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fffb532378
linux/arch/x86
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Nikunj A Dadhania fffb532378 KVM: x86: Check for rmaps allocation 
With TDP MMU being the default now, access to mmu_rmaps_stat debugfs
file causes following oops:

BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 7 PID: 3185 Comm: cat Not tainted 5.16.0-rc4+ #204
RIP: 0010:pte_list_count+0x6/0x40
 Call Trace:
  <TASK>
  ? kvm_mmu_rmaps_stat_show+0x15e/0x320
  seq_read_iter+0x126/0x4b0
  ? aa_file_perm+0x124/0x490
  seq_read+0xf5/0x140
  full_proxy_read+0x5c/0x80
  vfs_read+0x9f/0x1a0
  ksys_read+0x67/0xe0
  __x64_sys_read+0x19/0x20
  do_syscall_64+0x3b/0xc0
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7fca6fc13912

Return early when rmaps are not present.

Reported-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220105040337.4234-1-nikunj@amd.com>
Cc: stable@vger.kernel.org
Fixes: 3bcd0662d6 ("KVM: X86: Introduce mmu_rmaps_stat per-vm debugfs file")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-07 12:04:01 -05:00
..
boot - Do not #GP on userspace use of CLI/STI but pretend it was a NOP to 2021-11-02 07:56:47 -07:00
configs configs: remove the obsolete CONFIG_INPUT_POLLDEV 2021-09-08 11:50:28 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2021-11-01 21:24:02 -07:00
entry x86/xen: Add xenpv_restore_regs_and_return_to_usermode() 2021-12-03 19:21:15 +01:00
events x86/perf: Fix snapshot_branch_stack warning in VM 2021-11-17 14:48:43 +01:00
hyperv x86/hyperv: Move required MSRs check to initial platform probing 2021-11-15 12:37:08 +00:00
ia32 audit/stable-5.16 PR 20211101 2021-11-01 21:17:39 -07:00
include KVM: x86: Always set kvm_run->if_flag 2021-12-20 08:06:53 -05:00
kernel x86/sev: Fix SEV-ES INS/OUTS instructions for word, dword, and qword 2021-12-03 18:09:30 +01:00
kvm KVM: x86: Check for rmaps allocation 2022-01-07 12:04:01 -05:00
lib - Do not #GP on userspace use of CLI/STI but pretend it was a NOP to 2021-11-02 07:56:47 -07:00
math-emu x86/math-emu: Convert to fpstate 2021-10-20 23:57:54 +02:00
mm Merge branch 'kvm-guest-sev-migration' into kvm-master 2021-11-11 07:40:26 -05:00
net Core: 2021-11-02 06:20:58 -07:00
pci xen: branch for v5.16-rc1 2021-11-10 11:14:21 -08:00
platform Add an interface called cc_platform_has() which is supposed to be used 2021-11-01 15:16:52 -07:00
power x86/fpu: Replace the includes of fpu/internal.h 2021-10-20 15:27:29 +02:00
purgatory kernel.h: split out panic and oops helpers 2021-07-01 11:06:04 -07:00
ras
realmode x86/64/mm: Map all kernel memory into trampoline_pgd 2021-12-03 09:11:43 +01:00
tools Driver core changes for 5.16-rc1 2021-11-04 08:32:38 -07:00
um um: fix stub location calculation 2021-08-26 22:28:03 +02:00
video
xen x86/xen: Add xenpv_restore_regs_and_return_to_usermode() 2021-12-03 19:21:15 +01:00
.gitignore
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig ftrace/samples: add missing Kconfig option for ftrace direct multi sample 2021-11-18 17:50:54 +01:00
Kconfig.assembler
Kconfig.cpu x86/CPU: Add support for Vortex CPUs 2021-10-21 15:49:07 +02:00
Kconfig.debug tracing: Refactor TRACE_IRQFLAGS_SUPPORT in Kconfig 2021-08-16 11:37:21 -04:00
Makefile Kbuild updates for v5.16 2021-11-08 09:15:45 -08:00
Makefile_32.cpu x86/build: Do not add -falign flags unconditionally for clang 2021-09-19 10:35:53 +09:00
Makefile.um um: allow not setting extra rpaths in the linux binary 2021-06-17 21:54:15 +02:00