Commit ff49d74a authored by Yehuda Sadeh's avatar Yehuda Sadeh Committed by Linus Torvalds
Browse files

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: default avatarYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed a #ifdef)
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e3668dd8

include/linux/dynamic_debug.h

+2 −2
Original line number Diff line number Diff line
@@ -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;

}

kernel/module.c

+15 −8
Original line number Diff line number Diff line
@@ -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();

lib/dynamic_debug.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

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