We cannot unregister trace_uprobe when trace_uprobe is in use, otherwise resource will leak.
Just return -EBUSY if user want to unregister a trace_uprobe which in use. Signed-off-by: zhangwei(Jovi) <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> --- kernel/trace/trace_uprobe.c | 51 ++++++++++++++++++++++++++++++++----------- 1 file changed, 38 insertions(+), 13 deletions(-) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index d2da3ea..248757b 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -102,6 +102,11 @@ static inline bool is_ret_probe(struct trace_uprobe *tu) return tu->consumer.ret_handler != NULL; } +static inline bool is_trace_uprobe_enabled(struct trace_uprobe *tu) +{ + return tu->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE); +} + /* * Allocate new trace_uprobe and initialize it (including uprobes). */ @@ -171,11 +176,17 @@ static struct trace_uprobe *find_probe_event(const char *event, const char *grou } /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ -static void unregister_trace_uprobe(struct trace_uprobe *tu) +static int unregister_trace_uprobe(struct trace_uprobe *tu) { + /* Enabled event can not be unregistered */ + if (is_trace_uprobe_enabled(tu)) + return -EBUSY; + list_del(&tu->list); unregister_uprobe_event(tu); free_trace_uprobe(tu); + + return 0; } /* Register a trace_uprobe and probe_event */ @@ -188,9 +199,12 @@ static int register_trace_uprobe(struct trace_uprobe *tu) /* register as an event */ old_tp = find_probe_event(tu->call.name, tu->call.class->system); - if (old_tp) + if (old_tp) { /* delete old event */ - unregister_trace_uprobe(old_tp); + ret = unregister_trace_uprobe(old_tp); + if (ret < 0) + goto end; + } ret = register_uprobe_event(tu); if (ret) { @@ -276,9 +290,9 @@ static int create_trace_uprobe(int argc, char **argv) return -ENOENT; } /* delete an event */ - unregister_trace_uprobe(tu); + ret = unregister_trace_uprobe(tu); mutex_unlock(&uprobe_lock); - return 0; + return ret; } if (argc < 2) { @@ -413,16 +427,27 @@ fail_address_parse: return ret; } -static void cleanup_all_probes(void) +static int cleanup_all_probes(void) { struct trace_uprobe *tu; + int ret = 0; mutex_lock(&uprobe_lock); + + /* Ensure no probe is in use. */ + list_for_each_entry(tu, &uprobe_list, list) + if (is_trace_uprobe_enabled(tu)) { + ret = -EBUSY; + goto end; + } + while (!list_empty(&uprobe_list)) { tu = list_entry(uprobe_list.next, struct trace_uprobe, list); unregister_trace_uprobe(tu); } + end: mutex_unlock(&uprobe_lock); + return ret; } /* Probes listing interfaces */ @@ -467,8 +492,13 @@ static const struct seq_operations probes_seq_op = { static int probes_open(struct inode *inode, struct file *file) { - if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) - cleanup_all_probes(); + int ret; + + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { + ret = cleanup_all_probes(); + if (ret < 0) + return ret; + } return seq_open(file, &probes_seq_op); } @@ -622,11 +652,6 @@ partial: return TRACE_TYPE_PARTIAL_LINE; } -static inline bool is_trace_uprobe_enabled(struct trace_uprobe *tu) -{ - return tu->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE); -} - typedef bool (*filter_func_t)(struct uprobe_consumer *self, enum uprobe_filter_ctx ctx, struct mm_struct *mm); -- 1.7.9.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
