diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 5 | ||||
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 15 | ||||
| -rw-r--r-- | include/linux/device.h | 2 | ||||
| -rw-r--r-- | include/linux/dynamic_debug.h | 88 | ||||
| -rw-r--r-- | include/linux/dynamic_printk.h | 93 | ||||
| -rw-r--r-- | include/linux/kernel.h | 4 | ||||
| -rw-r--r-- | kernel/module.c | 25 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 2 | ||||
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/dynamic_debug.c | 756 | ||||
| -rw-r--r-- | lib/dynamic_printk.c | 414 | ||||
| -rw-r--r-- | net/netfilter/nf_conntrack_pptp.c | 2 | ||||
| -rw-r--r-- | scripts/Makefile.lib | 2 |
13 files changed, 867 insertions, 543 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 54f21a5c262..3a1aa8a4aff 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1816,11 +1816,6 @@ and is between 256 and 4096 characters. It is defined in the file autoconfiguration. Ranges are in pairs (memory base and size). - dynamic_printk Enables pr_debug()/dev_dbg() calls if - CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. - These can also be switched on/off via - <debugfs>/dynamic_printk/modules - print-fatal-signals= [KNL] debug: print fatal signals print-fatal-signals=1: print segfault info to diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index c61fab1dd2f..aca40b93bd2 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -80,6 +80,11 @@ VMLINUX_SYMBOL(__start___tracepoints) = .; \ *(__tracepoints) \ VMLINUX_SYMBOL(__stop___tracepoints) = .; \ + /* implement dynamic printk debug */ \ + . = ALIGN(8); \ + VMLINUX_SYMBOL(__start___verbose) = .; \ + *(__verbose) \ + VMLINUX_SYMBOL(__stop___verbose) = .; \ LIKELY_PROFILE() \ BRANCH_PROFILE() @@ -309,15 +314,7 @@ CPU_DISCARD(init.data) \ CPU_DISCARD(init.rodata) \ MEM_DISCARD(init.data) \ - MEM_DISCARD(init.rodata) \ - /* implement dynamic printk debug */ \ - VMLINUX_SYMBOL(__start___verbose_strings) = .; \ - *(__verbose_strings) \ - VMLINUX_SYMBOL(__stop___verbose_strings) = .; \ - . = ALIGN(8); \ - VMLINUX_SYMBOL(__start___verbose) = .; \ - *(__verbose) \ - VMLINUX_SYMBOL(__stop___verbose) = .; + MEM_DISCARD(init.rodata) #define INIT_TEXT \ *(.init.text) \ diff --git a/include/linux/device.h b/include/linux/device.h index f98d0cfb4f8..2918c0e8fdf 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -582,7 +582,7 @@ extern const char *dev_driver_string(const struct device *dev); #if defined(DEBUG) #define dev_dbg(dev, format, arg...) \ dev_printk(KERN_DEBUG , dev , format , ## arg) -#elif defined(CONFIG_DYNAMIC_PRINTK_DEBUG) +#elif defined(CONFIG_DYNAMIC_DEBUG) #define dev_dbg(dev, format, ...) do { \ dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \ } while (0) diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h new file mode 100644 index 00000000000..07781aaa116 --- /dev/null +++ b/include/linux/dynamic_debug.h @@ -0,0 +1,88 @@ +#ifndef _DYNAMIC_DEBUG_H +#define _DYNAMIC_DEBUG_H + +/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which + * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They + * use independent hash functions, to reduce the chance of false positives. + */ +extern long long dynamic_debug_enabled; +extern long long dynamic_debug_enabled2; + +/* + * 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; + char primary_hash; + char secondary_hash; + unsigned int lineno:24; + /* + * The flags field controls the behaviour at the callsite. + * The bits here are changed dynamically when the user + * writes commands to <debugfs>/dynamic_debug/ddebug + */ +#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */ +#define _DPRINTK_FLAGS_DEFAULT 0 + unsigned int flags:8; +} __attribute__((aligned(8))); + + +int ddebug_add_module(struct _ddebug *tab, unsigned int n, + const char *modname); + +#if defined(CONFIG_DYNAMIC_DEBUG) +extern int ddebug_remove_module(char *mod_name); + +#define __dynamic_dbg_enabled(dd) ({ \ + int __ret = 0; \ + if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) && \ + (dynamic_debug_enabled2 & (1LL << DEBUG_HASH2)))) \ + if (unlikely(dd.flags)) \ + __ret = 1; \ + __ret; }) + +#define dynamic_pr_debug(fmt, ...) do { \ + static struct _ddebug descriptor \ + __used \ + __attribute__((section("__verbose"), aligned(8))) = \ + { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ + DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ + if (__dynamic_dbg_enabled(descriptor)) \ + printk(KERN_DEBUG KBUILD_MODNAME ":" fmt, \ + ##__VA_ARGS__); \ + } while (0) + + +#define dynamic_dev_dbg(dev, fmt, ...) do { \ + static struct _ddebug descriptor \ + __used \ + __attribute__((section("__verbose"), aligned(8))) = \ + { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ + DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ + if (__dynamic_dbg_enabled(descriptor)) \ + dev_printk(KERN_DEBUG, dev, \ + KBUILD_MODNAME ": " fmt, \ + ##__VA_ARGS__); \ + } while (0) + +#else + +static inline int ddebug_remove_module(char *mod) +{ + return 0; +} + +#define dynamic_pr_debug(fmt, ...) do { } while (0) +#define dynamic_dev_dbg(dev, format, ...) do { } while (0) +#endif + +#endif diff --git a/include/linux/dynamic_printk.h b/include/linux/dynamic_printk.h deleted file mode 100644 index 2d528d00907..00000000000 --- a/include/linux/dynamic_printk.h +++ /dev/null @@ -1,93 +0,0 @@ -#ifndef _DYNAMIC_PRINTK_H -#define _DYNAMIC_PRINTK_H - -#define DYNAMIC_DEBUG_HASH_BITS 6 -#define DEBUG_HASH_TABLE_SIZE (1 << DYNAMIC_DEBUG_HASH_BITS) - -#define TYPE_BOOLEAN 1 - -#define DYNAMIC_ENABLED_ALL 0 -#define DYNAMIC_ENABLED_NONE 1 -#define DYNAMIC_ENABLED_SOME 2 - -extern int dynamic_enabled; - -/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which - * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They - * use independent hash functions, to reduce the chance of false positives. - */ -extern long long dynamic_printk_enabled; -extern long long dynamic_printk_enabled2; - -struct mod_debug { - char *modname; - char *logical_modname; - char *flag_names; - int type; - int hash; - int hash2; -} __attribute__((aligned(8))); - -int register_dynamic_debug_module(char *mod_name, int type, char *share_name, - char *flags, int hash, int hash2); - -#if defined(CONFIG_DYNAMIC_PRINTK_DEBUG) -extern int unregister_dynamic_debug_module(char *mod_name); -extern int __dynamic_dbg_enabled_helper(char *modname, int type, - int value, int hash); - -#define __dynamic_dbg_enabled(module, type, value, level, hash) ({ \ - int __ret = 0; \ - if (unlikely((dynamic_printk_enabled & (1LL << DEBUG_HASH)) && \ - (dynamic_printk_enabled2 & (1LL << DEBUG_HASH2)))) \ - __ret = __dynamic_dbg_enabled_helper(module, type, \ - value, hash);\ - __ret; }) - -#define dynamic_pr_debug(fmt, ...) do { \ - static char mod_name[] \ - __attribute__((section("__verbose_strings"))) \ - = KBUILD_MODNAME; \ - static struct mod_debug descriptor \ - __used \ - __attribute__((section("__verbose"), aligned(8))) = \ - { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\ - if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \ - 0, 0, DEBUG_HASH)) \ - printk(KERN_DEBUG KBUILD_MODNAME ":" fmt, \ - ##__VA_ARGS__); \ - } while (0) - -#define dynamic_dev_dbg(dev, format, ...) do { \ - static char mod_name[] \ - __attribute__((section("__verbose_strings"))) \ - = KBUILD_MODNAME; \ - static struct mod_debug descriptor \ - __used \ - __attribute__((section("__verbose"), aligned(8))) = \ - { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\ - if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \ - 0, 0, DEBUG_HASH)) \ - dev_printk(KERN_DEBUG, dev, \ - KBUILD_MODNAME ": " format, \ - ##__VA_ARGS__); \ - } while (0) - -#else - -static inline int unregister_dynamic_debug_module(const char *mod_name) -{ - return 0; -} -static inline int __dynamic_dbg_enabled_helper(char *modname, int type, - int value, int hash) -{ - return 0; -} - -#define __dynamic_dbg_enabled(module, type, value, level, hash) ({ 0; }) -#define dynamic_pr_debug(fmt, ...) do { } while (0) -#define dynamic_dev_dbg(dev, format, ...) do { } while (0) -#endif - -#endif diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 7fa371898e3..b5496ecbec7 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -16,7 +16,7 @@ #include <linux/log2.h> #include <linux/typecheck.h> #include <linux/ratelimit.h> -#include <linux/dynamic_printk.h> +#include <linux/dynamic_debug.h> #include <asm/byteorder.h> #include <asm/bug.h> @@ -358,7 +358,7 @@ static inline char *pack_hex_byte(char *buf, u8 byte) #if defined(DEBUG) #define pr_debug(fmt, ...) \ printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) -#elif defined(CONFIG_DYNAMIC_PRINTK_DEBUG) +#elif defined(CONFIG_DYNAMIC_DEBUG) #define pr_debug(fmt, ...) do { \ dynamic_pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ } while (0) diff --git a/kernel/module.c b/kernel/module.c index 1196f5d1170..77672233387 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -822,7 +822,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, mutex_lock(&module_mutex); /* Store the name of the last unloaded module for diagnostic purposes */ strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); - unregister_dynamic_debug_module(mod->name); + ddebug_remove_module(mod->name); free_module(mod); out: @@ -1827,19 +1827,13 @@ static inline void add_kallsyms(struct module *mod, } #endif /* CONFIG_KALLSYMS */ -static void dynamic_printk_setup(struct mod_debug *debug, unsigned int num) +static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num) { -#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG - unsigned int i; - - for (i = 0; i < num; i++) { - register_dynamic_debug_module(debug[i].modname, - debug[i].type, - debug[i].logical_modname, - debug[i].flag_names, - debug[i].hash, debug[i].hash2); - } -#endif /* CONFIG_DYNAMIC_PRINTK_DEBUG */ +#ifdef CONFIG_DYNAMIC_DEBUG + if (ddebug_add_module(debug, num, debug->modname)) + printk(KERN_ERR "dynamic debug error adding module: %s\n", + debug->modname); +#endif } static void *module_alloc_update_bounds(unsigned long size) @@ -2213,12 +2207,13 @@ static noinline struct module *load_module(void __user *umod, add_kallsyms(mod, sechdrs, symindex, strindex, secstrings); if (!mod->taints) { - struct mod_debug *debug; + struct _ddebug *debug; unsigned int num_debug; debug = section_objs(hdr, sechdrs, secstrings, "__verbose", sizeof(*debug), &num_debug); - dynamic_printk_setup(debug, num_debug); + if (debug) + dynamic_debug_setup(debug, num_debug); } /* sechdrs[0].sh_size is always zero */ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1bcf9cd4baa..0dd1c04c732 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -847,7 +847,7 @@ config BUILD_DOCSRC Say N if you are unsure. -config DYNAMIC_PRINTK_DEBUG +config DYNAMIC_DEBUG bool "Enable dynamic printk() call support" default n depends on PRINTK diff --git a/lib/Makefile b/lib/Makefile index 32b0e64ded2..8633d6be9d2 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -82,7 +82,7 @@ obj-$(CONFIG_HAVE_LMB) += lmb.o obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o -obj-$(CONFIG_DYNAMIC_PRINTK_DEBUG) += dynamic_printk.o +obj-$(CONFIG_DYNAMIC_DEBUG) += dynamic_debug.o hostprogs-y := gen_crc32table clean-files := crc32table.h diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c new file mode 100644 index 00000000000..9e123ae326b --- /dev/null +++ b/lib/dynamic_debug.c @@ -0,0 +1,756 @@ +/* + * 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. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/kallsyms.h> +#include <linux/version.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/uaccess.h> +#include <linux/dynamic_debug.h> +#include <linux/debugfs.h> + +extern struct _ddebug __start___verbose[]; +extern struct _ddebug __stop___verbose[]; + +/* dynamic_debug_enabled, and dynamic_debug_enabled2 are bitmasks in which + * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They + * use independent hash functions, to reduce the chance of false positives. + */ +long long dynamic_debug_enabled; +EXPORT_SYMBOL_GPL(dynamic_debug_enabled); +long long dynamic_debug_enabled2; +EXPORT_SYMBOL_GPL(dynamic_debug_enabled2); + +struct ddebug_table { + struct list_head link; + char *mod_name; + unsigned int num_ddebugs; + unsigned int num_enabled; + 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; +}; + +static DEFINE_MUTEX(ddebug_lock); +static LIST_HEAD(ddebug_tables); +static int verbose = 0; + +/* Return the last part of a pathname */ +static inline const char *basename(const char *path) +{ + const char *tail = strrchr(path, '/'); + return tail ? tail+1 : path; +} + +/* format a string into buf[] which describes the _ddebug's flags */ +static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, + size_t maxlen) +{ + char *p = buf; + + BUG_ON(maxlen < 4); + if (dp->flags & _DPRINTK_FLAGS_PRINT) + *p++ = 'p'; + if (p == buf) + *p++ = '-'; + *p = '\0'; + + return buf; +} + +/* + * must be called with ddebug_lock held + */ + +static int disabled_hash(char hash, bool first_table) +{ + struct ddebug_table *dt; + char table_hash_value; + + list_for_each_entry(dt, &ddebug_tables, link) { + if (first_table) + table_hash_value = dt->ddebugs->primary_hash; + else + table_hash_value = dt->ddebugs->secondary_hash; + if (dt->num_enabled && (hash == table_hash_value)) + return 0; + } + return 1; +} + +/* + * Search the tables for _ddebug's which match the given + * `query' and apply the `flags' and `mask' to them. Tells + * the user which ddebug's were changed, or whether none + * were matched. + */ +static void ddebug_change(const struct ddebug_query *query, + unsigned int flags, unsigned int mask) +{ + int i; + struct ddebug_table *dt; + unsigned int newflags; + unsigned int nfound = 0; + char flagbuf[8]; + + /* search for matching ddebugs */ + mutex_lock(&ddebug_lock); + list_for_each_entry(dt, &ddebug_tables, link) { + + /* match against the module name */ + if (query->module != NULL && + strcmp(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 != NULL && + strcmp(query->filename, dp->filename) && + strcmp(query->filename, basename(dp->filename))) + continue; + + /* match against the function */ + if (query->function != NULL && + strcmp(query->function, dp->function)) + continue; + + /* match against the format */ + if (query->format != NULL && + strstr(dp->format, query->format) == NULL) + 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 & mask) | flags; + if (newflags == dp->flags) + continue; + + if (!newflags) + dt->num_enabled--; + else if (!dp-flags) + dt->num_enabled++; + dp->flags = newflags; + if (newflags) { + dynamic_debug_enabled |= + (1LL << dp->primary_hash); + dynamic_debug_enabled2 |= + (1LL << dp->secondary_hash); + } else { + if (disabled_hash(dp->primary_hash, true)) + dynamic_debug_enabled &= + ~(1LL << dp->primary_hash); + if (disabled_hash(dp->secondary_hash, false)) + dynamic_debug_enabled2 &= + ~(1LL << dp->secondary_hash); + } + if (verbose) + printk(KERN_INFO + "ddebug: changed %s:%d [%s]%s %s\n", + dp->filename, dp->lineno, + dt->mod_name, dp->function, + ddebug_describe_flags(dp, flagbuf, + sizeof(flagbuf))); + } + } + mutex_unlock(&ddebug_lock); + + if (!nfound && verbose) + printk(KERN_INFO "ddebug: no matches for query\n"); +} + +/* + * Wrapper around strsep() to collapse the multiple empty tokens + * that it returns when fed sequences of separator characters. + * Now, if we had strtok_r()... + */ +static inline char *nearly_strtok_r(char **p, const char *sep) +{ + char *r; + + while ((r = strsep(p, sep)) != NULL && *r == '\0') + ; + return r; +} + +/* + * Split the buffer `buf' into space-separated words. + * Return the number of such words or <0 on error. + */ +static int ddebug_tokenize(char *buf, char *words[], int maxwords) +{ + int nwords = 0; + + while (nwords < maxwords && + (words[nwords] = nearly_strtok_r(&buf, " \t\r\n")) != NULL) + nwords++; + if (buf) + return -EINVAL; /* ran out of words[] before bytes */ + + if (verbose) { + int i; + printk(KERN_INFO "%s: split into words:", __func__); + for (i = 0 ; i < nwords ; i++) + printk(" \"%s\"", words[i]); + printk("\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) +{ + char *end = NULL; + BUG_ON(str == NULL); + if (*str == '\0') { + *val = 0; + return 0; + } + *val = simple_strtoul(str, &end, 10); + return end == NULL || end == str || *end != '\0' ? -EINVAL : 0; +} + +/* + * Undo octal escaping in a string, inplace. This is useful to + * allow the user to express a query which matches a format + * containing embedded spaces. + */ +#define isodigit(c) ((c) >= '0' && (c) <= '7') +static char *unescape(char *str) +{ + char *in = str; + char *out = str; + + while (*in) { + if (*in == '\\') { + if (in[1] == '\\') { + *out++ = '\\'; + in += 2; + continue; + } else if (in[1] == 't') { + *out++ = '\t'; + in += 2; + continue; + } else if (in[1] == 'n') { + *out++ = '\n'; + in += 2; + continue; + } else if (isodigit(in[1]) && + isodigit(in[2]) && + isodigit(in[3])) { + *out++ = ((in[1] - '0')<<6) | + ((in[2] - '0')<<3) | + (in[3] - '0'); + in += 4; + continue; + } + } + *out++ = *in++; + } + *out = '\0'; + + return str; +} + +/* + * 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 + */ +static int ddebug_parse_query(char *words[], int nwords, + struct ddebug_query *query) +{ + unsigned int i; + + /* check we have an even number of words */ + if (nwords % 2 != 0) + return -EINVAL; + memset(query, 0, sizeof(*query)); + + for (i = 0 ; i < nwords ; i += 2) { + if (!strcmp(words[i], "func")) + query->function = words[i+1]; + else if (!strcmp(words[i], "file")) + query->filename = words[i+1]; + else if (!strcmp(words[i], "module")) + query->module = words[i+1]; + else if (!strcmp(words[i], "format")) + query->format = unescape(words[i+1]); + else if (!strcmp(words[i], "line")) { + char *first = words[i+1]; + char *last = strchr(first, '-'); + if (last) + *last++ = '\0'; + if (parse_lineno(first, &query->first_lineno) < 0) + return -EINVAL; + if (last != NULL) { + /* range <first>-<last> */ + if (parse_lineno(last, &query->last_lineno) < 0) + return -EINVAL; + } else { + query->last_lineno = query->first_lineno; + } + } else { + if (verbose) + printk(KERN_ERR "%s: unknown keyword \"%s\"\n", + __func__, words[i]); + return -EINVAL; + } + } + + if (verbose) + printk(KERN_INFO "%s: q->function=\"%s\" q->filename=\"%s\" " + "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n", + __func__, query->function, query->filename, + query->module, query->format, query->first_lineno, + query->last_lineno); + + 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, unsigned int *flagsp, + unsigned int *maskp) +{ + unsigned flags = 0; + int op = '='; + + switch (*str) { + case '+': + case '-': + case '=': + op = *str++; + break; + default: + return -EINVAL; + } + if (verbose) + printk(KERN_INFO "%s: op='%c'\n", __func__, op); + + for ( ; *str ; ++str) { + switch (*str) { + case 'p': + flags |= _DPRINTK_FLAGS_PRINT; + break; + default: + return -EINVAL; + } + } + if (flags == 0) + return -EINVAL; + if (verbose) + printk(KERN_INFO "%s: flags=0x%x\n", __func__, flags); + + /* calculate final *flagsp, *maskp according to mask and op */ + switch (op) { + case '=': + *maskp = 0; + *flagsp = flags; + break; + case '+': + *maskp = ~0U; + *flagsp = flags; + break; + case '-': + *maskp = ~flags; + *flagsp = 0; + break; + } + if (verbose) + printk(KERN_INFO "%s: *flagsp=0x%x *maskp=0x%x\n", + __func__, *flagsp, *maskp); + return 0; +} + +/* + * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the + * command text from userspace, parses and executes it. + */ +static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, + size_t len, loff_t *offp) +{ + unsigned int flags = 0, mask = 0; + struct ddebug_query query; +#define MAXWORDS 9 + int nwords; + char *words[MAXWORDS]; + char tmpbuf[256]; + + if (len == 0) + return 0; + /* we don't check *offp -- multiple writes() are allowed */ + if (len > sizeof(tmpbuf)-1) + return -E2BIG; + if (copy_from_user(tmpbuf, ubuf, len)) + return -EFAULT; + tmpbuf[len] = '\0'; + if (verbose) + printk(KERN_INFO "%s: read %d bytes from userspace\n", + __func__, (int)len); + + nwords = ddebug_tokenize(tmpbuf, words, MAXWORDS); + if (nwords < 0) + return -EINVAL; + if (ddebug_parse_query(words, nwords-1, &query)) + return -EINVAL; + if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) + return -EINVAL; + + /* actually go and implement the change */ + ddebug_change(&query, flags, mask); + + *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; + + if (verbose) + printk(KERN_INFO "%s: called m=%p *pos=%lld\n", + __func__, m, (unsigned long long)*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 (verbose) + printk(KERN_INFO "%s: called m=%p p=%p *pos=%lld\n", + __func__, m, p, (unsigned long long)*pos); + + 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; + char flagsbuf[8]; + + if (verbose) + printk(KERN_INFO "%s: called m=%p p=%p\n", + __func__, m, p); + + 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 \"", + dp->filename, dp->lineno, + iter->table->mod_name, dp->function, + ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf))); + 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) +{ + if (verbose) + printk(KERN_INFO "%s: called m=%p p=%p\n", + __func__, m, 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 +}; + +/* + * File_ops->open method for <debugfs>/dynamic_debug/control. Does the seq_file + * setup dance, and also creates an iterator to walk the _ddebugs. + * Note that we create a seq_file always, even for O_WRONLY files + * where it's not needed, as doing so simplifies the ->release method. + */ +static int ddebug_proc_open(struct inode *inode, struct file *file) +{ + struct ddebug_iter *iter; + int err; + + if (verbose) + printk(KERN_INFO "%s: called\n", __func__); + + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (iter == NULL) + return -ENOMEM; + + err = seq_open(file, &ddebug_proc_seqops); + if (err) { + kfree(iter); + return err; + } + ((struct seq_file *) file->private_data)->private = iter; + return 0; +} + +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 +}; + +/* + * 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; + char *new_name; + + dt = kzalloc(sizeof(*dt), GFP_KERNEL); + if (dt == NULL) + return -ENOMEM; + new_name = kstrdup(name, GFP_KERNEL); + if (new_name == NULL) { + kfree(dt); + return -ENOMEM; + } + dt->mod_name = new_name; + dt->num_ddebugs = n; + dt->num_enabled = 0; + dt->ddebugs = tab; + + mutex_lock(&ddebug_lock); + list_add_tail(&dt->link, &ddebug_tables); + mutex_unlock(&ddebug_lock); + + if (verbose) + printk(KERN_INFO "%u debug prints in module %s\n", + n, dt->mod_name); + return 0; +} +EXPORT_SYMBOL_GPL(ddebug_add_module); + +static void ddebug_table_free(struct ddebug_table *dt) +{ + list_del_init(&dt->link); + kfree(dt->mod_name); + kfree(dt); +} + +/* + * Called in response to a module being unloaded. Removes + * any ddebug_table's which point at the module. + */ +int ddebug_remove_module(char *mod_name) +{ + struct ddebug_table *dt, *nextdt; + int ret = -ENOENT; + + if (verbose) + printk(KERN_INFO "%s: removing module \"%s\"\n", + __func__, mod_name); + + mutex_lock(&ddebug_lock); + list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) { + if (!strcmp(dt->mod_name, mod_name)) { + ddebug_table_free(dt); + ret = 0; + } + } + mutex_unlock(&ddebug_lock); + return ret; +} +EXPORT_SYMBOL_GPL(ddebug_remove_module); + +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); +} |