.*: Assembler messages: .*:6: Error: expecting indirect branch instruction after `notrack' .*:6: Warning: skipping prefixes on `call' .*:7: Error: expecting indirect branch instruction after `notrack' .*:9: Error: same type of prefix used twice .*:10: Error: same type of prefix used twice .*:13: Error: same type of prefix used twice .*:14: Error: same type of prefix used twice GAS LISTING .* [ ]*1[ ]+\# Check 64bit unsupported NOTRACK prefix [ ]*2[ ]+ [ ]*3[ ]+\.allow_index_reg [ ]*4[ ]+\.text [ ]*5[ ]+_start: [ ]*6[ ]+\?\?\?\? [0-9A-F]* notrack call foo \*\*\*\* Error: expecting indirect branch instruction after `notrack' \*\*\*\* Warning: skipping prefixes on `call' [ ]*6[ ]+[0-9A-F]* [ ]*7[ ]+\?\?\?\? [0-9A-F]* notrack jmp foo \*\*\*\* Error: expecting indirect branch instruction after `notrack' [ ]*7[ ]+[0-9A-F]* [ ]*8[ ]+ [ ]*9[ ]+fs notrack call \*%rax [ ]*10[ ]+notrack fs call \*%rax [ ]*11[ ]+ [ ]*12[ ]+\.intel_syntax noprefix [ ]*13[ ]+fs notrack call rax [ ]*14[ ]+notrack fs call rax #pass