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| author | Sverker Eriksson <[email protected]> | 2016-07-08 16:41:22 +0200 |
|---|---|---|
| committer | Sverker Eriksson <[email protected]> | 2016-07-08 16:41:22 +0200 |
| commit | 3585c1e6832083acbfc130c0aafc8f2db2f3f706 (patch) | |
| tree | 5e2e73ae6b662c3d33a20928875461260c023159 /erts/emulator | |
| parent | 0573efbc18fc20f8646cf3ff64d2affd06e03cb8 (diff) | |
| download | otp-3585c1e6832083acbfc130c0aafc8f2db2f3f706.tar.gz otp-3585c1e6832083acbfc130c0aafc8f2db2f3f706.tar.bz2 otp-3585c1e6832083acbfc130c0aafc8f2db2f3f706.zip | |
erts: Fix GC overrun bug in 'bsl' op with small Op1
Symptom: VM abort "Overrun stack and heap"
Problem: The temporary bignum created in buffer tmp_big[] will be
part of the GC initiated by TestHeapPreserve, but its size is not
included which can cause the GC to overflow if very unlucky.
Solution: Do not include tmp_big in the GC.
Diffstat (limited to 'erts/emulator')
| -rw-r--r-- | erts/emulator/beam/beam_emu.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c index 4716460a6b..c6258287c4 100644 --- a/erts/emulator/beam/beam_emu.c +++ b/erts/emulator/beam/beam_emu.c @@ -3032,6 +3032,7 @@ do { \ if (i == 0) { StoreBifResult(4, Op1); } + ires = big_size(Op1); goto big_shift; } } else if (is_big(Op2)) { @@ -3047,7 +3048,6 @@ do { \ OpCase(i_bsl_jIssd): GetArg2(2, Op1, Op2); - do_bsl: if (is_small(Op2)) { i = signed_val(Op2); @@ -3073,16 +3073,12 @@ do { \ StoreBifResult(4, Op1); } } - Op1 = small_to_big(ires, tmp_big); -#ifdef TAG_LITERAL_PTR - Op1 |= TAG_LITERAL_PTR; -#endif + ires = 1; /* big_size(small_to_big(Op1)) */ big_shift: if (i > 0) { /* Left shift. */ - ires = big_size(Op1) + (i / D_EXP); + ires += (i / D_EXP); } else { /* Right shift. */ - ires = big_size(Op1); if (ires <= (-i / D_EXP)) ires = 3; /* ??? */ else @@ -3101,6 +3097,9 @@ do { \ goto lb_Cl_error; } TestHeapPreserve(ires+1, Arg(1), Op1); + if (is_small(Op1)) { + Op1 = small_to_big(signed_val(Op1), tmp_big); + } bigp = HTOP; Op1 = big_lshift(Op1, i, bigp); if (is_big(Op1)) { @@ -3123,6 +3122,7 @@ do { \ if (i == 0) { StoreBifResult(4, Op1); } + ires = big_size(Op1); goto big_shift; } } else if (is_big(Op2)) { |