Merge android-4.4.194 (a749771) into msm-4.4

* refs/heads/tmp-a749771
  Linux 4.4.194
  net_sched: let qdisc_put() accept NULL pointer
  ARC: export "abort" for modules
  media: technisat-usb2: break out of loop at end of buffer
  floppy: fix usercopy direction
  keys: Fix missing null pointer check in request_key_auth_describe()
  dmaengine: ti: omap-dma: Add cleanup in omap_dma_probe()
  net: seeq: Fix the function used to release some memory in an error handling path
  tools/power turbostat: fix buffer overrun
  sky2: Disable MSI on yet another ASUS boards (P6Xxxx)
  cifs: Use kzfree() to zero out the password
  cifs: set domainName when a domain-key is used in multiuser
  NFSv2: Fix write regression
  NFSv2: Fix eof handling
  netfilter: nf_conntrack_ftp: Fix debug output
  x86/apic: Fix arch_dynirq_lower_bound() bug for DT enabled machines
  r8152: Set memory to all 0xFFs on failed reg reads
  ARM: 8874/1: mm: only adjust sections of valid mm structures
  Kconfig: Fix the reference to the IDT77105 Phy driver in the description of ATM_NICSTAR_USE_IDT77105
  NFS: Fix initialisation of I/O result struct in nfs_pgio_rpcsetup
  NFSv4: Fix return values for nfs4_file_open()
  s390/bpf: use 32-bit index for tail calls
  ARM: OMAP2+: Fix omap4 errata warning on other SoCs
  s390/bpf: fix lcgr instruction encoding
  mwifiex: Fix three heap overflow at parsing element in cfg80211_ap_settings
  tty/serial: atmel: reschedule TX after RX was started
  serial: sprd: correct the wrong sequence of arguments
  KVM: coalesced_mmio: add bounds checking
  xen-netfront: do not assume sk_buff_head list is empty in error handling
  x86/boot: Add missing bootparam that breaks boot on some platforms
  media: tm6000: double free if usb disconnect while streaming
  USB: usbcore: Fix slab-out-of-bounds bug during device reset
  ARC: configs: Remove CONFIG_INITRAMFS_SOURCE from defconfigs
  MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send()
  x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence GCC9 build warning
  crypto: talitos - check data blocksize in ablkcipher.
  crypto: talitos - check AES key size
  driver core: Fix use-after-free and double free on glue directory
  clk: rockchip: Don't yell about bad mmc phases when getting
  MIPS: VDSO: Use same -m%-float cflag as the kernel proper
  MIPS: VDSO: Prevent use of smp_processor_id()
  KVM: nVMX: handle page fault in vmread
  KVM: x86: work around leak of uninitialized stack contents
  KVM: s390: Do not leak kernel stack data in the KVM_S390_INTERRUPT ioctl
  genirq: Prevent NULL pointer dereference in resend_irqs()
  Btrfs: fix assertion failure during fsync and use of stale transaction
  Revert "MIPS: SiByte: Enable swiotlb for SWARM, LittleSur and BigSur"
  tun: fix use-after-free when register netdev failed
  tipc: add NULL pointer check before calling kfree_rcu
  tcp: fix tcp_ecn_withdraw_cwr() to clear TCP_ECN_QUEUE_CWR
  sctp: use transport pf_retrans in sctp_do_8_2_transport_strike
  sctp: Fix the link time qualifier of 'sctp_ctrlsock_exit()'
  sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero
  net: Fix null de-reference of device refcount
  isdn/capi: check message length in capi_write()
  ipv6: Fix the link time qualifier of 'ping_v6_proc_exit_net()'
  cdc_ether: fix rndis support for Mediatek based smartphones
  bridge/mdb: remove wrong use of NLM_F_MULTI

Change-Id: I950778c771159febb721a4ebc2656c57ef40ad83
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>

1 files changed, 10 insertions, 7 deletions

diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 571c1ce37d15..5c1efb869df2 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -39,7 +39,7 @@ static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
 	return 1;
 }
 
-static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev)
+static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev, u32 last)
 {
 	struct kvm_coalesced_mmio_ring *ring;
 	unsigned avail;
@@ -51,7 +51,7 @@ static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev)
 	 * there is always one unused entry in the buffer
 	 */
 	ring = dev->kvm->coalesced_mmio_ring;
-	avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX;
+	avail = (ring->first - last - 1) % KVM_COALESCED_MMIO_MAX;
 	if (avail == 0) {
 		/* full */
 		return 0;
@@ -66,24 +66,27 @@ static int coalesced_mmio_write(struct kvm_vcpu *vcpu,
 {
 	struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
 	struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring;
+	__u32 insert;
 
 	if (!coalesced_mmio_in_range(dev, addr, len))
 		return -EOPNOTSUPP;
 
 	spin_lock(&dev->kvm->ring_lock);
 
-	if (!coalesced_mmio_has_room(dev)) {
+	insert = READ_ONCE(ring->last);
+	if (!coalesced_mmio_has_room(dev, insert) ||
+	    insert >= KVM_COALESCED_MMIO_MAX) {
 		spin_unlock(&dev->kvm->ring_lock);
 		return -EOPNOTSUPP;
 	}
 
 	/* copy data in first free entry of the ring */
 
-	ring->coalesced_mmio[ring->last].phys_addr = addr;
-	ring->coalesced_mmio[ring->last].len = len;
-	memcpy(ring->coalesced_mmio[ring->last].data, val, len);
+	ring->coalesced_mmio[insert].phys_addr = addr;
+	ring->coalesced_mmio[insert].len = len;
+	memcpy(ring->coalesced_mmio[insert].data, val, len);
 	smp_wmb();
-	ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX;
+	ring->last = (insert + 1) % KVM_COALESCED_MMIO_MAX;
 	spin_unlock(&dev->kvm->ring_lock);
 	return 0;
 }