linux/arch/s390/kernel, branch v3.12.25

s390/time,vdso: fix clock_gettime for CLOCK_MONOTONIC

2014-04-03T08:32:22Z

commit ca5de58ba746b08c920b2024aaf01aa1500b110d upstream. 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 Signed-off-by: Jiri Slaby

s390,time: revert direct ktime path for s390 clockevent device

2014-03-12T08:42:16Z

commit 8adbf78ec4839c1dc4ff20c9a1f332a7bc99e6e6 upstream. Git commit 4f37a68cdaf6dea833cfdded2a3e0c47c0f006da "s390: Use direct ktime path for s390 clockevent device" makes use of the CLOCK_EVT_FEAT_KTIME clockevent option to avoid the delta calculation with ktime_get() in clockevents_program_event and the get_tod_clock() in s390_next_event. This is based on the assumption that the difference between the internal ktime and the hardware clock is reflected in the wall_to_monotonic delta. But this is not true, the ntp corrections are applied via changes to the tk->mult multiplier and this is not reflected in wall_to_monotonic. In theory this could be solved by using the raw monotonic clock but it is simpler to switch back to the standard clock delta calculation. Signed-off-by: Martin Schwidefsky Signed-off-by: Jiri Slaby

s390/time,vdso: convert to the new update_vsyscall interface

2014-03-12T08:41:25Z

commit 79c74ecbebf76732f91b82a62ce7fc8a88326962 upstream. Switch to the improved update_vsyscall interface that provides sub-nanosecond precision for gettimeofday and clock_gettime. Signed-off-by: Martin Schwidefsky Signed-off-by: Jiri Slaby

s390: fix kernel crash due to linkage stack instructions

2014-02-22T21:32:25Z

commit 8d7f6690cedb83456edd41c9bd583783f0703bf0 upstream. The kernel currently crashes with a low-address-protection exception if a user space process executes an instruction that tries to use the linkage stack. Set the base-ASTE origin and the subspace-ASTE origin of the dispatchable-unit-control-table to point to a dummy ASTE. Set up control register 15 to point to an empty linkage stack with no room left. A user space process with a linkage stack instruction will still crash but with a different exception which is correctly translated to a segmentation fault instead of a kernel oops. Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/vtime: correct idle time calculation

2013-11-29T19:28:12Z

commit 4560e7c3317c7a2b370e36dadd3a3bac2ed70818 upstream. Use the ACCESS_ONCE macro for both accesses to idle->sequence in the loops to calculate the idle time. If only one access uses the macro, the compiler is free to cache the value for the second access which can cause endless loops. Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/time: correct use of store clock fast

2013-10-22T07:16:40Z

The result of the store-clock-fast (STCKF) instruction is a bit fuzzy. It can happen that the value stored on one CPU is smaller than the value stored on another CPU, although the order of the stores is the other way around. This can cause deltas of get_tod_clock() values to become negative when they should not be. We need to be more careful with store-clock-fast, this patch partially reverts git commit e4b7b4238e666682555461fa52eecd74652f36bb "time: always use stckf instead of stck if available". The get_tod_clock() function now uses the store-clock-extended (STCKE) instruction. get_tod_clock_fast() can be used if the fuzziness of store-clock-fast is acceptable e.g. for wait loops local to a CPU. Signed-off-by: Martin Schwidefsky

s390/compat,signal: fix return value of copy_siginfo_(to|from)_user32()

2013-10-15T11:47:59Z

The return value of copy_siginfo_(to|from)_user32() gets passed to user space, however we do not convert a positive return value from copy_(to|from)_user to -EFAULT. Therefore these functions (and the calling system calls) my incorrectly return a positive number (bytes not copied) instead of -EFAULT. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: fix system call restart after inferior call

2013-09-30T11:04:40Z

Git commit 616498813b11ffef "s390: system call path micro optimization" introduced a regression in regard to system call restarting and inferior function calls via the ptrace interface. The pointer to the system call table needs to be loaded in sysc_sigpending if do_signal returns with TIF_SYSCALl set after it restored a system call context. Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Martin Schwidefsky

s390: Allow vmalloc target buffers for copy_from_oldmem()

2013-09-30T11:04:40Z

Currently copy_from_oldmem() is not able to copy to virtual memory. When using kexec pre-allocated ELF header, copy_from_oldmem() is used to copy the ELF notes information to vmalloc buffers. So fix this and use the new function copy_from_realmem() that allows copying also to vmalloc memory. Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky

s390/kprobes: add exrl to list of prohibited opcodes

2013-09-30T11:04:38Z

"execute relative long" may have all sorts of side effects dependend on the instructions it executes. Therefore prohibit setting a kprobe on exrl just like we do for the regular execute instruction. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky