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tracing: Verify if trace array exists before destroying it.

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A trace array can be destroyed from userspace or kernel. Verify if the
trace array exists before proceeding to destroy/remove it.

Link: http://lkml.kernel.org/r/1565805327-579-3-git-send-email-divya.indi@oracle.com

Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Divya Indi <divya.indi@oracle.com>
[ Removed unneeded braces ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Divya Indi 2019-08-14 10:55:24 -07:00 committed by Steven Rostedt (VMware)
parent 2d6425af61
commit e585e6469d
2 changed files with 17 additions and 4 deletions
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6
kernel/module.c
View File

@ -3728,7 +3728,6 @@ static int complete_formation(struct module *mod, struct load_info *info)
module_enable_ro(mod, false); module_enable_ro(mod, false);
module_enable_nx(mod); module_enable_nx(mod);
module_enable_x(mod);
/* Mark state as coming so strong_try_module_get() ignores us, /* Mark state as coming so strong_try_module_get() ignores us,
* but kallsyms etc. can see us. */ * but kallsyms etc. can see us. */
@ -3751,6 +3750,11 @@ static int prepare_coming_module(struct module *mod)
if (err) if (err)
return err; return err;
/* Make module executable after ftrace is enabled */
mutex_lock(&module_mutex);
module_enable_x(mod);
mutex_unlock(&module_mutex);
blocking_notifier_call_chain(&module_notify_list, blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_COMING, mod); MODULE_STATE_COMING, mod);
return 0; return 0;

13
kernel/trace/trace.c
View File

@ -8556,17 +8556,26 @@ static int __remove_instance(struct trace_array *tr)
return 0; return 0;
} }
int trace_array_destroy(struct trace_array *tr) int trace_array_destroy(struct trace_array *this_tr)
{ {
struct trace_array *tr;
int ret; int ret;
if (!tr) if (!this_tr)
return -EINVAL; return -EINVAL;
mutex_lock(&event_mutex); mutex_lock(&event_mutex);
mutex_lock(&trace_types_lock); mutex_lock(&trace_types_lock);
ret = -ENODEV;
/* Making sure trace array exists before destroying it. */
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
if (tr == this_tr) {
ret = __remove_instance(tr); ret = __remove_instance(tr);
break;
}
}
mutex_unlock(&trace_types_lock); mutex_unlock(&trace_types_lock);
mutex_unlock(&event_mutex); mutex_unlock(&event_mutex);