Bug 328670

This patch provides support for Accelerated TLS. Valgrind currently has missing support for hardware based Thread Context Switching. An optimization on CVM Octeon MIPS allows the "thread local storage pointer" (TLS) to be stored by the kernel in $k0. 

In MIPS/Linux thread local storage (TLS) is achieved via hardware register 29. GCC and Glibc and CVM VG use the instruction rdhwr v1, $29 to obtain the updated value
of   the   thread   pointer.   When the hardware register   29   doesn't   exist   on a MIPS   processors , the  kernel traps this  instruction  with  a  Reserved Instruction Exception the overhead of which is very high. On CVM Octeon, use of k0 and CVMSEG provides a fast access to the thread pointer allowing Octeon Linux to access the thread pointer using a single 
instruction. This improves the performance of TLS and thread intensive applications.
The instruction emulation, takes many hundreds of cycles, while this optimization allows a
single  cycle  local  access. This improved access support  is  part  of the Cavium  supplied
toolchain and programs running under Valgrind on CVM SDK fail if this optimization is not supported.

Reproducible: Always

Steps to Reproduce:
Executing valgrind using any of its regression tests on an Octeon II Processor using Cavium SDK 3.0 will produce this error.
Actual Results:  
==17094== Memcheck, a memory error detector
==17094== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==17094== Using Valgrind-3.9.0.SVN and LibVEX; rerun with -h for copyright info
==17094== Command: memcheck/tests/malloc1
==17094== Process terminating with default action of signal 10 (SIGBUS)
==17094==    at 0x40190AC: __dl_runtime_resolve (dl-trampoline.c:159)
==17094==    by 0x4018D88: _dl_runtime_resolve (in /usr/local/Cavium_Networks/OCTEON-SDK/tools/lib64/ld-2.16.so)
==17094== 
==17094== HEAP SUMMARY:
==17094==     in use at exit: 0 bytes in 0 blocks
==17094==   total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==17094== 
==17094== All heap blocks were freed -- no leaks are possible
==17094== 
==17094== For counts of detected and suppressed errors, rerun with: -v
==17094== ERROR SUMMARY: 9 errors from 8 contexts (suppressed: 0 from 0)
./vg-in-place: line 31: 17094 Bus error               VALGRIND_LIB="$vgbasedir/.in_place" VALGRIND_LIB_INNER="$vgbasedir/.in_place" "$vgbasedir/coregrind/valgrind" "$@"

Expected Results:  
==19650== Memcheck, a memory error detector
==19650== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==19650== Using Valgrind-3.9.0 and LibVEX; rerun with -h for copyright info
==19650== Command: memcheck/tests/inits
==19650== 
==19650== Conditional jump or move depends on uninitialised value(s)
==19650==    at 0x120000B90: main (inits.c:17)
==19650== 
==19650== 
==19650== HEAP SUMMARY:
==19650==     in use at exit: 0 bytes in 0 blocks
==19650==   total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==19650== 
==19650== All heap blocks were freed -- no leaks are possible
==19650== 
==19650== For counts of detected and suppressed errors, rerun with: -v
==19650== Use --track-origins=yes to see where uninitialised values come from
==19650== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)