runtime: Mark runtime_goexit function as noinline.

If the compiler inlines this function into kickoff, it may reuse
the TLS block address to load g. However, this is not necessarily
correct, as the call to g->entry in kickoff may cause the TLS
address to change. If the wrong value is loaded for g->status in
runtime_goexit, it may cause a runtime panic.

By marking the function as noinline we prevent the compiler from
reusing the TLS address.

From-SVN: r215484

diff --git a/libgo/runtime/proc.c b/libgo/runtime/proc.c
index 4195aff76a78a5f87ba1964ffaf57af449c15bdc..87cd3edac00aebce9602b0f1d6d011607db9bf65 100644 (file)
--- a/libgo/runtime/proc.c
+++ b/libgo/runtime/proc.c
@@ -1894,6 +1894,7 @@ runtime_gosched0(G *gp)
 // Need to mark it as nosplit, because it runs with sp > stackbase (as runtime_lessstack).
 // Since it does not return it does not matter.  But if it is preempted
 // at the split stack check, GC will complain about inconsistent sp.
+void runtime_goexit(void) __attribute__ ((noinline));
 void
 runtime_goexit(void)
 {