perf/trace: Add ability to set a target task for events

[deliverable/linux.git] / kernel / events / callchain.c

diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 6581a040f39926dd46878640413bfd180922415a..98d4597f43d69e35a76535fac7d0bb6821ebdf7f 100644 (file)
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -153,7 +153,8 @@ put_callchain_entry(int rctx)
        put_recursion_context(__get_cpu_var(callchain_recursion), rctx);
 }
 
-struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
+struct perf_callchain_entry *
+perf_callchain(struct perf_event *event, struct pt_regs *regs)
 {
        int rctx;
        struct perf_callchain_entry *entry;
@@ -178,6 +179,12 @@ struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
        }
 
        if (regs) {
+               /*
+                * Disallow cross-task user callchains.
+                */
+               if (event->ctx->task && event->ctx->task != current)
+                       goto exit_put;
+
                perf_callchain_store(entry, PERF_CONTEXT_USER);
                perf_callchain_user(entry, regs);
        }