In kvm_hv_flush_tlb(), valid_bank_mask is declared as unsigned long, but is used as u64, which is wrong for i386, and has been spotted by LKP after applying "KVM: x86: hyper-v: replace bitmap_weight() with hweight64()" https://lore.kernel.org/lkml/20220510154750.212913-12-yury.norov@xxxxxxxxx/ But it's wrong even without that patch because now bitmap_weight() dereferences a word after valid_bank_mask on i386. >> include/asm-generic/bitops/const_hweight.h:21:76: warning: right shift count >= width of type +[-Wshift-count-overflow] 21 | #define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32)) | ^~ include/asm-generic/bitops/const_hweight.h:10:16: note: in definition of macro '__const_hweight8' 10 | ((!!((w) & (1ULL << 0))) + \ | ^ include/asm-generic/bitops/const_hweight.h:20:31: note: in expansion of macro '__const_hweight16' 20 | #define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16)) | ^~~~~~~~~~~~~~~~~ include/asm-generic/bitops/const_hweight.h:21:54: note: in expansion of macro '__const_hweight32' 21 | #define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32)) | ^~~~~~~~~~~~~~~~~ include/asm-generic/bitops/const_hweight.h:29:49: note: in expansion of macro '__const_hweight64' 29 | #define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w)) | ^~~~~~~~~~~~~~~~~ arch/x86/kvm/hyperv.c:1983:36: note: in expansion of macro 'hweight64' 1983 | if (hc->var_cnt != hweight64(valid_bank_mask)) | ^~~~~~~~~ CC: Borislav Petkov <bp@xxxxxxxxx> CC: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> CC: H. Peter Anvin <hpa@xxxxxxxxx> CC: Ingo Molnar <mingo@xxxxxxxxxx> CC: Jim Mattson <jmattson@xxxxxxxxxx> CC: Joerg Roedel <joro@xxxxxxxxxx> CC: Paolo Bonzini <pbonzini@xxxxxxxxxx> CC: Sean Christopherson <seanjc@xxxxxxxxxx> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CC: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> CC: Wanpeng Li <wanpengli@xxxxxxxxxxx> CC: kvm@xxxxxxxxxxxxxxx CC: linux-kernel@xxxxxxxxxxxxxxx CC: x86@xxxxxxxxxx Reported-by: kernel test robot <lkp@xxxxxxxxx> Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx> --- arch/x86/kvm/hyperv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 58baf7f9acce..c8ca95d4e4e9 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1938,7 +1938,7 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) struct hv_send_ipi_ex send_ipi_ex; struct hv_send_ipi send_ipi; DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS); - unsigned long valid_bank_mask; + u64 valid_bank_mask; u64 sparse_banks[KVM_HV_MAX_SPARSE_VCPU_SET_BITS]; u32 vector; bool all_cpus; -- 2.32.0
