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| author | Ben Gamari <ben@smart-cactus.org> | 2022-11-16 09:36:26 -0500 |
|---|---|---|
| committer | Matthew Pickering <matthewtpickering@gmail.com> | 2022-12-15 09:38:30 +0000 |
| commit | 59a296f6f959fe912d19491d9a4dc7476259bd44 (patch) | |
| tree | 72ab600f5c9ae3f6a2d4809418b481247067a4e1 | |
| parent | 5e9ac6946d7082502fe05546d32429e2f3aca9b6 (diff) | |
| download | haskell-59a296f6f959fe912d19491d9a4dc7476259bd44.tar.gz | |
compiler: Ensure that MutVar operations have necessary barriers
Here we add acquire and release barriers in readMutVar# and
writeMutVar#, which are necessary for soundness.
Fixes #22468.
(cherry picked from commit a9834736a90aefdd32cfc15be507e22b57eedc07)
| -rw-r--r-- | compiler/GHC/StgToCmm/Prim.hs | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/compiler/GHC/StgToCmm/Prim.hs b/compiler/GHC/StgToCmm/Prim.hs index 2e646ef4fb..81f4f03a1c 100644 --- a/compiler/GHC/StgToCmm/Prim.hs +++ b/compiler/GHC/StgToCmm/Prim.hs @@ -283,9 +283,10 @@ emitPrimOp cfg primop = emitAssign (CmmLocal res) currentTSOExpr ReadMutVarOp -> \[mutv] -> opIntoRegs $ \[res] -> - emitAssign (CmmLocal res) (cmmLoadIndexW platform mutv (fixedHdrSizeW profile) (gcWord platform)) + emitPrimCall [res] (MO_AtomicRead (wordWidth platform) MemOrderAcquire) + [ cmmOffsetW platform mutv (fixedHdrSizeW profile) ] - WriteMutVarOp -> \[mutv, var] -> opIntoRegs $ \res@[] -> do + WriteMutVarOp -> \[mutv, var] -> opIntoRegs $ \[] -> do old_val <- CmmLocal <$> newTemp (cmmExprType platform var) emitAssign old_val (cmmLoadIndexW platform mutv (fixedHdrSizeW profile) (gcWord platform)) @@ -294,8 +295,8 @@ emitPrimOp cfg primop = -- Note that this also must come after we read the old value to ensure -- that the read of old_val comes before another core's write to the -- MutVar's value. - emitPrimCall res MO_WriteBarrier [] - emitStore (cmmOffsetW platform mutv (fixedHdrSizeW profile)) var + emitPrimCall [] (MO_AtomicWrite (wordWidth platform) MemOrderRelease) + [ cmmOffsetW platform mutv (fixedHdrSizeW profile), var ] platform <- getPlatform mkdirtyMutVarCCall <- getCode $! emitCCall |