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| author | Björn Gustavsson <[email protected]> | 2011-05-10 10:56:24 +0200 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2011-08-03 11:24:52 +0200 |
| commit | e8becad96454a8deb755f587ca0daaf96dfca90e (patch) | |
| tree | 40ba945786f497611441f5a13f07efdf2e210879 /erts/emulator/beam | |
| parent | 07936436b8a8b18b80451a09e040283ebecbd43b (diff) | |
| download | otp-e8becad96454a8deb755f587ca0daaf96dfca90e.tar.gz otp-e8becad96454a8deb755f587ca0daaf96dfca90e.tar.bz2 otp-e8becad96454a8deb755f587ca0daaf96dfca90e.zip | |
Fix construction of <<0:((1 bsl 32)-1)>>
Attempting to construct <<0:((1 bsl 32)-1)>>, the largest bitstring
allowed in a 32 bit emulator, would cause an emulator crash because
of integer overflow.
Fix the problem by using an Uint64 to avoid integer overflow.
Do not attempt to handle construction of <<0:((1 bsl 64)-1>> in
a 64-bit emulator, because that will certainly cause the emulator
to terminate anyway because of insufficient memory.
Diffstat (limited to 'erts/emulator/beam')
| -rw-r--r-- | erts/emulator/beam/beam_emu.c | 2 | ||||
| -rw-r--r-- | erts/emulator/beam/erl_bits.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c index fb90a7d4f7..937b3d9e53 100644 --- a/erts/emulator/beam/beam_emu.c +++ b/erts/emulator/beam/beam_emu.c @@ -3561,7 +3561,7 @@ void process_main(void) * Operands: NotUsed Live Dst */ do_bs_init_bits_known: - num_bytes = (num_bits+7) >> 3; + num_bytes = ((Uint64)num_bits+(Uint64)7) >> 3; if (num_bits & 7) { alloc += ERL_SUB_BIN_SIZE; } diff --git a/erts/emulator/beam/erl_bits.h b/erts/emulator/beam/erl_bits.h index 0f67733fa4..3309ea706b 100644 --- a/erts/emulator/beam/erl_bits.h +++ b/erts/emulator/beam/erl_bits.h @@ -150,7 +150,7 @@ void erts_bits_destroy_state(ERL_BITS_PROTO_0); * NBYTES(x) returns the number of bytes needed to store x bits. */ -#define NBYTES(x) (((x) + 7) >> 3) +#define NBYTES(x) (((Uint64)(x) + (Uint64) 7) >> 3) #define BYTE_OFFSET(ofs) ((Uint) (ofs) >> 3) #define BIT_OFFSET(ofs) ((ofs) & 7) |