arch/x86/kvm/x86.c:10408:32: sparse: sparse: Using plain integer as NULL pointer

From: kernel test robot
Date: Sat Feb 27 2021 - 15:29:56 EST

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tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 5695e51619745d4fe3ec2506a2f0cd982c5e27a4
commit: ff5a983cbb3746d371de2cc95ea7dcfd982b4084 KVM: X86: Don't track dirty for KVM_SET_[TSS_ADDR|IDENTITY_MAP_ADDR]
date: 3 months ago
config: x86_64-randconfig-s022-20210228 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.3-241-geaceeafa-dirty
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ff5a983cbb3746d371de2cc95ea7dcfd982b4084
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout ff5a983cbb3746d371de2cc95ea7dcfd982b4084
# save the attached .config to linux build tree
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

"sparse warnings: (new ones prefixed by >>)"
arch/x86/kvm/x86.c:2859:38: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected void const [noderef] __user * @@ got unsigned char [usertype] * @@
arch/x86/kvm/x86.c:2859:38: sparse: expected void const [noderef] __user *
arch/x86/kvm/x86.c:2859:38: sparse: got unsigned char [usertype] *
arch/x86/kvm/x86.c:8058:15: sparse: sparse: incompatible types in comparison expression (different address spaces):
arch/x86/kvm/x86.c:8058:15: sparse: struct kvm_apic_map [noderef] __rcu *
arch/x86/kvm/x86.c:8058:15: sparse: struct kvm_apic_map *
>> arch/x86/kvm/x86.c:10408:32: sparse: sparse: Using plain integer as NULL pointer
arch/x86/kvm/x86.c:10464:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
arch/x86/kvm/x86.c:10464:16: sparse: struct kvm_apic_map [noderef] __rcu *
arch/x86/kvm/x86.c:10464:16: sparse: struct kvm_apic_map *
arch/x86/kvm/x86.c:10465:15: sparse: sparse: incompatible types in comparison expression (different address spaces):
arch/x86/kvm/x86.c:10465:15: sparse: struct kvm_pmu_event_filter [noderef] __rcu *
arch/x86/kvm/x86.c:10465:15: sparse: struct kvm_pmu_event_filter *
arch/x86/kvm/x86.c: note: in included file (through include/linux/notifier.h, include/linux/memory_hotplug.h, include/linux/mmzone.h, ...):
include/linux/srcu.h:179:9: sparse: sparse: context imbalance in 'vcpu_enter_guest' - unexpected unlock

vim +10408 arch/x86/kvm/x86.c

ff5a983cbb3746 Peter Xu 2020-09-30 10358
ff5a983cbb3746 Peter Xu 2020-09-30 10359 /**
ff5a983cbb3746 Peter Xu 2020-09-30 10360 * __x86_set_memory_region: Setup KVM internal memory slot
ff5a983cbb3746 Peter Xu 2020-09-30 10361 *
ff5a983cbb3746 Peter Xu 2020-09-30 10362 * @kvm: the kvm pointer to the VM.
ff5a983cbb3746 Peter Xu 2020-09-30 10363 * @id: the slot ID to setup.
ff5a983cbb3746 Peter Xu 2020-09-30 10364 * @gpa: the GPA to install the slot (unused when @size == 0).
ff5a983cbb3746 Peter Xu 2020-09-30 10365 * @size: the size of the slot. Set to zero to uninstall a slot.
ff5a983cbb3746 Peter Xu 2020-09-30 10366 *
ff5a983cbb3746 Peter Xu 2020-09-30 10367 * This function helps to setup a KVM internal memory slot. Specify
ff5a983cbb3746 Peter Xu 2020-09-30 10368 * @size > 0 to install a new slot, while @size == 0 to uninstall a
ff5a983cbb3746 Peter Xu 2020-09-30 10369 * slot. The return code can be one of the following:
ff5a983cbb3746 Peter Xu 2020-09-30 10370 *
ff5a983cbb3746 Peter Xu 2020-09-30 10371 * HVA: on success (uninstall will return a bogus HVA)
ff5a983cbb3746 Peter Xu 2020-09-30 10372 * -errno: on error
ff5a983cbb3746 Peter Xu 2020-09-30 10373 *
ff5a983cbb3746 Peter Xu 2020-09-30 10374 * The caller should always use IS_ERR() to check the return value
ff5a983cbb3746 Peter Xu 2020-09-30 10375 * before use. Note, the KVM internal memory slots are guaranteed to
ff5a983cbb3746 Peter Xu 2020-09-30 10376 * remain valid and unchanged until the VM is destroyed, i.e., the
ff5a983cbb3746 Peter Xu 2020-09-30 10377 * GPA->HVA translation will not change. However, the HVA is a user
ff5a983cbb3746 Peter Xu 2020-09-30 10378 * address, i.e. its accessibility is not guaranteed, and must be
ff5a983cbb3746 Peter Xu 2020-09-30 10379 * accessed via __copy_{to,from}_user().
ff5a983cbb3746 Peter Xu 2020-09-30 10380 */
ff5a983cbb3746 Peter Xu 2020-09-30 10381 void __user * __x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa,
ff5a983cbb3746 Peter Xu 2020-09-30 10382 u32 size)
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10383 {
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10384 int i, r;
3f649ab728cda8 Kees Cook 2020-06-03 10385 unsigned long hva, old_npages;
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10386 struct kvm_memslots *slots = kvm_memslots(kvm);
0577d1abe704c3 Sean Christopherson 2020-02-18 10387 struct kvm_memory_slot *slot;
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10388
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10389 /* Called with kvm->slots_lock held. */
1d8007bdee074f Paolo Bonzini 2015-10-12 10390 if (WARN_ON(id >= KVM_MEM_SLOTS_NUM))
ff5a983cbb3746 Peter Xu 2020-09-30 10391 return ERR_PTR_USR(-EINVAL);
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10392
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10393 slot = id_to_memslot(slots, id);
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10394 if (size) {
0577d1abe704c3 Sean Christopherson 2020-02-18 10395 if (slot && slot->npages)
ff5a983cbb3746 Peter Xu 2020-09-30 10396 return ERR_PTR_USR(-EEXIST);
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10397
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10398 /*
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10399 * MAP_SHARED to prevent internal slot pages from being moved
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10400 * by fork()/COW.
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10401 */
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10402 hva = vm_mmap(NULL, 0, size, PROT_READ | PROT_WRITE,
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10403 MAP_SHARED | MAP_ANONYMOUS, 0);
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10404 if (IS_ERR((void *)hva))
ff5a983cbb3746 Peter Xu 2020-09-30 10405 return (void __user *)hva;
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10406 } else {
0577d1abe704c3 Sean Christopherson 2020-02-18 10407 if (!slot || !slot->npages)
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 @10408 return 0;
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10409
0577d1abe704c3 Sean Christopherson 2020-02-18 10410 old_npages = slot->npages;
e0135a104c52cc Paolo Bonzini 2020-06-11 10411 hva = 0;
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10412 }
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10413
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10414 for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
1d8007bdee074f Paolo Bonzini 2015-10-12 10415 struct kvm_userspace_memory_region m;
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10416
1d8007bdee074f Paolo Bonzini 2015-10-12 10417 m.slot = id | (i << 16);
1d8007bdee074f Paolo Bonzini 2015-10-12 10418 m.flags = 0;
1d8007bdee074f Paolo Bonzini 2015-10-12 10419 m.guest_phys_addr = gpa;
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10420 m.userspace_addr = hva;
1d8007bdee074f Paolo Bonzini 2015-10-12 10421 m.memory_size = size;
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10422 r = __kvm_set_memory_region(kvm, &m);
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10423 if (r < 0)
ff5a983cbb3746 Peter Xu 2020-09-30 10424 return ERR_PTR_USR(r);
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10425 }
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10426
103c763c72dd2d Eric Biggers 2018-01-31 10427 if (!size)
0577d1abe704c3 Sean Christopherson 2020-02-18 10428 vm_munmap(hva, old_npages * PAGE_SIZE);
f0d648bdf0a5bb Paolo Bonzini 2015-10-12 10429
ff5a983cbb3746 Peter Xu 2020-09-30 10430 return (void __user *)hva;
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10431 }
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10432 EXPORT_SYMBOL_GPL(__x86_set_memory_region);
9da0e4d5ac9699 Paolo Bonzini 2015-05-18 10433

:::::: The code at line 10408 was first introduced by commit
:::::: f0d648bdf0a5bbc91da6099d5282f77996558ea4 KVM: x86: map/unmap private slots in __x86_set_memory_region

:::::: TO: Paolo Bonzini <pbonzini@xxxxxxxxxx>
:::::: CC: Paolo Bonzini <pbonzini@xxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

Attachment: .config.gz
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Next message: Palmer Dabbelt: "[GIT PULL] RISC-V Patches for the 5.12 Merge Window, Part 2"
Previous message: Sedat Dilek: "Re: [PATCH] [RFC] arm64: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION"
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