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path: root/erts/emulator/beam/erl_bits.c
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2015-03-12Merge branch 'maint'Henrik Nord
Conflicts: erts/emulator/hipe/hipe_bif0.c
2015-02-14don't leave a heap hole in erts_bs_get_integer_2Mikael Pettersson
Reset p->htop in the oversize bignum error case to avoid leaving a hole in the heap, which would crash the debug emulator.
2015-02-04don't create oversize bignums in binary matchingMikael Pettersson
Bignums are artifically restricted in size. Arithmetic and logical operations check the sizes of resulting bignums, and turn oversize results into system_limit exceptions. However, this check is not performed when bignums are constructed by binary matching. The consequence is that such matchings can construct oversize bignums that satisfy is_integer/1 yet don't work. Performing arithmetic such as Term - 0 fails with a system_limit exception. Worse, performing a logical operation such as Term band Term results in []. The latter occurs because the size checking (e.g. in erts_band()) is a simple ASSERT(is_not_nil(...)) on the result of the bignum operation, which internally is [] (NIL) in the case of oversize results. However, ASSERT is a no-op in release builds, so the error goes unnoticed and [] is returned as the result of the band/2. This patch addresses this by preventing oversize bignums from entering the VM via binary matching: - the internal bytes_to_big() procedure is augmented to return NIL for oversize results, just like big_norm() - callers of bytes_to_big() are augmented to check for NIL returns and signal errors in those cases - erts_bs_get_integer_2() can only fail with badmatch, so that is the Erlang-level result of oversize bignums from binary matches - big_SUITE.erl is extended with a test case that fails without this fix (no error signalled) and passes with it (badmatch occurs) Credit goes to Nico Kruber for the initial bug report.
2014-09-04erts: Refactor binary allocation interface to also initialize BinarySverker Eriksson
except the reference counter 'refc', as different callers have different strategies regarding the lifetime of the binary.
2013-11-27erts: Fix invalid read when appending binaries during call traceSverker Eriksson
Found by valgrind. Probably safe on opt-VM due to CHICKEN_PAD.
2013-11-26erts: Optimize comparison for bitstrings with byte aligned startSverker Eriksson
2013-11-26erts: Fix invalid read in bitstring comparisonSverker Eriksson
Valgrind complained that erts_cmp_bits sometimes read one byte too much from bitstrings. The byte was never used and the invalid read is safe in opt-VM due to padding in binary allocation (CHICKED_PAD).
2013-06-14Fix binary construction on floating point middle-endian machinesJohannes Weißl
This complements 933e701 (OTP-10209). Without this patch the test cases "in_guard/1" and "coerce_to_float/1" in bs_construct_SUITE fail. The added lines in bs_construct_SUITE cover all branches that were not covered before (small and big numbers if BIT_OFFSET(erts_bin_offset) != 0).
2013-06-14Fix binary matching on floating point middle-endian machinesJohannes Weißl
This complements 933e701 (OTP-10209). Without this patch the test case "bs_match_misc_SUITE:t_float/1" fails. Simple error example: 1> <<_,_,_,_,_,_,_,_>> = <<1.25/float>>. <<63,244,0,0,0,0,0,0>> 2> <<1.25/float>> = <<63,244,0,0,0,0,0,0>>. ** exception error: no match of right hand side value <<63,244,0,0,0,0,0,0>> The additional test case is added because in a former version of this patch the ERTS_FP_ERROR_THOROUGH check for NaN/infinity was mistakenly applied on the still word-switched double.
2012-11-05Fix binary append exceptionsBjörn Gustavsson
Code such as the following should cause an exception: Bin = <<0:1>>, <<Bin/binary,...>> (Because the "binary" type implies that the binary must have a size in bits that is a multiple of 8.) Depending on the binary, either no exception was thrown or the wrong exception was thrown (because c_p->freason was not set). Noticed-by: Adam Rutkowski
2012-08-31Update copyright yearsBjörn-Egil Dahlberg
2012-03-23Unbreak floating point on middle-endian machines.Mike Sperber
On some ARMs (and maybe other platforms), doubles are stored with the the two 32-bit words reversed with respect to more common architectures. The symptom is this: > io_lib:write(1.0). "0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000005299808824" Detect that and account for it when decoding floats.
2011-10-13Allow noncharacter code points in unicode encoding and decodingBjörn Gustavsson
The two noncharacter code points 16#FFFE and 16#FFFF were not allowed to be encoded or decoded using the unicode module or bit syntax. That causes an inconsistency, since the noncharacters 16#FDD0 to 16#FDEF could be encoded/decoded. There is two ways to fix that inconsistency. We have chosen to allow 16#FFFE and 16#FFFF to be encoded and decoded, because the noncharacters could be useful internally within an application and it will make encoding and decoding slightly faster. Reported-by: Alisdair Sullivan
2011-06-14Use new atomic API in runtime systemRickard Green
All uses of the old deprecated atomic API in the runtime system have been replaced with the use of the new atomic API. In a lot of places this change imply a relaxation of memory barriers used.
2011-05-20Update copyright yearsBjörn-Egil Dahlberg
2011-03-16erts: Remove unused variablesTuncer Ayaz
2010-12-21Fix type-checking of variable used in zero-width bit syntax constructionBjörn Gustavsson
<<A:0>> will always produce an empty binary, regardless of the type of A. The bug is in the run-time system. Fix it so that a non-numeric value for A will cause a badarg exception. Reported-by: Zvi
2010-08-12Increase vheap counter to Uint64Björn-Egil Dahlberg
This will reduce the risk of integer wrapping in bin vheap counting. The vheap size series will now use the golden ratio instead of doubling and fibonacci sequences. OTP #8730
2010-07-20One off-heap list, to eliminate two words per ETS object.Sverker Eriksson
Merging the three off-heap lists (binaries, funs and externals) into one list. This reduces memory consumption by two words (pointers) per ETS object.
2010-03-22Merge branch 'pan/otp_8332_halfword' into devErlang/OTP
* pan/otp_8332_halfword: Teach testcase in driver_suite the new prototype for driver_async wx: Correct usage of driver callbacks from wx thread Adopt the new (R13B04) Nif functionality to the halfword codebase Support monitoring and demonitoring from driver threads Fix further test-suite problems Correct the VM to work for more test suites Teach {wordsize,internal|external} to system_info/1 Make tracing and distribution work Turn on instruction packing in the loader and virtual machine Add the BeamInstr data type for loaded BEAM code Fix the BEAM dissambler for the half-word emulator Store pointers to heap data in 32-bit words Add a custom mmap wrapper to force heaps into the lower address range Fit all heap data into the 32-bit address range
2010-03-10Store pointers to heap data in 32-bit wordsPatrik Nyblom
Store Erlang terms in 32-bit entities on the heap, expanding the pointers to 64-bit when needed. This works because all terms are stored on addresses in the 32-bit address range (the 32 most significant bits of pointers to term data are always 0). Introduce a new datatype called UWord (along with its companion SWord), which is an integer having the exact same size as the machine word (a void *), but might be larger than Eterm/Uint. Store code as machine words, as the instructions are pointers to executable code which might reside outside the 32-bit address range. Continuation pointers are stored on the 32-bit stack and hence must point to addresses in the low range, which means that loaded beam code much be placed in the low 32-bit address range (but, as said earlier, the instructions themselves are full words). No Erlang term data can be stored on C stacks (enforced by an earlier commit). This version gives a prompt, but test cases still fail (and dump core). The loader (and emulator loop) has instruction packing disabled. The main issues has been in rewriting loader and actual virtual machine. Subsystems (like distribution) does not work yet.
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP