Subject: Strange failures on 4.9.6-3 kernel



Hi all,

While testing glibc on the kindly provided T5 machine from Debian environment,
I started to see some strange issues on sparc64 where glibc is failing on
mostly static tests.

Funny thing is I checked the latest working revision I used to update 2.25
release page [1] and now the tests that used to pass are now failing. In
fact I checked even the 2.23 and 2.24 glibc releases and both show the same
issues as master branch, so I am almost ruling out a glibc regression (which
was my first idea).

I noted that the machine kernel was updated (from 4.9.2-2 to 4.9.6-3), but
I am not sure if this is something to kernel. I haven't recorded the
gcc revision I used on my initial testings. The static tets are failing due
a memcpy call that issues bogus instructions:

(gdb) r
Starting program: /home/azanella/glibc/glibc-git-build/elf/tst-tls1-static

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000340 in ?? ()
(gdb) bt
#0 0x0000000000000340 in ?? ()
#1 0x0000000000101fd8 in __libc_setup_tls () at libc-tls.c:180
#2 0x0000000000101950 in __libc_start_main (main=0x4e8, argc=<optimized out>,
argv=0x7feffffef78, init=0x4a8, fini=0x220, rtld_fini=0x0, stack_end=0x1)
at libc-start.c:189
#3 0x0000000000100704 in _start () at ../sysdeps/sparc/sparc64/start.S:88
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

(gdb) up
[...]
0x0000000000101fc8 <+344>: add %l4, %o0, %o0
0x0000000000101fcc <+348>: mov %i1, %o1
0x0000000000101fd0 <+352>: call 0x2949c0
0x0000000000101fd4 <+356>: stx %o0, [ %i4 + 0x20 ]
=> 0x0000000000101fd8 <+360>: sethi %hi(0x4800), %g3

It seems 0x2949c0 is a unknown address, where it should be the memcpy one.
At first I thought it was lacking of ifunc support on static build,
so I checked disabling multiarch support (--disab...

le-multi-arch) and
later checked with a master binutils (2.28.51.20170209) but without
success.

My next plan is rebuild GCC and check if it is something related to
system installed gcc.

Any ideas what it might be?

[1] https://sourceware.org/glibc/wiki/Release/2.25



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