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| author | Lukas Larsson <[email protected]> | 2014-11-05 15:27:06 +0100 |
|---|---|---|
| committer | Lukas Larsson <[email protected]> | 2014-11-05 15:27:06 +0100 |
| commit | 7513bb7670cf7081c4b70e240f99f9424b612f0b (patch) | |
| tree | bc9aabb5e925541f41301a93d40bf11b00bfe533 | |
| parent | 965187787f603181aadbe5effdbb8fa6dc90b9ac (diff) | |
| parent | 16d8a6ce56fd066efa9ecb1d3fa3b3dab6d9613c (diff) | |
| download | otp-7513bb7670cf7081c4b70e240f99f9424b612f0b.tar.gz otp-7513bb7670cf7081c4b70e240f99f9424b612f0b.tar.bz2 otp-7513bb7670cf7081c4b70e240f99f9424b612f0b.zip | |
Merge branch 'lukas/erts/fix_undefined_behaviour/OTP-12290' into maint
* lukas/erts/fix_undefined_behaviour/OTP-12290:
erts: Fix ub in list_to_integer and bignum div
| -rw-r--r-- | erts/emulator/beam/bif.c | 8 | ||||
| -rw-r--r-- | erts/emulator/beam/big.c | 7 |
2 files changed, 8 insertions, 7 deletions
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c index a5be8e1529..42dd160e38 100644 --- a/erts/emulator/beam/bif.c +++ b/erts/emulator/beam/bif.c @@ -2772,6 +2772,7 @@ static int do_list_to_integer(Process *p, Eterm orig_list, Eterm *integer, Eterm *rest) { Sint i = 0; + Uint ui = 0; int skip = 0; int neg = 0; int n = 0; @@ -2825,8 +2826,8 @@ static int do_list_to_integer(Process *p, Eterm orig_list, unsigned_val(CAR(list_val(lst))) > '9') { break; } - i = i * 10; - i = i + unsigned_val(CAR(list_val(lst))) - '0'; + ui = ui * 10; + ui = ui + unsigned_val(CAR(list_val(lst))) - '0'; n++; lst = CDR(list_val(lst)); if (is_nil(lst)) { @@ -2850,7 +2851,8 @@ static int do_list_to_integer(Process *p, Eterm orig_list, */ if (n <= SMALL_DIGITS) { /* It must be small */ - if (neg) i = -i; + if (neg) i = -(Sint)ui; + else i = (Sint)ui; res = make_small(i); } else { lg2 = (n+1)*230/69+1; diff --git a/erts/emulator/beam/big.c b/erts/emulator/beam/big.c index a8710dd910..de7d370938 100644 --- a/erts/emulator/beam/big.c +++ b/erts/emulator/beam/big.c @@ -274,10 +274,9 @@ _b = _b << _s; \ _vn1 = _b >> H_EXP; \ _vn0 = _b & LO_MASK; \ - /* Sometimes _s is 0 which triggers undefined behaviour for the \ - (_a0>>(D_EXP-_s)) shift, but this is ok because the \ - & -s will make it all to 0 later anyways. */ \ - _un32 = (_a1 << _s) | ((_a0>>(D_EXP-_s)) & (-_s >> (D_EXP-1))); \ + /* If needed to avoid undefined behaviour */ \ + if (_s) _un32 = (_a1 << _s) | ((_a0>>(D_EXP-_s)) & (-_s >> (D_EXP-1))); \ + else _un32 = _a1; \ _un10 = _a0 << _s; \ _un1 = _un10 >> H_EXP; \ _un0 = _un10 & LO_MASK; \ |