linux/arch/x86
Toshi Kani d9fe4fab11 x86/mm/pat: Add untrack_pfn_moved for mremap
mremap() with MREMAP_FIXED on a VM_PFNMAP range causes the following
WARN_ON_ONCE() message in untrack_pfn().

  WARNING: CPU: 1 PID: 3493 at arch/x86/mm/pat.c:985 untrack_pfn+0xbd/0xd0()
  Call Trace:
  [<ffffffff817729ea>] dump_stack+0x45/0x57
  [<ffffffff8109e4b6>] warn_slowpath_common+0x86/0xc0
  [<ffffffff8109e5ea>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8106a88d>] untrack_pfn+0xbd/0xd0
  [<ffffffff811d2d5e>] unmap_single_vma+0x80e/0x860
  [<ffffffff811d3725>] unmap_vmas+0x55/0xb0
  [<ffffffff811d916c>] unmap_region+0xac/0x120
  [<ffffffff811db86a>] do_munmap+0x28a/0x460
  [<ffffffff811dec33>] move_vma+0x1b3/0x2e0
  [<ffffffff811df113>] SyS_mremap+0x3b3/0x510
  [<ffffffff817793ee>] entry_SYSCALL_64_fastpath+0x12/0x71

MREMAP_FIXED moves a pfnmap from old vma to new vma.  untrack_pfn() is
called with the old vma after its pfnmap page table has been removed,
which causes follow_phys() to fail.  The new vma has a new pfnmap to
the same pfn & cache type with VM_PAT set.  Therefore, we only need to
clear VM_PAT from the old vma in this case.

Add untrack_pfn_moved(), which clears VM_PAT from a given old vma.
move_vma() is changed to call this function with the old vma when
VM_PFNMAP is set.  move_vma() then calls do_munmap(), and untrack_pfn()
is a no-op since VM_PAT is cleared.

Reported-by: Stas Sergeev <stsp@list.ru>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1450832064-10093-2-git-send-email-toshi.kani@hpe.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-05 11:10:05 +01:00
..
boot kasan: move KASAN_SANITIZE in arch/x86/boot/Makefile 2015-11-05 19:34:48 -08:00
configs Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-09-04 15:49:32 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-11-04 09:11:12 -08:00
entry mm: mlock: add new mlock system call 2015-11-05 19:34:48 -08:00
ia32 Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:05:40 -08:00
include Merge branch 'pm-tools' 2015-11-16 22:57:02 +01:00
kernel x86/LDT: Print the real LDT base address 2015-12-29 12:34:38 +01:00
kvm Four changes: 2015-11-12 14:34:06 -08:00
lguest genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
lib Linux 4.3-rc1 2015-09-13 11:25:35 +02:00
math-emu Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:05:40 -08:00
mm x86/mm/pat: Add untrack_pfn_moved for mremap 2016-01-05 11:10:05 +01:00
net ebpf: migrate bpf_prog's flags to bitfield 2015-10-03 05:02:39 -07:00
oprofile
pci PCI changes for the v4.4 merge window: 2015-11-06 11:29:53 -08:00
platform Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:33:18 -08:00
power x86/ldt: Make modify_ldt synchronous 2015-07-31 10:23:23 +02:00
purgatory
ras x86/ras/mce_amd_inj: Inject bank 4 errors on the NBC 2015-10-12 16:15:48 +02:00
realmode
tools
um Merge branch 'for-linus-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2015-11-10 16:33:37 -08:00
video
xen xen: features for 4.4-rc0 2015-11-04 17:32:42 -08:00
.gitignore
Kbuild x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/ 2015-06-03 18:51:37 +02:00
Kconfig Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 18:59:10 -08:00
Kconfig.cpu x86/Kconfig/cpus: Fix/complete CPU type help texts 2015-10-21 11:12:56 +02:00
Kconfig.debug x86/mm: Turn CONFIG_X86_PTDUMP into a module 2015-11-23 10:50:13 +01:00
Makefile Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-11-04 09:11:12 -08:00
Makefile.um
Makefile_32.cpu