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Diffstat (limited to 'lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc')
-rw-r--r--lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc10
1 files changed, 8 insertions, 2 deletions
diff --git a/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc b/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
index e1cb6f76f..ea864e59e 100644
--- a/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
@@ -57,6 +57,14 @@
#include "sanitizer_mutex.h"
#include "sanitizer_placement_new.h"
+// Sufficiently old kernel headers don't provide this value, but we can still
+// call prctl with it. If the runtime kernel is new enough, the prctl call will
+// have the desired effect; if the kernel is too old, the call will error and we
+// can ignore said error.
+#ifndef PR_SET_PTRACER
+#define PR_SET_PTRACER 0x59616d61
+#endif
+
// This module works by spawning a Linux task which then attaches to every
// thread in the caller process with ptrace. This suspends the threads, and
// PTRACE_GETREGS can then be used to obtain their register state. The callback
@@ -433,9 +441,7 @@ void StopTheWorld(StopTheWorldCallback callback, void *argument) {
ScopedSetTracerPID scoped_set_tracer_pid(tracer_pid);
// On some systems we have to explicitly declare that we want to be traced
// by the tracer thread.
-#ifdef PR_SET_PTRACER
internal_prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
-#endif
// Allow the tracer thread to start.
tracer_thread_argument.mutex.Unlock();
// NOTE: errno is shared between this thread and the tracer thread.