linux/arch/arm64/include/asm
Catalin Marinas 66dbd6e61a arm64: Implement ptep_set_access_flags() for hardware AF/DBM
When hardware updates of the access and dirty states are enabled, the
default ptep_set_access_flags() implementation based on calling
set_pte_at() directly is potentially racy. This triggers the "racy dirty
state clearing" warning in set_pte_at() because an existing writable PTE
is overridden with a clean entry.

There are two main scenarios for this situation:

1. The CPU getting an access fault does not support hardware updates of
   the access/dirty flags. However, a different agent in the system
   (e.g. SMMU) can do this, therefore overriding a writable entry with a
   clean one could potentially lose the automatically updated dirty
   status

2. A more complex situation is possible when all CPUs support hardware
   AF/DBM:

   a) Initial state: shareable + writable vma and pte_none(pte)
   b) Read fault taken by two threads of the same process on different
      CPUs
   c) CPU0 takes the mmap_sem and proceeds to handling the fault. It
      eventually reaches do_set_pte() which sets a writable + clean pte.
      CPU0 releases the mmap_sem
   d) CPU1 acquires the mmap_sem and proceeds to handle_pte_fault(). The
      pte entry it reads is present, writable and clean and it continues
      to pte_mkyoung()
   e) CPU1 calls ptep_set_access_flags()

   If between (d) and (e) the hardware (another CPU) updates the dirty
   state (clears PTE_RDONLY), CPU1 will override the PTR_RDONLY bit
   marking the entry clean again.

This patch implements an arm64-specific ptep_set_access_flags() function
to perform an atomic update of the PTE flags.

Fixes: 2f4b829c62 ("arm64: Add support for hardware updates of the access and dirty pte bits")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Ming Lei <tom.leiming@gmail.com>
Tested-by: Julien Grall <julien.grall@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org> # 4.3+
[will: reworded comment]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-15 18:06:09 +01:00
..
xen xen/events: Support event channel rebind on ARM 2015-08-20 12:24:15 +01:00
acenv.h ARM64 / ACPI: Get RSDP and ACPI boot-time tables 2015-03-25 11:49:30 +00:00
acpi.h arm64: kernel: implement ACPI parking protocol 2016-02-16 15:12:32 +00:00
alternative.h arm64: switch to relative exception tables 2016-02-24 14:57:26 +00:00
arch_gicv3.h irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is visible on redestributor 2016-02-11 10:20:02 +00:00
arch_timer.h arm64: fix missing linux/bug.h include in asm/arch_timer.h 2015-01-07 11:40:59 +00:00
arm-cci.h arm-cci: Get rid of secure transactions for PMU driver 2015-03-27 13:44:35 +00:00
asm-offsets.h
assembler.h arm64: switch to relative exception tables 2016-02-24 14:57:26 +00:00
atomic_ll_sc.h arm64: cmpxchg_dbl: fix return value type 2015-11-05 17:29:40 +00:00
atomic_lse.h arm64: lse: deal with clobbered IP registers after branch via PLT 2016-02-26 18:35:02 +00:00
atomic.h arm64 updates for 4.4: 2015-11-04 14:47:13 -08:00
barrier.h arm64: define __smp_xxx 2016-01-12 20:46:53 +02:00
bitops.h arch,arm64: Convert smp_mb__*() 2014-04-18 11:40:33 +02:00
bitrev.h ARM: 8189/1: arm64:add bitrev.h file to support rbit instruction 2014-12-22 16:47:32 +00:00
boot.h arm64: allow kernel Image to be loaded anywhere in physical memory 2016-02-18 18:16:53 +00:00
brk-imm.h arm64: move brk immediate argument definitions to separate header 2016-02-23 17:43:25 +00:00
bug.h arm64: move brk immediate argument definitions to separate header 2016-02-23 17:43:25 +00:00
cache.h arm64: Increase the max granular size 2015-10-28 19:09:17 +00:00
cacheflush.h 2nd set of arm64 updates for 4.6: 2016-03-24 19:13:59 -07:00
cachetype.h arm64: cachetype: fix definitions of ICACHEF_* flags 2015-10-28 18:32:12 +00:00
cmpxchg.h arm64: cmpxchg: Don't incldue linux/mmdebug.h 2015-12-10 17:36:09 +00:00
compat.h arm64: do not include ptrace.h from compat.h 2015-11-17 13:24:36 +00:00
compiler.h
cpu_ops.h ARM64: kernel: unify ACPI and DT cpus initialization 2015-05-19 16:09:29 +01:00
cpu.h arm64: add ARMv8.2 id_aa64mmfr2 boiler plate 2016-02-18 12:00:01 +00:00
cpufeature.h arm64 updates for 4.6: 2016-03-17 20:03:47 -07:00
cpuidle.h arm64: kernel: rename __cpu_suspend to keep it aligned with arm 2015-06-19 14:46:39 +01:00
cputype.h ARM: SoC 64-bit changes for v4.6 2016-03-20 15:08:45 -07:00
dcc.h ARM64: TTY: hvc_dcc: Add support for ARM64 dcc 2015-10-04 17:49:27 +01:00
debug-monitors.h arm64: move brk immediate argument definitions to separate header 2016-02-23 17:43:25 +00:00
device.h arm64: introduce is_device_dma_coherent 2014-12-04 12:41:49 +00:00
dma-mapping.h dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
dmi.h arm64: dmi: Add SMBIOS/DMI support 2014-11-05 09:03:25 +01:00
efi.h arm64/efi: refactor EFI init and runtime code for reuse by 32-bit ARM 2015-12-09 16:57:23 +00:00
elf.h arm64: add support for building vmlinux as a relocatable PIE binary 2016-02-24 14:57:27 +00:00
esr.h arm64/debug: Add missing #includes 2015-07-27 11:08:42 +01:00
exception.h arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
exec.h
fb.h
fixmap.h arm64: Remove fixmap include fragility 2016-02-26 15:22:53 +00:00
fpsimd.h arm64: add support for kernel mode NEON in interrupt context 2014-05-08 11:31:57 +02:00
fpsimdmacros.h arm64: Avoid breakage caused by .altmacro in fpsimd save/restore macros 2015-01-29 17:24:39 +00:00
ftrace.h arm64: Fix misspellings in comments. 2016-03-04 18:19:17 +00:00
futex.h arm64: switch to relative exception tables 2016-02-24 14:57:26 +00:00
hardirq.h arm64: kernel: implement ACPI parking protocol 2016-02-16 15:12:32 +00:00
hugetlb.h arm64: hugetlb: add support for PTE contiguous bit 2015-12-21 17:26:00 +00:00
hw_breakpoint.h arm64: hw_breakpoint: Allow EL2 breakpoints if running in HYP 2016-02-29 18:34:18 +00:00
hwcap.h arm64/HWCAP: Use system wide safe values 2015-10-21 15:35:58 +01:00
hypervisor.h
insn.h arm64: insn: Add aarch64_{get,set}_branch_offset 2015-06-03 15:43:24 +01:00
io.h Revert "arm64: ioremap: add ioremap_cache macro" 2015-10-13 16:18:17 +01:00
irq_work.h arm64: force CONFIG_SMP=y and remove redundant #ifdefs 2015-07-27 11:08:40 +01:00
irq.h arm64: remove irq_count and do_softirq_own_stack() 2015-12-21 17:26:01 +00:00
irqflags.h arm64: Add macros to manage processor debug state 2014-02-26 11:16:25 +00:00
jump_label.h locking/static_keys: Add a new static_key interface 2015-08-03 11:34:15 +02:00
kasan.h arm64: move kernel image to base of vmalloc area 2016-02-18 18:16:44 +00:00
Kbuild ARM64: PCI: Remove generated include of asm-generic/pci-bridge.h 2016-02-05 16:29:12 -06:00
kernel-pgtable.h arm64: choose memstart_addr based on minimum sparsemem section alignment 2016-04-14 16:15:08 +01:00
kgdb.h arm64: Fix typos in KGDB macros 2014-09-25 15:35:41 +01:00
kvm_arm.h arm64: kvm: 4.6-rc1: Fix VTCR_EL2 VS setting 2016-03-30 22:09:15 +02:00
kvm_asm.h arm64: KVM: Turn kvm_ksym_ref into a NOP on VHE 2016-03-21 10:47:18 +01:00
kvm_coproc.h arm64: KVM: common infrastructure for handling AArch32 CP14/CP15 2014-07-11 04:57:44 -07:00
kvm_emulate.h arm64: KVM: VHE: Implement VHE activate/deactivate_traps 2016-02-29 18:34:17 +00:00
kvm_host.h arm64: perf: Move PMU register related defines to asm/perf_event.h 2016-03-29 16:04:57 +01:00
kvm_hyp.h arm64: perf: Move PMU register related defines to asm/perf_event.h 2016-03-29 16:04:57 +01:00
kvm_mmio.h arm64: KVM: Turn system register numbers to an enum 2015-12-14 11:30:43 +00:00
kvm_mmu.h arm64 updates for 4.6: 2016-03-17 20:03:47 -07:00
kvm_psci.h ARM/ARM64: KVM: Make kvm_psci_call() return convention more flexible 2014-04-30 04:18:57 -07:00
linkage.h
lse.h arm64: lse: deal with clobbered IP registers after branch via PLT 2016-02-26 18:35:02 +00:00
memblock.h
memory.h arm64: mm: restrict virt_to_page() to the linear mapping 2016-04-14 16:31:49 +01:00
mmu_context.h arm64: Ensure the secondary CPUs have safe ASIDBits size 2016-02-25 10:33:06 +00:00
mmu.h arm64: Move unflatten_device_tree() call earlier. 2016-04-15 18:06:08 +01:00
mmzone.h arm64, numa: Add NUMA support for arm64 platforms. 2016-04-15 18:06:09 +01:00
module.h arm64: add support for kernel ASLR 2016-02-24 14:57:27 +00:00
neon.h arm64: add support for kernel mode NEON in interrupt context 2014-05-08 11:31:57 +02:00
numa.h arm64, numa: Add NUMA support for arm64 platforms. 2016-04-15 18:06:09 +01:00
opcodes.h arm64: opcodes.h: Add arm big-endian config options before including arm header 2016-03-29 16:04:57 +01:00
page.h arm64: asm: Explicitly include linux/personality.h in asm/page.h 2016-02-03 19:22:02 +00:00
paravirt.h arm64: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops 2015-12-21 14:40:54 +00:00
pci.h PCI: Move pci_dma_* helpers to common code 2016-03-07 10:40:02 -06:00
percpu.h arm64: force CONFIG_SMP=y and remove redundant #ifdefs 2015-07-27 11:08:40 +01:00
perf_event.h arm64: perf: Move PMU register related defines to asm/perf_event.h 2016-03-29 16:04:57 +01:00
pgalloc.h arm64: mm: add __{pud,pgd}_populate 2016-02-16 15:10:46 +00:00
pgtable-hwdef.h arm64: hugetlb: add support for PTE contiguous bit 2015-12-21 17:26:00 +00:00
pgtable-prot.h arm64: Remove fixmap include fragility 2016-02-26 15:22:53 +00:00
pgtable-types.h arm64: expose number of page table levels on Kconfig level 2015-04-14 16:49:01 -07:00
pgtable.h arm64: Implement ptep_set_access_flags() for hardware AF/DBM 2016-04-15 18:06:09 +01:00
proc-fns.h arm64: kill flush_cache_all() 2015-05-19 15:27:42 +01:00
processor.h arm64: kernel: Add support for User Access Override 2016-02-18 17:27:04 +00:00
ptrace.h arm64: Rework valid_user_regs 2016-03-02 15:49:28 +00:00
seccomp.h arm64: add seccomp support 2014-11-28 10:24:59 +00:00
shmparam.h arm64: fix COMPAT_SHMLBA definition for large pages 2015-12-02 14:00:10 +00:00
signal32.h arm64: Use get_signal() signal_setup_done() 2014-08-06 12:56:16 +02:00
smp_plat.h arm64: remove dead-code depending on CONFIG_UP_LATE_INIT 2015-07-29 18:32:09 +01:00
smp.h arm64: Add cpu_panic_kernel helper 2016-04-15 18:06:06 +01:00
sparsemem.h arm64: mm: update max pa bits to 48 2014-08-19 20:23:02 +01:00
spinlock_types.h arm64: include linux/types.h in asm/spinlock_types.h 2015-07-27 11:09:34 +01:00
spinlock.h arm64: spinlock: serialise spin_unlock_wait against concurrent lockers 2015-12-03 19:37:59 +00:00
stackprotector.h arm64: Add CONFIG_CC_STACKPROTECTOR 2014-07-09 12:23:48 +01:00
stacktrace.h arm64: ftrace: fix a stack tracer's output under function graph tracer 2015-12-21 17:26:02 +00:00
stat.h
string.h arm64: add KASAN support 2015-10-12 17:46:36 +01:00
suspend.h arm64: kernel: rename __cpu_suspend to keep it aligned with arm 2015-06-19 14:46:39 +01:00
sync_bitops.h
syscall.h arm64: Add audit support 2014-07-10 11:06:00 +01:00
sysreg.h arm64: cpufeature: append additional id_aa64mmfr2 fields to cpufeature 2016-04-13 14:49:23 +01:00
system_misc.h arm64: use private ratelimit state along with show_unhandled_signals 2015-06-19 16:26:15 +01:00
thread_info.h arm64: Remove the get_thread_info() function 2016-02-18 17:27:05 +00:00
timex.h
tlb.h arm64: tlbflush: avoid flushing when fullmm == 1 2015-10-07 11:56:21 +01:00
tlbflush.h arm64: tlb: remove redundant barrier from __flush_tlb_pgtable 2015-10-07 11:56:33 +01:00
topology.h arm64, numa: Add NUMA support for arm64 platforms. 2016-04-15 18:06:09 +01:00
traps.h arm64: Add __exception_irq_entry definition for function graph 2015-08-12 17:23:45 +01:00
uaccess.h arm64: switch to relative exception tables 2016-02-24 14:57:26 +00:00
unistd32.h arm64: compat: wire up new syscalls 2015-10-14 13:51:41 +01:00
unistd.h arm64: compat: wire up new syscalls 2015-10-14 13:51:41 +01:00
vdso_datapage.h
vdso.h
virt.h arm64: vhe: Verify CPU Exception Levels 2016-04-15 18:06:07 +01:00
word-at-a-time.h arm64: switch to relative exception tables 2016-02-24 14:57:26 +00:00