ARM64: smp: Fix suspicious RCU usage with ipi tracepoints
authorStephen Boyd <sboyd@codeaurora.org>
Wed, 24 Jun 2015 20:14:18 +0000 (13:14 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 3 Aug 2015 16:29:18 +0000 (09:29 -0700)
commit2dd7172e36d015013859e5afd3abaeffa92e9397
tree9b58fe9e1eac0d5e8c9fb23f9746b8c9db1c96ed
parent409e901e4d22f51cbe19a9ec1f943fbbdcc35853
ARM64: smp: Fix suspicious RCU usage with ipi tracepoints

commit be081d9bf3e163a9ed1ca2f0f14f08424c7f9016 upstream.

John Stultz reported an RCU splat on ARM with ipi trace events
enabled. It looks like the same problem exists on ARM64.

At this point in the IPI handling path we haven't called
irq_enter() yet, so RCU doesn't know that we're about to exit
idle and properly warns that we're using RCU from an idle CPU.
Use trace_ipi_entry_rcuidle() instead of trace_ipi_entry() so
that RCU is informed about our exit from idle.

Cc: John Stultz <john.stultz@linaro.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Fixes: 45ed695ac10a ("ARM64: add IPI tracepoints")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm64/kernel/smp.c