Merge 4.19.272 into android-4.19-stable

Changes in 4.19.272
	ARM: dts: imx6qdl-gw560x: Remove incorrect 'uart-has-rtscts'
	HID: intel_ish-hid: Add check for ishtp_dma_tx_map
	EDAC/highbank: Fix memory leak in highbank_mc_probe()
	tomoyo: fix broken dependency on *.conf.default
	IB/hfi1: Reject a zero-length user expected buffer
	IB/hfi1: Reserve user expected TIDs
	IB/hfi1: Fix expected receive setup error exit issues
	affs: initialize fsdata in affs_truncate()
	amd-xgbe: TX Flow Ctrl Registers are h/w ver dependent
	amd-xgbe: Delay AN timeout during KR training
	bpf: Fix pointer-leak due to insufficient speculative store bypass mitigation
	phy: rockchip-inno-usb2: Fix missing clk_disable_unprepare() in rockchip_usb2phy_power_on()
	net: nfc: Fix use-after-free in local_cleanup()
	wifi: rndis_wlan: Prevent buffer overflow in rndis_query_oid
	net: usb: sr9700: Handle negative len
	net: mdio: validate parameter addr in mdiobus_get_phy()
	HID: check empty report_list in hid_validate_values()
	usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait
	usb: gadget: f_fs: Ensure ep0req is dequeued before free_request
	net: mlx5: eliminate anonymous module_init & module_exit
	dmaengine: Fix double increment of client_count in dma_chan_get()
	net: macb: fix PTP TX timestamp failure due to packet padding
	HID: betop: check shape of output reports
	dmaengine: xilinx_dma: commonize DMA copy size calculation
	dmaengine: xilinx_dma: program hardware supported buffer length
	dmaengine: xilinx_dma: Fix devm_platform_ioremap_resource error handling
	dmaengine: xilinx_dma: call of_node_put() when breaking out of for_each_child_of_node()
	tcp: avoid the lookup process failing to get sk in ehash table
	w1: fix deadloop in __w1_remove_master_device()
	w1: fix WARNING after calling w1_process()
	netfilter: conntrack: do not renew entry stuck in tcp SYN_SENT state
	block: fix and cleanup bio_check_ro
	perf env: Do not return pointers to local variables
	fs: reiserfs: remove useless new_opts in reiserfs_remount
	Bluetooth: hci_sync: cancel cmd_timer if hci_open failed
	scsi: hpsa: Fix allocation size for scsi_host_alloc()
	module: Don't wait for GOING modules
	tracing: Make sure trace_printk() can output as soon as it can be used
	trace_events_hist: add check for return value of 'create_hist_field'
	smbd: Make upper layer decide when to destroy the transport
	cifs: Fix oops due to uncleared server->smbd_conn in reconnect
	ARM: 9280/1: mm: fix warning on phys_addr_t to void pointer assignment
	EDAC/device: Respect any driver-supplied workqueue polling value
	net: fix UaF in netns ops registration error path
	netfilter: nft_set_rbtree: skip elements in transaction from garbage collection
	netlink: remove hash::nelems check in netlink_insert
	netlink: annotate data races around nlk->portid
	netlink: annotate data races around dst_portid and dst_group
	netlink: annotate data races around sk_state
	ipv4: prevent potential spectre v1 gadget in ip_metrics_convert()
	netfilter: conntrack: fix vtag checks for ABORT/SHUTDOWN_COMPLETE
	netrom: Fix use-after-free of a listening socket.
	sctp: fail if no bound addresses can be used for a given scope
	net: ravb: Fix possible hang if RIS2_QFF1 happen
	net/tg3: resolve deadlock in tg3_reset_task() during EEH
	Revert "Input: synaptics - switch touchpad on HP Laptop 15-da3001TU to RMI mode"
	x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL
	drm/i915/display: fix compiler warning about array overrun
	x86/asm: Fix an assembler warning with current binutils
	x86/entry/64: Add instruction suffix to SYSRET
	ARM: dts: imx: Fix pca9547 i2c-mux node name
	dmaengine: imx-sdma: Fix a possible memory leak in sdma_transfer_init
	sysctl: add a new register_sysctl_init() interface
	panic: unset panic_on_warn inside panic()
	exit: Add and use make_task_dead.
	objtool: Add a missing comma to avoid string concatenation
	hexagon: Fix function name in die()
	h8300: Fix build errors from do_exit() to make_task_dead() transition
	ia64: make IA64_MCA_RECOVERY bool instead of tristate
	exit: Put an upper limit on how often we can oops
	exit: Expose "oops_count" to sysfs
	exit: Allow oops_limit to be disabled
	panic: Consolidate open-coded panic_on_warn checks
	panic: Introduce warn_limit
	panic: Expose "warn_count" to sysfs
	docs: Fix path paste-o for /sys/kernel/warn_count
	exit: Use READ_ONCE() for all oops/warn limit reads
	ipv6: ensure sane device mtu in tunnels
	usb: host: xhci-plat: add wakeup entry at sysfs
	Linux 4.19.272

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I4f9ddce1e108e81409d47e00fdeef2bc0d34f793

kernel/panic.c

@@ -29,6 +29,7 @@
 #include <linux/bug.h>
 #include <linux/ratelimit.h>
 #include <linux/debugfs.h>
+#include <linux/sysfs.h>
 #include <asm/sections.h>
 
 #define PANIC_TIMER_STEP 100
@@ -42,6 +43,7 @@ static int pause_on_oops_flag;
 static DEFINE_SPINLOCK(pause_on_oops_lock);
 bool crash_kexec_post_notifiers;
 int panic_on_warn __read_mostly;
+static unsigned int warn_limit __read_mostly;
 
 int panic_timeout = CONFIG_PANIC_TIMEOUT;
 EXPORT_SYMBOL_GPL(panic_timeout);
@@ -52,6 +54,45 @@ EXPORT_SYMBOL(panic_notifier_list);
 void (*vendor_panic_cb)(u64 sp);
 EXPORT_SYMBOL_GPL(vendor_panic_cb);
 
+#ifdef CONFIG_SYSCTL
+static struct ctl_table kern_panic_table[] = {
+	{
+		.procname       = "warn_limit",
+		.data           = &warn_limit,
+		.maxlen         = sizeof(warn_limit),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec,
+	},
+	{ }
+};
+
+static __init int kernel_panic_sysctls_init(void)
+{
+	register_sysctl_init("kernel", kern_panic_table);
+	return 0;
+}
+late_initcall(kernel_panic_sysctls_init);
+#endif
+
+static atomic_t warn_count = ATOMIC_INIT(0);
+
+#ifdef CONFIG_SYSFS
+static ssize_t warn_count_show(struct kobject *kobj, struct kobj_attribute *attr,
+			       char *page)
+{
+	return sysfs_emit(page, "%d\n", atomic_read(&warn_count));
+}
+
+static struct kobj_attribute warn_count_attr = __ATTR_RO(warn_count);
+
+static __init int kernel_panic_sysfs_init(void)
+{
+	sysfs_add_file_to_group(kernel_kobj, &warn_count_attr.attr, NULL);
+	return 0;
+}
+late_initcall(kernel_panic_sysfs_init);
+#endif
+
 static long no_blink(int state)
 {
 	return 0;
@@ -127,6 +168,19 @@ void nmi_panic(struct pt_regs *regs, const char *msg)
 }
 EXPORT_SYMBOL(nmi_panic);
 
+void check_panic_on_warn(const char *origin)
+{
+	unsigned int limit;
+
+	if (panic_on_warn)
+		panic("%s: panic_on_warn set ...\n", origin);
+
+	limit = READ_ONCE(warn_limit);
+	if (atomic_inc_return(&warn_count) >= limit && limit)
+		panic("%s: system warned too often (kernel.warn_limit is %d)",
+		      origin, limit);
+}
+
 /**
  *	panic - halt the system
  *	@fmt: The text string to print
@@ -144,6 +198,16 @@ void panic(const char *fmt, ...)
 	int old_cpu, this_cpu;
 	bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
 
+	if (panic_on_warn) {
+		/*
+		 * This thread may hit another WARN() in the panic path.
+		 * Resetting this prevents additional WARN() from panicking the
+		 * system on this thread.  Other threads are blocked by the
+		 * panic_mutex in panic().
+		 */
+		panic_on_warn = 0;
+	}
+
 	/*
 	 * Disable local interrupts. This will prevent panic_smp_self_stop
 	 * from deadlocking the first cpu that invokes the panic, since
@@ -536,16 +600,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
 	if (args)
 		vprintk(args->fmt, args->args);
 
-	if (panic_on_warn) {
-		/*
-		 * This thread may hit another WARN() in the panic path.
-		 * Resetting this prevents additional WARN() from panicking the
-		 * system on this thread.  Other threads are blocked by the
-		 * panic_mutex in panic().
-		 */
-		panic_on_warn = 0;
-		panic("panic_on_warn set ...\n");
-	}
+	check_panic_on_warn("kernel");
 
 	print_modules();