TencentOS-kernel/arch/powerpc
Aneesh Kumar K.V 6b0a557727 powerpc/kvm/book3s64: Fix kernel crash with nested kvm & DEBUG_VIRTUAL
[ Upstream commit c1ed1754f271f6b7acb1bfdc8cfb62220fbed423 ]

With CONFIG_DEBUG_VIRTUAL=y, __pa() checks for addr value and if it's
less than PAGE_OFFSET it leads to a BUG().

  #define __pa(x)
  ({
  	VIRTUAL_BUG_ON((unsigned long)(x) < PAGE_OFFSET);
  	(unsigned long)(x) & 0x0fffffffffffffffUL;
  })

  kernel BUG at arch/powerpc/kvm/book3s_64_mmu_radix.c:43!
  cpu 0x70: Vector: 700 (Program Check) at [c0000018a2187360]
      pc: c000000000161b30: __kvmhv_copy_tofrom_guest_radix+0x130/0x1f0
      lr: c000000000161d5c: kvmhv_copy_from_guest_radix+0x3c/0x80
  ...
  kvmhv_copy_from_guest_radix+0x3c/0x80
  kvmhv_load_from_eaddr+0x48/0xc0
  kvmppc_ld+0x98/0x1e0
  kvmppc_load_last_inst+0x50/0x90
  kvmppc_hv_emulate_mmio+0x288/0x2b0
  kvmppc_book3s_radix_page_fault+0xd8/0x2b0
  kvmppc_book3s_hv_page_fault+0x37c/0x1050
  kvmppc_vcpu_run_hv+0xbb8/0x1080
  kvmppc_vcpu_run+0x34/0x50
  kvm_arch_vcpu_ioctl_run+0x2fc/0x410
  kvm_vcpu_ioctl+0x2b4/0x8f0
  ksys_ioctl+0xf4/0x150
  sys_ioctl+0x28/0x80
  system_call_exception+0x104/0x1d0
  system_call_common+0xe8/0x214

kvmhv_copy_tofrom_guest_radix() uses a NULL value for to/from to
indicate direction of copy.

Avoid calling __pa() if the value is NULL to avoid the BUG().

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Massage change log a bit to mention CONFIG_DEBUG_VIRTUAL]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200611120159.680284-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-16 16:31:27 +08:00
..
boot Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
configs Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
crypto Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
include powerpc/64s/pgtable: fix an undefined behaviour 2021-03-16 16:30:21 +08:00
kernel powerpc: Fix kernel crash in show_instructions() w/DEBUG_VIRTUAL 2021-03-16 16:30:37 +08:00
kvm powerpc/kvm/book3s64: Fix kernel crash with nested kvm & DEBUG_VIRTUAL 2021-03-16 16:31:27 +08:00
lib Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
math-emu Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
mm powerpc/32s: Don't warn when mapping RO data ROX. 2021-03-16 16:30:24 +08:00
net Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
oprofile Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
perf powerpc/perf/hv-24x7: Fix inconsistent output values incase multiple hv-24x7 events run 2021-03-16 16:30:04 +08:00
platforms powerpc/4xx: Don't unmap NULL mbase 2021-03-16 16:30:26 +08:00
purgatory Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
sysdev powerpc/xive: Clear the page tables for the ESB IO mapping 2021-03-16 16:28:56 +08:00
tools Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
xmon powerpc/xmon: Restrict when kernel is locked down 2021-03-16 16:28:45 +08:00
Kbuild Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT 2021-03-16 16:29:58 +08:00
Kconfig.debug Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Makefile Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Makefile.postlink Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00