
return -1;
}
}
EXPORT_SYMBOL(param_get_dyndbg_classes);
const struct kernel_param_ops param_ops_dyndbg_classes = {
.set = param_set_dyndbg_classes,
.get = param_get_dyndbg_classes,
};
EXPORT_SYMBOL(param_ops_dyndbg_classes);
#define PREFIX_SIZE 64
static int remaining(int wrote)
{
if (PREFIX_SIZE - wrote > 0)
return PREFIX_SIZE - wrote;
return 0;
}
static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
{
int pos_after_tid;
int pos = 0;
if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
if (in_interrupt())
pos += snprintf(buf + pos, remaining(pos), "<intr> ");
else
pos += snprintf(buf + pos, remaining(pos), "[%d] ",
task_pid_vnr(current));
}
pos_after_tid = pos;
if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
pos += snprintf(buf + pos, remaining(pos), "%s:",
desc->modname);
if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
pos += snprintf(buf + pos, remaining(pos), "%s:",
desc->function);
if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
pos += snprintf(buf + pos, remaining(pos), "%d:",
desc->lineno);
if (pos - pos_after_tid)
pos += snprintf(buf + pos, remaining(pos), " ");
if (pos >= PREFIX_SIZE)
buf[PREFIX_SIZE - 1] = '\0';
return buf;
}
static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
{
if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))
return __dynamic_emit_prefix(desc, buf);
return buf;
}
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
{
va_list args;
struct va_format vaf;
char buf[PREFIX_SIZE] = "";
BUG_ON(!descriptor);
BUG_ON(!fmt);
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
va_end(args);
}
EXPORT_SYMBOL(__dynamic_pr_debug);
void __dynamic_dev_dbg(struct _ddebug *descriptor,
const struct device *dev, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
BUG_ON(!descriptor);
BUG_ON(!fmt);
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
if (!dev) {
printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
} else {
char buf[PREFIX_SIZE] = "";
dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
dynamic_emit_prefix(descriptor, buf),
dev_driver_string(dev), dev_name(dev),
&vaf);
}
va_end(args);
}
EXPORT_SYMBOL(__dynamic_dev_dbg);
#ifdef CONFIG_NET
void __dynamic_netdev_dbg(struct _ddebug *descriptor,
const struct net_device *dev, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
BUG_ON(!descriptor);
BUG_ON(!fmt);
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
if (dev && dev->dev.parent) {
char buf[PREFIX_SIZE] = "";
dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
"%s%s %s %s%s: %pV",
dynamic_emit_prefix(descriptor, buf),
dev_driver_string(dev->dev.parent),
dev_name(dev->dev.parent),
netdev_name(dev), netdev_reg_state(dev),
&vaf);
} else if (dev) {
printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
netdev_reg_state(dev), &vaf);
} else {
printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
}
va_end(args);
}
EXPORT_SYMBOL(__dynamic_netdev_dbg);
#endif
#if IS_ENABLED(CONFIG_INFINIBAND)
void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
const struct ib_device *ibdev, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
if (ibdev && ibdev->dev.parent) {
char buf[PREFIX_SIZE] = "";
dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
"%s%s %s %s: %pV",
dynamic_emit_prefix(descriptor, buf),
dev_driver_string(ibdev->dev.parent),
dev_name(ibdev->dev.parent),
dev_name(&ibdev->dev),
&vaf);
} else if (ibdev) {
printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
} else {
printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
}
va_end(args);
}
EXPORT_SYMBOL(__dynamic_ibdev_dbg);
#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)
{
return 1;
}
__setup("dyndbg=", dyndbg_setup);
/*
* File_ops->write method for <debugfs>/dynamic_debug/control. Gathers the
* command text from userspace, parses and executes it.
*/
#define USER_BUF_PAGE 4096
static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
size_t len, loff_t *offp)
{
char *tmpbuf;