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Aneesh Kumar K.V authored
With CONFIG_DEBUG_VIRTUAL=y, __pa() checks for addr value and if it's less than PAGE_OFFSET it leads to a BUG(). #define __pa(x) ({ VIRTUAL_BUG_ON((unsigned long)(x) < PAGE_OFFSET); (unsigned long)(x) & 0x0fffffffffffffffUL; }) kernel BUG at arch/powerpc/kvm/book3s_64_mmu_radix.c:43! cpu 0x70: Vector: 700 (Program Check) at [c0000018a2187360] pc: c000000000161b30: __kvmhv_copy_tofrom_guest_radix+0x130/0x1f0 lr: c000000000161d5c: kvmhv_copy_from_guest_radix+0x3c/0x80 ... kvmhv_copy_from_guest_radix+0x3c/0x80 kvmhv_load_from_eaddr+0x48/0xc0 kvmppc_ld+0x98/0x1e0 kvmppc_load_last_inst+0x50/0x90 kvmppc_hv_emulate_mmio+0x288/0x2b0 kvmppc_book3s_radix_page_fault+0xd8/0x2b0 kvmppc_book3s_hv_page_fault+0x37c/0x1050 kvmppc_vcpu_run_hv+0xbb8/0x1080 kvmppc_vcpu_run+0x34/0x50 kvm_arch_vcpu_ioctl_run+0x2fc/0x410 kvm_vcpu_ioctl+0x2b4/0x8f0 ksys_ioctl+0xf4/0x150 sys_ioctl+0x28/0x80 system_call_exception+0x104/0x1d0 system_call_common+0xe8/0x214 kvmhv_copy_tofrom_guest_radix() uses a NULL value for to/from to indicate direction of copy. Avoid calling __pa() if the value is NULL to avoid the BUG(). Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Massage change log a bit to mention CONFIG_DEBUG_VIRTUAL] Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200611120159.680284-1-aneesh.kumar@linux.ibm.com
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