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Re: [PATCH] S390: Support PLT and GOT references in check-localplt.


On 08/09/2016 03:34 PM, Stefan Liebler wrote:
Hi,

on s390x the test elf/check-localplt is failing after recent commits:
"elf: Do not use memalign for TCB/TLS blocks allocation [BZ #17730]"
"elf: Avoid using memalign for TLS allocations [BZ #17730]"
"elf: dl-minimal malloc needs to respect fundamental alignment"
due to "Missing required PLT reference: ld.so: __libc_memalign".

After the commits __libc_memalign is only called in elf/dl-minimal.c in
malloc() function in ld.so and gcc -O2/-O3 leads to R_390_GLOB_DAT
instead of R_390_JMP_SLOT. __libc_memalign is called via
function-pointer loaded from GOT instead of calling via a plt-stub. In
this case there is the R_390_GLOB_DAT relocation in section .rela.dyn
instead of R_390_JMP_SLOT in .rela.plt.
This patch marks ld.so: __libc_memalign with R_390_GLOB_DAT in
localplt.data to allow both relocations.
If build with -fno-optimize-sibling-calls or on s390(31bit) a
R_390_JMP_SLOT is generated.

Okay to commit?

Bye
Stefan

ChangeLog:

    * sysdeps/unix/sysv/linux/s390/localplt.data: Mark
    ld.so: __libc_memalign with "+ RELA R_390_GLOB_DAT".
Are there any objections?
Otherwise I'll commit this patch tomorrow.

Bye
Stefan


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