[Bug ld/26312] ld produces broken PLT on aarch64 with BTI+PAC

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=26312

--- Comment #10 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot 
gnu.org> ---
The binutils-2_34-branch branch has been updated by Szabolcs Nagy
<nsz@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e3b314d3a61db4b0b36975fa00eb9043a6142448

commit e3b314d3a61db4b0b36975fa00eb9043a6142448
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Wed Jul 29 15:47:50 2020 +0100

    aarch64: set sh_entsize of .plt to 0

    On aarch64 the first PLT entry is 32 bytes, subsequent entries
    are 16 bytes by default but can be 24 bytes with BTI or with
    PAC-PLT.

    sh_entsize of .plt was set to the PLT entry size, so in some
    cases sh_size % sh_entsize != 0, which breaks some tools.

    Note that PLT0 (and the TLSDESC stub code which is also in the
    PLT) were historically not padded up to meet the sh_size
    requirement, but to ensure that PLT stub code is aligned on
    cache lines. Similar layout is present on other targets too
    which just happens to make sh_size a multiple of sh_entsize and
    it is not expected that sh_entsize of .plt is used for anything.

    This patch sets sh_entsize of .plt to 0: the section does not
    hold a table of fixed-size entries so other values are not
    conforming in principle to the ELF spec.

    bfd/ChangeLog:

            Backport from mainline.
            2020-07-30  Szabolcs Nagy  <szabolcs.nagy@arm.com>

            PR ld/26312
            * elfnn-aarch64.c (elfNN_aarch64_init_small_plt0_entry): Set
sh_entsize
            to 0.
            (elfNN_aarch64_finish_dynamic_sections): Remove sh_entsize setting.

    (cherry picked from commit 4d3bb35620e70d543d438bf21be1307f7ea0f5d0)

-- 
You are receiving this mail because:
You are on the CC list for the bug.