[GHC] #14262: fdReady cannot wait more than 49 days
#14262: fdReady cannot wait more than 49 days -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: x86_64 | Type of failure: None/Unknown (amd64) | Test Case: | Blocked By: Blocking: | Related Tickets: #8684, #13497 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{ import System.IO hWaitForInput stdin 4294968296 }}} This code waits for 1 second instead of 49.something days. The culprit: {{{ hWaitForInput :: Handle -> Int -> IO Bool fdReady(..., int msecs, ...) }}} Haskell `Int` is usally 64 bits. C `int` is usually 32 bits. Called here: {{{ ready :: FD -> Bool -> Int -> IO Bool ready fd write msecs = do r <- throwErrnoIfMinus1Retry "GHC.IO.FD.ready" $ fdReady (fdFD fd) (fromIntegral $ fromEnum $ write) (fromIntegral msecs) foreign import ccall safe "fdReady" fdReady :: CInt -> CInt -> CInt -> CInt -> IO CInt }}} We `fromIntegral` `Int` to `CInt` (== `Int32`), overflowing. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14262 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14262: fdReady cannot wait more than 49 days -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: x86_64 | (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #8684, #13497 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by nh2): `fromIntegral` is somewhere between partial functions and `unsafeCoerce` on the evilness scale. IMO think it's time to split `fromIntegral` into `safeFromIntegral` (that can only cast into larger domains) and `overflowingFromIntegral`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14262#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14262: fdReady cannot wait more than 49 days -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: x86_64 | (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #8684, #13497 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by Iceland_jack): * cc: Iceland_jack (added) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14262#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14262: fdReady cannot wait more than 49 days -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: x86_64 | (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #8684, #13497 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by mboes): * cc: mboes (added) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14262#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14262: fdReady cannot wait more than 49 days -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: x86_64 | (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #8684, #13497, | Differential Rev(s): #14267 | Wiki Page: | -------------------------------------+------------------------------------- Changes (by nh2): * related: #8684, #13497 => #8684, #13497, #14267 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14262#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14262: fdReady cannot wait more than 49 days -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: x86_64 | (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #8684, #13497, | Differential Rev(s): #14267 | Wiki Page: | -------------------------------------+------------------------------------- Changes (by osa1): * cc: osa1 (added) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14262#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14262: fdReady cannot wait more than 49 days
-------------------------------------+-------------------------------------
Reporter: nh2 | Owner: (none)
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 8.2.1
Resolution: | Keywords:
Operating System: Unknown/Multiple | Architecture: x86_64
| (amd64)
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: #8684, #13497, | Differential Rev(s):
#14267 |
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Ben Gamari
#14262: fdReady cannot wait more than 49 days -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.4.1 Component: Compiler | Version: 8.2.1 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: x86_64 | (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #8684, #13497, | Differential Rev(s): #14267 | Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => closed * resolution: => fixed * milestone: => 8.4.1 Old description:
{{{ import System.IO hWaitForInput stdin 4294968296 }}}
This code waits for 1 second instead of 49.something days.
The culprit:
{{{ hWaitForInput :: Handle -> Int -> IO Bool fdReady(..., int msecs, ...) }}}
Haskell `Int` is usally 64 bits. C `int` is usually 32 bits.
Called here:
{{{ ready :: FD -> Bool -> Int -> IO Bool ready fd write msecs = do r <- throwErrnoIfMinus1Retry "GHC.IO.FD.ready" $ fdReady (fdFD fd) (fromIntegral $ fromEnum $ write) (fromIntegral msecs)
foreign import ccall safe "fdReady" fdReady :: CInt -> CInt -> CInt -> CInt -> IO CInt }}}
We `fromIntegral` `Int` to `CInt` (== `Int32`), overflowing.
New description: {{{#!hs import System.IO hWaitForInput stdin 4294968296 }}} This code waits for 1 second instead of 49.something days. The culprit: {{{#!hs hWaitForInput :: Handle -> Int -> IO Bool fdReady(..., int msecs, ...) }}} Haskell `Int` is usally 64 bits. C `int` is usually 32 bits. Called here: {{{#!hs ready :: FD -> Bool -> Int -> IO Bool ready fd write msecs = do r <- throwErrnoIfMinus1Retry "GHC.IO.FD.ready" $ fdReady (fdFD fd) (fromIntegral $ fromEnum $ write) (fromIntegral msecs) foreign import ccall safe "fdReady" fdReady :: CInt -> CInt -> CInt -> CInt -> IO CInt }}} We `fromIntegral` `Int` to `CInt` (== `Int32`), overflowing. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14262#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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