aboutsummaryrefslogtreecommitdiffstats
path: root/lib/dynamic_debug.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/dynamic_debug.c')
-rw-r--r--lib/dynamic_debug.c140
1 files changed, 76 insertions, 64 deletions
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 02afc253372..3094318bfea 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);