Merge 4.4.218 into android-4.4-p

Changes in 4.4.218
	spi: qup: call spi_qup_pm_resume_runtime before suspending
	powerpc: Include .BTF section
	ARM: dts: dra7: Add "dma-ranges" property to PCIe RC DT nodes
	spi/zynqmp: remove entry that causes a cs glitch
	drm/exynos: dsi: propagate error value and silence meaningless warning
	drm/exynos: dsi: fix workaround for the legacy clock name
	altera-stapl: altera_get_note: prevent write beyond end of 'key'
	USB: Disable LPM on WD19's Realtek Hub
	usb: quirks: add NO_LPM quirk for RTL8153 based ethernet adapters
	USB: serial: option: add ME910G1 ECM composition 0x110b
	usb: host: xhci-plat: add a shutdown
	USB: serial: pl2303: add device-id for HP LD381
	ALSA: line6: Fix endless MIDI read loop
	ALSA: seq: virmidi: Fix running status after receiving sysex
	ALSA: seq: oss: Fix running status after receiving sysex
	ALSA: pcm: oss: Avoid plugin buffer overflow
	ALSA: pcm: oss: Remove WARNING from snd_pcm_plug_alloc() checks
	staging: rtl8188eu: Add device id for MERCUSYS MW150US v2
	staging/speakup: fix get_word non-space look-ahead
	intel_th: Fix user-visible error codes
	rtc: max8907: add missing select REGMAP_IRQ
	memcg: fix NULL pointer dereference in __mem_cgroup_usage_unregister_event
	mm: slub: be more careful about the double cmpxchg of freelist
	mm, slub: prevent kmalloc_node crashes and memory leaks
	x86/mm: split vmalloc_sync_all()
	USB: cdc-acm: fix close_delay and closing_wait units in TIOCSSERIAL
	USB: cdc-acm: fix rounding error in TIOCSSERIAL
	kbuild: Disable -Wpointer-to-enum-cast
	futex: Fix inode life-time issue
	futex: Unbreak futex hashing
	ALSA: hda/realtek: Fix pop noise on ALC225
	arm64: smp: fix smp_send_stop() behaviour
	Revert "drm/dp_mst: Skip validating ports during destruction, just ref"
	hsr: fix general protection fault in hsr_addr_is_self()
	net: dsa: Fix duplicate frames flooded by learning
	net_sched: cls_route: remove the right filter from hashtable
	net_sched: keep alloc_hash updated after hash allocation
	NFC: fdp: Fix a signedness bug in fdp_nci_send_patch()
	slcan: not call free_netdev before rtnl_unlock in slcan_open
	vxlan: check return value of gro_cells_init()
	hsr: use rcu_read_lock() in hsr_get_node_{list/status}()
	hsr: add restart routine into hsr_get_node_list()
	hsr: set .netnsok flag
	vhost: Check docket sk_family instead of call getname
	IB/ipoib: Do not warn if IPoIB debugfs doesn't exist
	uapi glibc compat: fix outer guard of net device flags enum
	KVM: VMX: Do not allow reexecute_instruction() when skipping MMIO instr
	drivers/hwspinlock: use correct radix tree API
	net: ipv4: don't let PMTU updates increase route MTU
	cpupower: avoid multiple definition with gcc -fno-common
	dt-bindings: net: FMan erratum A050385
	scsi: ipr: Fix softlockup when rescanning devices in petitboot
	mac80211: Do not send mesh HWMP PREQ if HWMP is disabled
	sxgbe: Fix off by one in samsung driver strncpy size arg
	i2c: hix5hd2: add missed clk_disable_unprepare in remove
	perf probe: Do not depend on dwfl_module_addrsym()
	scripts/dtc: Remove redundant YYLOC global declaration
	scsi: sd: Fix optimal I/O size for devices that change reported values
	mac80211: mark station unauthorized before key removal
	genirq: Fix reference leaks on irq affinity notifiers
	vti[6]: fix packet tx through bpf_redirect() in XinY cases
	xfrm: fix uctx len check in verify_sec_ctx_len
	xfrm: add the missing verify_sec_ctx_len check in xfrm_add_acquire
	xfrm: policy: Fix doulbe free in xfrm_policy_timer
	vti6: Fix memory leak of skb if input policy check fails
	tools: Let O= makes handle a relative path with -C option
	USB: serial: option: add support for ASKEY WWHC050
	USB: serial: option: add BroadMobi BM806U
	USB: serial: option: add Wistron Neweb D19Q1
	USB: cdc-acm: restore capability check order
	USB: serial: io_edgeport: fix slab-out-of-bounds read in edge_interrupt_callback
	usb: musb: fix crash with highmen PIO and usbmon
	media: flexcop-usb: fix endpoint sanity check
	media: usbtv: fix control-message timeouts
	staging: rtl8188eu: Add ASUS USB-N10 Nano B1 to device table
	staging: wlan-ng: fix use-after-free Read in hfa384x_usbin_callback
	libfs: fix infoleak in simple_attr_read()
	media: ov519: add missing endpoint sanity checks
	media: dib0700: fix rc endpoint lookup
	media: stv06xx: add missing descriptor sanity checks
	media: xirlink_cit: add missing descriptor sanity checks
	vt: selection, introduce vc_is_sel
	vt: ioctl, switch VT_IS_IN_USE and VT_BUSY to inlines
	vt: switch vt_dont_switch to bool
	vt: vt_ioctl: remove unnecessary console allocation checks
	vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console
	locking/atomic, kref: Add kref_read()
	vt: vt_ioctl: fix use-after-free in vt_in_use()
	bpf: Explicitly memset the bpf_attr structure
	net: ks8851-ml: Fix IO operations, again
	perf map: Fix off by one in strncpy() size argument
	Linux 4.4.218

Change-Id: I8de6cf91805269943a4c08f8b08e6a0b8539c08e
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

3 files changed, 65 insertions, 41 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 15d850ffbe29..a322303b4d75 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -378,9 +378,9 @@ static inline int hb_waiters_pending(struct futex_hash_bucket *hb)
  */
 static struct futex_hash_bucket *hash_futex(union futex_key *key)
 {
-	u32 hash = jhash2((u32*)&key->both.word,
-			  (sizeof(key->both.word)+sizeof(key->both.ptr))/4,
+	u32 hash = jhash2((u32 *)key, offsetof(typeof(*key), both.offset) / 4,
 			  key->both.offset);
+
 	return &futex_queues[hash & (futex_hashsize - 1)];
 }
 
@@ -407,7 +407,7 @@ static void get_futex_key_refs(union futex_key *key)
 
 	switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
 	case FUT_OFF_INODE:
-		ihold(key->shared.inode); /* implies MB (B) */
+		smp_mb();		/* explicit smp_mb(); (B) */
 		break;
 	case FUT_OFF_MMSHARED:
 		futex_get_mm(key); /* implies MB (B) */
@@ -438,7 +438,6 @@ static void drop_futex_key_refs(union futex_key *key)
 
 	switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
 	case FUT_OFF_INODE:
-		iput(key->shared.inode);
 		break;
 	case FUT_OFF_MMSHARED:
 		mmdrop(key->private.mm);
@@ -446,6 +445,46 @@ static void drop_futex_key_refs(union futex_key *key)
 	}
 }
 
+/*
+ * Generate a machine wide unique identifier for this inode.
+ *
+ * This relies on u64 not wrapping in the life-time of the machine; which with
+ * 1ns resolution means almost 585 years.
+ *
+ * This further relies on the fact that a well formed program will not unmap
+ * the file while it has a (shared) futex waiting on it. This mapping will have
+ * a file reference which pins the mount and inode.
+ *
+ * If for some reason an inode gets evicted and read back in again, it will get
+ * a new sequence number and will _NOT_ match, even though it is the exact same
+ * file.
+ *
+ * It is important that match_futex() will never have a false-positive, esp.
+ * for PI futexes that can mess up the state. The above argues that false-negatives
+ * are only possible for malformed programs.
+ */
+static u64 get_inode_sequence_number(struct inode *inode)
+{
+	static atomic64_t i_seq;
+	u64 old;
+
+	/* Does the inode already have a sequence number? */
+	old = atomic64_read(&inode->i_sequence);
+	if (likely(old))
+		return old;
+
+	for (;;) {
+		u64 new = atomic64_add_return(1, &i_seq);
+		if (WARN_ON_ONCE(!new))
+			continue;
+
+		old = atomic64_cmpxchg_relaxed(&inode->i_sequence, 0, new);
+		if (old)
+			return old;
+		return new;
+	}
+}
+
 /**
  * get_futex_key() - Get parameters which are the keys for a futex
  * @uaddr:	virtual address of the futex
@@ -458,9 +497,15 @@ static void drop_futex_key_refs(union futex_key *key)
  *
  * The key words are stored in *key on success.
  *
- * For shared mappings, it's (page->index, file_inode(vma->vm_file),
- * offset_within_page).  For private mappings, it's (uaddr, current->mm).
- * We can usually work out the index without swapping in the page.
+ * For shared mappings (when @fshared), the key is:
+ *   ( inode->i_sequence, page->index, offset_within_page )
+ * [ also see get_inode_sequence_number() ]
+ *
+ * For private mappings (or when !@fshared), the key is:
+ *   ( current->mm, address, 0 )
+ *
+ * This allows (cross process, where applicable) identification of the futex
+ * without keeping the page pinned for the duration of the FUTEX_WAIT.
  *
  * lock_page() might sleep, the caller should not hold a spinlock.
  */
@@ -628,8 +673,6 @@ again:
 		key->private.mm = mm;
 		key->private.address = address;
 
-		get_futex_key_refs(key); /* implies smp_mb(); (B) */
-
 	} else {
 		struct inode *inode;
 
@@ -661,40 +704,14 @@ again:
 			goto again;
 		}
 
-		/*
-		 * Take a reference unless it is about to be freed. Previously
-		 * this reference was taken by ihold under the page lock
-		 * pinning the inode in place so i_lock was unnecessary. The
-		 * only way for this check to fail is if the inode was
-		 * truncated in parallel which is almost certainly an
-		 * application bug. In such a case, just retry.
-		 *
-		 * We are not calling into get_futex_key_refs() in file-backed
-		 * cases, therefore a successful atomic_inc return below will
-		 * guarantee that get_futex_key() will still imply smp_mb(); (B).
-		 */
-		if (!atomic_inc_not_zero(&inode->i_count)) {
-			rcu_read_unlock();
-			put_page(page_head);
-
-			goto again;
-		}
-
-		/* Should be impossible but lets be paranoid for now */
-		if (WARN_ON_ONCE(inode->i_mapping != mapping)) {
-			err = -EFAULT;
-			rcu_read_unlock();
-			iput(inode);
-
-			goto out;
-		}
-
 		key->both.offset |= FUT_OFF_INODE; /* inode-based key */
-		key->shared.inode = inode;
+		key->shared.i_seq = get_inode_sequence_number(inode);
 		key->shared.pgoff = basepage_index(page);
 		rcu_read_unlock();
 	}
 
+	get_futex_key_refs(key); /* implies smp_mb(); (B) */
+
 out:
 	put_page(page_head);
 	return err;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 92c7eb1aeded..14aaaa61e905 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -220,7 +220,11 @@ int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
 
 	if (desc->affinity_notify) {
 		kref_get(&desc->affinity_notify->kref);
-		schedule_work(&desc->affinity_notify->work);
+		if (!schedule_work(&desc->affinity_notify->work)) {
+			/* Work was already scheduled, drop our extra ref */
+			kref_put(&desc->affinity_notify->kref,
+				 desc->affinity_notify->release);
+		}
 	}
 	irqd_set(data, IRQD_AFFINITY_SET);
 
@@ -320,7 +324,10 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 
 	if (old_notify) {
-		cancel_work_sync(&old_notify->work);
+		if (cancel_work_sync(&old_notify->work)) {
+			/* Pending work had a ref, put that one too */
+			kref_put(&old_notify->kref, old_notify->release);
+		}
 		kref_put(&old_notify->kref, old_notify->release);
 	}
 
diff --git a/kernel/notifier.c b/kernel/notifier.c
index fd2c9acbcc19..0f70f1b6fdaa 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -552,7 +552,7 @@ NOKPROBE_SYMBOL(notify_die);
 
 int register_die_notifier(struct notifier_block *nb)
 {
-	vmalloc_sync_all();
+	vmalloc_sync_mappings();
 	return atomic_notifier_chain_register(&die_chain, nb);
 }
 EXPORT_SYMBOL_GPL(register_die_notifier);