[PATCH 0/2] arm64/kdump: Fix OOPS and OOM issues in kdump kernel

[Bhupesh Sharma]

Prabhakar recently reported a kdump kernel boot failure on ThunderX2
arm64 plaforms (which I was able to reproduce on ampere arm64 machines
as well), (see [1]), which is seen when a corner case is hit on some
arm64 boards when kdump kernel runs with "cgroup_disable=memory" passed
to the kdump kernel (via bootargs) and the crashkernel was originally
allocated from either a ZONE_DMA32 memory or mixture of memory chunks
belonging to both ZONE_DMA and ZONE_DMA32 regions.

While [PATCH 1/2] fixes the OOPS inside mem_cgroup_get_nr_swap_pages()
function, [PATCH 2/2] fixes the OOM seen inside the kdump kernel by
allocating the crashkernel inside ZONE_DMA region only.

[1]. https://marc.info/?l=kexec&m=158954035710703&w=4

Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: cgroups@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: kexec@xxxxxxxxxxxxxxxxxxx
Reported-by: Prabhakar Kushwaha <pkushwaha@xxxxxxxxxxx>
Signed-off-by: Bhupesh Sharma <bhsharma@xxxxxxxxxx>

Bhupesh Sharma (2):
  mm/memcontrol: Fix OOPS inside mem_cgroup_get_nr_swap_pages()
  arm64: Allocate crashkernel always in ZONE_DMA

 arch/arm64/mm/init.c | 16 ++++++++++++++--
 mm/memcontrol.c      |  9 ++++++++-
 2 files changed, 22 insertions(+), 3 deletions(-)

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2.7.4