linux-toradex.git/arch/s390/kernel/vdso32, branch v4.10

s390/time: steer clocksource on STP sync events

2016-10-28T08:09:02+00:00

On STP sync events the TOD clock will jump in time, either forward or
backward. The TOD clocksource claims to be continuous but in case of
an STP sync with a negative offset it is not.

Subtract the offset injected by the STP sync check from the result of
the TOD clocksource to make it continuous again. Add code to drift the
offset towards zero with a fixed rate, steering 1 second in ~9 hours.

Suggested-by: David Hildenbrand 
Signed-off-by: Martin Schwidefsky

s390: enable UBSAN

2016-09-20T12:26:23+00:00

This enables UBSAN for s390. We have to disable the null sanitizer
as s390 code does access memory via a null pointer (the prefix page).

Signed-off-by: Christian Borntraeger 
Acked-by: Andrey Ryabinin 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390: enable kcov support

2016-06-28T07:32:39+00:00

Now that hopefully all inline assemblies have been converted to single
basic blocks we can enable kcov on s390.

Note that this patch does not disable as many files on s390 like the
x86 variant does. Right now I didn't see a reason to do that, however
additional files or directories can be excluded at any time.

The runtime overhead seems to be quite high.

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

s390/vdso: optimize getcpu system call

2016-01-11T12:01:24+00:00

Add the CPU number to the per-cpu vdso data page and add the
__kernel_getcpu function to the vdso object to retrieve the
CPU number in user space.

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

s390/vdso: emit a GNU hash

2015-08-07T07:57:39+00:00

As proposed by Andy Lutomirski create the SysV and the GNU hash
for the vdso objects. This may make some dynamic loaders a bit
faster.

Signed-off-by: Martin Schwidefsky

s390/vdso: fix stack corruption

2014-10-27T12:27:02+00:00

The kernel provided vdso functions do not get a stack frame from the
calling function and therefore may not change the stack contents, unless
they allocate space on their own.

This problem was exposed with 070b7be633dc "s390/vdso: replace stck with
stcke" which writes 16 bytes instead of 8 bytes into the stack frame. These
additional 8 bytes however were indeed used by the caller (glibc) to save
data and therefore this data was corrupted by the vdso code.

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

s390/vdso: add vdso support for coarse clocks

2014-09-09T06:53:27+00:00

Add CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE optimization to
the 64-bit and 31-bit vdso.

Signed-off-by: Martin Schwidefsky

s390/vdso: replace stck with stcke

2014-09-09T06:53:27+00:00

If gettimeofday / clock_gettime are called multiple times in a row
the STCK instruction will stall until a difference in the result is
visible. This unnecessarily slows down the vdso calls, use stcke
instead of stck to get rid of the stall.

Signed-off-by: Martin Schwidefsky

s390/vdso: remove NULL pointer check from clock_gettime

2014-09-01T07:56:29+00:00

The explicit NULL pointer check on the timespec argument is only
required for clock_getres but not for clock_gettime.

Signed-off-by: Martin Schwidefsky

s390/time,vdso: fix clock_gettime for CLOCK_MONOTONIC

2013-12-02T17:15:25+00:00

With git commit 79c74ecbebf76732f91b82a62ce7fc8a88326962
"s390/time,vdso: convert to the new update_vsyscall interface"
the new update_vsyscall function already does the sum of xtime
and wall_to_monotonic. The old update_vsyscall function only
copied the wall_to_monotonic offset. The vdso code needs to be
modified to take this into consideration.

Signed-off-by: Martin Schwidefsky