diff options
Diffstat (limited to 'lib/dynamic_debug.c')
| -rw-r--r-- | lib/dynamic_debug.c | 140 |
1 files changed, 76 insertions, 64 deletions
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 02afc25..3094318 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -26,19 +26,11 @@ #include <linux/dynamic_debug.h> #include <linux/debugfs.h> #include <linux/slab.h> +#include <linux/jump_label.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; @@ -88,26 +80,6 @@ static char *ddebug_describe_flags(struct _ddebug *dp, char *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 @@ -170,17 +142,9 @@ static void ddebug_change(const struct ddebug_query *query, dt->num_enabled++; dp->flags = newflags; if (newflags) { - dynamic_debug_enabled |= - (1LL << dp->primary_hash); - dynamic_debug_enabled2 |= - (1LL << dp->secondary_hash); + jump_label_enable(&dp->enabled); } 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); + jump_label_disable(&dp->enabled); } if (verbose) printk(KERN_INFO @@ -429,6 +393,40 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, return 0; } +static int ddebug_exec_query(char *query_string) +{ + unsigned int flags = 0, mask = 0; + struct ddebug_query query; +#define MAXWORDS 9 + int nwords; + char *words[MAXWORDS]; + + nwords = ddebug_tokenize(query_string, 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); + return 0; +} + +static __initdata char ddebug_setup_string[1024]; +static __init int ddebug_setup_query(char *str) +{ + if (strlen(str) >= 1024) { + pr_warning("ddebug boot param string too large\n"); + return 0; + } + strcpy(ddebug_setup_string, str); + return 1; +} + +__setup("ddebug_query=", ddebug_setup_query); + /* * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the * command text from userspace, parses and executes it. @@ -436,12 +434,8 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, 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]; + int ret; if (len == 0) return 0; @@ -455,16 +449,9 @@ static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, 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); + ret = ddebug_exec_query(tmpbuf); + if (ret) + return ret; *offp += len; return len; @@ -725,13 +712,14 @@ static void ddebug_remove_all_tables(void) mutex_unlock(&ddebug_lock); } -static int __init dynamic_debug_init(void) +static __initdata int ddebug_init_success; + +static int __init dynamic_debug_init_debugfs(void) { struct dentry *dir, *file; - struct _ddebug *iter, *iter_start; - const char *modname = NULL; - int ret = 0; - int n = 0; + + if (!ddebug_init_success) + return -ENODEV; dir = debugfs_create_dir("dynamic_debug", NULL); if (!dir) @@ -742,6 +730,16 @@ static int __init dynamic_debug_init(void) debugfs_remove(dir); return -ENOMEM; } + return 0; +} + +static int __init dynamic_debug_init(void) +{ + struct _ddebug *iter, *iter_start; + const char *modname = NULL; + int ret = 0; + int n = 0; + if (__start___verbose != __stop___verbose) { iter = __start___verbose; modname = iter->modname; @@ -759,12 +757,26 @@ static int __init dynamic_debug_init(void) } ret = ddebug_add_module(iter_start, n, modname); } + + /* ddebug_query boot param got passed -> set it up */ + if (ddebug_setup_string[0] != '\0') { + ret = ddebug_exec_query(ddebug_setup_string); + if (ret) + pr_warning("Invalid ddebug boot param %s", + ddebug_setup_string); + else + pr_info("ddebug initialized with string %s", + ddebug_setup_string); + } + out_free: - if (ret) { + if (ret) ddebug_remove_all_tables(); - debugfs_remove(dir); - debugfs_remove(file); - } + else + ddebug_init_success = 1; return 0; } -module_init(dynamic_debug_init); +/* Allow early initialization for boot messages via boot param */ +arch_initcall(dynamic_debug_init); +/* Debugfs setup must be done later */ +module_init(dynamic_debug_init_debugfs); |
