linux_dsm_epyc7002/arch/powerpc
Cédric Le Goater a9dadc1c51 powerpc/xive: Fix the size of the cpumask used in xive_find_target_in_mask()
When called from xive_irq_startup(), the size of the cpumask can be
larger than nr_cpu_ids. This can result in a WARN_ON such as:

  WARNING: CPU: 10 PID: 1 at ../arch/powerpc/sysdev/xive/common.c:476 xive_find_target_in_mask+0x110/0x2f0
  ...
  NIP [c00000000008a310] xive_find_target_in_mask+0x110/0x2f0
  LR [c00000000008a2e4] xive_find_target_in_mask+0xe4/0x2f0
  Call Trace:
    xive_find_target_in_mask+0x74/0x2f0 (unreliable)
    xive_pick_irq_target.isra.1+0x200/0x230
    xive_irq_startup+0x60/0x180
    irq_startup+0x70/0xd0
    __setup_irq+0x7bc/0x880
    request_threaded_irq+0x14c/0x2c0
    request_event_sources_irqs+0x100/0x180
    __machine_initcall_pseries_init_ras_IRQ+0x104/0x134
    do_one_initcall+0x68/0x1d0
    kernel_init_freeable+0x290/0x374
    kernel_init+0x24/0x170
    ret_from_kernel_thread+0x5c/0x74

This happens because we're being called with our affinity mask set to
irq_default_affinity. That in turn was populated using
cpumask_setall(), which sets NR_CPUs worth of bits, not nr_cpu_ids
worth. Finally cpumask_weight() will return > nr_cpu_ids when passed a
mask which has > nr_cpu_ids bits set.

Fix it by limiting the value returned by cpumask_weight().

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[mpe: Add change log details on actual cause]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-24 15:20:18 +10:00
..
boot Merge branch 'fixes' into next 2017-08-23 22:20:10 +10:00
configs Merge branch 'fixes' into next 2017-08-23 22:20:10 +10:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-05-02 15:53:46 -07:00
include powerpc/mm: Make switch_mm_irqs_off() out of line 2017-08-23 22:48:51 +10:00
kernel powerpc/64: Optimise set/clear of CTRL[RUN] (runlatch) 2017-08-23 23:48:38 +10:00
kvm Merge branch 'fixes' into next 2017-08-23 22:20:10 +10:00
lib powerpc/string: Implement optimized memset variants 2017-08-17 23:04:35 +10:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm powerpc/mm: Make switch_mm_irqs_off() out of line 2017-08-23 22:48:51 +10:00
net powerpc/bpf: Use memset32() to pre-fill traps in BPF page(s) 2017-08-17 23:04:47 +10:00
oprofile ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
perf Merge branch 'topic/ppc-kvm' into next 2017-08-17 23:14:17 +10:00
platforms powerpc: pseries: remove dlpar_attach_node dependency on full path 2017-08-23 22:27:04 +10:00
purgatory powerpc: Fix invalid use of register expressions 2017-08-10 22:29:41 +10:00
sysdev powerpc/xive: Fix the size of the cpumask used in xive_find_target_in_mask() 2017-08-24 15:20:18 +10:00
tools powerpc/64: Tool to check head sections location sanity 2017-05-30 14:59:51 +10:00
xmon powerpc/xmon: Exclude all of xmon from ftrace 2017-08-15 15:30:17 +10:00
Kconfig powerpc/mm: Implement STRICT_KERNEL_RWX on PPC32 2017-08-15 22:55:57 +10:00
Kconfig.debug powerpc/xmon: Enable disassembly files (compilation changes) 2017-02-15 20:02:42 +11:00
Makefile Merge branch 'fixes' into next 2017-08-23 22:20:10 +10:00
Makefile.postlink powerpc/64: Tool to check head sections location sanity 2017-05-30 14:59:51 +10:00