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| author | Björn Gustavsson <[email protected]> | 2017-08-18 15:50:30 +0200 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2017-08-23 05:57:38 +0200 |
| commit | 961f96e9c7c4ad0b64bc6c88700c6eedd30162b5 (patch) | |
| tree | d714c87cc91c523dbd550bef0dcf81e5df3dca30 | |
| parent | acad85c9831452e5865f2bd3fdd31455b493f091 (diff) | |
| download | otp-961f96e9c7c4ad0b64bc6c88700c6eedd30162b5.tar.gz otp-961f96e9c7c4ad0b64bc6c88700c6eedd30162b5.tar.bz2 otp-961f96e9c7c4ad0b64bc6c88700c6eedd30162b5.zip | |
beam_makeops: Prevent truncation when packing 'I' values
BEAM_WIDE_MASK covered the 16 right-most bits, instead of the 32
right-most bits. This bug will bite us when we'll do more packing in
the future.
This bug has been harmless in the past. It has been used in
test_heap and allocate instructions for the number of heap words
needed. It would be theoretically possible to construct a program
that would need 65536 or more heap words, but it is hard to imagine
a practical use for such a program. (The program would have to build
a tuple or list with at least one variable and the rest of the elements
being literals.)
| -rwxr-xr-x | erts/emulator/utils/beam_makeops | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops index f9e22444f3..c3ff7bf31f 100755 --- a/erts/emulator/utils/beam_makeops +++ b/erts/emulator/utils/beam_makeops @@ -705,7 +705,7 @@ sub emulator_output { print "#if !defined(ARCH_64)\n"; print qq[ #error "64-bit architecture assumed, but ARCH_64 not defined"\n]; print "#endif\n"; - print "#define BEAM_WIDE_MASK 0xFFFFUL\n"; + print "#define BEAM_WIDE_MASK 0xFFFFFFFFUL\n"; print "#define BEAM_LOOSE_MASK 0xFFFFUL\n"; print "#define BEAM_TIGHT_MASK 0xFFFFUL\n"; print "#define BEAM_WIDE_SHIFT 32\n"; |