linux-toradex.git/arch/s390/kernel, branch v4.3.1

s390/kernel: fix ptrace peek/poke for floating point registers

2015-12-09T19:34:33+00:00

commit 55a423b6f105fa323168f15f4bb67f23b21da44e upstream.

git commit 155e839a814834a3b4b31e729f4716e59d3d2dd4
"s390/kernel: dynamically allocate FP register save area"
introduced a regression in regard to ptrace.

If the vector register extension is not present or unused the
ptrace peek of a floating pointer register return incorrect data
and the ptrace poke to a floating pointer register overwrites the
task structure starting at task->thread.fpu.fprs.

Signed-off-by: Martin Schwidefsky 
Signed-off-by: Greg Kroah-Hartman

s390/vtime: correct scaled cputime of partially idle CPUs

2015-09-30T14:22:38+00:00

The calculation for the SMT scaling factor for a hardware thread
which has been partially idle needs to disregard the cycles spent
by the other threads of the core while the thread is idle.

Signed-off-by: Martin Schwidefsky

s390: wire up separate socketcalls system calls

2015-09-18T09:16:53+00:00

As discussed on linux-arch all architectures should wire up the separate
system calls that are hidden behind the socketcall multiplexer system call.

It's just a couple more system calls and gives us a very small performance
improvement.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/compat: remove superfluous compat wrappers

2015-09-18T09:16:52+00:00

A couple of compat wrapper functions are simply trampolines to the real
system call. This happened because the compat wrapper defines will only
sign and zero extend system call parameters which are of different size
on s390/s390x (longs and pointers).
All other parameters will be correctly sign and zero extended by the
normal system call wrappers.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/compat: do not trace compat wrapper functions

2015-09-18T09:16:50+00:00

Add notrace to the compat wrapper define to disable tracing of compat
wrapper functions. These are supposed to be very small and more or less
just a trampoline to the real system call.

Also fix indentation.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/s390x: allocate sys_membarrier system call number

2015-09-17T11:43:44+00:00

Signed-off-by: Mathieu Desnoyers 
CC: Andrew Morton 
CC: linux-api@vger.kernel.org
CC: Heiko Carstens 
CC: linux-s390@vger.kernel.org
Signed-off-by: Martin Schwidefsky

s390: wire up userfaultfd system call

2015-09-17T11:43:43+00:00

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/vtime: correct scaled cputime for SMT

2015-09-17T11:43:43+00:00

The scaled cputime is supposed to be derived from the normal per-thread
cputime by dividing it with the average thread density in the last interval.

The calculation of the scaling values for the average thread density is
incorrect. The current, incorrect calculation:

    Ci = cycle count with i active threads
    T = unscaled cputime, sT = scaled cputime
    sT = T * (C1 + C2 + ... + Cn) / (1*C1 + 2*C2 + ... + n*Cn)

The calculation happens to yield the correct numbers for the simple cases
with only one Ci value not zero. But for cases with multiple Ci values not
zero it fails. E.g. on a SMT-2 system with one thread active half the time
and two threads active for the other half of the time it fails, the scaling
factor should be 3/4 but the formula gives 2/3.

The correct formula is

    sT = T * (C1/1 + C2/2 + ... + Cn/n) / (C1 + C2 + ... + Cn)

Signed-off-by: Martin Schwidefsky

s390/cpum_cf: Corrected return code for unauthorized counter sets

2015-09-17T11:43:42+00:00

Previously, the cpum_cf PMU returned -EPERM if a counter is requested and
the counter set to which the counter belongs is not authorized.  According
to the perf_event_open() system call manual, an error code of EPERM indicates
an unsupported exclude setting or CAP_SYS_ADMIN is missing.

Use ENOENT to indicate that particular counters are not available when the
counter set which contains the counter is not authorized.  For generic events,
this might trigger a fall back, for example, to a software event.

Signed-off-by: Hendrik Brueckner 
Signed-off-by: Martin Schwidefsky

s390/compat: correct uc_sigmask of the compat signal frame

2015-09-17T11:43:42+00:00

The uc_sigmask in the ucontext structure is an array of words to keep
the 64 signal bits (or 1024 if you ask glibc but the kernel sigset_t
only has 64 bits).

For 64 bit the sigset_t contains a single 8 byte word, but for 31 bit
there are two 4 byte words. The compat signal handler code uses a
simple copy of the 64 bit sigset_t to the 31 bit compat_sigset_t.
As s390 is a big-endian architecture this is incorrect, the two words
in the 31 bit sigset_t array need to be swapped.

Cc: 
Reported-by: Stefan Liebler 
Signed-off-by: Martin Schwidefsky