Boqun Feng b862789aa5 kvm/x86: Handle async PF in RCU read-side critical sections ...

Sasha Levin reported a WARNING:

| WARNING: CPU: 0 PID: 6974 at kernel/rcu/tree_plugin.h:329
| rcu_preempt_note_context_switch kernel/rcu/tree_plugin.h:329 [inline]
| WARNING: CPU: 0 PID: 6974 at kernel/rcu/tree_plugin.h:329
| rcu_note_context_switch+0x16c/0x2210 kernel/rcu/tree.c:458
...
| CPU: 0 PID: 6974 Comm: syz-fuzzer Not tainted 4.13.0-next-20170908+ #246
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
| 1.10.1-1ubuntu1 04/01/2014
| Call Trace:
...
| RIP: 0010:rcu_preempt_note_context_switch kernel/rcu/tree_plugin.h:329 [inline]
| RIP: 0010:rcu_note_context_switch+0x16c/0x2210 kernel/rcu/tree.c:458
| RSP: 0018:ffff88003b2debc8 EFLAGS: 00010002
| RAX: 0000000000000001 RBX: 1ffff1000765bd85 RCX: 0000000000000000
| RDX: 1ffff100075d7882 RSI: ffffffffb5c7da20 RDI: ffff88003aebc410
| RBP: ffff88003b2def30 R08: dffffc0000000000 R09: 0000000000000001
| R10: 0000000000000000 R11: 0000000000000000 R12: ffff88003b2def08
| R13: 0000000000000000 R14: ffff88003aebc040 R15: ffff88003aebc040
| __schedule+0x201/0x2240 kernel/sched/core.c:3292
| schedule+0x113/0x460 kernel/sched/core.c:3421
| kvm_async_pf_task_wait+0x43f/0x940 arch/x86/kernel/kvm.c:158
| do_async_page_fault+0x72/0x90 arch/x86/kernel/kvm.c:271
| async_page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1069
| RIP: 0010:format_decode+0x240/0x830 lib/vsprintf.c:1996
| RSP: 0018:ffff88003b2df520 EFLAGS: 00010283
| RAX: 000000000000003f RBX: ffffffffb5d1e141 RCX: ffff88003b2df670
| RDX: 0000000000000001 RSI: dffffc0000000000 RDI: ffffffffb5d1e140
| RBP: ffff88003b2df560 R08: dffffc0000000000 R09: 0000000000000000
| R10: ffff88003b2df718 R11: 0000000000000000 R12: ffff88003b2df5d8
| R13: 0000000000000064 R14: ffffffffb5d1e140 R15: 0000000000000000
| vsnprintf+0x173/0x1700 lib/vsprintf.c:2136
| sprintf+0xbe/0xf0 lib/vsprintf.c:2386
| proc_self_get_link+0xfb/0x1c0 fs/proc/self.c:23
| get_link fs/namei.c:1047 [inline]
| link_path_walk+0x1041/0x1490 fs/namei.c:2127
...

This happened when the host hit a page fault, and delivered it as in an
async page fault, while the guest was in an RCU read-side critical
section.  The guest then tries to reschedule in kvm_async_pf_task_wait(),
but rcu_preempt_note_context_switch() would treat the reschedule as a
sleep in RCU read-side critical section, which is not allowed (even in
preemptible RCU).  Thus the WARN.

To cure this, make kvm_async_pf_task_wait() go to the halt path if the
PF happens in a RCU read-side critical section.

Reported-by: Sasha Levin <levinsasha928@gmail.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2017-09-29 17:05:17 +02:00

..

acpi

dmi: Mark all struct dmi_system_id instances const

2017-09-14 11:59:30 +02:00

apic

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-12 11:34:39 -07:00

cpu

x86/hyper-V: Allocate the IDT entry early in boot

2017-09-13 11:02:26 +02:00

fpu

KVM: x86: Fix load damaged SSEx MXCSR register

2017-05-15 16:08:56 +02:00

kprobes

kprobes/x86: Do not jump-optimize kprobes on irq entry code

2017-08-10 16:28:53 +02:00

.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

x86: remove arch specific dma_supported implementation

2017-06-28 06:54:46 -07:00

amd_nb.c

…

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

dmi: Mark all struct dmi_system_id instances const

2017-09-14 11:59:30 +02:00

asm-offsets_32.c

x86/lguest: Remove lguest support

2017-08-24 09:57:28 +02:00

asm-offsets_64.c

x86/xen: Get rid of paravirt op adjust_exception_frame

2017-08-31 21:35:10 +02:00

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

x86/devicetree: Convert to using %pOF instead of ->full_name

2017-07-21 10:14:15 +02:00

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/dumpstack: Fix interrupt and exception stack boundary checks

2017-07-18 10:56:23 +02:00

dumpstack_64.c

x86/dumpstack: Fix interrupt and exception stack boundary checks

2017-07-18 10:56:23 +02:00

dumpstack.c

x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads

2017-07-30 12:04:41 +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

ACPI updates for v4.14-rc1

2017-09-05 12:45:03 -07:00

ebda.c

…

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

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/idt: Move early IDT setup out of 32-bit asm

2017-08-29 12:07:26 +02:00

head64.c

Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-04 17:43:56 -07:00

head_32.S

x86/idt: Remove superfluous ALIGNment

2017-08-31 15:47:02 +02:00

head_64.S

x86/mm: Provide general kernel support for memory encryption

2017-07-18 11:38:00 +02:00

hpet.c

x86/hpet: Cure interface abuse in the resume path

2017-08-01 13:02:37 +02:00

hw_breakpoint.c

…

i8237.c

…

i8253.c

…

i8259.c

x86: i8259: export legacy_pic symbol

2017-04-14 12:08:51 +02:00

idt.c

x86/idt: Fix the X86_TRAP_BP gate

2017-09-01 11:04:56 +02:00

io_delay.c

dmi: Mark all struct dmi_system_id instances const

2017-09-14 11:59:30 +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

…

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_work: Make it depend on APIC

2017-08-29 11:42:30 +02:00

irq.c

x86/ipi: Make platform IPI depend on APIC

2017-08-29 11:42:29 +02:00

irqinit.c

x86/idt: Move interrupt gate initialization to IDT code

2017-08-29 12:07:28 +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

…

ksysfs.c

Merge branch 'linus' into x86/mm to pick up fixes and to fix conflicts

2017-08-26 09:19:13 +02:00

kvm.c

kvm/x86: Handle async PF in RCU read-side critical sections

2017-09-29 17:05:17 +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/64: Refresh DS and ES when modify_ldt changes an entry

2017-07-27 09:12:57 +02:00

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

x86/idt: Create file for IDT related code

2017-08-29 12:07:25 +02:00

mmconf-fam10h_64.c

…

module.c

x86/unwind: Add the ORC unwinder

2017-07-26 13:18:20 +02:00

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

x86/nmi: Use raw lock

2017-08-16 20:40:09 +02:00

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/paravirt: Remove no longer used paravirt functions

2017-09-13 10:55:15 +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/lguest: Remove lguest support

2017-08-24 09:57:28 +02:00

pmem.c

…

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

Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-04 13:56:37 -07:00

process_64.c

Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-04 13:56:37 -07:00

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

treewide: Consolidate Apple DMI checks

2017-08-03 23:26:22 +02:00

reboot_fixups_32.c

…

reboot.c

dmi: Mark all struct dmi_system_id instances const

2017-09-14 11:59:30 +02:00

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

x86/boot/e820: Harmonize the 'struct e820_table' fields

2017-01-28 09:33:16 +01:00

rtc.c

…

setup_percpu.c

treewide: make "nr_cpu_ids" unsigned

2017-09-08 18:26:48 -07:00

setup.c

x86/mm/64: Initialize CR4.PCIDE early

2017-09-13 09:54:43 +02:00

signal_compat.c

signal: Remove kernel interal si_code magic

2017-07-24 14:30:28 -05:00

signal.c

x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads

2017-07-30 12:04:41 +02:00

smp.c

x86/tracing: Disentangle pagefault and resched IPI tracing key

2017-08-29 11:42:29 +02:00

smpboot.c

x86/mm/64: Initialize CR4.PCIDE early

2017-09-13 09:54:43 +02:00

stacktrace.c

stacktrace/x86: add function for detecting reliable stack traces

2017-03-08 09:18:02 +01:00

step.c

x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads

2017-07-30 12:04:41 +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

…

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/asm: Replace access to desc_struct:a/b fields

2017-08-29 12:07:25 +02:00

tls.h

…

topology.c

…

trace_clock.c

…

tracepoint.c

x86/tracing: Disentangle pagefault and resched IPI tracing key

2017-08-29 11:42:29 +02:00

traps.c

x86/idt: Move regular trap init to tables

2017-08-29 12:07:27 +02:00

tsc_msr.c

…

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

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-04 09:52:57 -07:00

unwind_guess.c

x86/unwind: Add the ORC unwinder

2017-07-26 13:18:20 +02:00

unwind_orc.c

x86/unwind: Add the ORC unwinder

2017-07-26 13:18:20 +02:00

uprobes.c

…

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

x86/unwind: Add the ORC unwinder

2017-07-26 13:18:20 +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