From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Christopherson Date: Tue, 22 Oct 2019 00:35:29 +0000 Subject: [PATCH v2 07/15] KVM: Refactor error handling for setting memory region Message-Id: <20191022003537.13013-8-sean.j.christopherson@intel.com> List-Id: References: <20191022003537.13013-1-sean.j.christopherson@intel.com> In-Reply-To: <20191022003537.13013-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: James Hogan , Paul Mackerras , Christian Borntraeger , Janosch Frank , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Marc Zyngier Cc: David Hildenbrand , Cornelia Huck , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , James Morse , Julien Thierry , Suzuki K Poulose , linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Replace a big pile o' gotos with returns to make it more obvious what error code is being returned, and to prepare for refactoring the functional, i.e. post-checks, portion of __kvm_set_memory_region(). Reviewed-by: Janosch Frank Signed-off-by: Sean Christopherson --- virt/kvm/kvm_main.c | 40 ++++++++++++++++++---------------------- 1 file changed, 18 insertions(+), 22 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 26151e2e3365..40e27ffaf29a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -930,34 +930,33 @@ int __kvm_set_memory_region(struct kvm *kvm, r = check_memory_region_flags(mem); if (r) - goto out; + return r; - r = -EINVAL; as_id = mem->slot >> 16; id = (u16)mem->slot; /* General sanity checks */ if (mem->memory_size & (PAGE_SIZE - 1)) - goto out; + return -EINVAL; if (mem->guest_phys_addr & (PAGE_SIZE - 1)) - goto out; + return -EINVAL; /* We can read the guest memory with __xxx_user() later on. */ if ((id < KVM_USER_MEM_SLOTS) && ((mem->userspace_addr & (PAGE_SIZE - 1)) || !access_ok((void __user *)(unsigned long)mem->userspace_addr, mem->memory_size))) - goto out; + return -EINVAL; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM) - goto out; + return -EINVAL; if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) - goto out; + return -EINVAL; slot = id_to_memslot(__kvm_memslots(kvm, as_id), id); base_gfn = mem->guest_phys_addr >> PAGE_SHIFT; npages = mem->memory_size >> PAGE_SHIFT; if (npages > KVM_MEM_MAX_NR_PAGES) - goto out; + return -EINVAL; new = old = *slot; @@ -974,20 +973,18 @@ int __kvm_set_memory_region(struct kvm *kvm, if ((new.userspace_addr != old.userspace_addr) || (npages != old.npages) || ((new.flags ^ old.flags) & KVM_MEM_READONLY)) - goto out; + return -EINVAL; if (base_gfn != old.base_gfn) change = KVM_MR_MOVE; else if (new.flags != old.flags) change = KVM_MR_FLAGS_ONLY; - else { /* Nothing to change. */ - r = 0; - goto out; - } + else /* Nothing to change. */ + return 0; } } else { if (!old.npages) - goto out; + return -EINVAL; change = KVM_MR_DELETE; new.base_gfn = 0; @@ -996,29 +993,29 @@ int __kvm_set_memory_region(struct kvm *kvm, if ((change = KVM_MR_CREATE) || (change = KVM_MR_MOVE)) { /* Check for overlaps */ - r = -EEXIST; kvm_for_each_memslot(slot, __kvm_memslots(kvm, as_id)) { if (slot->id = id) continue; if (!((base_gfn + npages <= slot->base_gfn) || (base_gfn >= slot->base_gfn + slot->npages))) - goto out; + return -EEXIST; } } - r = -ENOMEM; - /* Allocate/free page dirty bitmap as needed */ if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES)) new.dirty_bitmap = NULL; else if (!new.dirty_bitmap) { - if (kvm_create_dirty_bitmap(&new) < 0) - goto out; + r = kvm_create_dirty_bitmap(&new); + if (r) + return r; } slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL_ACCOUNT); - if (!slots) + if (!slots) { + r = -ENOMEM; goto out_bitmap; + } memcpy(slots, __kvm_memslots(kvm, as_id), sizeof(struct kvm_memslots)); if ((change = KVM_MR_DELETE) || (change = KVM_MR_MOVE)) { @@ -1069,7 +1066,6 @@ int __kvm_set_memory_region(struct kvm *kvm, out_bitmap: if (new.dirty_bitmap && !old.dirty_bitmap) kvm_destroy_dirty_bitmap(&new); -out: return r; } EXPORT_SYMBOL_GPL(__kvm_set_memory_region); -- 2.22.0