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author | Björn Gustavsson <[email protected]> | 2018-02-09 10:37:48 +0100 |
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committer | Björn Gustavsson <[email protected]> | 2018-02-12 13:31:27 +0100 |
commit | a48ec9a2750260845f035c2e968244cb5cd33a3d (patch) | |
tree | 9a44bfd630ad11aa5ac03a8b273ccbc796704672 /lib/compiler/src/beam_z.erl | |
parent | cd9b6371a13c37f8f82586fcd82f212d306d8fad (diff) | |
download | otp-a48ec9a2750260845f035c2e968244cb5cd33a3d.tar.gz otp-a48ec9a2750260845f035c2e968244cb5cd33a3d.tar.bz2 otp-a48ec9a2750260845f035c2e968244cb5cd33a3d.zip |
Fix unsafe use of 'allocate' where 'allocate_zero' should be used
The more aggressive optimizations of 'allocate_zero' introduced
in cb6fc15c35c7e could produce unsafe code such as the following:
{allocate,0,1}.
{bif,element,{f,0},[{integer,1},{x,0}],{x,0}}.
The code is not safe because if element/2 fails, the runtime
system may scan the stack and find garbage that looks like a
catch tag, and would most probably crash.
Fix the problem by making beam_utils:is_killed/3 be more conservative
when asked whether a Y register will be killed.
Also fix an unsafe move upwards of an allocation instruction
in beam_block.
Diffstat (limited to 'lib/compiler/src/beam_z.erl')
0 files changed, 0 insertions, 0 deletions