lkml.org 
[lkml]   [2017]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] module: fix ddebug_remove_module()
Date
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>
---
kernel/module.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index 4a3665f..dac9805 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2703,21 +2703,21 @@ static void add_kallsyms(struct module *mod, const struct load_info *info)
}
#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)
return;
#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",
debug->modname);
#endif
}

-static void dynamic_debug_remove(struct _ddebug *debug)
+static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
{
if (debug)
- ddebug_remove_module(debug->modname);
+ ddebug_remove_module(mod->name);
}

void * __weak module_alloc(unsigned long size)
@@ -3697,7 +3697,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
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_module_init(mod);
@@ -3761,7 +3761,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
module_disable_nx(mod);

ddebug_cleanup:
- dynamic_debug_remove(info->debug);
+ dynamic_debug_remove(mod, info->debug);
synchronize_sched();
kfree(mod->args);
free_arch_cleanup:
--
1.8.3.1
\
 
 \ /
  Last update: 2017-07-07 05:18    [W:0.038 / U:2.000 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site