Commit 28a1f53 delays setting %pil to avoid potential
hardirq stack overflow in the common rtrap_irq path.
Setting %pil also needs to be delayed in the rtrap_nmi
path for the same reason.
Signed-off-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull irq cleanups from Ingo Molnar:
"This is a multi-arch cleanup series from Thomas Gleixner, which we
kept to near the end of the merge window, to not interfere with
architecture updates.
This series (motivated by the -rt kernel) unifies more aspects of IRQ
handling and generalizes PREEMPT_ACTIVE"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
preempt: Make PREEMPT_ACTIVE generic
sparc: Use preempt_schedule_irq
ia64: Use preempt_schedule_irq
m32r: Use preempt_schedule_irq
hardirq: Make hardirq bits generic
m68k: Simplify low level interrupt handling code
genirq: Prevent spurious detection for unconditionally polled interrupts
Mark the places when the system are in user or are in kernel.
This is used to make full dynticks system (tickless) --
CONFIG_NO_HZ_FULL dependence.
Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The low level preemption code fiddles with the PREEMPT_ACTIVE bit for
no reason and calls schedule() with interrupts disabled, which is
wrong to begin with. Remove the PREEMPT_ACTIVE fiddling and call the
proper schedule_preempt_irq() function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20130917183628.966769884@linutronix.de
The invocation of softirq is now handled by irq_exit(), so there is no
need for sparc64 to invoke it on the trap-return path. In fact, doing so
is a bug because if the trap occurred in the idle loop, this invocation
can result in lockdep-RCU failures. The problem is that RCU ignores idle
CPUs, and the sparc64 trap-return path to the softirq handlers fails to
tell RCU that the CPU must be considered non-idle while those handlers
are executing. This means that RCU is ignoring any RCU read-side critical
sections in those handlers, which in turn means that RCU-protected data
can be yanked out from under those read-side critical sections.
The shiny new lockdep-RCU ability to detect RCU read-side critical sections
that RCU is ignoring located this problem.
The fix is straightforward: Make sparc64 stop manually invoking the
softirq handlers.
Reported-by: Meelis Roos <mroos@linux.ee>
Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Meelis Roos <mroos@linux.ee>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Analog of what commit 494486a1d2 had done
to alpha (another architecture with similar bug).
One note: in rtrap_32.S part clr %l6 has been a rudiment of left after
commit 28e6103665 (sparc: Fix debugger syscall
restart interactions) has killed %l6 use in there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can overflow the hardirq stack if we set the %pil here
so early, just let the normal control flow do it.
This is fine as we are allowed to do the actual IRQ enable
at any point after we call trace_hardirqs_on.
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
sparc64: Make prom entry spinlock NMI safe.
sparc64: Kill off old sys_perfctr system call and state.
sparc: Update defconfigs.
sparc: Provide io{read,write}{16,32}be().
People should be using the perf events interfaces, and
the way these system call facilities used the %pcr conflicts
with the usage of the NMI watchdog and perf events.
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that the return from alloc_percpu is compatible with the address
of per-cpu vars, it makes sense to hand around the address of per-cpu
variables. To make this sane, we remove the per_cpu__ prefix we used
created to stop people accidentally using these vars directly.
Now we have sparse, we can use that (next patch).
tj: * Updated to convert stuff which were missed by or added after the
original patch.
* Kill per_cpu_var() macro.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
o Move all files from sparc64/kernel/ to sparc/kernel
- rename as appropriate
o Update sparc/Makefile to the changes
o Update sparc/kernel/Makefile to include the sparc64 files
NOTE: This commit changes link order on sparc64!
Link order had to change for either of sparc32 and sparc64.
And assuming sparc64 see more testing than sparc32 change link
order on sparc64 where issues will be caught faster.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
