linux-toradex.git/arch/s390/kernel/asm-offsets.c, branch v3.0.68

[S390] pfault: cpu hotplug vs missing completion interrupts

2011-05-23T08:24:29+00:00

On cpu hot remove a PFAULT CANCEL command is sent to the hypervisor
which in turn will cancel all outstanding pfault requests that have
been issued on that cpu (the same happens with a SIGP cpu reset).

The result is that we end up with uninterruptible processes where
the interrupt that would wake up these processes never arrives.

In order to solve this all processes which wait for a pfault
completion interrupt get woken up after a cpu hot remove. The worst
case that could happen is that they fault again and in turn need to
wait again.

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

[S390] Remove data execution protection

2011-05-23T08:24:28+00:00

The noexec support on s390 does not rely on a bit in the page table
entry but utilizes the secondary space mode to distinguish between
memory accesses for instructions vs. data. The noexec code relies
on the assumption that the cpu will always use the secondary space
page table for data accesses while it is running in the secondary
space mode. Up to the z9-109 class machines this has been the case.
Unfortunately this is not true anymore with z10 and later machines.
The load-relative-long instructions lrl, lgrl and lgfrl access the
memory operand using the same addressing-space mode that has been
used to fetch the instruction.
This breaks the noexec mode for all user space binaries compiled
with march=z10 or later. The only option is to remove the current
noexec support.

Signed-off-by: Martin Schwidefsky

[S390] ptrace cleanup

2011-01-05T11:47:31+00:00

Overhaul program event recording and the code dealing with the ptrace
user space interface.

Signed-off-by: Martin Schwidefsky

[S390] vdso: get rid of redefinition warnings

2010-10-29T14:50:50+00:00

The CLOCK_* defines in asm-offsets.c are only used for the vdso code
however in the meantime they cause other trouble.
Just rename them to get permanently rid of this:

In file included from /home2/heicarst/linux-2.6/arch/s390/include/asm/asm-offsets.h:1:0,
                 from arch/s390/mm/fault.c:33:
include/generated/asm-offsets.h:53:0: warning: "CLOCK_REALTIME" redefined
include/linux/time.h:286:0: note: this is the location of the previous definition
include/generated/asm-offsets.h:54:0: warning: "CLOCK_MONOTONIC" redefined
include/linux/time.h:287:0: note: this is the location of the previous definition

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

[S390] cleanup lowcore access from external interrupts

2010-10-25T14:10:19+00:00

Read external interrupts parameters from the lowcore in the first
level interrupt handler in entry[64].S.

Signed-off-by: Martin Schwidefsky

[S390] cleanup lowcore access from program checks

2010-10-25T14:10:19+00:00

Read all required fields for program checks from the lowcore in the
first level interrupt handler in entry[64].S. If the context that
caused the fault was enabled for interrupts we can now re-enable the
irqs in entry[64].S.

Signed-off-by: Martin Schwidefsky

[S390] spp: fix compilation for CONFIG_32BIT

2010-05-26T21:26:29+00:00

Fix build breakage for CONFIG_32BIT caused by cd3b70f5
"[S390] virtualization aware cpu measurement"

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

[S390] add breaking event address for user space

2010-05-17T08:00:15+00:00

Copy the last breaking event address from the lowcore to a new
field in the thread_struct on each system entry. Add a new
ptrace request PTRACE_GET_LAST_BREAK and a new utrace regset
REGSET_LAST_BREAK to query the last breaking event.

This is useful for debugging wild branches in user space code.

Signed-off-by: Martin Schwidefsky

[S390] virtualization aware cpu measurement

2010-05-17T08:00:15+00:00

Use the SPP instruction to set a tag on entry to / exit of the virtual
machine context. This allows the cpu measurement facility to distinguish
the samples from the host and the different guests.

Signed-off-by: Carsten Otte

[S390] idle time accounting vs. machine checks

2010-05-17T08:00:15+00:00

A machine check can interrupt the i/o and external interrupt handler
anytime. If the machine check occurs while the interrupt handler is
waking up from idle vtime_start_cpu can get executed a second time
and the int_clock / async_enter_timer values in the lowcore get
clobbered. This can confuse the cpu time accounting.
To fix this problem two changes are needed. First the machine check
handler has to use its own copies of int_clock and async_enter_timer,
named mcck_clock and mcck_enter_timer. Second the nested execution
of vtime_start_cpu has to be prevented. This is done in s390_idle_check
by checking the wait bit in the program status word.

Signed-off-by: Martin Schwidefsky