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| author | Niklas Hambüchen <mail@nh2.me> | 2019-02-17 20:48:45 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2019-02-21 20:58:47 -0500 |
| commit | 0e2d300a59b1b5c167d2e7d99a448c8663ba6d7d (patch) | |
| tree | 99a368451db415ee4f0f364ee6ff8e91e306d42f | |
| parent | 9db92cf0baada362f2b1bd69fbfd156f415d4053 (diff) | |
| download | haskell-0e2d300a59b1b5c167d2e7d99a448c8663ba6d7d.tar.gz | |
compiler: Write .o files atomically. See #14533
This issue was reproduced with, and the fix confirmed with,
the `hatrace` tool for syscall-based fault injection:
https://github.com/nh2/hatrace
The concrete test case for GHC is at
https://github.com/nh2/hatrace/blob/e23d35a2d2c79e8bf49e9e2266b3ff7094267f29/test/HatraceSpec.hs#L185
A previous, nondeterministic reproducer for the issue was provided by
Alexey Kuleshevich in
https://github.com/lehins/exec-kill-loop
Signed-off-by: Niklas Hambüchen <niklas@fpcomplete.com>
Reviewed-by: Alexey Kuleshevich <alexey@fpcomplete.com>
| -rw-r--r-- | compiler/main/DriverPipeline.hs | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/compiler/main/DriverPipeline.hs b/compiler/main/DriverPipeline.hs index 5fe2362973..3f59ed3bbf 100644 --- a/compiler/main/DriverPipeline.hs +++ b/compiler/main/DriverPipeline.hs @@ -1375,7 +1375,12 @@ runPhase (RealPhase (As with_cpp)) input_fn dflags ]) liftIO $ debugTraceMsg dflags 4 (text "Running the assembler") - runAssembler input_fn output_fn + + -- Atomic write by writing to temp file and then renaming + let temp_output_fn = output_fn <.> "tmp" + runAssembler input_fn temp_output_fn + liftIO $ renameFile temp_output_fn output_fn + return (RealPhase next_phase, output_fn) |