linux/arch/powerpc/kvm
Paul Mackerras 6579804c43 KVM: PPC: Book3S HV: Avoid crash from THP collapse during radix page fault
Commit 71d29f43b6 ("KVM: PPC: Book3S HV: Don't use compound_order to
determine host mapping size", 2018-09-11) added a call to 
__find_linux_pte() and a dereference of the returned PTE pointer to the
radix page fault path in the common case where the page is normal
system memory.  Previously, __find_linux_pte() was only called for
mappings to physical addresses which don't have a page struct (e.g.
memory-mapped I/O) or where the page struct is marked as reserved
memory.

This exposes us to the possibility that the returned PTE pointer
could be NULL, for example in the case of a concurrent THP collapse
operation.  Dereferencing the returned NULL pointer causes a host
crash.

To fix this, we check for NULL, and if it is NULL, we retry the
operation by returning to the guest, with the expectation that it
will generate the same page fault again (unless of course it has
been fixed up by another CPU in the meantime).

Fixes: 71d29f43b6 ("KVM: PPC: Book3S HV: Don't use compound_order to determine host mapping size")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-10-04 14:51:11 +10:00
..
book3s_32_mmu_host.c
book3s_32_mmu.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
book3s_32_sr.S
book3s_64_mmu_host.c
book3s_64_mmu_hv.c PPC KVM fixes for 4.19 2018-09-04 21:12:46 +02:00
book3s_64_mmu_radix.c KVM: PPC: Book3S HV: Avoid crash from THP collapse during radix page fault 2018-10-04 14:51:11 +10:00
book3s_64_mmu.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
book3s_64_slb.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
book3s_64_vio_hv.c KVM: PPC: Avoid marking DMA-mapped pages dirty in real mode 2018-09-12 08:49:54 +10:00
book3s_64_vio.c Minor code cleanups for PPC. 2018-08-19 10:38:36 -07:00
book3s_emulate.c KVM: PPC: Book3S PR: Fix failure status setting in tabort. emulation 2018-06-13 09:46:13 +10:00
book3s_exports.c
book3s_hv_builtin.c mm/cma: remove unsupported gfp_mask parameter from cma_alloc() 2018-08-17 16:20:32 -07:00
book3s_hv_hmi.c
book3s_hv_interrupts.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
book3s_hv_ras.c Merge branch 'topic/ppc-kvm' into next 2018-01-21 22:43:43 +11:00
book3s_hv_rm_mmu.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
book3s_hv_rm_xics.c KVM: PPC: Add pt_regs into kvm_vcpu_arch and move vcpu->arch.gpr[] into it 2018-05-18 15:38:23 +10:00
book3s_hv_rm_xive.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
book3s_hv_rmhandlers.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
book3s_hv_tm_builtin.c KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch 2018-05-18 15:38:23 +10:00
book3s_hv_tm.c KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch 2018-05-18 15:38:23 +10:00
book3s_hv.c powerpc fixes for 4.19 #2 2018-08-24 09:34:23 -07:00
book3s_interrupts.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
book3s_mmu_hpte.c
book3s_paired_singles.c
book3s_pr_papr.c KVM: PPC: Book3S PR: Enable in-kernel TCE handlers for PR KVM 2017-10-14 16:38:19 +11:00
book3s_pr.c treewide: correct "differenciate" and "instanciate" typos 2018-08-23 18:48:43 -07:00
book3s_rmhandlers.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
book3s_rtas.c
book3s_segment.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
book3s_xics.c powerpc: Use octal numbers for file permissions 2018-01-22 05:48:33 +11:00
book3s_xics.h
book3s_xive_template.c powerpc/64s: Remove POWER9 DD1 support 2018-07-16 11:37:21 +10:00
book3s_xive.c treewide: correct "differenciate" and "instanciate" typos 2018-08-23 18:48:43 -07:00
book3s_xive.h KVM: PPC: Book3S HV: Enable use of the new XIVE "single escalation" feature 2018-01-19 12:10:21 +11:00
book3s.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
book3s.h KVM: PPC: Book3S PR: Add guard code to prevent returning to guest with PR=0 and Transactional state 2018-06-01 10:30:39 +10:00
booke_emulate.c KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch 2018-05-18 15:38:23 +10:00
booke_interrupts.S
booke.c KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch 2018-05-18 15:38:23 +10:00
booke.h
bookehv_interrupts.S
e500_emulate.c KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch 2018-05-18 15:38:23 +10:00
e500_mmu_host.c KVM: PPC: Reimplement non-SIMD LOAD/STORE instruction mmio emulation with analyse_instr() input 2018-05-22 19:51:08 +10:00
e500_mmu_host.h
e500_mmu.c KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch 2018-05-18 15:38:23 +10:00
e500.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
e500.h
e500mc.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
emulate_loadstore.c KVM: PPC: Remove mmio_vsx_tx_sx_enabled in KVM MMIO emulation 2018-07-18 15:14:45 +10:00
emulate.c powerpc/64s: Remove POWER4 support 2018-04-01 00:47:50 +11:00
fpu.S
irq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig Second PPC KVM update for 4.16 2018-02-09 22:03:06 +01:00
Makefile KVM: PPC: Book3S PR: Move kvmppc_save_tm/kvmppc_restore_tm to separate file 2018-05-31 11:35:12 +10:00
mpic.c
powerpc.c Minor code cleanups for PPC. 2018-08-19 10:38:36 -07:00
timing.c KVM: PPC: Use seq_puts() in kvmppc_exit_timing_show() 2018-01-11 20:36:06 +11:00
timing.h
tm.S KVM: PPC: Book3S PR: Support TAR handling for PR KVM HTM 2018-06-01 10:30:43 +10:00
trace_book3s.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_booke.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_hv.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_pr.h KVM: PPC: Remove unused kvm_unmap_hva callback 2018-03-19 10:08:29 +11:00
trace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00