Commit 5125e757 authored by Yafang Shao's avatar Yafang Shao Committed by Alexei Starovoitov
Browse files

bpf: Clear the probe_addr for uprobe 



To avoid returning uninitialized or random values when querying the file
descriptor (fd) and accessing probe_addr, it is necessary to clear the
variable prior to its use.

Fixes: 41bdc4b4 ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY")
Signed-off-by: default avatarYafang Shao <laoar.shao@gmail.com>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230709025630.3735-6-laoar.shao@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent f1a41453

include/linux/trace_events.h

+2 −1
Original line number Diff line number Diff line
@@ -864,7 +864,8 @@ extern int perf_uprobe_init(struct perf_event *event, 
extern void perf_uprobe_destroy(struct perf_event *event);

extern int bpf_get_uprobe_info(const struct perf_event *event,

			       u32 *fd_type, const char **filename,

			       u64 *probe_offset, bool perf_type_tracepoint);

			       u64 *probe_offset, u64 *probe_addr,

			       bool perf_type_tracepoint);

#endif

extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,

				     char *filter_str);

kernel/trace/bpf_trace.c

+1 −1
Original line number Diff line number Diff line
@@ -2384,7 +2384,7 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 
#ifdef CONFIG_UPROBE_EVENTS

		if (flags & TRACE_EVENT_FL_UPROBE)

			err = bpf_get_uprobe_info(event, fd_type, buf,

						  probe_offset,

						  probe_offset, probe_addr,

						  event->attr.type == PERF_TYPE_TRACEPOINT);

#endif

	}

kernel/trace/trace_uprobe.c

+2 −1
Original line number Diff line number Diff line
@@ -1415,7 +1415,7 @@ static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, 


int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,

			const char **filename, u64 *probe_offset,

			bool perf_type_tracepoint)

			u64 *probe_addr, bool perf_type_tracepoint)

{

	const char *pevent = trace_event_name(event->tp_event);

	const char *group = event->tp_event->class->system;
@@ -1432,6 +1432,7 @@ int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, 
				    : BPF_FD_TYPE_UPROBE;

	*filename = tu->filename;

	*probe_offset = tu->offset;

	*probe_addr = 0;

	return 0;

}

#endif	/* CONFIG_PERF_EVENTS */