diff options
Diffstat (limited to 'lib/dynamic_debug.c')
| -rw-r--r-- | lib/dynamic_debug.c | 1127 |
1 files changed, 1127 insertions, 0 deletions
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c new file mode 100644 index 000000000..10a50c030 --- /dev/null +++ b/lib/dynamic_debug.c @@ -0,0 +1,1127 @@ +/* + * lib/dynamic_debug.c + * + * make pr_debug()/dev_dbg() calls runtime configurable based upon their + * source module. + * + * Copyright (C) 2008 Jason Baron <jbaron@redhat.com> + * By Greg Banks <gnb@melbourne.sgi.com> + * Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved. + * Copyright (C) 2011 Bart Van Assche. All Rights Reserved. + * Copyright (C) 2013 Du, Changbin <changbin.du@gmail.com> + */ + +#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[]; + +struct ddebug_table { + struct list_head link; + 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; + unsigned int first_lineno, last_lineno; +}; + +struct ddebug_iter { + struct ddebug_table *table; + unsigned 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); + +/* 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__) + +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--; + } + + vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n", + msg, + query->function ?: "", + query->filename ?: "", + query->module ?: "", + fmtlen, query->format ?: "", + query->first_lineno, query->last_lineno); +} + +/* + * 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; + + /* 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; + + for (i = 0; i < dt->num_ddebugs; i++) { + struct _ddebug *dp = &dt->ddebugs[i]; + + /* 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 + dp->flags = newflags; + v2pr_info("changed %s:%d [%s]%s =%s\n", + trim_prefix(dp->filename), dp->lineno, + dt->mod_name, dp->function, + ddebug_describe_flags(dp->flags, &fbuf)); + } + } + 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) { + 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; + } + vpr_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 { + 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; + } + vpr_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; + } + } + vpr_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; + } + vpr_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\"\n", i, query); + + rc = ddebug_exec_query(query, modname); + if (rc < 0) { + errs++; + exitcode = rc; + } else { + nfound += rc; + } + i++; + } + vpr_info("processed %d queries, with %d matches, %d errs\n", + i, nfound, errs); + + if (exitcode) + return exitcode; + return nfound; +} + +#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; + + *buf = '\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; +} + +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 + +#define DDEBUG_STRING_SIZE 1024 +static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE]; + +static __init int ddebug_setup_query(char *str) +{ + if (strlen(str) >= DDEBUG_STRING_SIZE) { + pr_warn("ddebug boot param string too large\n"); + return 0; + } + strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE); + return 1; +} + +__setup("ddebug_query=", ddebug_setup_query); + +/* + * 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; + int ret; + + if (len == 0) + return 0; + if (len > USER_BUF_PAGE - 1) { + pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE); + return -E2BIG; + } + tmpbuf = memdup_user_nul(ubuf, len); + if (IS_ERR(tmpbuf)) + return PTR_ERR(tmpbuf); + vpr_info("read %d bytes from userspace\n", (int)len); + + ret = ddebug_exec_queries(tmpbuf, NULL); + kfree(tmpbuf); + if (ret < 0) + return ret; + + *offp += len; + return len; +} + +/* + * 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) +{ + if (list_empty(&ddebug_tables)) { + iter->table = NULL; + iter->idx = 0; + return NULL; + } + iter->table = list_entry(ddebug_tables.next, + struct ddebug_table, link); + iter->idx = 0; + return &iter->table->ddebugs[iter->idx]; +} + +/* + * 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) +{ + if (iter->table == NULL) + return NULL; + if (++iter->idx == iter->table->num_ddebugs) { + /* iterate to next table */ + iter->idx = 0; + if (list_is_last(&iter->table->link, &ddebug_tables)) { + iter->table = NULL; + return NULL; + } + iter->table = list_entry(iter->table->link.next, + struct ddebug_table, link); + } + return &iter->table->ddebugs[iter->idx]; +} + +/* + * 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) +{ + struct ddebug_iter *iter = m->private; + struct _ddebug *dp; + int n = *pos; + + mutex_lock(&ddebug_lock); + + if (!n) + return SEQ_START_TOKEN; + if (n < 0) + return NULL; + dp = ddebug_iter_first(iter); + while (dp != NULL && --n > 0) + dp = ddebug_iter_next(iter); + return dp; +} + +/* + * 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) +{ + struct ddebug_iter *iter = m->private; + struct _ddebug *dp; + + if (p == SEQ_START_TOKEN) + dp = ddebug_iter_first(iter); + else + dp = ddebug_iter_next(iter); + ++*pos; + return 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) +{ + struct ddebug_iter *iter = m->private; + struct _ddebug *dp = p; + struct flagsbuf flags; + + if (p == SEQ_START_TOKEN) { + seq_puts(m, + "# filename:lineno [module]function flags format\n"); + return 0; + } + + seq_printf(m, "%s:%u [%s]%s =%s \"", + trim_prefix(dp->filename), dp->lineno, + iter->table->mod_name, dp->function, + ddebug_describe_flags(dp->flags, &flags)); + seq_escape(m, dp->format, "\t\r\n\""); + seq_puts(m, "\"\n"); + + return 0; +} + +/* + * 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) +{ + mutex_unlock(&ddebug_lock); +} + +static const struct seq_operations ddebug_proc_seqops = { + .start = ddebug_proc_start, + .next = ddebug_proc_next, + .show = ddebug_proc_show, + .stop = ddebug_proc_stop +}; + +static int ddebug_proc_open(struct inode *inode, struct file *file) +{ + vpr_info("called\n"); + return seq_open_private(file, &ddebug_proc_seqops, + sizeof(struct ddebug_iter)); +} + +static const struct file_operations ddebug_proc_fops = { + .owner = THIS_MODULE, + .open = ddebug_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, + .write = ddebug_proc_write +}; + +static const struct proc_ops proc_fops = { + .proc_open = ddebug_proc_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = seq_release_private, + .proc_write = ddebug_proc_write +}; + +/* + * Allocate a new ddebug_table for the given module + * and add it to the global list. + */ +int ddebug_add_module(struct _ddebug *tab, unsigned int n, + const char *name) +{ + struct ddebug_table *dt; + + dt = kzalloc(sizeof(*dt), GFP_KERNEL); + if (dt == NULL) { + pr_err("error adding module: %s\n", name); + return -ENOMEM; + } + /* + * For built-in modules, name lives in .rodata and is + * immortal. For loaded modules, name points at the name[] + * member of struct module, which lives at least as long as + * this struct ddebug_table. + */ + dt->mod_name = name; + dt->num_ddebugs = n; + dt->ddebugs = tab; + + mutex_lock(&ddebug_lock); + list_add(&dt->link, &ddebug_tables); + mutex_unlock(&ddebug_lock); + + v2pr_info("%3u debug prints in module %s\n", n, dt->mod_name); + return 0; +} + +/* helper for ddebug_dyndbg_(boot|module)_param_cb */ +static int ddebug_dyndbg_param_cb(char *param, char *val, + const char *modname, int on_err) +{ + char *sep; + + sep = strchr(param, '.'); + if (sep) { + /* needed only for ddebug_dyndbg_boot_param_cb */ + *sep = '\0'; + modname = param; + param = sep + 1; + } + if (strcmp(param, "dyndbg")) + return on_err; /* determined by caller */ + + ddebug_exec_queries((val ? val : "+p"), modname); + + return 0; /* query failure shouldnt stop module load */ +} + +/* 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) +{ + vpr_info("%s=\"%s\"\n", param, val); + return ddebug_dyndbg_param_cb(param, val, NULL, 0); +} + +/* + * 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) +{ + vpr_info("module: %s %s=\"%s\"\n", module, param, val); + return ddebug_dyndbg_param_cb(param, val, module, -ENOENT); +} + +static void ddebug_table_free(struct ddebug_table *dt) +{ + list_del_init(&dt->link); + kfree(dt); +} + +/* + * Called in response to a module being unloaded. Removes + * any ddebug_table's which point at the module. + */ +int ddebug_remove_module(const char *mod_name) +{ + struct ddebug_table *dt, *nextdt; + int ret = -ENOENT; + + v2pr_info("removing module \"%s\"\n", mod_name); + + mutex_lock(&ddebug_lock); + list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) { + if (dt->mod_name == mod_name) { + ddebug_table_free(dt); + ret = 0; + break; + } + } + mutex_unlock(&ddebug_lock); + return ret; +} + +static void ddebug_remove_all_tables(void) +{ + mutex_lock(&ddebug_lock); + while (!list_empty(&ddebug_tables)) { + struct ddebug_table *dt = list_entry(ddebug_tables.next, + struct ddebug_table, + link); + ddebug_table_free(dt); + } + mutex_unlock(&ddebug_lock); +} + +static __initdata int ddebug_init_success; + +static int __init dynamic_debug_init_control(void) +{ + struct proc_dir_entry *procfs_dir; + struct dentry *debugfs_dir; + + if (!ddebug_init_success) + return -ENODEV; + + /* Create the control file in debugfs if it is enabled */ + if (debugfs_initialized()) { + debugfs_dir = debugfs_create_dir("dynamic_debug", NULL); + debugfs_create_file("control", 0644, debugfs_dir, NULL, + &ddebug_proc_fops); + } + + /* Also create the control file in procfs */ + procfs_dir = proc_mkdir("dynamic_debug", NULL); + if (procfs_dir) + proc_create("control", 0644, procfs_dir, &proc_fops); + + return 0; +} + +static int __init dynamic_debug_init(void) +{ + struct _ddebug *iter, *iter_start; + const char *modname = NULL; + char *cmdline; + int ret = 0; + int n = 0, entries = 0, modct = 0; + + if (&__start___dyndbg == &__stop___dyndbg) { + if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) { + pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n"); + return 1; + } + pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n"); + ddebug_init_success = 1; + return 0; + } + iter = __start___dyndbg; + modname = iter->modname; + iter_start = iter; + for (; iter < __stop___dyndbg; iter++) { + entries++; + if (strcmp(modname, iter->modname)) { + modct++; + ret = ddebug_add_module(iter_start, n, modname); + if (ret) + goto out_err; + n = 0; + modname = iter->modname; + iter_start = iter; + } + n++; + } + ret = ddebug_add_module(iter_start, n, modname); + if (ret) + goto out_err; + + ddebug_init_success = 1; + vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in __dyndbg section\n", + modct, entries, (int)(modct * sizeof(struct ddebug_table)), + (int)(entries * sizeof(struct _ddebug))); + + /* apply ddebug_query boot param, dont unload tables on err */ + if (ddebug_setup_string[0] != '\0') { + pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n"); + ret = ddebug_exec_queries(ddebug_setup_string, NULL); + if (ret < 0) + pr_warn("Invalid ddebug boot param %s\n", + ddebug_setup_string); + else + pr_info("%d changes by ddebug_query\n", ret); + } + /* now that ddebug tables are loaded, process all boot args + * again to find and activate queries given in dyndbg params. + * While this has already been done for known boot params, it + * ignored the unknown ones (dyndbg in particular). Reusing + * parse_args avoids ad-hoc parsing. This will also attempt + * to activate queries for not-yet-loaded modules, which is + * slightly noisy if verbose, but harmless. + */ + cmdline = kstrdup(saved_command_line, GFP_KERNEL); + parse_args("dyndbg params", cmdline, NULL, + 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb); + kfree(cmdline); + return 0; + +out_err: + ddebug_remove_all_tables(); + return 0; +} +/* 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); |