powerpc/perf: Fix usage of nest_imc_refc
authorMadhavan Srinivasan <maddy@linux.vnet.ibm.com>
Wed, 16 Aug 2017 16:21:34 +0000 (21:51 +0530)
committerMichael Ellerman <mpe@ellerman.id.au>
Thu, 17 Aug 2017 11:56:36 +0000 (21:56 +1000)
commit711bd207a233141308d0aea0d2e286ee6b4b23cd
tree42306fde9a5de9467b487118d6f8e0adb646179c
parent8bfa42ab84910841336218265fcee94fd1e6285a
powerpc/perf: Fix usage of nest_imc_refc

nest_imc_refc is a reference count struct, used to track number of
active perf sessions using the nest units.

Currently the code accesses nest_imc_refc using node_id, which is
incorrect, the array is indexed by node number. Meaning in the case of
sparse node ids we index off the end of the array.

Fix it to use get_nest_pmu_ref() which uses the existing per-cpu
variable local_nest_imc_refc.

Fixes: 885dcd709ba91 ('powerpc/perf: Add nest IMC PMU support')
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
[mpe: Tweak change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/perf/imc-pmu.c