https://sourceware.org/bugzilla/show_bug.cgi?id=31323
--- Comment #2 from Sourceware Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by H.J. Lu <h...@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=46bd909328c3c8f3d6fc7a505b2fad1eea72d872 commit 46bd909328c3c8f3d6fc7a505b2fad1eea72d872 Author: H.J. Lu <hjl.to...@gmail.com> Date: Thu Feb 1 14:42:08 2024 -0800 x86: Disallow instructions with length > 15 bytes It is a hard error when an instruction length exceeds the limit of 15 bytes: [hjl@gnu-cfl-3 tmp]$ cat x.s .text xacquire lock addq $0x11223344, %fs:(,%eax) [hjl@gnu-cfl-3 tmp]$ gcc -c x.s x.s: Assembler messages: x.s:2: Warning: instruction length of 16 bytes exceeds the limit of 15 [hjl@gnu-cfl-3 tmp]$ objdump -dw x.o x.o: file format elf64-x86-64 Disassembly of section .text: 0000000000000000 <.text>: 0: 64 67 f2 f0 48 81 04 05 00 00 00 00 44 33 22 xacquire lock (bad) f: 11 .byte 0x11 [hjl@gnu-cfl-3 tmp]$ and [hjl@gnu-cfl-3 tmp]$ cat z.s addq $0xe0, %fs:0, %rdx [hjl@gnu-cfl-3 tmp]$ as -o z.o z.s z.s: Assembler messages: z.s:1: Warning: instruction length of 16 bytes exceeds the limit of 15 [hjl@gnu-cfl-3 tmp]$ objdump -dw z.o z.o: file format elf64-x86-64 Disassembly of section .text: 0000000000000000 <.text>: 0: 64 62 f4 ec 18 81 04 25 00 00 00 00 e0 00 00 (bad) ... [hjl@gnu-cfl-3 pr31323]$ Instructions with length > 15 bytes are always invalid. It is quite easy to generate invalid instructions with AVX now. We should issue an error when instruction length exceeds the limit of 15 bytes. PR gas/31323 * config/tc-i386.c (output_insn): Issue an error when instruction length exceeds the limit of 15 bytes. * testsuite/gas/i386/oversized16.l: Updated. * testsuite/gas/i386/oversized64.l: Likewise. * testsuite/gas/i386/x86-64-apx-inval.l: New file. * testsuite/gas/i386/x86-64-apx-inval.s: Likewise. -- You are receiving this mail because: You are on the CC list for the bug.
