PR442528

4 files changed, 45 insertions, 0 deletions

diff --git a/elaborate.h b/elaborate.h
index c0e35477..afc0c569 100644
--- a/elaborate.h
+++ b/elaborate.h
@@ -132,6 +132,10 @@ struct derived_probe: public probe
   // From within unparser::emit_probe, initialized any extra variables
   // in this probe's context locals.
 
+  virtual void emit_probe_local_init (translator_output*) {}
+  // From within unparser::emit_probe, emit any extra processing block
+  // for this probe.
+
 public:
   static void emit_common_header (translator_output* o);
   // from c_unparser::emit_common_header
diff --git a/runtime/regs-ia64.c b/runtime/regs-ia64.c
index 66dc60f3..fd8d8ca8 100644
--- a/runtime/regs-ia64.c
+++ b/runtime/regs-ia64.c
@@ -35,6 +35,32 @@ static void ia64_stap_get_arbsp(struct unw_frame_info *info, void *arg)
 	lp->address = 0;
 }
 
+/*
+ * bspcache: get cached unwound address and
+ * 	     set a probe local cache of the offset of unwound address.
+ */
+#define bspcache(cache, regs, pp)\
+	if(regs) {\
+		static unsigned __offset = 0; /* probe local cache */\
+		static const char * __pp = NULL; /* reference probe point */\
+		unsigned long *bsp;\
+		asm volatile("{ flushrs }\n"); /* flushrs for fixing bsp */\
+		bsp = (void*)ia64_getreg(_IA64_REG_AR_BSP);\
+		if (__offset == 0) {\
+			struct ia64_stap_get_arbsp_param pa;\
+			pa.ip = regs->cr_iip;\
+			unw_init_running(ia64_stap_get_arbsp, &pa);\
+			if (pa.address != 0) {\
+				__offset = ia64_rse_num_regs(pa.address, bsp)\
+					-(regs->cr_ifs & 127);\
+				__pp = (const char *)pp;\
+				cache = pa.address;\
+			}\
+		} else if (pp == __pp)\
+			cache = ia64_rse_skip_regs(bsp,\
+				-(__offset + (regs->cr_ifs & 127)));\
+	}
+
 static long ia64_fetch_register(int regno, struct pt_regs *pt_regs, unsigned long **cache)
 {
 	struct ia64_stap_get_arbsp_param pa;
@@ -89,6 +115,10 @@ static void ia64_store_register(int regno,
 	return;
 }
 
+#else /* if defined __ia64__ */
+
+#define bspcache(cache, regs, pp) do {} while(0)
+
 #endif /* if defined __ia64__ */
 
 
diff --git a/tapsets.cxx b/tapsets.cxx
index 3d5af360..5cd6f8a2 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -2329,6 +2329,8 @@ struct dwarf_derived_probe: public derived_probe
 
   void join_group (systemtap_session& s);
 
+  void emit_probe_local_init(translator_output * o);
+
   // Pattern registration helpers.
   static void register_statement_variants(match_node * root,
 					  dwarf_builder * dw);
@@ -4528,6 +4530,12 @@ dwarf_derived_probe::register_patterns(match_node * root)
   // register_function_and_statement_variants(root->bind_str(TOK_PROCESS), dw);
 }
 
+void
+dwarf_derived_probe::emit_probe_local_init(translator_output * o)
+{
+  // emit bsp cache setup
+  o->newline() << "bspcache(c->unwaddr, c->regs, c->probe_point);";
+}
 
 // ------------------------------------------------------------------------
 
diff --git a/translate.cxx b/translate.cxx
index c69dc201..c62ba9fd 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -1515,6 +1515,9 @@ c_unparser::emit_probe (derived_probe* v)
       o->newline() << "c->statp = & time_" << v->basest()->name << ";";
       o->newline() << "#endif";
 
+      // emit probe local initialization block
+      v->emit_probe_local_init(o);
+
       // emit all read/write locks for global variables
       varuse_collecting_visitor vut;
       if (v->needs_global_locks ())