linux_dsm_epyc7002/arch/powerpc/perf
Anju T Sudhakar d2032678e5 powerpc/perf: Fix memory allocation for core-imc based on num_possible_cpus()
Currently memory is allocated for core-imc based on cpu_present_mask,
which has bit 'cpu' set iff cpu is populated. We use (cpu number / threads
per core) as the array index to access the memory.

Under some circumstances firmware marks a CPU as GUARDed CPU and boot the
system, until cleared of errors, these CPU's are unavailable for all
subsequent boots. GUARDed CPUs are possible but not present from linux
view, so it blows a hole when we assume the max length of our allocation
is driven by our max present cpus, where as one of the cpus might be online
and be beyond the max present cpus, due to the hole.
So (cpu number / threads per core) value bounds the array index and leads
to memory overflow.

Call trace observed during a guard test:

Faulting instruction address: 0xc000000000149f1c
cpu 0x69: Vector: 380 (Data Access Out of Range) at [c000003fea303420]
    pc:c000000000149f1c: prefetch_freepointer+0x14/0x30
    lr:c00000000014e0f8: __kmalloc+0x1a8/0x1ac
    sp:c000003fea3036a0
   msr:9000000000009033
   dar:c9c54b2c91dbf6b7
  current = 0xc000003fea2c0000
  paca    = 0xc00000000fddd880	 softe: 3	 irq_happened: 0x01
    pid   = 1, comm = swapper/104
Linux version 4.16.7-openpower1 (smc@smc-desktop) (gcc version 6.4.0
(Buildroot 2018.02.1-00006-ga8d1126)) #2 SMP Fri May 4 16:44:54 PDT 2018
enter ? for help
call trace:
	 __kmalloc+0x1a8/0x1ac
	 (unreliable)
	 init_imc_pmu+0x7f4/0xbf0
	 opal_imc_counters_probe+0x3fc/0x43c
	 platform_drv_probe+0x48/0x80
	 driver_probe_device+0x22c/0x308
	 __driver_attach+0xa0/0xd8
	 bus_for_each_dev+0x88/0xb4
	 driver_attach+0x2c/0x40
	 bus_add_driver+0x1e8/0x228
	 driver_register+0xd0/0x114
	 __platform_driver_register+0x50/0x64
	 opal_imc_driver_init+0x24/0x38
	 do_one_initcall+0x150/0x15c
	 kernel_init_freeable+0x250/0x254
	 kernel_init+0x1c/0x150
	 ret_from_kernel_thread+0x5c/0xc8

Allocating memory for core-imc based on cpu_possible_mask, which has
bit 'cpu' set iff cpu is populatable, will fix this issue.

Reported-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Tested-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
Fixes: 39a846db1d ("powerpc/perf: Add core IMC PMU support")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-18 21:57:49 +10:00
..
req-gen License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
8xx-pmu.c powerpc/8xx: Only perform perf counting when perf is in use. 2018-01-16 23:47:12 +11:00
bhrb.S powerpc/perf: Add basic assembly code to read BHRB entries on POWER8 2013-04-26 16:11:11 +10:00
callchain.c powerpc/mm: Rename find_linux_pte_or_hugepte() 2017-08-17 23:13:46 +10:00
core-book3s.c powerpc updates for 4.17 2018-04-07 12:08:19 -07:00
core-fsl-emb.c perf: Fix sibling iteration 2018-03-16 20:44:12 +01:00
e500-pmu.c powerpc/perf: Add stalled-cycles events 2013-01-10 17:00:56 +11:00
e6500-pmu.c powerpc/perf: Add e6500 PMU driver 2013-08-07 18:38:04 -05:00
hv-24x7-catalog.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hv-24x7-domains.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hv-24x7.c powerpc/perf/hv-24x7: Fix incorrect comparison in memord 2017-10-22 12:08:31 +02:00
hv-24x7.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hv-common.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hv-common.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hv-gpci-requests.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hv-gpci.c powerpc/sparse: Make a bunch of things static 2016-09-13 17:35:47 +10:00
hv-gpci.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
imc-pmu.c powerpc/perf: Fix memory allocation for core-imc based on num_possible_cpus() 2018-05-18 21:57:49 +10:00
isa207-common.c powerpc/perf: Factor out PPMU_ONLY_COUNT_RUN check code from power8 2017-08-10 22:30:05 +10:00
isa207-common.h powerpc/perf: Factor out PPMU_ONLY_COUNT_RUN check code from power8 2017-08-10 22:30:05 +10:00
Makefile powerpc/64s: Remove POWER4 support 2018-04-01 00:47:50 +11:00
mpc7450-pmu.c powerpc/perf: Pass the struct perf_events down to compute_mmcr() 2014-07-28 14:30:47 +10:00
perf_regs.c powerpc/perf: Fix oops when kthread execs user process 2017-06-16 21:02:46 +10:00
power5-pmu.c powerpc/perf: Pass the struct perf_events down to compute_mmcr() 2014-07-28 14:30:47 +10:00
power5+-pmu.c powerpc/perf: Pass the struct perf_events down to compute_mmcr() 2014-07-28 14:30:47 +10:00
power6-pmu.c powerpc/perf: Pass the struct perf_events down to compute_mmcr() 2014-07-28 14:30:47 +10:00
power7-events-list.h powerpc/perf: Make some new raw event codes available in sysfs 2014-03-24 09:48:23 +11:00
power7-pmu.c powerpc/sparse: Make a bunch of things static 2016-09-13 17:35:47 +10:00
power8-events-list.h powerpc/perf: Add Power8 mem_access event to sysfs 2017-04-19 20:00:23 +10:00
power8-pmu.c powerpc/perf: Factor out PPMU_ONLY_COUNT_RUN check code from power8 2017-08-10 22:30:05 +10:00
power9-events-list.h powerpc/perf: Add blacklisted events for Power9 DD2.2 2018-03-27 19:25:11 +11:00
power9-pmu.c powerpc/perf: Add blacklisted events for Power9 DD2.2 2018-03-27 19:25:11 +11:00
ppc970-pmu.c powerpc/perf: Pass the struct perf_events down to compute_mmcr() 2014-07-28 14:30:47 +10:00