Author: Armin Rigo <[email protected]>
Branch:
Changeset: r46484:dbecbb82ebbb
Date: 2011-08-13 21:00 +0200
http://bitbucket.org/pypy/pypy/changeset/dbecbb82ebbb/
Log: Bug fix. Hard to test.
diff --git a/pypy/jit/backend/x86/assembler.py
b/pypy/jit/backend/x86/assembler.py
--- a/pypy/jit/backend/x86/assembler.py
+++ b/pypy/jit/backend/x86/assembler.py
@@ -92,6 +92,7 @@
self.datablockwrapper = None
self.stack_check_slowpath = 0
self.propagate_exception_path = 0
+ self.gcrootmap_retaddr_forced = 0
self.teardown()
def leave_jitted_hook(self):
@@ -357,6 +358,7 @@
self.stack_check_slowpath = rawstart
@staticmethod
+ @rgc.no_collect
def _release_gil_asmgcc(css):
# similar to trackgcroot.py:pypy_asm_stackwalk, first part
from pypy.rpython.memory.gctransform import asmgcroot
@@ -372,6 +374,7 @@
before()
@staticmethod
+ @rgc.no_collect
def _reacquire_gil_asmgcc(css):
# first reacquire the GIL
after = rffi.aroundstate.after
@@ -386,12 +389,14 @@
next.prev = prev
@staticmethod
+ @rgc.no_collect
def _release_gil_shadowstack():
before = rffi.aroundstate.before
if before:
before()
@staticmethod
+ @rgc.no_collect
def _reacquire_gil_shadowstack():
after = rffi.aroundstate.after
if after:
@@ -2218,13 +2223,27 @@
css = get_ebp_ofs(pos + use_words - 1)
self._regalloc.close_stack_struct = css
# The location where the future CALL will put its return address
- # will be [ESP-WORD], so save that as the next frame's top address
- self.mc.LEA_rs(eax.value, -WORD) # LEA EAX, [ESP-4]
+ # will be [ESP-WORD]. But we can't use that as the next frame's
+ # top address! As the code after releasegil() runs without the
+ # GIL, it might not be set yet by the time we need it (very
+ # unlikely), or it might be overwritten by the following call
+ # to reaquiregil() (much more likely). So we hack even more
+ # and use a dummy location containing a dummy value (a pointer
+ # to itself) which we pretend is the return address :-/ :-/ :-/
+ # It prevents us to store any %esp-based stack locations but we
+ # don't so far.
+ adr = self.datablockwrapper.malloc_aligned(WORD, WORD)
+ rffi.cast(rffi.CArrayPtr(lltype.Signed), adr)[0] = adr
+ self.gcrootmap_retaddr_forced = adr
frame_ptr = css + WORD * (2+asmgcroot.FRAME_PTR)
- self.mc.MOV_br(frame_ptr, eax.value) # MOV [css.frame], EAX
+ if rx86.fits_in_32bits(adr):
+ self.mc.MOV_bi(frame_ptr, adr) # MOV [css.frame], adr
+ else:
+ self.mc.MOV_ri(eax.value, adr) # MOV EAX, adr
+ self.mc.MOV_br(frame_ptr, eax.value) # MOV [css.frame], EAX
# Save ebp
index_of_ebp = css + WORD * (2+asmgcroot.INDEX_OF_EBP)
- self.mc.MOV_br(index_of_ebp, ebp.value) # MOV [css.ebp], EBP
+ self.mc.MOV_br(index_of_ebp, ebp.value) # MOV [css.ebp], EBP
# Call the closestack() function (also releasing the GIL)
if IS_X86_32:
reg = eax
@@ -2252,6 +2271,9 @@
if gcrootmap.is_shadow_stack:
args = []
else:
+ assert self.gcrootmap_retaddr_forced == -1, (
+ "missing mark_gc_roots() in CALL_RELEASE_GIL")
+ self.gcrootmap_retaddr_forced = 0
css = self._regalloc.close_stack_struct
assert css != 0
if IS_X86_32:
@@ -2502,7 +2524,13 @@
if gcrootmap.is_shadow_stack:
gcrootmap.write_callshape(mark, force_index)
else:
- self.mc.insert_gcroot_marker(mark)
+ if self.gcrootmap_retaddr_forced == 0:
+ self.mc.insert_gcroot_marker(mark) # common case
+ else:
+ assert self.gcrootmap_retaddr_forced != -1, (
+ "two mark_gc_roots() in a CALL_RELEASE_GIL")
+ gcrootmap.put(self.gcrootmap_retaddr_forced, mark)
+ self.gcrootmap_retaddr_forced = -1
def target_arglocs(self, loop_token):
return loop_token._x86_arglocs
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