Question: Does uclibc support NPTL TLS ?

[Sheng Yong]

Hi,

I encountered a problem when I test thread local storage
on my arm board (kernel 3.10.77 and uclibc 0.99.3.2).

Please let me know if I am doing something wrong for
debugging TLS.

on my x86 host machine:
root at kernel-host:~> cat tls.c
__thread int i =5;

int
main (int argc, char **argv)
{
  return 0;
}

root at kernel-host:~> arm-linux-uclibceabi-gcc -o tls tls.c -g -lpthread

on my arm board:
-bash-4.2# gdb ./tls
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "arm-euler-linux-uclibceabi".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /tmp/zz/tls...done.
(gdb) b main
Breakpoint 1 at 0x8518: file tls.c, line 6.
(gdb) r
Starting program: /tmp/zz/tls
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/libthread_db.so.1".

Breakpoint 1, main (argc=1, argv=0xbefffd84) at tls.c:6
6	tls.c: No such file or directory.
(gdb) whatis i
type = int
(gdb) p i
Cannot find thread-local storage for Thread 0xb6ffb000 (LWP 538), executable file /tmp/zz/tls:
*capability not available*
(gdb)

Thanks,
Sheng