Merge 4.4.242 into android-4.4-p

Changes in 4.4.242
	SUNRPC: ECONNREFUSED should cause a rebind.
	scripts/setlocalversion: make git describe output more reliable
	powerpc/powernv/opal-dump : Use IRQ_HANDLED instead of numbers in interrupt handler
	efivarfs: Replace invalid slashes with exclamation marks in dentries.
	ravb: Fix bit fields checking in ravb_hwtstamp_get()
	tipc: fix memory leak caused by tipc_buf_append()
	mtd: lpddr: Fix bad logic in print_drs_error
	ata: sata_rcar: Fix DMA boundary mask
	fscrypt: return -EXDEV for incompatible rename or link into encrypted dir
	f2fs crypto: avoid unneeded memory allocation in ->readdir
	powerpc/powernv/smp: Fix spurious DBG() warning
	sparc64: remove mm_cpumask clearing to fix kthread_use_mm race
	f2fs: fix to check segment boundary during SIT page readahead
	um: change sigio_spinlock to a mutex
	xfs: fix realtime bitmap/summary file truncation when growing rt volume
	video: fbdev: pvr2fb: initialize variables
	ath10k: fix VHT NSS calculation when STBC is enabled
	mmc: via-sdmmc: Fix data race bug
	printk: reduce LOG_BUF_SHIFT range for H8300
	kgdb: Make "kgdbcon" work properly with "kgdb_earlycon"
	USB: adutux: fix debugging
	drivers/net/wan/hdlc_fr: Correctly handle special skb->protocol values
	power: supply: test_power: add missing newlines when printing parameters by sysfs
	md/bitmap: md_bitmap_get_counter returns wrong blocks
	clk: ti: clockdomain: fix static checker warning
	net: 9p: initialize sun_server.sun_path to have addr's value only when addr is valid
	drivers: watchdog: rdc321x_wdt: Fix race condition bugs
	ext4: Detect already used quota file early
	gfs2: add validation checks for size of superblock
	memory: emif: Remove bogus debugfs error handling
	ARM: dts: s5pv210: move PMU node out of clock controller
	ARM: dts: s5pv210: remove dedicated 'audio-subsystem' node
	md/raid5: fix oops during stripe resizing
	leds: bcm6328, bcm6358: use devres LED registering function
	NFS: fix nfs_path in case of a rename retry
	ACPI / extlog: Check for RDMSR failure
	ACPI: video: use ACPI backlight for HP 635 Notebook
	acpi-cpufreq: Honor _PSD table setting on new AMD CPUs
	w1: mxc_w1: Fix timeout resolution problem leading to bus error
	scsi: mptfusion: Fix null pointer dereferences in mptscsih_remove()
	btrfs: reschedule if necessary when logging directory items
	vt: keyboard, simplify vt_kdgkbsent
	vt: keyboard, extend func_buf_lock to readers
	dmaengine: dma-jz4780: Fix race in jz4780_dma_tx_status
	iio:gyro:itg3200: Fix timestamp alignment and prevent data leak.
	powerpc/powernv/elog: Fix race while processing OPAL error log event.
	ubifs: dent: Fix some potential memory leaks while iterating entries
	ubi: check kthread_should_stop() after the setting of task state
	ia64: fix build error with !COREDUMP
	ceph: promote to unsigned long long before shifting
	libceph: clear con->out_msg on Policy::stateful_server faults
	9P: Cast to loff_t before multiplying
	ring-buffer: Return 0 on success from ring_buffer_resize()
	vringh: fix __vringh_iov() when riov and wiov are different
	tty: make FONTX ioctl use the tty pointer they were actually passed
	arm64: berlin: Select DW_APB_TIMER_OF
	cachefiles: Handle readpage error correctly
	hil/parisc: Disable HIL driver when it gets stuck
	ARM: samsung: fix PM debug build with DEBUG_LL but !MMU
	ARM: s3c24xx: fix missing system reset
	device property: Keep secondary firmware node secondary by type
	device property: Don't clear secondary pointer for shared primary firmware node
	staging: comedi: cb_pcidas: Allow 2-channel commands for AO subdevice
	xen/events: don't use chip_data for legacy IRQs
	tipc: fix use-after-free in tipc_bcast_get_mode
	gianfar: Replace skb_realloc_headroom with skb_cow_head for PTP
	gianfar: Account for Tx PTP timestamp in the skb headroom
	Fonts: Replace discarded const qualifier
	ALSA: usb-audio: Add implicit feedback quirk for Qu-16
	ftrace: Fix recursion check for NMI test
	ftrace: Handle tracing when switching between context
	ARM: dts: sun4i-a10: fix cpu_alert temperature
	x86/kexec: Use up-to-dated screen_info copy to fill boot params
	of: Fix reserved-memory overlap detection
	scsi: core: Don't start concurrent async scan on same host
	vsock: use ns_capable_noaudit() on socket create
	vt: Disable KD_FONT_OP_COPY
	fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent
	serial: 8250_mtk: Fix uart_get_baud_rate warning
	serial: txx9: add missing platform_driver_unregister() on error in serial_txx9_init
	USB: serial: cyberjack: fix write-URB completion race
	USB: serial: option: add LE910Cx compositions 0x1203, 0x1230, 0x1231
	USB: serial: option: add Telit FN980 composition 0x1055
	USB: Add NO_LPM quirk for Kingston flash drive
	ARC: stack unwinding: avoid indefinite looping
	Revert "ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACE"
	Linux 4.4.242

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I9c6408c403a91272e8255725dc8de294e522dc90

5 files changed, 53 insertions, 22 deletions

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 321ccdbb7364..bc791cec58e6 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -94,14 +94,6 @@ int dbg_switch_cpu;
 /* Use kdb or gdbserver mode */
 int dbg_kdb_mode = 1;
 
-static int __init opt_kgdb_con(char *str)
-{
-	kgdb_use_con = 1;
-	return 0;
-}
-
-early_param("kgdbcon", opt_kgdb_con);
-
 module_param(kgdb_use_con, int, 0644);
 module_param(kgdbreboot, int, 0644);
 
@@ -811,6 +803,20 @@ static struct console kgdbcons = {
 	.index		= -1,
 };
 
+static int __init opt_kgdb_con(char *str)
+{
+	kgdb_use_con = 1;
+
+	if (kgdb_io_module_registered && !kgdb_con_registered) {
+		register_console(&kgdbcons);
+		kgdb_con_registered = 1;
+	}
+
+	return 0;
+}
+
+early_param("kgdbcon", opt_kgdb_con);
+
 #ifdef CONFIG_MAGIC_SYSRQ
 static void sysrq_handle_dbg(int key)
 {
diff --git a/kernel/fork.c b/kernel/fork.c
index a6c855aec68e..f7e3c2721238 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1568,14 +1568,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	/* ok, now we should be set up.. */
 	p->pid = pid_nr(pid);
 	if (clone_flags & CLONE_THREAD) {
-		p->exit_signal = -1;
 		p->group_leader = current->group_leader;
 		p->tgid = current->tgid;
 	} else {
-		if (clone_flags & CLONE_PARENT)
-			p->exit_signal = current->group_leader->exit_signal;
-		else
-			p->exit_signal = (clone_flags & CSIGNAL);
 		p->group_leader = p;
 		p->tgid = p->pid;
 	}
@@ -1620,9 +1615,14 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
 		p->real_parent = current->real_parent;
 		p->parent_exec_id = current->parent_exec_id;
+		if (clone_flags & CLONE_THREAD)
+			p->exit_signal = -1;
+		else
+			p->exit_signal = current->group_leader->exit_signal;
 	} else {
 		p->real_parent = current;
 		p->parent_exec_id = current->self_exec_id;
+		p->exit_signal = (clone_flags & CSIGNAL);
 	}
 
 	spin_lock(&current->sighand->siglock);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 1cf2402c6922..1c1ecc1d49ad 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1659,18 +1659,18 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long nr_pages;
-	int cpu, err = 0;
+	int cpu, err;
 
 	/*
 	 * Always succeed at resizing a non-existent buffer:
 	 */
 	if (!buffer)
-		return size;
+		return 0;
 
 	/* Make sure the requested buffer exists */
 	if (cpu_id != RING_BUFFER_ALL_CPUS &&
 	    !cpumask_test_cpu(cpu_id, buffer->cpumask))
-		return size;
+		return 0;
 
 	nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
 
@@ -1810,7 +1810,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
 	}
 
 	mutex_unlock(&buffer->mutex);
-	return size;
+	return 0;
 
  out_err:
 	for_each_buffer_cpu(buffer, cpu) {
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index f62768288592..6f9534635129 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -478,6 +478,12 @@ enum {
  * can only be modified by current, we can reuse trace_recursion.
  */
 	TRACE_IRQ_BIT,
+
+	/*
+	 * When transitioning between context, the preempt_count() may
+	 * not be correct. Allow for a single recursion to cover this case.
+	 */
+	TRACE_TRANSITION_BIT,
 };
 
 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
@@ -522,14 +528,27 @@ static __always_inline int trace_test_and_set_recursion(int start, int max)
 		return 0;
 
 	bit = trace_get_context_bit() + start;
-	if (unlikely(val & (1 << bit)))
-		return -1;
+	if (unlikely(val & (1 << bit))) {
+		/*
+		 * It could be that preempt_count has not been updated during
+		 * a switch between contexts. Allow for a single recursion.
+		 */
+		bit = TRACE_TRANSITION_BIT;
+		if (trace_recursion_test(bit))
+			return -1;
+		trace_recursion_set(bit);
+		barrier();
+		return bit + 1;
+	}
+
+	/* Normal check passed, clear the transition to allow it again */
+	trace_recursion_clear(TRACE_TRANSITION_BIT);
 
 	val |= 1 << bit;
 	current->trace_recursion = val;
 	barrier();
 
-	return bit;
+	return bit + 1;
 }
 
 static __always_inline void trace_clear_recursion(int bit)
@@ -539,6 +558,7 @@ static __always_inline void trace_clear_recursion(int bit)
 	if (!bit)
 		return;
 
+	bit--;
 	bit = 1 << bit;
 	val &= ~bit;
 
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index ca70d11b8aa7..f444f57f1338 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -490,8 +490,13 @@ trace_selftest_function_recursion(void)
 	unregister_ftrace_function(&test_rec_probe);
 
 	ret = -1;
-	if (trace_selftest_recursion_cnt != 1) {
-		pr_cont("*callback not called once (%d)* ",
+	/*
+	 * Recursion allows for transitions between context,
+	 * and may call the callback twice.
+	 */
+	if (trace_selftest_recursion_cnt != 1 &&
+	    trace_selftest_recursion_cnt != 2) {
+		pr_cont("*callback not called once (or twice) (%d)* ",
 			trace_selftest_recursion_cnt);
 		goto out;
 	}