MIPS: KVM: Fix NULL pointer dereference
After commit
45c7e8af4a5e3f0bea4ac209 ("MIPS: Remove KVM_TE support") we
get a NULL pointer dereference when creating a KVM guest:
[ 146.243409] Starting KVM with MIPS VZ extensions
[ 149.849151] CPU 3 Unable to handle kernel paging request at virtual address
0000000000000300, epc ==
ffffffffc06356ec, ra ==
ffffffffc063568c
[ 149.849177] Oops[#1]:
[ 149.849182] CPU: 3 PID: 2265 Comm: qemu-system-mip Not tainted 6.4.0-rc3+ #1671
[ 149.849188] Hardware name: THTF CX TL630 Series/THTF-LS3A4000-7A1000-ML4A, BIOS KL4.1F.TF.D.166.201225.R 12/25/2020
[ 149.849192] $ 0 :
0000000000000000 000000007400cce0 0000000000400004 ffffffff8119c740
[ 149.849209] $ 4 :
000000007400cce1 000000007400cce1 0000000000000000 0000000000000000
[ 149.849221] $ 8 :
000000240058bb36 ffffffff81421ac0 0000000000000000 0000000000400dc0
[ 149.849233] $12 :
9800000102a07cc8 ffffffff80e40e38 0000000000000001 0000000000400dc0
[ 149.849245] $16 :
0000000000000000 9800000106cd0000 9800000106cd0000 9800000100cce000
[ 149.849257] $20 :
ffffffffc0632b28 ffffffffc05b31b0 9800000100ccca00 0000000000400000
[ 149.849269] $24 :
9800000106cd09ce ffffffff802f69d0
[ 149.849281] $28 :
9800000102a04000 9800000102a07cd0 98000001106a8000 ffffffffc063568c
[ 149.849293] Hi :
00000335b2111e66
[ 149.849295] Lo :
6668d90061ae0ae9
[ 149.849298] epc :
ffffffffc06356ec kvm_vz_vcpu_setup+0xc4/0x328 [kvm]
[ 149.849324] ra :
ffffffffc063568c kvm_vz_vcpu_setup+0x64/0x328 [kvm]
[ 149.849336] Status:
7400cce3 KX SX UX KERNEL EXL IE
[ 149.849351] Cause :
1000000c (ExcCode 03)
[ 149.849354] BadVA :
0000000000000300
[ 149.849357] PrId :
0014c004 (ICT Loongson-3)
[ 149.849360] Modules linked in: kvm nfnetlink_queue nfnetlink_log nfnetlink fuse sha256_generic libsha256 cfg80211 rfkill binfmt_misc vfat fat snd_hda_codec_hdmi input_leds led_class snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hda_core snd_pcm snd_timer snd serio_raw xhci_pci radeon drm_suballoc_helper drm_display_helper xhci_hcd ip_tables x_tables
[ 149.849432] Process qemu-system-mip (pid: 2265, threadinfo=
00000000ae2982d2, task=
0000000038e09ad4, tls=
000000ffeba16030)
[ 149.849439] Stack :
9800000000000003 9800000100ccca00 9800000100ccc000 ffffffffc062cef4
[ 149.849453]
9800000102a07d18 c89b63a7ab338e00 0000000000000000 ffffffff811a0000
[ 149.849465]
0000000000000000 9800000106cd0000 ffffffff80e59938 98000001106a8920
[ 149.849476]
ffffffff80e57f30 ffffffffc062854c ffffffff811a0000 9800000102bf4240
[ 149.849488]
ffffffffc05b0000 ffffffff80e3a798 000000ff78000000 000000ff78000010
[ 149.849500]
0000000000000255 98000001021f7de0 98000001023f0078 ffffffff81434000
[ 149.849511]
0000000000000000 0000000000000000 9800000102ae0000 980000025e92ae28
[ 149.849523]
0000000000000000 c89b63a7ab338e00 0000000000000001 ffffffff8119dce0
[ 149.849535]
000000ff78000010 ffffffff804f3d3c 9800000102a07eb0 0000000000000255
[ 149.849546]
0000000000000000 ffffffff8049460c 000000ff78000010 0000000000000255
[ 149.849558] ...
[ 149.849565] Call Trace:
[ 149.849567] [<
ffffffffc06356ec>] kvm_vz_vcpu_setup+0xc4/0x328 [kvm]
[ 149.849586] [<
ffffffffc062cef4>] kvm_arch_vcpu_create+0x184/0x228 [kvm]
[ 149.849605] [<
ffffffffc062854c>] kvm_vm_ioctl+0x64c/0xf28 [kvm]
[ 149.849623] [<
ffffffff805209c0>] sys_ioctl+0xc8/0x118
[ 149.849631] [<
ffffffff80219eb0>] syscall_common+0x34/0x58
The root cause is the deletion of kvm_mips_commpage_init() leaves vcpu
->arch.cop0 NULL. So fix it by making cop0 from a pointer to an embedded
object.
Fixes:
45c7e8af4a5e3f0bea4ac209 ("MIPS: Remove KVM_TE support")
Cc: stable@vger.kernel.org
Reported-by: Yu Zhao <yuzhao@google.com>
Suggested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>