diff options
Diffstat (limited to 'tapsets.cxx')
| -rw-r--r-- | tapsets.cxx | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/tapsets.cxx b/tapsets.cxx index 12982259..5390ee2d 100644 --- a/tapsets.cxx +++ b/tapsets.cxx @@ -3506,8 +3506,15 @@ mark_derived_probe::emit_registrations (translator_output * o, unsigned i) o->newline(1) << "void (**fn) (" << probe_sig_expanded << ") = (void *)" << address << "UL;"; + o->newline() << "#if __HAVE_ARCH_CMPXCHG"; + o->newline() << "unsigned long *fnpp = (unsigned long *) (void *) fn;"; + o->newline() << "unsigned long fnp = (unsigned long) (void *) & enter_" << i << ";"; + o->newline() << "unsigned long oldval = cmpxchg (fnpp, 0, fnp);"; + o->newline() << "if (oldval != 0) rc = 1;"; // XXX: could retry a few times + o->newline() << "#else"; // XXX: need proper synchronization for concurrent registration attempts o->newline() << "if (*fn == 0) *fn = & enter_" << i << ";"; + o->newline() << "#endif"; o->newline() << "mb ();"; o->newline() << "if (*fn != & enter_" << i << ") rc = 1;"; @@ -3523,7 +3530,14 @@ mark_derived_probe::emit_deregistrations (translator_output * o, unsigned i) o->newline() << "{"; o->newline(1) << "void (**fn) (" << probe_sig_expanded << ") = (void *)" << address << "UL;"; + o->newline() << "#if __HAVE_ARCH_CMPXCHG"; + o->newline() << "unsigned long *fnpp = (unsigned long *) (void *) fn;"; + o->newline() << "unsigned long fnp = (unsigned long) (void *) & enter_" << i << ";"; + o->newline() << "unsigned long oldval = cmpxchg (fnpp, fnp, 0);"; + o->newline() << "if (oldval != fnp) ;"; // XXX: should not happen + o->newline() << "#else"; o->newline(0) << "*fn = 0;"; + o->newline() << "#endif"; o->newline(-1) << "}"; } |