[pypy-commit] pypy default: Phew. A passing test checking that gc pointers are correctly

arigo noreply at buildbot.pypy.org
Tue Feb 28 17:13:21 CET 2012


Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r52991:e6f349cd4a97
Date: 2012-02-28 17:13 +0100
http://bitbucket.org/pypy/pypy/changeset/e6f349cd4a97/

Log:	Phew. A passing test checking that gc pointers are correctly saved
	and correctly restored around CALL_MALLOC_NURSERY.

diff --git a/pypy/jit/backend/x86/test/test_gc_integration.py b/pypy/jit/backend/x86/test/test_gc_integration.py
--- a/pypy/jit/backend/x86/test/test_gc_integration.py
+++ b/pypy/jit/backend/x86/test/test_gc_integration.py
@@ -184,6 +184,8 @@
         self.addrs[1] = self.addrs[0] + 64
         self.calls = []
         def malloc_slowpath(size):
+            if self.gcrootmap is not None:   # hook
+                self.gcrootmap.hook_malloc_slowpath()
             self.calls.append(size)
             # reset the nursery
             nadr = rffi.cast(lltype.Signed, self.nursery)
@@ -320,3 +322,155 @@
             s1ref = self.cpu.get_latest_value_ref(i)
             s1 = lltype.cast_opaque_ptr(lltype.Ptr(S1), s1ref)
             assert s1 == getattr(s2, 's%d' % i)
+
+
+class MockShadowStackRootMap(MockGcRootMap):
+    is_shadow_stack = True
+    MARKER_FRAME = 88       # this marker follows the frame addr
+    S1 = lltype.GcStruct('S1')
+
+    def __init__(self):
+        self.addrs = lltype.malloc(rffi.CArray(lltype.Signed), 20,
+                                   flavor='raw')
+        # root_stack_top
+        self.addrs[0] = rffi.cast(lltype.Signed, self.addrs) + 3*WORD
+        # random stuff
+        self.addrs[1] = 123456
+        self.addrs[2] = 654321
+        self.check_initial_and_final_state()
+        self.callshapes = {}
+        self.should_see = []
+
+    def check_initial_and_final_state(self):
+        assert self.addrs[0] == rffi.cast(lltype.Signed, self.addrs) + 3*WORD
+        assert self.addrs[1] == 123456
+        assert self.addrs[2] == 654321
+
+    def get_root_stack_top_addr(self):
+        return rffi.cast(lltype.Signed, self.addrs)
+
+    def compress_callshape(self, shape, datablockwrapper):
+        assert shape[0] == 'shape'
+        return ['compressed'] + shape[1:]
+
+    def write_callshape(self, mark, force_index):
+        assert mark[0] == 'compressed'
+        assert force_index not in self.callshapes
+        assert force_index == 42 + len(self.callshapes)
+        self.callshapes[force_index] = mark
+
+    def hook_malloc_slowpath(self):
+        num_entries = self.addrs[0] - rffi.cast(lltype.Signed, self.addrs)
+        assert num_entries == 5*WORD    # 3 initially, plus 2 by the asm frame
+        assert self.addrs[1] == 123456  # unchanged
+        assert self.addrs[2] == 654321  # unchanged
+        frame_addr = self.addrs[3]                   # pushed by the asm frame
+        assert self.addrs[4] == self.MARKER_FRAME    # pushed by the asm frame
+        #
+        from pypy.jit.backend.x86.arch import FORCE_INDEX_OFS
+        addr = rffi.cast(rffi.CArrayPtr(lltype.Signed),
+                         frame_addr + FORCE_INDEX_OFS)
+        force_index = addr[0]
+        assert force_index == 43    # in this test: the 2nd call_malloc_nursery
+        #
+        # The callshapes[43] saved above should list addresses both in the
+        # COPY_AREA and in the "normal" stack, where all the 16 values p1-p16
+        # of test_save_regs_at_correct_place should have been stored.  Here
+        # we replace them with new addresses, to emulate a moving GC.
+        shape = self.callshapes[force_index]
+        assert len(shape[1:]) == len(self.should_see)
+        new_objects = [None] * len(self.should_see)
+        for ofs in shape[1:]:
+            assert isinstance(ofs, int)    # not a register at all here
+            addr = rffi.cast(rffi.CArrayPtr(lltype.Signed), frame_addr + ofs)
+            contains = addr[0]
+            for j in range(len(self.should_see)):
+                obj = self.should_see[j]
+                if contains == rffi.cast(lltype.Signed, obj):
+                    assert new_objects[j] is None   # duplicate?
+                    break
+            else:
+                assert 0   # the value read from the stack looks random?
+            new_objects[j] = lltype.malloc(self.S1)
+            addr[0] = rffi.cast(lltype.Signed, new_objects[j])
+        self.should_see[:] = new_objects
+
+
+class TestMallocShadowStack(BaseTestRegalloc):
+
+    def setup_method(self, method):
+        cpu = CPU(None, None)
+        cpu.gc_ll_descr = GCDescrFastpathMalloc()
+        cpu.gc_ll_descr.gcrootmap = MockShadowStackRootMap()
+        cpu.setup_once()
+        for i in range(42):
+            cpu.reserve_some_free_fail_descr_number()
+        self.cpu = cpu
+
+    def test_save_regs_at_correct_place(self):
+        cpu = self.cpu
+        gc_ll_descr = cpu.gc_ll_descr
+        S1 = gc_ll_descr.gcrootmap.S1
+        S2 = lltype.GcStruct('S2', ('s0', lltype.Ptr(S1)),
+                                   ('s1', lltype.Ptr(S1)),
+                                   ('s2', lltype.Ptr(S1)),
+                                   ('s3', lltype.Ptr(S1)),
+                                   ('s4', lltype.Ptr(S1)),
+                                   ('s5', lltype.Ptr(S1)),
+                                   ('s6', lltype.Ptr(S1)),
+                                   ('s7', lltype.Ptr(S1)),
+                                   ('s8', lltype.Ptr(S1)),
+                                   ('s9', lltype.Ptr(S1)),
+                                   ('s10', lltype.Ptr(S1)),
+                                   ('s11', lltype.Ptr(S1)),
+                                   ('s12', lltype.Ptr(S1)),
+                                   ('s13', lltype.Ptr(S1)),
+                                   ('s14', lltype.Ptr(S1)),
+                                   ('s15', lltype.Ptr(S1)))
+        self.namespace = self.namespace.copy()
+        for i in range(16):
+            self.namespace['ds%i' % i] = cpu.fielddescrof(S2, 's%d' % i)
+        ops = '''
+        [p0]
+        p1 = getfield_gc(p0, descr=ds0)
+        p2 = getfield_gc(p0, descr=ds1)
+        p3 = getfield_gc(p0, descr=ds2)
+        p4 = getfield_gc(p0, descr=ds3)
+        p5 = getfield_gc(p0, descr=ds4)
+        p6 = getfield_gc(p0, descr=ds5)
+        p7 = getfield_gc(p0, descr=ds6)
+        p8 = getfield_gc(p0, descr=ds7)
+        p9 = getfield_gc(p0, descr=ds8)
+        p10 = getfield_gc(p0, descr=ds9)
+        p11 = getfield_gc(p0, descr=ds10)
+        p12 = getfield_gc(p0, descr=ds11)
+        p13 = getfield_gc(p0, descr=ds12)
+        p14 = getfield_gc(p0, descr=ds13)
+        p15 = getfield_gc(p0, descr=ds14)
+        p16 = getfield_gc(p0, descr=ds15)
+        #
+        # now all registers are in use
+        p17 = call_malloc_nursery(40)
+        p18 = call_malloc_nursery(40)     # overflow
+        #
+        finish(p1, p2, p3, p4, p5, p6, p7, p8,         \
+               p9, p10, p11, p12, p13, p14, p15, p16)
+        '''
+        s2 = lltype.malloc(S2)
+        for i in range(16):
+            s1 = lltype.malloc(S1)
+            setattr(s2, 's%d' % i, s1)
+            gc_ll_descr.gcrootmap.should_see.append(s1)
+        s2ref = lltype.cast_opaque_ptr(llmemory.GCREF, s2)
+        #
+        self.interpret(ops, [s2ref])
+        gc_ll_descr.check_nothing_in_nursery()
+        assert gc_ll_descr.calls == [40]
+        gc_ll_descr.gcrootmap.check_initial_and_final_state()
+        # check the returned pointers
+        for i in range(16):
+            s1ref = self.cpu.get_latest_value_ref(i)
+            s1 = lltype.cast_opaque_ptr(lltype.Ptr(S1), s1ref)
+            for j in range(16):
+                assert s1 != getattr(s2, 's%d' % j)
+            assert s1 == gc_ll_descr.gcrootmap.should_see[i]


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