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b569bab78d
linux/arch/x86/kernel
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Kirill A. Shutemov b569bab78d x86/mm: Prepare to expose larger address space to userspace 
On x86, 5-level paging enables 56-bit userspace virtual address space.
Not all user space is ready to handle wide addresses. It's known that
at least some JIT compilers use higher bits in pointers to encode their
information. It collides with valid pointers with 5-level paging and
leads to crashes.

To mitigate this, we are not going to allocate virtual address space
above 47-bit by default.

But userspace can ask for allocation from full address space by
specifying hint address (with or without MAP_FIXED) above 47-bits.

If hint address set above 47-bit, but MAP_FIXED is not specified, we try
to look for unmapped area by specified address. If it's already
occupied, we look for unmapped area in *full* address space, rather than
from 47-bit window.

A high hint address would only affect the allocation in question, but not
any future mmap()s.

Specifying high hint address on older kernel or on machine without 5-level
paging support is safe. The hint will be ignored and kernel will fall back
to allocation from 47-bit address space.

This approach helps to easily make application's memory allocator aware
about large address space without manually tracking allocated virtual
address space.

The patch puts all machinery in place, but not yet allows userspace to have
mappings above 47-bit -- TASK_SIZE_MAX has to be raised to get the effect.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170716225954.74185-7-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-21 10:05:18 +02:00
..
acpi x86, mpparse, x86/acpi, x86/PCI, x86/dmi, SFI: Use memremap() for RAM mappings 2017-07-18 11:37:58 +02:00
apic kernel/watchdog: split up config options 2017-07-12 16:26:02 -07:00
cpu x86/cpu/AMD: Make the microcode level available earlier in the boot 2017-07-18 11:38:03 +02:00
fpu KVM: x86: Fix load damaged SSEx MXCSR register 2017-05-15 16:08:56 +02:00
kprobes objtool, x86: Add several functions and files to the objtool whitelist 2017-06-30 10:19:19 +02:00
.gitignore
alternative.c x86/alternatives: Prevent uninitialized stack byte read in apply_alternatives() 2017-05-24 16:18:12 +02:00
amd_gart_64.c x86: remove arch specific dma_supported implementation 2017-06-28 06:54:46 -07:00
amd_nb.c x86/amd_nb: Add SMN and Indirect Data Fabric access for AMD Fam17h 2016-11-16 20:46:38 +01:00
apb_timer.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
aperture_64.c x86/boot/e820: Prefix the E820_* type names with "E820_TYPE_" 2017-01-28 22:55:22 +01:00
apm_32.c x86: Remap GDT tables in the fixmap section 2017-03-16 09:06:35 +01:00
asm-offsets_32.c sched/x86: Rewrite the switch_to() code 2016-08-24 12:31:41 +02:00
asm-offsets_64.c x86/kvm: Provide optimized version of vcpu_is_preempted() for x86-64 2017-02-21 12:48:35 +01:00
asm-offsets.c efi: Get and store the secure boot status 2017-02-07 10:42:10 +01:00
audit_64.c
bootflag.c
check.c
cpuid.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-12 19:25:04 -08:00
crash_dump_32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
crash_dump_64.c
crash.c kexec: move vmcoreinfo out of the kernel's .bss section 2017-07-12 16:25:59 -07:00
devicetree.c
doublefault.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h> 2017-03-02 08:42:34 +01:00
dumpstack_32.c x86/debug: Implement __WARN() using UD0 2017-03-27 10:20:28 +02:00
dumpstack_64.c x86/debug: Implement __WARN() using UD0 2017-03-27 10:20:28 +02:00
dumpstack.c x86/unwind: Ensure stack pointer is aligned 2017-04-18 10:30:23 +02:00
e820.c x86/boot/e820: Add support to determine the E820 type of an address 2017-07-18 11:38:01 +02:00
early_printk.c x86/earlyprintk: Add support for earlyprintk via USB3 debug port 2017-03-21 12:30:16 +01:00
early-quirks.c main drm pull request for 4.12 kernel 2017-05-03 11:44:24 -07:00
ebda.c x86/boot: Simplify EBDA-vs-BIOS reservation logic 2016-07-22 11:46:01 +02:00
espfix_64.c x86/mm: Provide general kernel support for memory encryption 2017-07-18 11:38:00 +02:00
ftrace_32.S x86/ftrace: Fix ebp in ftrace_regs_caller that screws up unwinder 2017-04-21 09:48:16 +02:00
ftrace_64.S x86/ftrace: Use Makefile logic instead of #ifdef for compiling ftrace_*.o 2017-03-24 10:14:08 +01:00
ftrace.c x86/ftrace: Make sure that ftrace trampolines are not RWX 2017-05-26 22:37:02 -04:00
head32.c x86/boot/e820: Move asm/e820.h to asm/e820/api.h 2017-01-28 09:31:13 +01:00
head64.c x86/mm: Add support to make use of Secure Memory Encryption 2017-07-18 20:23:26 +02:00
head_32.S x86/boot/32: Convert the 32-bit pgtable setup code from assembly to C 2017-01-06 08:39:26 +01:00
head_64.S x86/mm: Provide general kernel support for memory encryption 2017-07-18 11:38:00 +02:00
hpet.c x86/hpet: Do not use smp_processor_id() in preemptible code 2017-06-20 12:23:26 +02:00
hw_breakpoint.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
i8237.c
i8253.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
i8259.c x86: i8259: export legacy_pic symbol 2017-04-14 12:08:51 +02:00
io_delay.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
ioport.c Second batch of KVM changes for 4.11 merge window 2017-03-04 11:36:19 -08:00
irq_32.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
irq_64.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
irq_work.c x86/irq, trace: Add __irq_entry annotation to x86's platform IRQ handlers 2017-01-05 08:58:49 +01:00
irq.c x86/irq: Use irq_migrate_all_off_this_cpu() 2017-06-22 18:21:18 +02:00
irqinit.c x86/irq: Remove a redundant #ifdef directive 2017-04-14 22:43:01 +02:00
itmt.c sched/x86: Remove unnecessary TBM3 check to update topology 2017-01-19 08:42:37 +01:00
jump_label.c jump_label: Reorder hotplug lock and jump_label_lock 2017-05-26 10:10:45 +02:00
kdebugfs.c x86, mpparse, x86/acpi, x86/PCI, x86/dmi, SFI: Use memremap() for RAM mappings 2017-07-18 11:37:58 +02:00
kexec-bzimage64.c x86/boot/e820: Rename the e820_table_firmware to e820_table_kexec 2017-07-05 10:09:02 +02:00
kgdb.c sched/x86: Add 'struct inactive_task_frame' to better document the sleeping task stack frame 2016-08-24 12:27:41 +02:00
ksysfs.c x86, mpparse, x86/acpi, x86/PCI, x86/dmi, SFI: Use memremap() for RAM mappings 2017-07-18 11:37:58 +02:00
kvm.c KVM: async_pf: Let guest support delivery of async_pf from guest mode 2017-07-14 14:26:16 +02:00
kvmclock.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
ldt.c x86/ldt: Rename ldt_struct::size to ::nr_entries 2017-06-08 09:28:21 +02:00
livepatch.c livepatch/x86: apply alternatives and paravirt patches after relocations 2016-08-18 23:41:55 +02:00
machine_kexec_32.c x86: use set_memory.h header 2017-05-08 17:15:13 -07:00
machine_kexec_64.c x86/mm, kexec: Allow kexec to be used with SME 2017-07-18 11:38:04 +02:00
Makefile Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 14:45:09 -07:00
mmconf-fam10h_64.c
module.c mm, vmalloc: use __GFP_HIGHMEM implicitly 2017-05-08 17:15:13 -07:00
mpparse.c x86/boot: Use memremap() to map the MPF and MPC data 2017-07-18 11:38:02 +02:00
msr.c x86/msr: Remove bogus cleanup from the error path 2016-12-25 10:47:41 +01:00
nmi_selftest.c x86/nmi: Fix timeout test in test_nmi_ipi() 2017-06-20 12:52:43 +02:00
nmi.c * An EDAC driver for Cavium ThunderX RAS IP (Sergey Temerkhanov) 2017-05-01 11:36:00 -07:00
paravirt_patch_32.c x86/paravirt: Mark unused patch_default label 2016-12-22 17:43:35 +01:00
paravirt_patch_64.c x86/paravirt: Mark unused patch_default label 2016-12-22 17:43:35 +01:00
paravirt-spinlocks.c 4.11 is going to be a relatively large release for KVM, with a little over 2017-02-22 18:22:53 -08:00
paravirt.c x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3() 2017-06-13 08:48:09 +02:00
pci-calgary_64.c x86: remove arch specific dma_supported implementation 2017-06-28 06:54:46 -07:00
pci-dma.c x86, swiotlb: Add memory encryption support 2017-07-18 11:38:03 +02:00
pci-iommu_table.c
pci-nommu.c x86, swiotlb: Add memory encryption support 2017-07-18 11:38:03 +02:00
pci-swiotlb.c x86, swiotlb: Add memory encryption support 2017-07-18 11:38:03 +02:00
pcspeaker.c
perf_regs.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
platform-quirks.c x86/init: Add i8042 state to the platform data 2016-12-19 11:34:15 +01:00
pmem.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
probe_roms.c x86/boot/e820: Move asm/e820.h to asm/e820/api.h 2017-01-28 09:31:13 +01:00
process_32.c x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3() 2017-06-13 08:48:09 +02:00
process_64.c x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3() 2017-06-13 08:48:09 +02:00
process.c x86/mm, kexec: Allow kexec to be used with SME 2017-07-18 11:38:04 +02:00
ptrace.c x86/arch_prctl/64: Rename do_arch_prctl() to do_arch_prctl_64() 2017-03-20 16:10:32 +01:00
pvclock.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/nmi.h> 2017-03-02 08:42:30 +01:00
quirks.c x86/quirks: Hide maybe-uninitialized warning 2016-10-25 11:45:13 +02:00
reboot_fixups_32.c
reboot.c objtool, x86: Add several functions and files to the objtool whitelist 2017-06-30 10:19:19 +02:00
relocate_kernel_32.S
relocate_kernel_64.S
resource.c x86/boot/e820: Harmonize the 'struct e820_table' fields 2017-01-28 09:33:16 +01:00
rtc.c timekeeping: Ignore the bogus sleep time if pm_trace is enabled 2016-11-29 18:02:58 +01:00
setup_percpu.c x86/boot/32: Fix UP boot on Quark and possibly other platforms 2017-05-09 08:14:24 +02:00
setup.c x86/mm: Insure that boot memory areas are mapped properly 2017-07-18 11:38:01 +02:00
signal_compat.c x86/signals: Fix lower/upper bound reporting in compat siginfo 2017-04-05 10:16:43 +02:00
signal.c x86/debug: Fix the printk() debug output of signal_fault(), do_trap() and do_general_protection() 2017-04-11 09:11:13 +02:00
smp.c Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-01 20:51:12 -07:00
smpboot.c Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 14:45:09 -07:00
stacktrace.c stacktrace/x86: add function for detecting reliable stack traces 2017-03-08 09:18:02 +01:00
step.c x86/ldt: Rename ldt_struct::size to ::nr_entries 2017-06-08 09:28:21 +02:00
sys_x86_64.c x86/mm: Prepare to expose larger address space to userspace 2017-07-21 10:05:18 +02:00
sysfb_efi.c
sysfb_simplefb.c x86/sysfb: Fix lfb_size calculation 2016-11-16 09:38:23 +01:00
sysfb.c
tboot.c iommu/vt-d: Correctly disable Intel IOMMU force on 2017-06-15 16:41:10 +02:00
tce_64.c
time.c x86/time: Make setup_default_timer_irq() static 2017-06-13 08:42:09 +02:00
tls.c x86/tls: Forcibly set the accessed bit in TLS segments 2017-03-19 12:14:35 +01:00
tls.h
topology.c
trace_clock.c
tracepoint.c tracing: Have the reg function allow to fail 2016-12-09 09:13:30 -05:00
traps.c x86/debug: Handle early WARN_ONs proper 2017-06-12 21:17:48 +02:00
tsc_msr.c x86/tsc: Set TSC_KNOWN_FREQ and TSC_RELIABLE flags on Intel Atom SoCs 2016-11-18 10:58:31 +01:00
tsc_sync.c x86/tsc: Remove the TSC_ADJUST clamp 2017-06-04 21:55:53 +02:00
tsc.c Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 18:01:50 -07:00
unwind_frame.c x86/unwind: Add end-of-stack check for ftrace handlers 2017-05-24 09:05:16 +02:00
unwind_guess.c x86/unwind: Ensure stack pointer is aligned 2017-04-18 10:30:23 +02:00
uprobes.c uprobes/x86: Fix RIP-relative handling of EVEX-encoded instructions 2016-08-12 08:29:24 +02:00
verify_cpu.S
vm86_32.c x86/vm86/32: Switch to flush_tlb_mm_range() in mark_screen_rdonly() 2017-04-26 10:02:06 +02:00
vmlinux.lds.S debug: Fix __bug_table[] in arch linker scripts 2017-04-03 10:22:40 +02:00
vsmp_64.c
x86_init.c x86/boot/e820: Rename default_machine_specific_memory_setup() to e820__memory_setup_default() 2017-01-28 14:42:26 +01:00