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authorYehuda Sadeh <yehuda@hq.newdream.net>2010-07-03 07:07:35 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-07-05 07:17:22 +0400
commitff49d74ad383f54041378144ca1a229ee9aeaa59 (patch)
tree6f37335e313c9a680db8d4e4ce00d17aa11a099b
parente3668dd83ba5958429984286efbc3055be5344c4 (diff)
downloadlinux-ff49d74ad383f54041378144ca1a229ee9aeaa59.tar.xz
module: initialize module dynamic debug later
We should initialize the module dynamic debug datastructures only after determining that the module is not loaded yet. This fixes a bug that introduced in 2.6.35-rc2, where when a trying to load a module twice, we also load it's dynamic printing data twice which causes all sorts of nasty issues. Also handle the dynamic debug cleanup later on failure. Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed a #ifdef) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/dynamic_debug.h4
-rw-r--r--kernel/module.c23
-rw-r--r--lib/dynamic_debug.c2
3 files changed, 18 insertions, 11 deletions
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index b3cd4de9432b..52c0da4bdd18 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -40,7 +40,7 @@ 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);
+extern int ddebug_remove_module(const char *mod_name);
#define __dynamic_dbg_enabled(dd) ({ \
int __ret = 0; \
@@ -73,7 +73,7 @@ extern int ddebug_remove_module(char *mod_name);
#else
-static inline int ddebug_remove_module(char *mod)
+static inline int ddebug_remove_module(const char *mod)
{
return 0;
}
diff --git a/kernel/module.c b/kernel/module.c
index 8c6b42840dd1..5d2d28197c82 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2062,6 +2062,12 @@ static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
#endif
}
+static void dynamic_debug_remove(struct _ddebug *debug)
+{
+ if (debug)
+ ddebug_remove_module(debug->modname);
+}
+
static void *module_alloc_update_bounds(unsigned long size)
{
void *ret = module_alloc(size);
@@ -2124,6 +2130,8 @@ static noinline struct module *load_module(void __user *umod,
void *ptr = NULL; /* Stops spurious gcc warning */
unsigned long symoffs, stroffs, *strmap;
void __percpu *percpu;
+ struct _ddebug *debug = NULL;
+ unsigned int num_debug = 0;
mm_segment_t old_fs;
@@ -2476,15 +2484,9 @@ static noinline struct module *load_module(void __user *umod,
kfree(strmap);
strmap = NULL;
- if (!mod->taints) {
- struct _ddebug *debug;
- unsigned int num_debug;
-
+ if (!mod->taints)
debug = section_objs(hdr, sechdrs, secstrings, "__verbose",
sizeof(*debug), &num_debug);
- if (debug)
- dynamic_debug_setup(debug, num_debug);
- }
err = module_finalize(hdr, sechdrs, mod);
if (err < 0)
@@ -2526,10 +2528,13 @@ static noinline struct module *load_module(void __user *umod,
goto unlock;
}
+ if (debug)
+ dynamic_debug_setup(debug, num_debug);
+
/* Find duplicate symbols */
err = verify_export_symbols(mod);
if (err < 0)
- goto unlock;
+ goto ddebug;
list_add_rcu(&mod->list, &modules);
mutex_unlock(&module_mutex);
@@ -2557,6 +2562,8 @@ static noinline struct module *load_module(void __user *umod,
mutex_lock(&module_mutex);
/* Unlink carefully: kallsyms could be walking list. */
list_del_rcu(&mod->list);
+ ddebug:
+ dynamic_debug_remove(debug);
unlock:
mutex_unlock(&module_mutex);
synchronize_sched();
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 3df8eb17a607..02afc2533728 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -692,7 +692,7 @@ static void ddebug_table_free(struct ddebug_table *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)
+int ddebug_remove_module(const char *mod_name)
{
struct ddebug_table *dt, *nextdt;
int ret = -ENOENT;