module: fix ddebug_remove_module()

ddebug_remove_module() use mod->name to find the ddebug_table of the
module and remove it. But dynamic_debug_setup() use the first
_ddebug->modname to create ddebug_table for the module. It's ok when
the _ddebug->modname is the same with the mod->name.

But livepatch module is special, it may contain _ddebugs of other
modules, the modname of which is different from the name of livepatch
module. So ddebug_remove_module() can't use mod->name to find the
right ddebug_table and remove it. It can cause kernel crash when we cat
the file <debugfs>/dynamic_debug/control.

Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
This commit is contained in:
Zhou Chengming 2017-07-07 11:15:58 +08:00 committed by Jessica Yu
parent 4fd3e4ef1f
commit 5279631271

View File

@ -2707,21 +2707,21 @@ static void add_kallsyms(struct module *mod, const struct load_info *info)
} }
#endif /* CONFIG_KALLSYMS */ #endif /* CONFIG_KALLSYMS */
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num) static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
{ {
if (!debug) if (!debug)
return; return;
#ifdef CONFIG_DYNAMIC_DEBUG #ifdef CONFIG_DYNAMIC_DEBUG
if (ddebug_add_module(debug, num, debug->modname)) if (ddebug_add_module(debug, num, mod->name))
pr_err("dynamic debug error adding module: %s\n", pr_err("dynamic debug error adding module: %s\n",
debug->modname); debug->modname);
#endif #endif
} }
static void dynamic_debug_remove(struct _ddebug *debug) static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
{ {
if (debug) if (debug)
ddebug_remove_module(debug->modname); ddebug_remove_module(mod->name);
} }
void * __weak module_alloc(unsigned long size) void * __weak module_alloc(unsigned long size)
@ -3715,7 +3715,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
goto free_arch_cleanup; goto free_arch_cleanup;
} }
dynamic_debug_setup(info->debug, info->num_debug); dynamic_debug_setup(mod, info->debug, info->num_debug);
/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
ftrace_module_init(mod); ftrace_module_init(mod);
@ -3779,7 +3779,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
module_disable_nx(mod); module_disable_nx(mod);
ddebug_cleanup: ddebug_cleanup:
dynamic_debug_remove(info->debug); dynamic_debug_remove(mod, info->debug);
synchronize_sched(); synchronize_sched();
kfree(mod->args); kfree(mod->args);
free_arch_cleanup: free_arch_cleanup: