beam_load.c: Add overflow check of tag values

The handling of large values for other tags than TAG_i (integer) is
buggy.  Any tag value equal to or greater than 2^40 (5 bytes) will
abort loading.  Tag values fitting in 5 bytes will be truncated to 4
bytes values.

Those bugs cause real problems because the bs_init2/6 and
bs_init_bits/6 instructions unfortunately use TAG_u to encode literal
sizes (using TAG_i would have been a better choice, but it is too late
to change that now).  Any binary size that cannot fit in an Uint
should cause a system_limit exception at run-time, but instead the
buggy handling will either cause an emulator crash (for values in the
range 2^32 to 2^40-1) or abort loading.

In this commit, implement overflow checking of tag values as a
preparation for fixing the binary construction instructions.  If any
tag value cannot fit in an Uint (except for TAG_i), change the
tag to the special TAG_o overflow tag.

1 files changed, 1 insertions, 1 deletions

diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops
index 1a117b168f..354439b5e3 100755
--- a/erts/emulator/utils/beam_makeops
+++ b/erts/emulator/utils/beam_makeops
@@ -110,7 +110,7 @@ my @pred_table;
 # Operand types for generic instructions.
 
 my $compiler_types = "uiaxyfhz";
-my $loader_types = "nprvlq";
+my $loader_types = "nprvlqo";
 my $genop_types = $compiler_types . $loader_types;
 
 #