Reduce stack usage for overflow checks
This reduces the stack space reserved for overflow checks to 12K, split
into an 8K gap and a 4K protected region. GC needs over 8K when running
in a stack overflow situation.
Also prevents signal runaway by detecting a signal inside code that
resulted from a signal handler invokation. And adds a max signal count to
the SignalTest to prevent it running forever.
Also reduces the number of iterations for the InterfaceTest as this was
taking (almost) forever with the --trace option on run-test.
Bug: 15435566
Change-Id: Id4fd46f22d52d42a9eb431ca07948673e8fda694
diff --git a/runtime/arch/x86/fault_handler_x86.cc b/runtime/arch/x86/fault_handler_x86.cc
index 89baded..c143c5d 100644
--- a/runtime/arch/x86/fault_handler_x86.cc
+++ b/runtime/arch/x86/fault_handler_x86.cc
@@ -34,7 +34,7 @@
#define CTX_ESP uc_mcontext->__ss.__rsp
#define CTX_EIP uc_mcontext->__ss.__rip
#define CTX_EAX uc_mcontext->__ss.__rax
-#define CTX_METHOD uc_mcontext->__ss.__rax
+#define CTX_METHOD uc_mcontext->__ss.__rdi
#else
// 32 bit mac build.
#define CTX_ESP uc_mcontext->__ss.__esp
@@ -71,7 +71,7 @@
#define EXT_SYM(sym) _ ## sym
#else
extern "C" void art_quick_throw_null_pointer_exception();
-extern "C" void art_quick_throw_stack_overflow_from_signal();
+extern "C" void art_quick_throw_stack_overflow();
extern "C" void art_quick_test_suspend();
#define EXT_SYM(sym) sym
#endif
@@ -382,30 +382,20 @@
uintptr_t overflow_addr = sp - GetStackOverflowReservedBytes(kX86);
#endif
- Thread* self = Thread::Current();
- uintptr_t pregion = reinterpret_cast<uintptr_t>(self->GetStackEnd()) -
- Thread::kStackOverflowProtectedSize;
-
// Check that the fault address is the value expected for a stack overflow.
if (fault_addr != overflow_addr) {
VLOG(signals) << "Not a stack overflow";
return false;
}
- // We know this is a stack overflow. We need to move the sp to the overflow region
- // that exists below the protected region. Determine the address of the next
- // available valid address below the protected region.
- VLOG(signals) << "setting sp to overflow region at " << std::hex << pregion;
+ VLOG(signals) << "Stack overflow found";
// Since the compiler puts the implicit overflow
// check before the callee save instructions, the SP is already pointing to
// the previous frame.
- // Tell the stack overflow code where the new stack pointer should be.
- uc->CTX_EAX = pregion;
-
- // Now arrange for the signal handler to return to art_quick_throw_stack_overflow_from_signal.
- uc->CTX_EIP = reinterpret_cast<uintptr_t>(EXT_SYM(art_quick_throw_stack_overflow_from_signal));
+ // Now arrange for the signal handler to return to art_quick_throw_stack_overflow.
+ uc->CTX_EIP = reinterpret_cast<uintptr_t>(art_quick_throw_stack_overflow);
return true;
}