linux/arch/arm64
Mika Penttilä 57adec866c arm64: mm: avoid calling apply_to_page_range on empty range
Calling apply_to_page_range with an empty range results in a BUG_ON
from the core code. This can be triggered by trying to load the st_drv
module with CONFIG_DEBUG_SET_MODULE_RONX enabled:

  kernel BUG at mm/memory.c:1874!
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 3 PID: 1764 Comm: insmod Not tainted 4.5.0-rc1+ #2
  Hardware name: ARM Juno development board (r0) (DT)
  task: ffffffc9763b8000 ti: ffffffc975af8000 task.ti: ffffffc975af8000
  PC is at apply_to_page_range+0x2cc/0x2d0
  LR is at change_memory_common+0x80/0x108

This patch fixes the issue by making change_memory_common (called by the
set_memory_* functions) a NOP when numpages == 0, therefore avoiding the
erroneous call to apply_to_page_range and bringing us into line with x86
and s390.

Cc: <stable@vger.kernel.org>
Reviewed-by: Laura Abbott <labbott@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-26 15:56:44 +00:00
..
boot ARM: SoC support for Tegra platforms for v4.5 2016-01-22 17:30:52 -08:00
configs arm64: defconfig: updates for 4.5 2016-01-26 11:24:41 +00:00
crypto
include arm64: Honour !PTE_WRITE in set_pte_at() for kernel mappings 2016-01-25 11:09:06 +00:00
kernel arm64: kernel: fix architected PMU registers unconditional access 2016-01-25 11:09:06 +00:00
kvm arm64: KVM: Add support for 16-bit VMID 2015-12-18 10:15:12 +00:00
lib
mm arm64: mm: avoid calling apply_to_page_range on empty range 2016-01-26 15:56:44 +00:00
net arm64: bpf: add extra pass to handle faulty codegen 2016-01-17 19:15:26 -05:00
xen xen/arm: introduce HYPERVISOR_platform_op on arm and arm64 2015-12-21 14:40:56 +00:00
Kconfig dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
Kconfig.debug arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug 2016-01-09 06:30:49 -08:00
Kconfig.platforms ARM: SoC support for Tegra platforms for v4.5 2016-01-22 17:30:52 -08:00
Makefile arm64: errata: Add -mpc-relative-literal-loads to build flags 2016-01-26 11:17:23 +00:00