[Bug dynamic-link/31218] PLT rewrite overflows large displacement on x32

["cvs-commit at gcc dot gnu.org" <sourceware-bugzilla@sourceware.org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=31218

--- 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=glibc.git;h=0f9afc265a4a0f4ba658d7f71c9602a3fda3538e

commit 0f9afc265a4a0f4ba658d7f71c9602a3fda3538e
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Sat Jan 6 14:03:37 2024 -0800

    x32: Handle displacement overflow in PLT rewrite [BZ #31218]

    PLT rewrite calculated displacement with

    ElfW(Addr) disp = value - branch_start - JMP32_INSN_SIZE;

    On x32, displacement from 0xf7fbe060 to 0x401030 was calculated as

    unsigned int disp = 0x401030 - 0xf7fbe060 - 5;

    with disp == 0x8442fcb and caused displacement overflow. The PLT entry
    was changed to:

    0xf7fbe060 <+0>:        e9 cb 2f 44 08          jmp    0x401030
    0xf7fbe065 <+5>:        cc                      int3
    0xf7fbe066 <+6>:        cc                      int3
    0xf7fbe067 <+7>:        cc                      int3
    0xf7fbe068 <+8>:        cc                      int3
    0xf7fbe069 <+9>:        cc                      int3
    0xf7fbe06a <+10>:       cc                      int3
    0xf7fbe06b <+11>:       cc                      int3
    0xf7fbe06c <+12>:       cc                      int3
    0xf7fbe06d <+13>:       cc                      int3
    0xf7fbe06e <+14>:       cc                      int3
    0xf7fbe06f <+15>:       cc                      int3

    x32 has 32-bit address range, but it doesn't wrap address around at 4GB,
    JMP target was changed to 0x100401030 (0xf7fbe060LL + 0x8442fcbLL + 5),
    which is above 4GB.

    Always use uint64_t to calculate displacement.  This fixes BZ #31218.
    Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>

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