Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index fec6b4c..c56d352 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -14,6 +14,7 @@
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DEBUG_BUGVERBOSE
+	select HAVE_COPY_THREAD_TLS
 	select GENERIC_IRQ_SHOW
 	select GENERIC_CPU_DEVICES
 	select GENERIC_CLOCKEVENTS
diff --git a/arch/um/Kconfig.debug b/arch/um/Kconfig.debug
index 85726ee..e4a0f12 100644
--- a/arch/um/Kconfig.debug
+++ b/arch/um/Kconfig.debug
@@ -17,6 +17,7 @@
 	bool "Enable gcov support"
 	depends on DEBUG_INFO
 	depends on !KCOV
+	depends on !MODULES
 	help
 	  This option allows developers to retrieve coverage data from a UML
 	  session.
diff --git a/arch/um/Makefile b/arch/um/Makefile
index d2daa20..275f5ff 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -140,6 +140,7 @@
 # When cleaning we don't include .config, so we don't include
 # TT or skas makefiles and don't clean skas_ptregs.h.
 CLEAN_FILES += linux x.i gmon.out
+MRPROPER_DIRS += arch/$(SUBARCH)/include/generated
 
 archclean:
 	@find . \( -name '*.bb' -o -name '*.bbg' -o -name '*.da' \
diff --git a/arch/um/drivers/Kconfig b/arch/um/drivers/Kconfig
index fea5a0d..388096f 100644
--- a/arch/um/drivers/Kconfig
+++ b/arch/um/drivers/Kconfig
@@ -337,7 +337,7 @@
 endmenu
 
 config VIRTIO_UML
-	tristate "UML driver for virtio devices"
+	bool "UML driver for virtio devices"
 	select VIRTIO
 	help
 	  This driver provides support for virtio based paravirtual device
diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c
index 4d80526..6040817 100644
--- a/arch/um/drivers/chan_user.c
+++ b/arch/um/drivers/chan_user.c
@@ -26,10 +26,10 @@
 	n = read(fd, c_out, sizeof(*c_out));
 	if (n > 0)
 		return n;
-	else if (errno == EAGAIN)
-		return 0;
 	else if (n == 0)
 		return -EIO;
+	else if (errno == EAGAIN)
+		return 0;
 	return -errno;
 }
 
@@ -256,7 +256,8 @@
 		goto out_close;
 	}
 
-	if (os_set_fd_block(*fd_out, 0)) {
+	err = os_set_fd_block(*fd_out, 0);
+	if (err) {
 		printk(UM_KERN_ERR "winch_tramp: failed to set thread_fd "
 		       "non-blocking.\n");
 		goto out_close;
diff --git a/arch/um/drivers/slip_user.c b/arch/um/drivers/slip_user.c
index 8016d32..8d736eb 100644
--- a/arch/um/drivers/slip_user.c
+++ b/arch/um/drivers/slip_user.c
@@ -145,7 +145,8 @@
 	}
 	sfd = err;
 
-	if (set_up_tty(sfd))
+	err = set_up_tty(sfd);
+	if (err)
 		goto out_close2;
 
 	pri->slave = sfd;
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 6627d7c..4e59ab8 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -47,18 +47,25 @@
 /* Max request size is determined by sector mask - 32K */
 #define UBD_MAX_REQUEST (8 * sizeof(long))
 
+struct io_desc {
+	char *buffer;
+	unsigned long length;
+	unsigned long sector_mask;
+	unsigned long long cow_offset;
+	unsigned long bitmap_words[2];
+};
+
 struct io_thread_req {
 	struct request *req;
 	int fds[2];
 	unsigned long offsets[2];
 	unsigned long long offset;
-	unsigned long length;
-	char *buffer;
 	int sectorsize;
-	unsigned long sector_mask;
-	unsigned long long cow_offset;
-	unsigned long bitmap_words[2];
 	int error;
+
+	int desc_cnt;
+	/* io_desc has to be the last element of the struct */
+	struct io_desc io_desc[];
 };
 
 
@@ -524,12 +531,7 @@
 				blk_queue_max_write_zeroes_sectors(io_req->req->q, 0);
 				blk_queue_flag_clear(QUEUE_FLAG_DISCARD, io_req->req->q);
 			}
-			if ((io_req->error) || (io_req->buffer == NULL))
-				blk_mq_end_request(io_req->req, io_req->error);
-			else {
-				if (!blk_update_request(io_req->req, io_req->error, io_req->length))
-					__blk_mq_end_request(io_req->req, io_req->error);
-			}
+			blk_mq_end_request(io_req->req, io_req->error);
 			kfree(io_req);
 		}
 	}
@@ -945,6 +947,7 @@
 	blk_queue_write_cache(ubd_dev->queue, true, false);
 
 	blk_queue_max_segments(ubd_dev->queue, MAX_SG);
+	blk_queue_segment_boundary(ubd_dev->queue, PAGE_SIZE - 1);
 	err = ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, &ubd_gendisk[n]);
 	if(err){
 		*error_out = "Failed to register device";
@@ -1288,37 +1291,74 @@
 	*cow_offset += bitmap_offset;
 }
 
-static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
+static void cowify_req(struct io_thread_req *req, struct io_desc *segment,
+		       unsigned long offset, unsigned long *bitmap,
 		       __u64 bitmap_offset, __u64 bitmap_len)
 {
-	__u64 sector = req->offset >> SECTOR_SHIFT;
+	__u64 sector = offset >> SECTOR_SHIFT;
 	int i;
 
-	if (req->length > (sizeof(req->sector_mask) * 8) << SECTOR_SHIFT)
+	if (segment->length > (sizeof(segment->sector_mask) * 8) << SECTOR_SHIFT)
 		panic("Operation too long");
 
 	if (req_op(req->req) == REQ_OP_READ) {
-		for (i = 0; i < req->length >> SECTOR_SHIFT; i++) {
+		for (i = 0; i < segment->length >> SECTOR_SHIFT; i++) {
 			if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
 				ubd_set_bit(i, (unsigned char *)
-					    &req->sector_mask);
+					    &segment->sector_mask);
 		}
+	} else {
+		cowify_bitmap(offset, segment->length, &segment->sector_mask,
+			      &segment->cow_offset, bitmap, bitmap_offset,
+			      segment->bitmap_words, bitmap_len);
 	}
-	else cowify_bitmap(req->offset, req->length, &req->sector_mask,
-			   &req->cow_offset, bitmap, bitmap_offset,
-			   req->bitmap_words, bitmap_len);
 }
 
-static int ubd_queue_one_vec(struct blk_mq_hw_ctx *hctx, struct request *req,
-		u64 off, struct bio_vec *bvec)
+static void ubd_map_req(struct ubd *dev, struct io_thread_req *io_req,
+			struct request *req)
 {
-	struct ubd *dev = hctx->queue->queuedata;
-	struct io_thread_req *io_req;
-	int ret;
+	struct bio_vec bvec;
+	struct req_iterator iter;
+	int i = 0;
+	unsigned long byte_offset = io_req->offset;
+	int op = req_op(req);
 
-	io_req = kmalloc(sizeof(struct io_thread_req), GFP_ATOMIC);
+	if (op == REQ_OP_WRITE_ZEROES || op == REQ_OP_DISCARD) {
+		io_req->io_desc[0].buffer = NULL;
+		io_req->io_desc[0].length = blk_rq_bytes(req);
+	} else {
+		rq_for_each_segment(bvec, req, iter) {
+			BUG_ON(i >= io_req->desc_cnt);
+
+			io_req->io_desc[i].buffer =
+				page_address(bvec.bv_page) + bvec.bv_offset;
+			io_req->io_desc[i].length = bvec.bv_len;
+			i++;
+		}
+	}
+
+	if (dev->cow.file) {
+		for (i = 0; i < io_req->desc_cnt; i++) {
+			cowify_req(io_req, &io_req->io_desc[i], byte_offset,
+				   dev->cow.bitmap, dev->cow.bitmap_offset,
+				   dev->cow.bitmap_len);
+			byte_offset += io_req->io_desc[i].length;
+		}
+
+	}
+}
+
+static struct io_thread_req *ubd_alloc_req(struct ubd *dev, struct request *req,
+					   int desc_cnt)
+{
+	struct io_thread_req *io_req;
+	int i;
+
+	io_req = kmalloc(sizeof(*io_req) +
+			 (desc_cnt * sizeof(struct io_desc)),
+			 GFP_ATOMIC);
 	if (!io_req)
-		return -ENOMEM;
+		return NULL;
 
 	io_req->req = req;
 	if (dev->cow.file)
@@ -1326,26 +1366,41 @@
 	else
 		io_req->fds[0] = dev->fd;
 	io_req->error = 0;
-
-	if (bvec != NULL) {
-		io_req->buffer = page_address(bvec->bv_page) + bvec->bv_offset;
-		io_req->length = bvec->bv_len;
-	} else {
-		io_req->buffer = NULL;
-		io_req->length = blk_rq_bytes(req);
-	}
-
 	io_req->sectorsize = SECTOR_SIZE;
 	io_req->fds[1] = dev->fd;
-	io_req->cow_offset = -1;
-	io_req->offset = off;
-	io_req->sector_mask = 0;
+	io_req->offset = (u64) blk_rq_pos(req) << SECTOR_SHIFT;
 	io_req->offsets[0] = 0;
 	io_req->offsets[1] = dev->cow.data_offset;
 
-	if (dev->cow.file)
-		cowify_req(io_req, dev->cow.bitmap,
-			   dev->cow.bitmap_offset, dev->cow.bitmap_len);
+	for (i = 0 ; i < desc_cnt; i++) {
+		io_req->io_desc[i].sector_mask = 0;
+		io_req->io_desc[i].cow_offset = -1;
+	}
+
+	return io_req;
+}
+
+static int ubd_submit_request(struct ubd *dev, struct request *req)
+{
+	int segs = 0;
+	struct io_thread_req *io_req;
+	int ret;
+	int op = req_op(req);
+
+	if (op == REQ_OP_FLUSH)
+		segs = 0;
+	else if (op == REQ_OP_WRITE_ZEROES || op == REQ_OP_DISCARD)
+		segs = 1;
+	else
+		segs = blk_rq_nr_phys_segments(req);
+
+	io_req = ubd_alloc_req(dev, req, segs);
+	if (!io_req)
+		return -ENOMEM;
+
+	io_req->desc_cnt = segs;
+	if (segs)
+		ubd_map_req(dev, io_req, req);
 
 	ret = os_write_file(thread_fd, &io_req, sizeof(io_req));
 	if (ret != sizeof(io_req)) {
@@ -1356,22 +1411,6 @@
 	return ret;
 }
 
-static int queue_rw_req(struct blk_mq_hw_ctx *hctx, struct request *req)
-{
-	struct req_iterator iter;
-	struct bio_vec bvec;
-	int ret;
-	u64 off = (u64)blk_rq_pos(req) << SECTOR_SHIFT;
-
-	rq_for_each_segment(bvec, req, iter) {
-		ret = ubd_queue_one_vec(hctx, req, off, &bvec);
-		if (ret < 0)
-			return ret;
-		off += bvec.bv_len;
-	}
-	return 0;
-}
-
 static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx,
 				 const struct blk_mq_queue_data *bd)
 {
@@ -1384,17 +1423,12 @@
 	spin_lock_irq(&ubd_dev->lock);
 
 	switch (req_op(req)) {
-	/* operations with no lentgth/offset arguments */
 	case REQ_OP_FLUSH:
-		ret = ubd_queue_one_vec(hctx, req, 0, NULL);
-		break;
 	case REQ_OP_READ:
 	case REQ_OP_WRITE:
-		ret = queue_rw_req(hctx, req);
-		break;
 	case REQ_OP_DISCARD:
 	case REQ_OP_WRITE_ZEROES:
-		ret = ubd_queue_one_vec(hctx, req, (u64)blk_rq_pos(req) << 9, NULL);
+		ret = ubd_submit_request(ubd_dev, req);
 		break;
 	default:
 		WARN_ON_ONCE(1);
@@ -1482,22 +1516,22 @@
  * will result in unpredictable behaviour and/or crashes.
  */
 
-static int update_bitmap(struct io_thread_req *req)
+static int update_bitmap(struct io_thread_req *req, struct io_desc *segment)
 {
 	int n;
 
-	if(req->cow_offset == -1)
+	if (segment->cow_offset == -1)
 		return map_error(0);
 
-	n = os_pwrite_file(req->fds[1], &req->bitmap_words,
-			  sizeof(req->bitmap_words), req->cow_offset);
-	if (n != sizeof(req->bitmap_words))
+	n = os_pwrite_file(req->fds[1], &segment->bitmap_words,
+			  sizeof(segment->bitmap_words), segment->cow_offset);
+	if (n != sizeof(segment->bitmap_words))
 		return map_error(-n);
 
 	return map_error(0);
 }
 
-static void do_io(struct io_thread_req *req)
+static void do_io(struct io_thread_req *req, struct io_desc *desc)
 {
 	char *buf = NULL;
 	unsigned long len;
@@ -1512,21 +1546,20 @@
 		return;
 	}
 
-	nsectors = req->length / req->sectorsize;
+	nsectors = desc->length / req->sectorsize;
 	start = 0;
 	do {
-		bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask);
+		bit = ubd_test_bit(start, (unsigned char *) &desc->sector_mask);
 		end = start;
 		while((end < nsectors) &&
-		      (ubd_test_bit(end, (unsigned char *)
-				    &req->sector_mask) == bit))
+		      (ubd_test_bit(end, (unsigned char *) &desc->sector_mask) == bit))
 			end++;
 
 		off = req->offset + req->offsets[bit] +
 			start * req->sectorsize;
 		len = (end - start) * req->sectorsize;
-		if (req->buffer != NULL)
-			buf = &req->buffer[start * req->sectorsize];
+		if (desc->buffer != NULL)
+			buf = &desc->buffer[start * req->sectorsize];
 
 		switch (req_op(req->req)) {
 		case REQ_OP_READ:
@@ -1566,7 +1599,8 @@
 		start = end;
 	} while(start < nsectors);
 
-	req->error = update_bitmap(req);
+	req->offset += len;
+	req->error = update_bitmap(req, desc);
 }
 
 /* Changed in start_io_thread, which is serialized by being called only
@@ -1599,14 +1633,21 @@
 		}
 
 		for (count = 0; count < n/sizeof(struct io_thread_req *); count++) {
+			struct io_thread_req *req = (*io_req_buffer)[count];
+			int i;
+
 			io_count++;
-			do_io((*io_req_buffer)[count]);
+			for (i = 0; !req->error && i < req->desc_cnt; i++)
+				do_io(req, &(req->io_desc[i]));
+
 		}
 
 		written = 0;
 
 		do {
-			res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n);
+			res = os_write_file(kernel_fd,
+					    ((char *) io_req_buffer) + written,
+					    n - written);
 			if (res >= 0) {
 				written += res;
 			}
diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c
index fc8c52c..18618af 100644
--- a/arch/um/drivers/virtio_uml.c
+++ b/arch/um/drivers/virtio_uml.c
@@ -4,12 +4,12 @@
  *
  * Copyright(c) 2019 Intel Corporation
  *
- * This module allows virtio devices to be used over a vhost-user socket.
+ * This driver allows virtio devices to be used over a vhost-user socket.
  *
  * Guest devices can be instantiated by kernel module or command line
  * parameters. One device will be created for each parameter. Syntax:
  *
- *		[virtio_uml.]device=<socket>:<virtio_id>[:<platform_id>]
+ *		virtio_uml.device=<socket>:<virtio_id>[:<platform_id>]
  * where:
  *		<socket>	:= vhost-user socket path to connect
  *		<virtio_id>	:= virtio device id (as in virtio_ids.h)
@@ -83,7 +83,7 @@
 	return 0;
 }
 
-static int full_read(int fd, void *buf, int len)
+static int full_read(int fd, void *buf, int len, bool abortable)
 {
 	int rc;
 
@@ -93,7 +93,7 @@
 			buf += rc;
 			len -= rc;
 		}
-	} while (len && (rc > 0 || rc == -EINTR));
+	} while (len && (rc > 0 || rc == -EINTR || (!abortable && rc == -EAGAIN)));
 
 	if (rc < 0)
 		return rc;
@@ -104,7 +104,7 @@
 
 static int vhost_user_recv_header(int fd, struct vhost_user_msg *msg)
 {
-	return full_read(fd, msg, sizeof(msg->header));
+	return full_read(fd, msg, sizeof(msg->header), true);
 }
 
 static int vhost_user_recv(int fd, struct vhost_user_msg *msg,
@@ -118,7 +118,7 @@
 	size = msg->header.size;
 	if (size > max_payload_size)
 		return -EPROTO;
-	return full_read(fd, &msg->payload, size);
+	return full_read(fd, &msg->payload, size, false);
 }
 
 static int vhost_user_recv_resp(struct virtio_uml_device *vu_dev,
@@ -959,6 +959,7 @@
 	}
 
 	os_close_file(vu_dev->sock);
+	kfree(vu_dev);
 }
 
 /* Platform device */
@@ -977,7 +978,7 @@
 	if (!pdata)
 		return -EINVAL;
 
-	vu_dev = devm_kzalloc(&pdev->dev, sizeof(*vu_dev), GFP_KERNEL);
+	vu_dev = kzalloc(sizeof(*vu_dev), GFP_KERNEL);
 	if (!vu_dev)
 		return -ENOMEM;
 
diff --git a/arch/um/drivers/xterm.c b/arch/um/drivers/xterm.c
index fc7f1e7..87ca4a4 100644
--- a/arch/um/drivers/xterm.c
+++ b/arch/um/drivers/xterm.c
@@ -18,6 +18,7 @@
 struct xterm_chan {
 	int pid;
 	int helper_pid;
+	int chan_fd;
 	char *title;
 	int device;
 	int raw;
@@ -33,6 +34,7 @@
 		return NULL;
 	*data = ((struct xterm_chan) { .pid 		= -1,
 				       .helper_pid 	= -1,
+				       .chan_fd		= -1,
 				       .device 		= device,
 				       .title 		= opts->xterm_title,
 				       .raw  		= opts->raw } );
@@ -149,6 +151,7 @@
 		goto out_kill;
 	}
 
+	data->chan_fd = fd;
 	new = xterm_fd(fd, &data->helper_pid);
 	if (new < 0) {
 		err = new;
@@ -206,6 +209,8 @@
 		os_kill_process(data->helper_pid, 0);
 	data->helper_pid = -1;
 
+	if (data->chan_fd != -1)
+		os_close_file(data->chan_fd);
 	os_close_file(fd);
 }
 
diff --git a/arch/um/include/asm/common.lds.S b/arch/um/include/asm/common.lds.S
index d7086b9..4049f2c 100644
--- a/arch/um/include/asm/common.lds.S
+++ b/arch/um/include/asm/common.lds.S
@@ -83,8 +83,8 @@
 	__preinit_array_end = .;
   }
   .init_array : {
-        /* dummy - we call this ourselves */
 	__init_array_start = .;
+	*(.init_array)
 	__init_array_end = .;
   }
   .fini_array : {
diff --git a/arch/um/include/asm/ptrace-generic.h b/arch/um/include/asm/ptrace-generic.h
index 81c647e..adf91ef 100644
--- a/arch/um/include/asm/ptrace-generic.h
+++ b/arch/um/include/asm/ptrace-generic.h
@@ -36,7 +36,7 @@
 extern unsigned long getreg(struct task_struct *child, int regno);
 extern int putreg(struct task_struct *child, int regno, unsigned long value);
 
-extern int arch_copy_tls(struct task_struct *new);
+extern int arch_set_tls(struct task_struct *new, unsigned long tls);
 extern void clear_flushed_tls(struct task_struct *task);
 extern int syscall_trace_enter(struct pt_regs *regs);
 extern void syscall_trace_leave(struct pt_regs *regs);
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index 5aa8820..e698e0c 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -21,7 +21,6 @@
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)	+= gprof_syms.o
-obj-$(CONFIG_GCOV)	+= gmon_syms.o
 obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
 
diff --git a/arch/um/kernel/dyn.lds.S b/arch/um/kernel/dyn.lds.S
index c69d69e..a82ec01 100644
--- a/arch/um/kernel/dyn.lds.S
+++ b/arch/um/kernel/dyn.lds.S
@@ -6,6 +6,12 @@
 ENTRY(_start)
 jiffies = jiffies_64;
 
+VERSION {
+  {
+    local: *;
+  };
+}
+
 SECTIONS
 {
   PROVIDE (__executable_start = START);
@@ -103,6 +109,7 @@
      be empty, which isn't pretty.  */
   . = ALIGN(32 / 8);
   .preinit_array     : { *(.preinit_array) }
+  .init_array     : { *(.init_array) }
   .fini_array     : { *(.fini_array) }
   .data           : {
     INIT_TASK_DATA(KERNEL_STACK_SIZE)
diff --git a/arch/um/kernel/gmon_syms.c b/arch/um/kernel/gmon_syms.c
deleted file mode 100644
index 9361a8e..0000000
--- a/arch/um/kernel/gmon_syms.c
+++ /dev/null
@@ -1,16 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- */
-
-#include <linux/module.h>
-
-extern void __bb_init_func(void *)  __attribute__((weak));
-EXPORT_SYMBOL(__bb_init_func);
-
-extern void __gcov_init(void *)  __attribute__((weak));
-EXPORT_SYMBOL(__gcov_init);
-extern void __gcov_merge_add(void *, unsigned int)  __attribute__((weak));
-EXPORT_SYMBOL(__gcov_merge_add);
-extern void __gcov_exit(void)  __attribute__((weak));
-EXPORT_SYMBOL(__gcov_exit);
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 263a8f0..17045e7 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -153,8 +153,8 @@
 	userspace(&current->thread.regs.regs, current_thread_info()->aux_fp_regs);
 }
 
-int copy_thread(unsigned long clone_flags, unsigned long sp,
-		unsigned long arg, struct task_struct * p)
+int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
+		unsigned long arg, struct task_struct * p, unsigned long tls)
 {
 	void (*handler)(void);
 	int kthread = current->flags & PF_KTHREAD;
@@ -188,7 +188,7 @@
 		 * Set a new TLS for the child thread?
 		 */
 		if (clone_flags & CLONE_SETTLS)
-			ret = arch_copy_tls(p);
+			ret = arch_set_tls(p, tls);
 	}
 
 	return ret;
diff --git a/arch/um/kernel/sigio.c b/arch/um/kernel/sigio.c
index 10c99e0..d1cffc2 100644
--- a/arch/um/kernel/sigio.c
+++ b/arch/um/kernel/sigio.c
@@ -35,14 +35,14 @@
 }
 
 /* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
-static DEFINE_SPINLOCK(sigio_spinlock);
+static DEFINE_MUTEX(sigio_mutex);
 
 void sigio_lock(void)
 {
-	spin_lock(&sigio_spinlock);
+	mutex_lock(&sigio_mutex);
 }
 
 void sigio_unlock(void)
 {
-	spin_unlock(&sigio_spinlock);
+	mutex_unlock(&sigio_mutex);
 }
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index b7eaf65..1149913 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -126,6 +126,9 @@
 	struct host_vm_op *last;
 	int fd = -1, ret = 0;
 
+	if (virt + len > STUB_START && virt < STUB_END)
+		return -EINVAL;
+
 	if (hvc->userspace)
 		fd = phys_mapping(phys, &offset);
 	else
@@ -163,7 +166,7 @@
 	struct host_vm_op *last;
 	int ret = 0;
 
-	if ((addr >= STUB_START) && (addr < STUB_END))
+	if (addr + len > STUB_START && addr < STUB_END)
 		return -EINVAL;
 
 	if (hvc->index != 0) {
@@ -193,6 +196,9 @@
 	struct host_vm_op *last;
 	int ret = 0;
 
+	if (addr + len > STUB_START && addr < STUB_END)
+		return -EINVAL;
+
 	if (hvc->index != 0) {
 		last = &hvc->ops[hvc->index - 1];
 		if ((last->type == MPROTECT) &&
@@ -433,6 +439,10 @@
 	struct mm_id *mm_id;
 
 	address &= PAGE_MASK;
+
+	if (address >= STUB_START && address < STUB_END)
+		goto kill;
+
 	pgd = pgd_offset(mm, address);
 	if (!pgd_present(*pgd))
 		goto kill;
diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index 9f21443..85b404d 100644
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -7,6 +7,12 @@
 ENTRY(_start)
 jiffies = jiffies_64;
 
+VERSION {
+  {
+    local: *;
+  };
+}
+
 SECTIONS
 {
   /* This must contain the right address - not quite the default ELF one.*/
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index 5133e3a..3996937 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -8,6 +8,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
+#include <linux/falloc.h>
 #include <sys/ioctl.h>
 #include <sys/mount.h>
 #include <sys/socket.h>
diff --git a/arch/um/os-Linux/irq.c b/arch/um/os-Linux/irq.c
index d508310..f1732c3 100644
--- a/arch/um/os-Linux/irq.c
+++ b/arch/um/os-Linux/irq.c
@@ -48,7 +48,7 @@
 int os_event_mask(int irq_type)
 {
 	if (irq_type == IRQ_READ)
-		return EPOLLIN | EPOLLPRI;
+		return EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP | EPOLLRDHUP;
 	if (irq_type == IRQ_WRITE)
 		return EPOLLOUT;
 	return 0;
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
index 8014dfa..c8a42ec 100644
--- a/arch/um/os-Linux/main.c
+++ b/arch/um/os-Linux/main.c
@@ -170,7 +170,7 @@
 	 * that they won't be delivered after the exec, when
 	 * they are definitely not expected.
 	 */
-	unblock_signals_trace();
+	unblock_signals();
 
 	os_info("\n");
 	/* Reboot */
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
index 44def53..ea5c60f 100644
--- a/arch/um/os-Linux/umid.c
+++ b/arch/um/os-Linux/umid.c
@@ -137,20 +137,13 @@
 {
 	char pid[sizeof("nnnnn\0")], *end, *file;
 	int dead, fd, p, n, err;
-	size_t filelen;
+	size_t filelen = strlen(dir) + sizeof("/pid") + 1;
 
-	err = asprintf(&file, "%s/pid", dir);
-	if (err < 0)
-		return 0;
+	file = malloc(filelen);
+	if (!file)
+		return -ENOMEM;
 
-	filelen = strlen(file);
-
-	n = snprintf(file, filelen, "%s/pid", dir);
-	if (n >= filelen) {
-		printk(UM_KERN_ERR "is_umdir_used - pid filename too long\n");
-		err = -E2BIG;
-		goto out;
-	}
+	snprintf(file, filelen, "%s/pid", dir);
 
 	dead = 0;
 	fd = open(file, O_RDONLY);