Commit-ID: 63c45f4ba533e9749da16298db53e491c25d805b Gitweb: http://git.kernel.org/tip/63c45f4ba533e9749da16298db53e491c25d805b Author: Jiri Olsa <jolsa@xxxxxxxxxx> AuthorDate: Sun, 2 Mar 2014 16:56:39 +0100 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 11 Mar 2014 11:57:58 +0100 perf: Disallow user-space stack dumps for function trace events Recent issues with user space callchains processing within page fault handler tracing showed as Peter said 'there's just too much fail surface'. The user space stack dump is just another source of the this issue. Related list discussions: http://marc.info/?t=139302086500001&r=1&w=2 http://marc.info/?t=139301437300003&r=1&w=2 Suggested-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx> Cc: Vince Weaver <vincent.weaver@xxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1393775800-13524-3-git-send-email-jolsa@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/trace/trace_event_perf.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index d5e01c3..c894614 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -42,6 +42,13 @@ static int perf_trace_event_perm(struct ftrace_event_call *tp_event, */ if (!p_event->attr.exclude_callchain_user) return -EINVAL; + + /* + * Same reason to disable user stack dump as for user space + * callchains above. + */ + if (p_event->attr.sample_type & PERF_SAMPLE_STACK_USER) + return -EINVAL; } /* No tracing, just counting, so no obvious leak */ -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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