On Mon, Nov 14, 2022 at 4:46 PM Fangrui Song [off-list ref] wrote:

On 2022-11-14, Christophe Leroy wrote:

quoted

Le 28/09/2022 à 07:25, Fangrui Song a écrit :

quoted

On Sat, Sep 10, 2022 at 12:53 AM Fangrui Song [off-list ref] wrote:

quoted

On 2022-08-30, Fangrui Song wrote:

quoted

The actual intention is that no dynamic relocation exists. However, some
GNU ld ports produce unneeded R_*_NONE. (If a port is not care enough to
determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE
relocations. E.g. powerpc64le ld as of 2.38 has the issue with
defconfig.) R_*_NONE are generally no-op in the dynamic loaders. So just
ignore them.

With the change, we can remove ARCH_REL_TYPE_ABS. ARCH_REL_TYPE_ABS is a
bit misnomer as ports may check RELAVETIVE/GLOB_DAT/JUMP_SLOT which are
not called "absolute relocations". (The patch is motivated by the arm64
port missing R_AARCH64_RELATIVE.)

While here, replace "egrep" with "grep" as "egrep" is deprecated in GNU
grep 3.7.

Signed-off-by: Fangrui Song <redacted>
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[...]

Ping.

Ping^2 :)

Can you explain which ARCH_REL_TYPE_ABS can be removed with this change ?
How is the verification done if ARCH_REL_TYPE_ABS is removed ?

All ARCH_REL_TYPE_ABS relocation types can be removed. As explained, the
real intention is to check no dynamic relocation, and this is done by
the new

   cmd_vdso_check = if $(READELF) -rW $@ | grep -v _NONE | grep -q "R_\w*_"; \

in this patch.

grep -v _NONE is to work around some GNU ld ports (and likely older releases
of some ports even if their latest versions are fixed) which produce
unneeded R_*_NONE dynamic relocations.

Ping :)