[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 6 commits: base: Advertise linear time of readFloat
Marge Bot (@marge-bot)
gitlab at gitlab.haskell.org
Tue Sep 19 08:54:38 UTC 2023
Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC
Commits:
7ca0240e by Ben Gamari at 2023-09-18T15:16:48-04:00
base: Advertise linear time of readFloat
As noted in #23538, `readFloat` has runtime that scales nonlinearly in
the size of its input. Consequently, its use on untrusted input can
be exploited as a denial-of-service vector. Point this out and suggest
use of `read` instead.
See #23538.
- - - - -
f3f58f13 by Simon Peyton Jones at 2023-09-18T15:17:24-04:00
Remove dead code GHC.CoreToStg.Prep.canFloat
This function never fires, so we can delete it: #23965.
- - - - -
ccab5b15 by Ben Gamari at 2023-09-18T15:18:02-04:00
base/changelog: Move fix for #23907 to 9.8.1 section
Since the fix was backported to 9.8.1
- - - - -
03515da0 by Matthew Pickering at 2023-09-19T04:54:14-04:00
Add aarch64 alpine bindist
This is dynamically linked and makes creating statically linked
executables more straightforward.
Fixes #23482
- - - - -
18496c5b by Matthew Pickering at 2023-09-19T04:54:14-04:00
Add aarch64-deb11 bindist
This adds a debian 11 release job for aarch64.
Fixes #22005
- - - - -
bf71651a by Alexis King at 2023-09-19T04:54:25-04:00
Don’t store the async exception masking state in CATCH frames
- - - - -
20 changed files:
- .gitlab/generate-ci/gen_ci.hs
- .gitlab/jobs.yaml
- .gitlab/rel_eng/fetch-gitlab-artifacts/fetch_gitlab.py
- compiler/GHC/CoreToStg/Prep.hs
- libraries/base/Numeric.hs
- libraries/base/changelog.md
- libraries/ghc-heap/GHC/Exts/Heap/Closures.hs
- libraries/ghc-heap/GHC/Exts/Stack/Constants.hsc
- libraries/ghc-heap/GHC/Exts/Stack/Decode.hs
- libraries/ghc-heap/tests/stack_misc_closures.hs
- libraries/ghc-heap/tests/stack_misc_closures_c.c
- rts/Continuation.c
- rts/Exception.cmm
- rts/RaiseAsync.c
- rts/Schedule.c
- rts/include/rts/storage/Closures.h
- + testsuite/tests/rts/continuations/T23513.hs
- + testsuite/tests/rts/continuations/T23513.stdout
- testsuite/tests/rts/continuations/all.T
- utils/deriveConstants/Main.hs
Changes:
=====================================
.gitlab/generate-ci/gen_ci.hs
=====================================
@@ -114,7 +114,8 @@ data LinuxDistro
| Ubuntu2004
| Ubuntu1804
| Centos7
- | Alpine
+ | Alpine312
+ | Alpine318
| AlpineWasm
| Rocky8
deriving (Eq)
@@ -293,7 +294,8 @@ distroName Fedora38 = "fedora38"
distroName Ubuntu1804 = "ubuntu18_04"
distroName Ubuntu2004 = "ubuntu20_04"
distroName Centos7 = "centos7"
-distroName Alpine = "alpine3_12"
+distroName Alpine312 = "alpine3_12"
+distroName Alpine318 = "alpine3_18"
distroName AlpineWasm = "alpine3_17-wasm"
distroName Rocky8 = "rocky8"
@@ -430,9 +432,7 @@ opsysVariables _ (Windows {}) =
, "GHC_VERSION" =: "9.4.3" ]
opsysVariables _ _ = mempty
-
-distroVariables :: LinuxDistro -> Variables
-distroVariables Alpine = mconcat
+alpineVariables = mconcat
[ -- Due to #20266
"CONFIGURE_ARGS" =: "--disable-ld-override"
, "INSTALL_CONFIGURE_ARGS" =: "--disable-ld-override"
@@ -441,6 +441,11 @@ distroVariables Alpine = mconcat
-- T10458, ghcilink002: due to #17869
, "BROKEN_TESTS" =: "encoding004 T10458"
]
+
+
+distroVariables :: LinuxDistro -> Variables
+distroVariables Alpine312 = alpineVariables
+distroVariables Alpine318 = alpineVariables
distroVariables Centos7 = mconcat [
"HADRIAN_ARGS" =: "--docs=no-sphinx"
]
@@ -994,13 +999,15 @@ job_groups =
, allowFailureGroup (onlyRule FreeBSDLabel (validateBuilds Amd64 FreeBSD13 vanilla))
, fastCI (standardBuilds AArch64 Darwin)
, fastCI (standardBuildsWithConfig AArch64 (Linux Debian10) (splitSectionsBroken vanilla))
+ , disableValidate (standardBuildsWithConfig AArch64 (Linux Debian11) (splitSectionsBroken vanilla))
, disableValidate (validateBuilds AArch64 (Linux Debian10) llvm)
, standardBuildsWithConfig I386 (Linux Debian10) (splitSectionsBroken vanilla)
-- Fully static build, in theory usable on any linux distribution.
- , fullyStaticBrokenTests (standardBuildsWithConfig Amd64 (Linux Alpine) (splitSectionsBroken static))
+ , fullyStaticBrokenTests (standardBuildsWithConfig Amd64 (Linux Alpine312) (splitSectionsBroken static))
-- Dynamically linked build, suitable for building your own static executables on alpine
- , disableValidate (standardBuildsWithConfig Amd64 (Linux Alpine) (splitSectionsBroken vanilla))
- , fullyStaticBrokenTests (disableValidate (allowFailureGroup (standardBuildsWithConfig Amd64 (Linux Alpine) staticNativeInt)))
+ , disableValidate (standardBuildsWithConfig Amd64 (Linux Alpine312) (splitSectionsBroken vanilla))
+ , disableValidate (standardBuildsWithConfig AArch64 (Linux Alpine318) (splitSectionsBroken vanilla))
+ , fullyStaticBrokenTests (disableValidate (allowFailureGroup (standardBuildsWithConfig Amd64 (Linux Alpine312) staticNativeInt)))
, validateBuilds Amd64 (Linux Debian11) (crossConfig "aarch64-linux-gnu" (Emulator "qemu-aarch64 -L /usr/aarch64-linux-gnu") Nothing)
, validateBuilds Amd64 (Linux Debian11) (crossConfig "javascript-unknown-ghcjs" (Emulator "js-emulator") (Just "emconfigure")
)
=====================================
.gitlab/jobs.yaml
=====================================
@@ -253,6 +253,71 @@
"XZ_OPT": "-9"
}
},
+ "nightly-aarch64-linux-alpine3_18-validate": {
+ "after_script": [
+ ".gitlab/ci.sh save_cache",
+ ".gitlab/ci.sh save_test_output",
+ ".gitlab/ci.sh clean",
+ "cat ci_timings"
+ ],
+ "allow_failure": false,
+ "artifacts": {
+ "expire_in": "8 weeks",
+ "paths": [
+ "ghc-aarch64-linux-alpine3_18-validate.tar.xz",
+ "junit.xml",
+ "unexpected-test-output.tar.gz"
+ ],
+ "reports": {
+ "junit": "junit.xml"
+ },
+ "when": "always"
+ },
+ "cache": {
+ "key": "aarch64-linux-alpine3_18-$CACHE_REV",
+ "paths": [
+ "cabal-cache",
+ "toolchain"
+ ]
+ },
+ "dependencies": [],
+ "image": "registry.gitlab.haskell.org/ghc/ci-images/aarch64-linux-alpine3_18:$DOCKER_REV",
+ "needs": [
+ {
+ "artifacts": false,
+ "job": "hadrian-ghc-in-ghci"
+ }
+ ],
+ "rules": [
+ {
+ "if": "(\"true\" == \"true\") && ($RELEASE_JOB != \"yes\") && ($NIGHTLY)",
+ "when": "on_success"
+ }
+ ],
+ "script": [
+ "sudo chown ghc:ghc -R .",
+ ".gitlab/ci.sh setup",
+ ".gitlab/ci.sh configure",
+ ".gitlab/ci.sh build_hadrian",
+ ".gitlab/ci.sh test_hadrian"
+ ],
+ "stage": "full-build",
+ "tags": [
+ "aarch64-linux"
+ ],
+ "variables": {
+ "BIGNUM_BACKEND": "gmp",
+ "BIN_DIST_NAME": "ghc-aarch64-linux-alpine3_18-validate",
+ "BROKEN_TESTS": "encoding004 T10458",
+ "BUILD_FLAVOUR": "validate",
+ "CONFIGURE_ARGS": "--disable-ld-override --enable-strict-ghc-toolchain-check",
+ "HADRIAN_ARGS": "--docs=no-sphinx",
+ "INSTALL_CONFIGURE_ARGS": "--disable-ld-override",
+ "RUNTEST_ARGS": "",
+ "TEST_ENV": "aarch64-linux-alpine3_18-validate",
+ "XZ_OPT": "-9"
+ }
+ },
"nightly-aarch64-linux-deb10-validate": {
"after_script": [
".gitlab/ci.sh save_cache",
@@ -377,6 +442,68 @@
"XZ_OPT": "-9"
}
},
+ "nightly-aarch64-linux-deb11-validate": {
+ "after_script": [
+ ".gitlab/ci.sh save_cache",
+ ".gitlab/ci.sh save_test_output",
+ ".gitlab/ci.sh clean",
+ "cat ci_timings"
+ ],
+ "allow_failure": false,
+ "artifacts": {
+ "expire_in": "8 weeks",
+ "paths": [
+ "ghc-aarch64-linux-deb11-validate.tar.xz",
+ "junit.xml",
+ "unexpected-test-output.tar.gz"
+ ],
+ "reports": {
+ "junit": "junit.xml"
+ },
+ "when": "always"
+ },
+ "cache": {
+ "key": "aarch64-linux-deb11-$CACHE_REV",
+ "paths": [
+ "cabal-cache",
+ "toolchain"
+ ]
+ },
+ "dependencies": [],
+ "image": "registry.gitlab.haskell.org/ghc/ci-images/aarch64-linux-deb11:$DOCKER_REV",
+ "needs": [
+ {
+ "artifacts": false,
+ "job": "hadrian-ghc-in-ghci"
+ }
+ ],
+ "rules": [
+ {
+ "if": "(\"true\" == \"true\") && ($RELEASE_JOB != \"yes\") && ($NIGHTLY)",
+ "when": "on_success"
+ }
+ ],
+ "script": [
+ "sudo chown ghc:ghc -R .",
+ ".gitlab/ci.sh setup",
+ ".gitlab/ci.sh configure",
+ ".gitlab/ci.sh build_hadrian",
+ ".gitlab/ci.sh test_hadrian"
+ ],
+ "stage": "full-build",
+ "tags": [
+ "aarch64-linux"
+ ],
+ "variables": {
+ "BIGNUM_BACKEND": "gmp",
+ "BIN_DIST_NAME": "ghc-aarch64-linux-deb11-validate",
+ "BUILD_FLAVOUR": "validate",
+ "CONFIGURE_ARGS": "--enable-strict-ghc-toolchain-check",
+ "RUNTEST_ARGS": "",
+ "TEST_ENV": "aarch64-linux-deb11-validate",
+ "XZ_OPT": "-9"
+ }
+ },
"nightly-i386-linux-deb10-validate": {
"after_script": [
".gitlab/ci.sh save_cache",
@@ -2593,6 +2720,72 @@
"XZ_OPT": "-9"
}
},
+ "release-aarch64-linux-alpine3_18-release+no_split_sections": {
+ "after_script": [
+ ".gitlab/ci.sh save_cache",
+ ".gitlab/ci.sh save_test_output",
+ ".gitlab/ci.sh clean",
+ "cat ci_timings"
+ ],
+ "allow_failure": false,
+ "artifacts": {
+ "expire_in": "1 year",
+ "paths": [
+ "ghc-aarch64-linux-alpine3_18-release+no_split_sections.tar.xz",
+ "junit.xml",
+ "unexpected-test-output.tar.gz"
+ ],
+ "reports": {
+ "junit": "junit.xml"
+ },
+ "when": "always"
+ },
+ "cache": {
+ "key": "aarch64-linux-alpine3_18-$CACHE_REV",
+ "paths": [
+ "cabal-cache",
+ "toolchain"
+ ]
+ },
+ "dependencies": [],
+ "image": "registry.gitlab.haskell.org/ghc/ci-images/aarch64-linux-alpine3_18:$DOCKER_REV",
+ "needs": [
+ {
+ "artifacts": false,
+ "job": "hadrian-ghc-in-ghci"
+ }
+ ],
+ "rules": [
+ {
+ "if": "(\"true\" == \"true\") && ($RELEASE_JOB == \"yes\") && ($NIGHTLY == null)",
+ "when": "on_success"
+ }
+ ],
+ "script": [
+ "sudo chown ghc:ghc -R .",
+ ".gitlab/ci.sh setup",
+ ".gitlab/ci.sh configure",
+ ".gitlab/ci.sh build_hadrian",
+ ".gitlab/ci.sh test_hadrian"
+ ],
+ "stage": "full-build",
+ "tags": [
+ "aarch64-linux"
+ ],
+ "variables": {
+ "BIGNUM_BACKEND": "gmp",
+ "BIN_DIST_NAME": "ghc-aarch64-linux-alpine3_18-release+no_split_sections",
+ "BROKEN_TESTS": "encoding004 T10458",
+ "BUILD_FLAVOUR": "release+no_split_sections",
+ "CONFIGURE_ARGS": "--disable-ld-override --enable-strict-ghc-toolchain-check",
+ "HADRIAN_ARGS": "--hash-unit-ids --docs=no-sphinx",
+ "IGNORE_PERF_FAILURES": "all",
+ "INSTALL_CONFIGURE_ARGS": "--disable-ld-override",
+ "RUNTEST_ARGS": "",
+ "TEST_ENV": "aarch64-linux-alpine3_18-release+no_split_sections",
+ "XZ_OPT": "-9"
+ }
+ },
"release-aarch64-linux-deb10-release+no_split_sections": {
"after_script": [
".gitlab/ci.sh save_cache",
@@ -2657,6 +2850,70 @@
"XZ_OPT": "-9"
}
},
+ "release-aarch64-linux-deb11-release+no_split_sections": {
+ "after_script": [
+ ".gitlab/ci.sh save_cache",
+ ".gitlab/ci.sh save_test_output",
+ ".gitlab/ci.sh clean",
+ "cat ci_timings"
+ ],
+ "allow_failure": false,
+ "artifacts": {
+ "expire_in": "1 year",
+ "paths": [
+ "ghc-aarch64-linux-deb11-release+no_split_sections.tar.xz",
+ "junit.xml",
+ "unexpected-test-output.tar.gz"
+ ],
+ "reports": {
+ "junit": "junit.xml"
+ },
+ "when": "always"
+ },
+ "cache": {
+ "key": "aarch64-linux-deb11-$CACHE_REV",
+ "paths": [
+ "cabal-cache",
+ "toolchain"
+ ]
+ },
+ "dependencies": [],
+ "image": "registry.gitlab.haskell.org/ghc/ci-images/aarch64-linux-deb11:$DOCKER_REV",
+ "needs": [
+ {
+ "artifacts": false,
+ "job": "hadrian-ghc-in-ghci"
+ }
+ ],
+ "rules": [
+ {
+ "if": "(\"true\" == \"true\") && ($RELEASE_JOB == \"yes\") && ($NIGHTLY == null)",
+ "when": "on_success"
+ }
+ ],
+ "script": [
+ "sudo chown ghc:ghc -R .",
+ ".gitlab/ci.sh setup",
+ ".gitlab/ci.sh configure",
+ ".gitlab/ci.sh build_hadrian",
+ ".gitlab/ci.sh test_hadrian"
+ ],
+ "stage": "full-build",
+ "tags": [
+ "aarch64-linux"
+ ],
+ "variables": {
+ "BIGNUM_BACKEND": "gmp",
+ "BIN_DIST_NAME": "ghc-aarch64-linux-deb11-release+no_split_sections",
+ "BUILD_FLAVOUR": "release+no_split_sections",
+ "CONFIGURE_ARGS": "--enable-strict-ghc-toolchain-check",
+ "HADRIAN_ARGS": "--hash-unit-ids",
+ "IGNORE_PERF_FAILURES": "all",
+ "RUNTEST_ARGS": "",
+ "TEST_ENV": "aarch64-linux-deb11-release+no_split_sections",
+ "XZ_OPT": "-9"
+ }
+ },
"release-i386-linux-deb10-release+no_split_sections": {
"after_script": [
".gitlab/ci.sh save_cache",
=====================================
.gitlab/rel_eng/fetch-gitlab-artifacts/fetch_gitlab.py
=====================================
@@ -39,6 +39,8 @@ def job_triple(job_name):
'release-i386-linux-deb10-release': 'i386-deb10-linux',
'release-armv7-linux-deb10-release': 'armv7-deb10-linux',
'release-aarch64-linux-deb10-release': 'aarch64-deb10-linux',
+ 'release-aarch64-linux-deb11-release': 'aarch64-deb11-linux',
+ 'release-aarch64-linux-alpine_3_18-release': 'aarch64-alpine3_18-linux',
'release-aarch64-darwin-release': 'aarch64-apple-darwin',
'source-tarball': 'src',
=====================================
compiler/GHC/CoreToStg/Prep.hs
=====================================
@@ -657,9 +657,6 @@ cpePair top_lvl is_rec dmd is_unlifted env bndr rhs
| allLazyTop floats
= return (floats, rhs)
- | Just floats <- canFloat floats rhs
- = return floats
-
| otherwise
= dontFloat floats rhs
@@ -1954,32 +1951,6 @@ deFloatTop (Floats _ floats)
---------------------------------------------------------------------------
-canFloat :: Floats -> CpeRhs -> Maybe (Floats, CpeRhs)
-canFloat (Floats ok_to_spec fs) rhs
- | OkToSpec <- ok_to_spec -- Worth trying
- , Just fs' <- go nilOL (fromOL fs)
- = Just (Floats OkToSpec fs', rhs)
- | otherwise
- = Nothing
- where
- go :: OrdList FloatingBind -> [FloatingBind]
- -> Maybe (OrdList FloatingBind)
-
- go (fbs_out) [] = Just fbs_out
-
- go fbs_out (fb@(FloatLet _) : fbs_in)
- = go (fbs_out `snocOL` fb) fbs_in
-
- go fbs_out (fb at FloatString{} : fbs_in)
- -- See Note [ANF-ising literal string arguments]
- = go (fbs_out `snocOL` fb) fbs_in
-
- go fbs_out (ft at FloatTick{} : fbs_in)
- = go (fbs_out `snocOL` ft) fbs_in
-
- go _ (FloatCase{} : _) = Nothing
-
-
wantFloatNested :: RecFlag -> Demand -> Bool -> Floats -> CpeRhs -> Bool
wantFloatNested is_rec dmd rhs_is_unlifted floats rhs
= isEmptyFloats floats
=====================================
libraries/base/Numeric.hs
=====================================
@@ -117,6 +117,14 @@ readHex = readP_to_S L.readHexP
-- | Reads an /unsigned/ 'RealFrac' value,
-- expressed in decimal scientific notation.
+--
+-- Note that this function takes time linear in the magnitude of its input
+-- which can scale exponentially with input size (e.g. @"1e100000000"@ is a
+-- very large number while having a very small textual form).
+-- For this reason, users should take care to avoid using this function on
+-- untrusted input. Users needing to parse floating point values
+-- (e.g. 'Float') are encouraged to instead use 'read', which does
+-- not suffer from this issue.
readFloat :: RealFrac a => ReadS a
readFloat = readP_to_S readFloatP
=====================================
libraries/base/changelog.md
=====================================
@@ -4,7 +4,6 @@
* Export `foldl'` from `Prelude` ([CLC proposal #167](https://github.com/haskell/core-libraries-committee/issues/167))
* Add a `RULE` to `Prelude.lookup`, allowing it to participate in list fusion ([CLC proposal #174](https://github.com/haskell/core-libraries-committee/issues/175))
* The `Enum Int64` and `Enum Word64` instances now use native operations on 32-bit platforms, increasing performance by up to 1.5x on i386 and up to 5.6x with the JavaScript backend. ([CLC proposal #187](https://github.com/haskell/core-libraries-committee/issues/187))
- * Add rewrite rules for conversion between Int64/Word64 and Float/Double on 64-bit architectures ([CLC proposal #203](https://github.com/haskell/core-libraries-committee/issues/203)).
* Update to [Unicode 15.1.0](https://www.unicode.org/versions/Unicode15.1.0/).
## 4.19.0.0 *TBA*
@@ -44,6 +43,7 @@
* Deprecate `Data.List.NonEmpty.unzip` ([CLC proposal #86](https://github.com/haskell/core-libraries-committee/issues/86))
* Fixed exponent overflow/underflow bugs in the `Read` instances for `Float` and `Double` ([CLC proposal #192](https://github.com/haskell/core-libraries-committee/issues/192))
* Implement `copyBytes`, `fillBytes`, `moveBytes` and `stimes` for `Data.Array.Byte.ByteArray` using primops ([CLC proposal #188](https://github.com/haskell/core-libraries-committee/issues/188))
+ * Add rewrite rules for conversion between Int64/Word64 and Float/Double on 64-bit architectures ([CLC proposal #203](https://github.com/haskell/core-libraries-committee/issues/203)).
## 4.18.0.0 *March 2023*
* Shipped with GHC 9.6.1
=====================================
libraries/ghc-heap/GHC/Exts/Heap/Closures.hs
=====================================
@@ -412,7 +412,6 @@ data GenStackFrame b =
| CatchFrame
{ info_tbl :: !StgInfoTable
- , exceptions_blocked :: !Word
, handler :: !b
}
=====================================
libraries/ghc-heap/GHC/Exts/Stack/Constants.hsc
=====================================
@@ -23,10 +23,6 @@ offsetStgCatchFrameHandler :: WordOffset
offsetStgCatchFrameHandler = byteOffsetToWordOffset $
(#const OFFSET_StgCatchFrame_handler) + (#size StgHeader)
-offsetStgCatchFrameExceptionsBlocked :: WordOffset
-offsetStgCatchFrameExceptionsBlocked = byteOffsetToWordOffset $
- (#const OFFSET_StgCatchFrame_exceptions_blocked) + (#size StgHeader)
-
sizeStgCatchFrame :: Int
sizeStgCatchFrame = bytesToWords $
(#const SIZEOF_StgCatchFrame_NoHdr) + (#size StgHeader)
=====================================
libraries/ghc-heap/GHC/Exts/Stack/Decode.hs
=====================================
@@ -331,12 +331,10 @@ unpackStackFrame (StackSnapshot stackSnapshot#, index) = do
updatee = updatee'
}
CATCH_FRAME -> do
- let exceptions_blocked' = getWord stackSnapshot# (index + offsetStgCatchFrameExceptionsBlocked)
- handler' = getClosureBox stackSnapshot# (index + offsetStgCatchFrameHandler)
+ let handler' = getClosureBox stackSnapshot# (index + offsetStgCatchFrameHandler)
pure $
CatchFrame
{ info_tbl = info,
- exceptions_blocked = exceptions_blocked',
handler = handler'
}
UNDERFLOW_FRAME -> do
=====================================
libraries/ghc-heap/tests/stack_misc_closures.hs
=====================================
@@ -113,11 +113,10 @@ main = do
\case
CatchFrame {..} -> do
assertEqual (tipe info_tbl) CATCH_FRAME
- assertEqual exceptions_blocked 1
assertConstrClosure 1 handler
e -> error $ "Wrong closure type: " ++ show e
traceM "Test 4"
- testSize any_catch_frame# 3
+ testSize any_catch_frame# 2
traceM "Test 5"
test any_catch_stm_frame# $
\case
=====================================
libraries/ghc-heap/tests/stack_misc_closures_c.c
=====================================
@@ -25,7 +25,6 @@ void create_any_catch_frame(Capability *cap, StgStack *stack, StgWord w) {
StgCatchFrame *catchF = (StgCatchFrame *)stack->sp;
SET_HDR(catchF, &stg_catch_frame_info, CCS_SYSTEM);
StgClosure *payload = rts_mkWord(cap, w);
- catchF->exceptions_blocked = 1;
catchF->handler = payload;
}
=====================================
rts/Continuation.c
=====================================
@@ -374,12 +374,12 @@ StgClosure *captureContinuationAndAbort(Capability *cap, StgTSO *tso, StgPromptT
// 1. We walk the stack to find the prompt frame to capture up to (if any).
//
// 2. If we successfully find a matching prompt, we proceed with the actual
- // by allocating space for the continuation, performing the necessary
- // copying, and unwinding the stack.
+ // capture by allocating space for the continuation, performing the
+ // necessary copying, and unwinding the stack.
//
// These variables are modified in Phase 1 to keep track of how far we had to
// walk before finding the prompt frame. Afterwards, Phase 2 consults them to
- // determine how to proceed with the actual capture.
+ // determine how to proceed.
StgWord total_words = 0;
bool in_first_chunk = true;
=====================================
rts/Exception.cmm
=====================================
@@ -393,16 +393,14 @@ stg_killMyself
* kind of return to the activation record underneath us on the stack.
*/
-#define CATCH_FRAME_FIELDS(w_,p_,info_ptr,p1,p2,exceptions_blocked,handler) \
+#define CATCH_FRAME_FIELDS(w_,p_,info_ptr,p1,p2,handler) \
w_ info_ptr, \
PROF_HDR_FIELDS(w_,p1,p2) \
- w_ exceptions_blocked, \
p_ handler
INFO_TABLE_RET(stg_catch_frame, CATCH_FRAME,
- CATCH_FRAME_FIELDS(W_,P_,info_ptr, p1, p2,
- exceptions_blocked,handler))
+ CATCH_FRAME_FIELDS(W_,P_,info_ptr, p1, p2,handler))
return (P_ ret)
{
return (ret);
@@ -411,12 +409,7 @@ INFO_TABLE_RET(stg_catch_frame, CATCH_FRAME,
stg_catchzh ( P_ io, /* :: IO a */
P_ handler /* :: Exception -> IO a */ )
{
- W_ exceptions_blocked;
-
STK_CHK_GEN();
-
- exceptions_blocked =
- TO_W_(StgTSO_flags(CurrentTSO)) & (TSO_BLOCKEX | TSO_INTERRUPTIBLE);
TICK_CATCHF_PUSHED();
/* Apply R1 to the realworld token */
@@ -424,8 +417,7 @@ stg_catchzh ( P_ io, /* :: IO a */
TICK_SLOW_CALL_fast_v();
jump stg_ap_v_fast
- (CATCH_FRAME_FIELDS(,,stg_catch_frame_info, CCCS, 0,
- exceptions_blocked, handler))
+ (CATCH_FRAME_FIELDS(,,stg_catch_frame_info, CCCS, 0, handler))
(io);
}
@@ -599,26 +591,28 @@ retry_pop_stack:
frame = Sp;
if (frame_type == CATCH_FRAME)
{
+ // Note: if this branch is updated, there is a good chance that
+ // corresponding logic in `raiseAsync` must be updated to match!
+ // See Note [Apply the handler directly in raiseAsync] in RaiseAsync.c.
+
Sp = Sp + SIZEOF_StgCatchFrame;
- if ((StgCatchFrame_exceptions_blocked(frame) & TSO_BLOCKEX) == 0) {
+
+ W_ flags;
+ flags = TO_W_(StgTSO_flags(CurrentTSO));
+ if ((flags & TSO_BLOCKEX) == 0) {
Sp_adj(-1);
Sp(0) = stg_unmaskAsyncExceptionszh_ret_info;
}
/* Ensure that async exceptions are masked when running the handler.
- */
- StgTSO_flags(CurrentTSO) = %lobits32(
- TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX | TSO_INTERRUPTIBLE);
-
- /* The interruptible state is inherited from the context of the
+ *
+ * The interruptible state is inherited from the context of the
* catch frame, but note that TSO_INTERRUPTIBLE is only meaningful
* if TSO_BLOCKEX is set. (we got this wrong earlier, and #4988
* was a symptom of the bug).
*/
- if ((StgCatchFrame_exceptions_blocked(frame) &
- (TSO_BLOCKEX | TSO_INTERRUPTIBLE)) == TSO_BLOCKEX) {
- StgTSO_flags(CurrentTSO) = %lobits32(
- TO_W_(StgTSO_flags(CurrentTSO)) & ~TSO_INTERRUPTIBLE);
+ if ((flags & (TSO_BLOCKEX | TSO_INTERRUPTIBLE)) != TSO_BLOCKEX) {
+ StgTSO_flags(CurrentTSO) = %lobits32(flags | TSO_BLOCKEX | TSO_INTERRUPTIBLE);
}
}
else /* CATCH_STM_FRAME */
=====================================
rts/RaiseAsync.c
=====================================
@@ -951,44 +951,36 @@ raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception,
case CATCH_FRAME:
// If we find a CATCH_FRAME, and we've got an exception to raise,
- // then build the THUNK raise(exception), and leave it on
- // top of the CATCH_FRAME ready to enter.
- //
+ // then set up the top of the stack to apply the handler;
+ // see Note [Apply the handler directly in raiseAsync].
{
- StgCatchFrame *cf = (StgCatchFrame *)frame;
- StgThunk *raise;
-
if (exception == NULL) break;
- // we've got an exception to raise, so let's pass it to the
- // handler in this frame.
- //
- raise = (StgThunk *)allocate(cap,sizeofW(StgThunk)+1);
- TICK_ALLOC_SE_THK(sizeofW(StgThunk)+1,0);
- SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
- raise->payload[0] = exception;
+ StgClosure *handler = ((StgCatchFrame *)frame)->handler;
- // throw away the stack from Sp up to the CATCH_FRAME.
- //
- sp = frame - 1;
-
- /* Ensure that async exceptions are blocked now, so we don't get
- * a surprise exception before we get around to executing the
- * handler.
- */
- tso->flags |= TSO_BLOCKEX;
- if ((cf->exceptions_blocked & TSO_INTERRUPTIBLE) == 0) {
- tso->flags &= ~TSO_INTERRUPTIBLE;
- } else {
- tso->flags |= TSO_INTERRUPTIBLE;
+ // Throw away the stack from Sp up to and including the CATCH_FRAME.
+ sp = frame + stack_frame_sizeW((StgClosure *)frame);
+
+ // Unmask async exceptions after running the handler, if necessary.
+ if ((tso->flags & TSO_BLOCKEX) == 0) {
+ sp--;
+ sp[0] = (W_)&stg_unmaskAsyncExceptionszh_ret_info;
}
- /* Put the newly-built THUNK on top of the stack, ready to execute
- * when the thread restarts.
- */
- sp[0] = (W_)raise;
- sp[-1] = (W_)&stg_enter_info;
- stack->sp = sp-1;
+ // Ensure that async exceptions are masked while running the handler;
+ // see Note [Apply the handler directly in raiseAsync].
+ if ((tso->flags & (TSO_BLOCKEX | TSO_INTERRUPTIBLE)) != TSO_BLOCKEX) {
+ tso->flags |= TSO_BLOCKEX | TSO_INTERRUPTIBLE;
+ }
+
+ // Set up the top of the stack to apply the handler.
+ sp -= 4;
+ sp[0] = (W_)&stg_enter_info;
+ sp[1] = (W_)handler;
+ sp[2] = (W_)&stg_ap_pv_info;
+ sp[3] = (W_)exception;
+
+ stack->sp = sp;
RELAXED_STORE(&tso->what_next, ThreadRunGHC);
goto done;
}
@@ -1080,6 +1072,15 @@ raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception,
};
default:
+ // see Note [Update async masking state on unwind] in Schedule.c
+ if (*frame == (W_)&stg_unmaskAsyncExceptionszh_ret_info) {
+ tso->flags &= ~(TSO_BLOCKEX | TSO_INTERRUPTIBLE);
+ } else if (*frame == (W_)&stg_maskAsyncExceptionszh_ret_info) {
+ tso->flags |= TSO_BLOCKEX | TSO_INTERRUPTIBLE;
+ } else if (*frame == (W_)&stg_maskUninterruptiblezh_ret_info) {
+ tso->flags |= TSO_BLOCKEX;
+ tso->flags &= ~TSO_INTERRUPTIBLE;
+ }
break;
}
@@ -1098,3 +1099,26 @@ done:
return tso;
}
+
+/* Note [Apply the handler directly in raiseAsync]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+When we encounter a `catch#` frame while unwinding the stack due to an
+async exception, we need to set up the stack to resume execution by
+invoking the exception handler. One natural way to do it would be to
+simply place a `raise#` thunk on the top of the stack, ready to be
+entered. This would effectively convert the asynchronous exception to
+a synchronous one at a point where it’s known to be safe to do so.
+
+However, there is a danger to this strategy: if async exceptions are
+currently unmasked, it becomes possible for a second async exception
+to be delivered before we enter the application of `raise#`, which
+would result in the first exception being lost. The easiest way to
+prevent this race from happening is to have `raiseAsync` set up the
+stack to apply the handler directly, effectively emulating the
+behavior of `raise#`, as this allows exceptions to be preemptively
+masked before returning. This means `raiseAsync` must also push a
+frame to unmask async exceptions after the handler returns if
+necessary, just as `raise#` does.
+
+This strategy results in some logical duplication, but it is correct,
+and the duplicated logic is small enough to be acceptable. */
=====================================
rts/Schedule.c
=====================================
@@ -3019,19 +3019,6 @@ raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception)
// thunks which are currently under evaluation.
//
- // OLD COMMENT (we don't have MIN_UPD_SIZE now):
- // LDV profiling: stg_raise_info has THUNK as its closure
- // type. Since a THUNK takes at least MIN_UPD_SIZE words in its
- // payload, MIN_UPD_SIZE is more appropriate than 1. It seems that
- // 1 does not cause any problem unless profiling is performed.
- // However, when LDV profiling goes on, we need to linearly scan
- // small object pool, where raise_closure is stored, so we should
- // use MIN_UPD_SIZE.
- //
- // raise_closure = (StgClosure *)RET_STGCALL1(P_,allocate,
- // sizeofW(StgClosure)+1);
- //
-
//
// Walk up the stack, looking for the catch frame. On the way,
// we update any closures pointed to from update frames with the
@@ -3094,12 +3081,52 @@ raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception)
}
default:
+ // see Note [Update async masking state on unwind]
+ if (*p == (StgWord)&stg_unmaskAsyncExceptionszh_ret_info) {
+ tso->flags &= ~(TSO_BLOCKEX | TSO_INTERRUPTIBLE);
+ } else if (*p == (StgWord)&stg_maskAsyncExceptionszh_ret_info) {
+ tso->flags |= TSO_BLOCKEX | TSO_INTERRUPTIBLE;
+ } else if (*p == (StgWord)&stg_maskUninterruptiblezh_ret_info) {
+ tso->flags |= TSO_BLOCKEX;
+ tso->flags &= ~TSO_INTERRUPTIBLE;
+ }
p = next;
continue;
}
}
}
+/* Note [Update async masking state on unwind]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+When we raise an exception or capture a continuation, we unwind the
+stack by searching for an enclosing `catch#` or `prompt#` frame. If we
+unwind past frames intended to restore the async exception masking
+state, we must take care to reproduce their intended effect in order
+to ensure that async exceptions are properly unmasked or remasked.
+
+On paper, this seems as simple as updating `tso->flags` appropriately,
+but in fact there is one additional wrinkle: when async exceptions are
+*unmasked*, we must eagerly check for a pending async exception and
+raise it if necessary. This is not terribly involved, but it’s not
+trivial, either (see the definition of `stg_unmaskAsyncExceptionszh_ret`),
+so we’d prefer to avoid duplicating that logic in several places.
+
+Fortunately, when we’re unwinding the stack due to a raised exception,
+this detail is actually unimportant: `catch#` implicitly masks async
+exceptions while running the handler as we explicitly *don’t* want the
+thread to be interrupted before it has a chance to handle the
+exception. However, when capturing a continuation, we don’t have this
+luxury, so we take two different strategies:
+
+* When unwinding the stack due to a raised exception (synchonrous or
+ asynchronous), we just update `tso->flags` directly and take no
+ further action.
+
+* When unwinding the stack due to a continuation capture, we update
+ the masking state *indirectly* by pushing an appropriate frame onto
+ the stack before we return. This strategy is described at length
+ in Note [Continuations and async exception masking] in Continuation.c. */
+
/* -----------------------------------------------------------------------------
findRetryFrameHelper
=====================================
rts/include/rts/storage/Closures.h
=====================================
@@ -281,7 +281,6 @@ typedef struct {
// Closure types: CATCH_FRAME
typedef struct {
StgHeader header;
- StgWord exceptions_blocked;
StgClosure *handler;
} StgCatchFrame;
=====================================
testsuite/tests/rts/continuations/T23513.hs
=====================================
@@ -0,0 +1,36 @@
+-- This test checks that restoring a continuation that captures a CATCH frame
+-- properly adjusts the async exception masking state.
+
+import Control.Exception
+import Data.IORef
+
+import ContIO
+
+data E = E deriving (Show)
+instance Exception E
+
+printMaskingState :: IO ()
+printMaskingState = print =<< getMaskingState
+
+main :: IO ()
+main = do
+ tag <- newPromptTag
+ ref <- newIORef Nothing
+ mask_ $ prompt tag $
+ catch (control0 tag $ \k ->
+ writeIORef ref (Just k))
+ (\E -> printMaskingState)
+ Just k <- readIORef ref
+
+ let execute_test = do
+ k (printMaskingState *> throwIO E)
+ printMaskingState
+
+ putStrLn "initially unmasked:"
+ execute_test
+
+ putStrLn "\ninitially interruptibly masked:"
+ mask_ execute_test
+
+ putStrLn "\ninitially uninterruptibly masked:"
+ uninterruptibleMask_ execute_test
=====================================
testsuite/tests/rts/continuations/T23513.stdout
=====================================
@@ -0,0 +1,14 @@
+initially unmasked:
+Unmasked
+MaskedInterruptible
+Unmasked
+
+initially interruptibly masked:
+MaskedInterruptible
+MaskedInterruptible
+MaskedInterruptible
+
+initially uninterruptibly masked:
+MaskedUninterruptible
+MaskedUninterruptible
+MaskedUninterruptible
=====================================
testsuite/tests/rts/continuations/all.T
=====================================
@@ -7,3 +7,5 @@ test('cont_exn_masking', [extra_files(['ContIO.hs'])], multimod_compile_and_run,
test('cont_missing_prompt_err', [extra_files(['ContIO.hs']), exit_code(1)], multimod_compile_and_run, ['cont_missing_prompt_err', ''])
test('cont_nondet_handler', [extra_files(['ContIO.hs'])], multimod_compile_and_run, ['cont_nondet_handler', ''])
test('cont_stack_overflow', [extra_files(['ContIO.hs'])], multimod_compile_and_run, ['cont_stack_overflow', '-with-rtsopts "-ki1k -kc2k -kb256"'])
+
+test('T23513', [extra_files(['ContIO.hs'])], multimod_compile_and_run, ['T23513', ''])
=====================================
utils/deriveConstants/Main.hs
=====================================
@@ -484,7 +484,6 @@ wanteds os = concat
,closureField Both "StgOrigThunkInfoFrame" "info_ptr"
,closureField C "StgCatchFrame" "handler"
- ,closureField C "StgCatchFrame" "exceptions_blocked"
,structSize C "StgRetFun"
,fieldOffset C "StgRetFun" "size"
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/90d64ea2fd54cca954e5c593ba7b439d9a28c930...bf71651ac018aa31bfe901ba77267d5e40e44977
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/90d64ea2fd54cca954e5c593ba7b439d9a28c930...bf71651ac018aa31bfe901ba77267d5e40e44977
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