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[71.234.172.214]) by smtp.gmail.com with ESMTPSA id s64-v6sm5443004qkl.85.2018.05.18.00.50.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 18 May 2018 00:50:25 -0700 (PDT) From: Kent Overstreet To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Kent Overstreet , Andrew Morton , Dave Chinner , darrick.wong@oracle.com, tytso@mit.edu, linux-btrfs@vger.kernel.org, clm@fb.com, jbacik@fb.com, viro@zeniv.linux.org.uk, willy@infradead.org, peterz@infradead.org Subject: [PATCH 10/10] Dynamic fault injection Date: Fri, 18 May 2018 03:49:18 -0400 Message-Id: <20180518074918.13816-21-kent.overstreet@gmail.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180518074918.13816-1-kent.overstreet@gmail.com> References: <20180518074918.13816-1-kent.overstreet@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Kent Overstreet --- include/asm-generic/vmlinux.lds.h | 4 + include/linux/dynamic_fault.h | 117 +++++ lib/Kconfig.debug | 5 + lib/Makefile | 2 + lib/dynamic_fault.c | 760 ++++++++++++++++++++++++++++++ 5 files changed, 888 insertions(+) create mode 100644 include/linux/dynamic_fault.h create mode 100644 lib/dynamic_fault.c diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 1ab0e520d6..a4c9dfcbbd 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -246,6 +246,10 @@ VMLINUX_SYMBOL(__start___verbose) = .; \ KEEP(*(__verbose)) \ VMLINUX_SYMBOL(__stop___verbose) = .; \ + . = ALIGN(8); \ + VMLINUX_SYMBOL(__start___faults) = .; \ + *(__faults) \ + VMLINUX_SYMBOL(__stop___faults) = .; \ LIKELY_PROFILE() \ BRANCH_PROFILE() \ TRACE_PRINTKS() \ diff --git a/include/linux/dynamic_fault.h b/include/linux/dynamic_fault.h new file mode 100644 index 0000000000..6e7bb56ae8 --- /dev/null +++ b/include/linux/dynamic_fault.h @@ -0,0 +1,117 @@ +#ifndef _DYNAMIC_FAULT_H +#define _DYNAMIC_FAULT_H + +#include +#include +#include + +enum dfault_enabled { + DFAULT_DISABLED, + DFAULT_ENABLED, + DFAULT_ONESHOT, +}; + +union dfault_state { + struct { + unsigned enabled:2; + unsigned count:30; + }; + + struct { + unsigned v; + }; +}; + +/* + * An instance of this structure is created in a special + * ELF section at every dynamic fault callsite. At runtime, + * the special section is treated as an array of these. + */ +struct _dfault { + const char *modname; + const char *function; + const char *filename; + const char *class; + + const u16 line; + + unsigned frequency; + union dfault_state state; + + struct static_key enabled; +} __aligned(8); + + +#ifdef CONFIG_DYNAMIC_FAULT + +int dfault_add_module(struct _dfault *tab, unsigned int n, const char *mod); +int dfault_remove_module(char *mod_name); +bool __dynamic_fault_enabled(struct _dfault *); + +#define dynamic_fault(_class) \ +({ \ + static struct _dfault descriptor \ + __used __aligned(8) __attribute__((section("__faults"))) = { \ + .modname = KBUILD_MODNAME, \ + .function = __func__, \ + .filename = __FILE__, \ + .line = __LINE__, \ + .class = _class, \ + }; \ + \ + static_key_false(&descriptor.enabled) && \ + __dynamic_fault_enabled(&descriptor); \ +}) + +#define memory_fault() dynamic_fault("memory") +#define race_fault() dynamic_fault("race") + +#define kmalloc(...) \ + (memory_fault() ? NULL : kmalloc(__VA_ARGS__)) +#define kzalloc(...) \ + (memory_fault() ? NULL : kzalloc(__VA_ARGS__)) +#define krealloc(...) \ + (memory_fault() ? NULL : krealloc(__VA_ARGS__)) + +#define mempool_alloc(pool, gfp_mask) \ + ((!gfpflags_allow_blocking(gfp_mask) && memory_fault()) \ + ? NULL : mempool_alloc(pool, gfp_mask)) + +#define __get_free_pages(...) \ + (memory_fault() ? 0 : __get_free_pages(__VA_ARGS__)) +#define alloc_pages_node(...) \ + (memory_fault() ? NULL : alloc_pages_node(__VA_ARGS__)) +#define alloc_pages_nodemask(...) \ + (memory_fault() ? NULL : alloc_pages_nodemask(__VA_ARGS__)) + +#define bio_alloc_bioset(gfp_mask, ...) \ + ((!gfpflags_allow_blocking(gfp_mask) && memory_fault()) \ + ? NULL : bio_alloc_bioset(gfp_mask, __VA_ARGS__)) + +#define bio_clone(bio, gfp_mask) \ + ((!gfpflags_allow_blocking(gfp_mask) && memory_fault()) \ + ? NULL : bio_clone(bio, gfp_mask)) + +#define bio_clone_bioset(bio, gfp_mask, bs) \ + ((!gfpflags_allow_blocking(gfp_mask) && memory_fault()) \ + ? NULL : bio_clone_bioset(bio, gfp_mask, bs)) + +#define bio_kmalloc(...) \ + (memory_fault() ? NULL : bio_kmalloc(__VA_ARGS__)) +#define bio_clone_kmalloc(...) \ + (memory_fault() ? NULL : bio_clone_kmalloc(__VA_ARGS__)) + +#define bio_iov_iter_get_pages(...) \ + (memory_fault() ? -ENOMEM : bio_iov_iter_get_pages(__VA_ARGS__)) + +#else /* CONFIG_DYNAMIC_FAULT */ + +#define dfault_add_module(tab, n, modname) 0 +#define dfault_remove_module(mod) 0 +#define dynamic_fault(_class) 0 +#define memory_fault() 0 +#define race_fault() 0 + +#endif /* CONFIG_DYNAMIC_FAULT */ + +#endif diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 427292a759..7b7ca0d813 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1599,6 +1599,11 @@ config LATENCYTOP Enable this option if you want to use the LatencyTOP tool to find out which userspace is blocking on what kernel operations. +config DYNAMIC_FAULT + bool "Enable dynamic fault support" + default n + depends on DEBUG_FS + source kernel/trace/Kconfig config PROVIDE_OHCI1394_DMA_INIT diff --git a/lib/Makefile b/lib/Makefile index 66d2231d70..f6f70f4771 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -158,6 +158,8 @@ obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o obj-$(CONFIG_DYNAMIC_DEBUG) += dynamic_debug.o +obj-$(CONFIG_DYNAMIC_FAULT) += dynamic_fault.o + obj-$(CONFIG_NLATTR) += nlattr.o obj-$(CONFIG_LRU_CACHE) += lru_cache.o diff --git a/lib/dynamic_fault.c b/lib/dynamic_fault.c new file mode 100644 index 0000000000..75fc9a1b4b --- /dev/null +++ b/lib/dynamic_fault.c @@ -0,0 +1,760 @@ +/* + * lib/dynamic_fault.c + * + * make dynamic_fault() calls runtime configurable based upon their + * source module. + * + * Copyright (C) 2011 Adam Berkan + * Based on dynamic_debug.c: + * Copyright (C) 2008 Jason Baron + * By Greg Banks + * Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved. + * + */ + +#define pr_fmt(fmt) "dfault: " fmt "\n" + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#undef kzalloc + +extern struct _dfault __start___faults[]; +extern struct _dfault __stop___faults[]; + +struct dfault_table { + struct list_head link; + char *mod_name; + unsigned int num_dfaults; + struct _dfault *dfaults; +}; + +struct dfault_query { + const char *filename; + const char *module; + const char *function; + const char *class; + unsigned int first_line, last_line; + unsigned int first_index, last_index; + + unsigned match_line:1; + unsigned match_index:1; + + unsigned set_enabled:1; + unsigned enabled:2; + + unsigned set_frequency:1; + unsigned frequency; +}; + +struct dfault_iter { + struct dfault_table *table; + unsigned int idx; +}; + +static DEFINE_MUTEX(dfault_lock); +static LIST_HEAD(dfault_tables); + +bool __dynamic_fault_enabled(struct _dfault *df) +{ + union dfault_state old, new; + unsigned v = df->state.v; + bool ret; + + do { + old.v = new.v = v; + + if (new.enabled == DFAULT_DISABLED) + return false; + + ret = df->frequency + ? ++new.count >= df->frequency + : true; + if (ret) + new.count = 0; + if (ret && new.enabled == DFAULT_ONESHOT) + new.enabled = DFAULT_DISABLED; + } while ((v = cmpxchg(&df->state.v, old.v, new.v)) != old.v); + + if (ret) + pr_debug("returned true for %s:%u", df->filename, df->line); + + return ret; +} +EXPORT_SYMBOL(__dynamic_fault_enabled); + +/* 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 _dfault's flags */ +static char *dfault_describe_flags(struct _dfault *df, char *buf, size_t buflen) +{ + switch (df->state.enabled) { + case DFAULT_DISABLED: + strlcpy(buf, "disabled", buflen); + break; + case DFAULT_ENABLED: + strlcpy(buf, "enabled", buflen); + break; + case DFAULT_ONESHOT: + strlcpy(buf, "oneshot", buflen); + break; + default: + BUG(); + } + + return buf; +} + +/* + * must be called with dfault_lock held + */ + +/* + * Search the tables for _dfault's which match the given + * `query' and apply the `flags' and `mask' to them. Tells + * the user which dfault's were changed, or whether none + * were matched. + */ +static int dfault_change(const struct dfault_query *query) +{ + struct dfault_table *dt; + unsigned int nfound = 0; + unsigned i, index = 0; + char flagbuf[16]; + + /* search for matching dfaults */ + mutex_lock(&dfault_lock); + list_for_each_entry(dt, &dfault_tables, link) { + + /* match against the module name */ + if (query->module != NULL && + strcmp(query->module, dt->mod_name)) + continue; + + for (i = 0 ; i < dt->num_dfaults ; i++) { + struct _dfault *df = &dt->dfaults[i]; + + /* match against the source filename */ + if (query->filename != NULL && + strcmp(query->filename, df->filename) && + strcmp(query->filename, basename(df->filename))) + continue; + + /* match against the function */ + if (query->function != NULL && + strcmp(query->function, df->function)) + continue; + + /* match against the class */ + if (query->class) { + size_t len = strlen(query->class); + + if (strncmp(query->class, df->class, len)) + continue; + + if (df->class[len] && df->class[len] != ':') + continue; + } + + /* match against the line number range */ + if (query->match_line && + (df->line < query->first_line || + df->line > query->last_line)) + continue; + + /* match against the fault index */ + if (query->match_index && + (index < query->first_index || + index > query->last_index)) { + index++; + continue; + } + + if (query->set_enabled && + query->enabled != df->state.enabled) { + if (query->enabled != DFAULT_DISABLED) + static_key_slow_inc(&df->enabled); + else if (df->state.enabled != DFAULT_DISABLED) + static_key_slow_dec(&df->enabled); + + df->state.enabled = query->enabled; + } + + if (query->set_frequency) + df->frequency = query->frequency; + + pr_debug("changed %s:%d [%s]%s #%d %s", + df->filename, df->line, dt->mod_name, + df->function, index, + dfault_describe_flags(df, flagbuf, + sizeof(flagbuf))); + + index++; + nfound++; + } + } + mutex_unlock(&dfault_lock); + + pr_debug("dfault: %u matches", nfound); + + return nfound ? 0 : -ENOENT; +} + +/* + * 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 dfault_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 */ + + /* Run `end' over a word, either whitespace separated or quoted + */ + if (*buf == '"' || *buf == '\'') { + int quote = *buf++; + + for (end = buf ; *end && *end != quote ; end++) + ; + if (!*end) + return -EINVAL; /* unclosed quote */ + } else { + for (end = buf ; *end && !isspace(*end) ; end++) + ; + BUG_ON(end == buf); + } + /* Here `buf' is the start of the word, `end' is one past the + * end + */ + + if (nwords == maxwords) + return -EINVAL; /* ran out of words[] before bytes */ + if (*end) + *end++ = '\0'; /* terminate the word */ + words[nwords++] = buf; + buf = end; + } + + return nwords; +} + +/* + * Parse a range. + */ +static inline int parse_range(char *str, + unsigned int *first, + unsigned int *last) +{ + char *first_str = str; + char *last_str = strchr(first_str, '-'); + + if (last_str) + *last_str++ = '\0'; + + if (kstrtouint(first_str, 10, first)) + return -EINVAL; + + if (!last_str) + *last = *first; + else if (kstrtouint(last_str, 10, last)) + return -EINVAL; + + return 0; +} + +enum dfault_token { + TOK_INVALID, + + /* Queries */ + TOK_FUNC, + TOK_FILE, + TOK_LINE, + TOK_MODULE, + TOK_CLASS, + TOK_INDEX, + + /* Commands */ + TOK_DISABLE, + TOK_ENABLE, + TOK_ONESHOT, + TOK_FREQUENCY, +}; + +static const struct { + const char *str; + enum dfault_token tok; + unsigned args_required; +} dfault_token_strs[] = { + { "func", TOK_FUNC, 1, }, + { "file", TOK_FILE, 1, }, + { "line", TOK_LINE, 1, }, + { "module", TOK_MODULE, 1, }, + { "class", TOK_CLASS, 1, }, + { "index", TOK_INDEX, 1, }, + { "disable", TOK_DISABLE, 0, }, + { "enable", TOK_ENABLE, 0, }, + { "oneshot", TOK_ONESHOT, 0, }, + { "frequency", TOK_FREQUENCY, 1, }, +}; + +static enum dfault_token str_to_token(const char *word, unsigned nr_words) +{ + unsigned i; + + for (i = 0; i < ARRAY_SIZE(dfault_token_strs); i++) + if (!strcmp(word, dfault_token_strs[i].str)) { + if (nr_words < dfault_token_strs[i].args_required) { + pr_debug("insufficient arguments to \"%s\"", + word); + return TOK_INVALID; + } + + return dfault_token_strs[i].tok; + } + + pr_debug("unknown keyword \"%s\"", word); + + return TOK_INVALID; +} + +static int dfault_parse_command(struct dfault_query *query, + enum dfault_token tok, + char *words[], size_t nr_words) +{ + unsigned i = 0; + int ret; + + switch (tok) { + case TOK_INVALID: + return -EINVAL; + case TOK_FUNC: + query->function = words[i++]; + case TOK_FILE: + query->filename = words[i++]; + return 1; + case TOK_LINE: + ret = parse_range(words[i++], + &query->first_line, + &query->last_line); + if (ret) + return ret; + query->match_line = true; + break; + case TOK_MODULE: + query->module = words[i++]; + break; + case TOK_CLASS: + query->class = words[i++]; + break; + case TOK_INDEX: + ret = parse_range(words[i++], + &query->first_index, + &query->last_index); + if (ret) + return ret; + query->match_index = true; + break; + case TOK_DISABLE: + query->set_enabled = true; + query->enabled = DFAULT_DISABLED; + break; + case TOK_ENABLE: + query->set_enabled = true; + query->enabled = DFAULT_ENABLED; + break; + case TOK_ONESHOT: + query->set_enabled = true; + query->enabled = DFAULT_ONESHOT; + break; + case TOK_FREQUENCY: + query->set_frequency = 1; + ret = kstrtouint(words[i++], 10, &query->frequency); + if (ret) + return ret; + + if (!query->set_enabled) { + query->set_enabled = 1; + query->enabled = DFAULT_ENABLED; + } + break; + } + + return i; +} + +/* + * Parse words[] as a dfault query specification, which is a series + * of (keyword, value) pairs chosen from these possibilities: + * + * func + * file + * file + * module + * line + * line - // where either may be empty + * index - // dynamic faults numbered from + * // to inside each matching function + */ +static int dfault_parse_query(struct dfault_query *query, + char *words[], size_t nr_words) +{ + unsigned i = 0; + + while (i < nr_words) { + const char *tok_str = words[i++]; + enum dfault_token tok = str_to_token(tok_str, nr_words - i); + int ret = dfault_parse_command(query, tok, words + i, + nr_words - i); + + if (ret < 0) + return ret; + i += ret; + BUG_ON(i > nr_words); + } + + return 0; +} + +/* + * File_ops->write method for /dynamic_fault/conrol. Gathers the + * command text from userspace, parses and executes it. + */ +static ssize_t dfault_proc_write(struct file *file, const char __user *ubuf, + size_t len, loff_t *offp) +{ + struct dfault_query query; +#define MAXWORDS 9 + int nwords; + char *words[MAXWORDS]; + char tmpbuf[256]; + int ret; + + memset(&query, 0, sizeof(query)); + + 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'; + + pr_debug("read %zu bytes from userspace", len); + + nwords = dfault_tokenize(tmpbuf, words, MAXWORDS); + if (nwords < 0) + return -EINVAL; + if (dfault_parse_query(&query, words, nwords)) + return -EINVAL; + + /* actually go and implement the change */ + ret = dfault_change(&query); + if (ret < 0) + return ret; + + *offp += len; + return len; +} + +/* Control file read code */ + +/* + * Set the iterator to point to the first _dfault object + * and return a pointer to that first object. Returns + * NULL if there are no _dfaults at all. + */ +static struct _dfault *dfault_iter_first(struct dfault_iter *iter) +{ + if (list_empty(&dfault_tables)) { + iter->table = NULL; + iter->idx = 0; + return NULL; + } + iter->table = list_entry(dfault_tables.next, + struct dfault_table, link); + iter->idx = 0; + return &iter->table->dfaults[iter->idx]; +} + +/* + * Advance the iterator to point to the next _dfault + * object from the one the iterator currently points at, + * and returns a pointer to the new _dfault. Returns + * NULL if the iterator has seen all the _dfaults. + */ +static struct _dfault *dfault_iter_next(struct dfault_iter *iter) +{ + if (iter->table == NULL) + return NULL; + if (++iter->idx == iter->table->num_dfaults) { + /* iterate to next table */ + iter->idx = 0; + if (list_is_last(&iter->table->link, &dfault_tables)) { + iter->table = NULL; + return NULL; + } + iter->table = list_entry(iter->table->link.next, + struct dfault_table, link); + } + return &iter->table->dfaults[iter->idx]; +} + +/* + * Seq_ops start method. Called at the start of every + * read() call from userspace. Takes the dfault_lock and + * seeks the seq_file's iterator to the given position. + */ +static void *dfault_proc_start(struct seq_file *m, loff_t *pos) +{ + struct dfault_iter *iter = m->private; + struct _dfault *dp; + int n = *pos; + + mutex_lock(&dfault_lock); + + if (n < 0) + return NULL; + dp = dfault_iter_first(iter); + while (dp != NULL && --n >= 0) + dp = dfault_iter_next(iter); + return dp; +} + +/* + * Seq_ops next method. Called several times within a read() + * call from userspace, with dfault_lock held. Walks to the + * next _dfault object with a special case for the header line. + */ +static void *dfault_proc_next(struct seq_file *m, void *p, loff_t *pos) +{ + struct dfault_iter *iter = m->private; + struct _dfault *dp; + + if (p == SEQ_START_TOKEN) + dp = dfault_iter_first(iter); + else + dp = dfault_iter_next(iter); + ++*pos; + return dp; +} + +/* + * Seq_ops show method. Called several times within a read() + * call from userspace, with dfault_lock held. Formats the + * current _dfault as a single human-readable line, with a + * special case for the header line. + */ +static int dfault_proc_show(struct seq_file *m, void *p) +{ + struct dfault_iter *iter = m->private; + struct _dfault *df = p; + char flagsbuf[8]; + + seq_printf(m, "%s:%u class:%s module:%s func:%s %s \"\"\n", + df->filename, df->line, df->class, + iter->table->mod_name, df->function, + dfault_describe_flags(df, flagsbuf, sizeof(flagsbuf))); + + return 0; +} + +/* + * Seq_ops stop method. Called at the end of each read() + * call from userspace. Drops dfault_lock. + */ +static void dfault_proc_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&dfault_lock); +} + +static const struct seq_operations dfault_proc_seqops = { + .start = dfault_proc_start, + .next = dfault_proc_next, + .show = dfault_proc_show, + .stop = dfault_proc_stop +}; + +/* + * File_ops->open method for /dynamic_fault/control. Does the seq_file + * setup dance, and also creates an iterator to walk the _dfaults. + * 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 dfault_proc_open(struct inode *inode, struct file *file) +{ + struct dfault_iter *iter; + int err; + + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (iter == NULL) + return -ENOMEM; + + err = seq_open(file, &dfault_proc_seqops); + if (err) { + kfree(iter); + return err; + } + ((struct seq_file *) file->private_data)->private = iter; + return 0; +} + +static const struct file_operations dfault_proc_fops = { + .owner = THIS_MODULE, + .open = dfault_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, + .write = dfault_proc_write +}; + +/* + * Allocate a new dfault_table for the given module + * and add it to the global list. + */ +int dfault_add_module(struct _dfault *tab, unsigned int n, + const char *name) +{ + struct dfault_table *dt; + char *new_name; + const char *func = NULL; + int i; + + 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_dfaults = n; + dt->dfaults = tab; + + mutex_lock(&dfault_lock); + list_add_tail(&dt->link, &dfault_tables); + mutex_unlock(&dfault_lock); + + /* __attribute__(("section")) emits things in reverse order */ + for (i = n - 1; i >= 0; i--) + if (!func || strcmp(tab[i].function, func)) + func = tab[i].function; + + return 0; +} +EXPORT_SYMBOL_GPL(dfault_add_module); + +static void dfault_table_free(struct dfault_table *dt) +{ + list_del_init(&dt->link); + kfree(dt->mod_name); + kfree(dt); +} + +/* + * Called in response to a module being unloaded. Removes + * any dfault_table's which point at the module. + */ +int dfault_remove_module(char *mod_name) +{ + struct dfault_table *dt, *nextdt; + int ret = -ENOENT; + + mutex_lock(&dfault_lock); + list_for_each_entry_safe(dt, nextdt, &dfault_tables, link) { + if (!strcmp(dt->mod_name, mod_name)) { + dfault_table_free(dt); + ret = 0; + } + } + mutex_unlock(&dfault_lock); + return ret; +} +EXPORT_SYMBOL_GPL(dfault_remove_module); + +static void dfault_remove_all_tables(void) +{ + mutex_lock(&dfault_lock); + while (!list_empty(&dfault_tables)) { + struct dfault_table *dt = list_entry(dfault_tables.next, + struct dfault_table, + link); + dfault_table_free(dt); + } + mutex_unlock(&dfault_lock); +} + +static int __init dynamic_fault_init(void) +{ + struct dentry *dir, *file; + struct _dfault *iter, *iter_start; + const char *modname = NULL; + int ret = 0; + int n = 0; + + dir = debugfs_create_dir("dynamic_fault", NULL); + if (!dir) + return -ENOMEM; + file = debugfs_create_file("control", 0644, dir, NULL, + &dfault_proc_fops); + if (!file) { + debugfs_remove(dir); + return -ENOMEM; + } + if (__start___faults != __stop___faults) { + iter = __start___faults; + modname = iter->modname; + iter_start = iter; + for (; iter < __stop___faults; iter++) { + if (strcmp(modname, iter->modname)) { + ret = dfault_add_module(iter_start, n, modname); + if (ret) + goto out_free; + n = 0; + modname = iter->modname; + iter_start = iter; + } + n++; + } + ret = dfault_add_module(iter_start, n, modname); + } +out_free: + if (ret) { + dfault_remove_all_tables(); + debugfs_remove(dir); + debugfs_remove(file); + } + return 0; +} +module_init(dynamic_fault_init);