[Bug gas/31323] [x86] GAS does not error out instruction that exceed 15 bytes

[cvs-commit at gcc dot gnu.org]

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 <hjl@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=46bd909328c3c8f3d6fc7a505b2fad1eea72d872

commit 46bd909328c3c8f3d6fc7a505b2fad1eea72d872
Author: H.J. Lu <hjl.tools@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.