[RFC] DT_X86_64_PLT* dependency

["H.J. Lu" <hjl.tools@gmail.com>]

Hi,

I checked in a linker patch:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=832ca732b8a96ff9a3e7c4abf24098bf2a59a96d

to generate DT_X86_64_PLT, DT_X86_64_PLTSZ and DT_X86_64_PLTENT for

https://gitlab.com/x86-psABIs/x86-64-ABI/-/commit/6d824a52a42d173eb838b879616c1be5870b593e

When these tags are generated, the r_addend field of the R_X86_64_JUMP_SLOT
relocation stores the offset of the indirect branch instruction.  However, glibc
versions which don't have this commit in glibc 2.36:

commit f8587a61892cbafd98ce599131bf4f103466f084
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri May 20 19:21:48 2022 -0700

    x86-64: Ignore r_addend for R_X86_64_GLOB_DAT/R_X86_64_JUMP_SLOT

    According to x86-64 psABI, r_addend should be ignored for R_X86_64_GLOB_DAT
    and R_X86_64_JUMP_SLOT.  Since linkers always set their r_addends to 0, we
    can ignore their r_addends.

    Reviewed-by: Fangrui Song <maskray@google.com>

won't ignore the r_addend value in the R_X86_64_JUMP_SLOT relocation.   Such
binaries will fail to run with these versions of glibc.  I am working
on a linker patch
to add a glibc version dependency similar to GLIBC_ABI_DT_RELR for DT_RELR.
Although this commit has been backported to glibc 2.33/2.34/2.35
release branches,
there may be 2.33/2.34/2.35 glibc binaries without the fix.   Should
binaries with
DT_X86_64_PLT tags depend on glibc 2.36 or 2.33?

Thanks.

-- 
H.J.