linux-toradex.git/arch/s390/kernel/entry64.S, branch v3.0.95

[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] kernel: Initialize register 14 when starting new CPU

2011-05-10T15:13:42+00:00

When starting a new CPU we currently jump to start_secondary() without
setting register 14 (the return address) correctly. Therefore on the stack
frame for start_secondary an invalid return address is stored. This leads
to wrong stack back traces in kernel dumps.

Example:

 #00 [1f33fe48] cpu_idle at 10614a
 #01 [1f33fe90] start_secondary at 54fa88
 #02 [1f33feb8] (null) at 0                 <--- invalid

To fix this start_secondary() is called now with basr/brasl that sets
register 14 correctly. The output of the stack backtrace looks then
like the following:

 #00 [1f33fe48] cpu_idle at 10614a
 #01 [1f33fe90] start_secondary at 54fa88
 #02 [1f33feb8] restart_base at 54f41e      <--- correct

Signed-off-by: Michael Holzheu 
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] add kprobes annotations

2011-01-05T11:47:24+00:00

Add kprobes annotations to get the massive 'probe kernel.function("*") {}'
stress test working.

Signed-off-by: Martin Schwidefsky

[S390] fix kprobes single stepping

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

Fix kprobes after git commit 1e54622e0403891b10f2105663e0f9dd595a1f17
broke it. The kprobe_handler is now called with interrupts in the state
at the time of the breakpoint. The single step of the replaced instruction
is done with interrupts off which makes it necessary to enable and disable
the interupts in the kprobes code.

Signed-off-by: Martin Schwidefsky

[S390] cleanup system call parameter setup

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

Do the setup of the stack overflow argument for the sixth system
call parameter right before the branch to the system call function.
That simplifies the system call parameter access code.

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] Fix IRQ tracing in case of PER

2010-07-27T17:29:42+00:00

In case user space is single stepped (PER) the program check handler
claims too early that IRQs are enabled on the return path.
Subsequent checks will notice that the IRQ mask in the PSW and
what lockdep thinks the IRQ mask should be do not correlate and
therefore will print a warning to the console and disable lockdep.

Fix this by doing all the work within the correct context.

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

[S390] spp: remove KVM_AWARE_CMF config option

2010-05-26T21:26:30+00:00

This config option enables or disables three single instructions
which aren't expensive. This is too fine grained.
Besided that everybody who uses kvm would enable it anyway in order
to debug performance problems.
Just remove it.

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