On 1/7/22 18:01, Sean Christopherson wrote:
On Wed, Jan 05, 2022, Peter Xu wrote:
On Wed, Jan 05, 2022 at 09:33:37AM +0530, Nikunj A Dadhania wrote:
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@xxxxxxx>
Tested-by: Vasant Hegde <vasant.hegde@xxxxxxx>
Signed-off-by: Nikunj A Dadhania <nikunj@xxxxxxx>
---
Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Queued, thanks.
Paolo
