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c2b3496bb3
linux/arch/x86/kernel
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Peter Zijlstra c2b3496bb3 x86/ldt: Rework locking 
The LDT is duplicated on fork() and on exec(), which is wrong as exec()
should start from a clean state, i.e. without LDT. To fix this the LDT
duplication code will be moved into arch_dup_mmap() which is only called
for fork().

This introduces a locking problem. arch_dup_mmap() holds mmap_sem of the
parent process, but the LDT duplication code needs to acquire
mm->context.lock to access the LDT data safely, which is the reverse lock
order of write_ldt() where mmap_sem nests into context.lock.

Solve this by introducing a new rw semaphore which serializes the
read/write_ldt() syscall operations and use context.lock to protect the
actual installment of the LDT descriptor.

So context.lock stabilizes mm->context.ldt and can nest inside of the new
semaphore or mmap_sem.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: dan.j.williams@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22 20:13:01 +01:00
..
acpi License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
apic x86/virt, x86/platform: Merge 'struct x86_hyper' into 'struct x86_platform' and 'struct x86_init' 2017-11-10 10:03:12 +01:00
cpu x86/cpufeatures: Make CPU bugs sticky 2017-12-17 14:27:53 +01:00
fpu Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
kprobes License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
.gitignore
alternative.c x86: Clarify/fix no-op barriers for text_poke_bp() 2017-08-10 17:35:19 +02:00
amd_gart_64.c
amd_nb.c x86/cpu/AMD: Apply the Erratum 688 fix when the BIOS doesn't 2017-10-22 13:06:02 +02:00
apb_timer.c
aperture_64.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
apm_32.c dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
asm-offsets_32.c x86/entry/64: Make cpu_entry_area.tss read-only 2017-12-17 14:27:52 +01:00
asm-offsets_64.c x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0 2017-12-17 13:59:56 +01:00
asm-offsets.c x86/entry/64: Make cpu_entry_area.tss read-only 2017-12-17 14:27:52 +01:00
audit_64.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bootflag.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
check.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cpuid.c
crash_dump_32.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crash_dump_64.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crash.c
devicetree.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
doublefault.c x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss 2017-12-17 13:59:55 +01:00
dumpstack_32.c x86/dumpstack: Add get_stack_info() support for the SYSENTER stack 2017-12-17 13:59:54 +01:00
dumpstack_64.c x86/dumpstack: Add get_stack_info() support for the SYSENTER stack 2017-12-17 13:59:54 +01:00
dumpstack.c x86/entry: Clean up the SYSENTER_stack code 2017-12-17 14:27:51 +01:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
early-quirks.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ebda.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
eisa.c x86/eisa: Add missing include 2017-08-31 21:34:48 +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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ftrace_64.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ftrace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
head32.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
head64.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
head_32.S Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
head_64.S Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
hpet.c x86/hpet: Cure interface abuse in the resume path 2017-08-01 13:02:37 +02:00
hw_breakpoint.c
i8237.c
i8253.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
i8259.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
idt.c x86/idt: Remove X86_TRAP_BP initialization in idt_setup_traps() 2017-11-08 21:05:23 +01:00
io_delay.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ioport.c x86/entry/64: Make cpu_entry_area.tss read-only 2017-12-17 14:27:52 +01:00
irq_32.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq_64.c x86/irq/64: Print the offending IP in the stack overflow warning 2017-12-17 13:59:53 +01:00
irq_work.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq.c x86/irq: Remove an old outdated comment about context tracking races 2017-12-17 13:59:53 +01:00
irqinit.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
itmt.c
jump_label.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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
kgdb.c
ksysfs.c x86/sysfs: Fix off-by-one error in loop termination 2017-09-25 09:36:16 +02:00
kvm.c x86/virt: Add enum for hypervisors to replace x86_hyper 2017-11-10 10:03:12 +01:00
kvmclock.c kvm: Return -ENODEV from update_persistent_clock 2017-11-02 18:23:18 +01:00
ldt.c x86/ldt: Rework locking 2017-12-22 20:13:01 +01:00
livepatch.c
machine_kexec_32.c x86/idt: Consolidate IDT invalidation 2017-08-29 12:07:26 +02:00
machine_kexec_64.c x86/mm, kexec: Fix memory corruption with SME on successive kexecs 2017-07-30 12:09:12 +02:00
Makefile Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
mmconf-fam10h_64.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
module.c x86/module: Detect and skip invalid relocations 2017-11-05 09:52:16 +01:00
mpparse.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
msr.c
nmi_selftest.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nmi.c x86/nmi: Use raw lock 2017-08-16 20:40:09 +02:00
paravirt_patch_32.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
paravirt_patch_64.c x86/paravirt: Dont patch flush_tlb_single 2017-12-17 14:27:52 +01:00
paravirt-spinlocks.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
paravirt.c x86/paravirt: Remove no longer used paravirt functions 2017-09-13 10:55:15 +02:00
pci-calgary_64.c
pci-dma.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pci-iommu_table.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pci-nommu.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pci-swiotlb.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pcspeaker.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
perf_regs.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
platform-quirks.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
probe_roms.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
process_32.c x86/entry/64: Make cpu_entry_area.tss read-only 2017-12-17 14:27:52 +01:00
process_64.c x86/entry/64: Make cpu_entry_area.tss read-only 2017-12-17 14:27:52 +01:00
process.c x86/entry/64: Make cpu_entry_area.tss read-only 2017-12-17 14:27:52 +01:00
ptrace.c
pvclock.c
quirks.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
reboot_fixups_32.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
reboot.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
relocate_kernel_32.S
relocate_kernel_64.S x86/mm, kexec: Fix memory corruption with SME on successive kexecs 2017-07-30 12:09:12 +02:00
resource.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rtc.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
setup_percpu.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
setup.c x86/mm/64: Initialize CR4.PCIDE early 2017-09-13 09:54:43 +02:00
signal_compat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
signal.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smp.c x86/tracing: Disentangle pagefault and resched IPI tracing key 2017-08-29 11:42:29 +02:00
smpboot.c Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
stacktrace.c
step.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sys_x86_64.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sysfb_efi.c
sysfb_simplefb.c
sysfb.c
tboot.c
tce_64.c
time.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tls.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tls.h
topology.c
trace_clock.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tracepoint.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
traps.c x86/entry/64: Make cpu_entry_area.tss read-only 2017-12-17 14:27:52 +01:00
tsc_msr.c
tsc_sync.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tsc.c x86/smpboot: Make optimization of delay calibration work correctly 2017-11-07 16:04:54 +01:00
unwind_frame.c x86/unwind: Disable unwinder warnings on 32-bit 2017-10-10 12:49:49 +02:00
unwind_guess.c x86/unwind: Add the ORC unwinder 2017-07-26 13:18:20 +02:00
unwind_orc.c x86/unwinder: Handle stack overflows more gracefully 2017-12-17 13:59:52 +01:00
uprobes.c
verify_cpu.S x86/boot: Annotate verify_cpu() as a callable function 2017-09-28 09:39:03 +02:00
vm86_32.c Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
vmlinux.lds.S x86/entry/64: Create a per-CPU SYSCALL entry trampoline 2017-12-17 14:27:50 +01:00
vsmp_64.c
x86_init.c x86/virt, x86/platform: Merge 'struct x86_hyper' into 'struct x86_platform' and 'struct x86_init' 2017-11-10 10:03:12 +01:00