From ff49d74ad383f54041378144ca1a229ee9aeaa59 Mon Sep 17 00:00:00 2001 From: Yehuda Sadeh Date: Sat, 3 Jul 2010 13:07:35 +1000 Subject: 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 Signed-off-by: Rusty Russell (removed a #ifdef) Signed-off-by: Linus Torvalds --- kernel/module.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 8c6b42840dd..5d2d28197c8 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(); -- cgit v1.2.3-70-g09d2 From b82bab4bbe9efa7bc7177fc20620fff19bd95484 Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Tue, 27 Jul 2010 13:18:01 -0700 Subject: dynamic debug: move ddebug_remove_module() down into free_module() The command echo "file ec.c +p" >/sys/kernel/debug/dynamic_debug/control causes an oops. Move the call to ddebug_remove_module() down into free_module(). In this way it should be called from all error paths. Currently, we are missing the remove if the module init routine fails. Signed-off-by: Jason Baron Reported-by: Thomas Renninger Tested-by: Thomas Renninger Cc: [2.6.32+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 5d2d28197c8..6c562828c85 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -787,7 +787,6 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, /* Store the name of the last unloaded module for diagnostic purposes */ strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); - ddebug_remove_module(mod->name); free_module(mod); return 0; @@ -1550,6 +1549,9 @@ static void free_module(struct module *mod) remove_sect_attrs(mod); mod_kobject_remove(mod); + /* Remove dynamic debug info */ + ddebug_remove_module(mod->name); + /* Arch-specific cleanup. */ module_arch_cleanup(mod); -- cgit v1.2.3-70-g09d2