iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
b05d59dfce
linux/arch/arm64/mm
History
Mark Salter 4797ec2dc8 arm64: fix pud_huge() for 2-level pagetables 
The following happens when trying to run a kvm guest on a kernel
configured for 64k pages. This doesn't happen with 4k pages:

  BUG: failure at include/linux/mm.h:297/put_page_testzero()!
  Kernel panic - not syncing: BUG!
  CPU: 2 PID: 4228 Comm: qemu-system-aar Tainted: GF            3.13.0-0.rc7.31.sa2.k32v1.aarch64.debug #1
  Call trace:
  [<fffffe0000096034>] dump_backtrace+0x0/0x16c
  [<fffffe00000961b4>] show_stack+0x14/0x1c
  [<fffffe000066e648>] dump_stack+0x84/0xb0
  [<fffffe0000668678>] panic+0xf4/0x220
  [<fffffe000018ec78>] free_reserved_area+0x0/0x110
  [<fffffe000018edd8>] free_pages+0x50/0x88
  [<fffffe00000a759c>] kvm_free_stage2_pgd+0x30/0x40
  [<fffffe00000a5354>] kvm_arch_destroy_vm+0x18/0x44
  [<fffffe00000a1854>] kvm_put_kvm+0xf0/0x184
  [<fffffe00000a1938>] kvm_vm_release+0x10/0x1c
  [<fffffe00001edc1c>] __fput+0xb0/0x288
  [<fffffe00001ede4c>] ____fput+0xc/0x14
  [<fffffe00000d5a2c>] task_work_run+0xa8/0x11c
  [<fffffe0000095c14>] do_notify_resume+0x54/0x58

In arch/arm/kvm/mmu.c:unmap_range(), we end up doing an extra put_page()
on the stage2 pgd which leads to the BUG in put_page_testzero(). This
happens because a pud_huge() test in unmap_range() returns true when it
should always be false with 2-level pages tables used by 64k pages.
This patch removes support for huge puds if 2-level pagetables are
being used.

Signed-off-by: Mark Salter <msalter@redhat.com>
[catalin.marinas@arm.com: removed #ifndef around PUD_SIZE check]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org> # v3.11+
2014-05-16 17:34:40 +01:00
..
cache.S arm64: Fix DMA range invalidation for cache line unaligned buffers 2014-04-08 11:45:08 +01:00
context.c arm64: Process management 2012-09-17 13:41:58 +01:00
copypage.c arm64: MMU fault handling and page table management 2012-09-17 13:41:57 +01:00
dma-mapping.c arm64: Use bus notifiers to set per-device coherent DMA ops 2014-05-03 22:20:34 +01:00
extable.c arm64: MMU fault handling and page table management 2012-09-17 13:41:57 +01:00
fault.c arm64: Make do_bad_area() function static 2013-09-20 09:56:05 +01:00
flush.c arm64: Remove __flush_dcache_page() 2013-06-07 17:58:30 +01:00
hugetlbpage.c arm64: fix pud_huge() for 2-level pagetables 2014-05-16 17:34:40 +01:00
init.c Devicetree changes for v3.15 2014-04-02 14:27:15 -07:00
ioremap.c arm64: add early_ioremap support 2014-04-07 16:36:15 -07:00
Makefile ARM64: mm: HugeTLB support. 2013-06-14 09:52:40 +01:00
mm.h arm64: Remove __flush_dcache_page() 2013-06-07 17:58:30 +01:00
mmap.c mm: remove free_area_cache 2013-07-10 18:11:34 -07:00
mmu.c arm64: Fix for the arm64 kern_addr_valid() function 2014-05-03 22:20:29 +01:00
pgd.c arm64: simplify pgd_alloc 2014-02-05 10:45:07 +00:00
proc-macros.S arm64: mm: use ubfm for dcache_line_size 2014-01-22 16:23:58 +00:00
proc.S arm64: Update the TCR_EL1 translation granule definitions for 16K pages 2014-04-03 10:43:11 +01:00
tlb.S arm64: use correct register width when retrieving ASID 2013-09-25 16:42:23 +01:00