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authorLinus Torvalds <torvalds@linux-foundation.org>2018-06-23 20:44:11 +0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-23 20:44:11 +0800
commit4ab59fcfd56670df8f9c964240e25944a1b42eef (patch)
treeed478f05fae5f40a3288048913b61569fd506048 /drivers
parent894b8c000ae6c106cc434ee0000dfb77df8bd9db (diff)
parenteef04c7b3786ff0c9cb1019278b6c6c2ea0ad4ff (diff)
downloadlinux-4ab59fcfd56670df8f9c964240e25944a1b42eef.tar.bz2
Merge tag 'for-linus-4.18-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross: "This contains the following fixes/cleanups: - the removal of a BUG_ON() which wasn't necessary and which could trigger now due to a recent change - a correction of a long standing bug happening very rarely in Xen dom0 when a hypercall buffer from user land was not accessible by the hypervisor for very short periods of time due to e.g. page migration or compaction - usage of EXPORT_SYMBOL_GPL() instead of EXPORT_SYMBOL() in a Xen-related driver (no breakage possible as using those symbols without others already exported via EXPORT-SYMBOL_GPL() wouldn't make any sense) - a simplification for Xen PVH or Xen ARM guests - some additional error handling for callers of xenbus_printf()" * tag 'for-linus-4.18-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: Remove unnecessary BUG_ON from __unbind_from_irq() xen: add new hypercall buffer mapping device xen/scsiback: add error handling for xenbus_printf scsi: xen-scsifront: add error handling for xenbus_printf xen/grant-table: Export gnttab_{alloc|free}_pages as GPL xen: add error handling for xenbus_printf xen: share start flags between PV and PVH
Diffstat (limited to 'drivers')
-rw-r--r--drivers/scsi/xen-scsifront.c33
-rw-r--r--drivers/xen/Makefile2
-rw-r--r--drivers/xen/events/events_base.c2
-rw-r--r--drivers/xen/grant-table.c4
-rw-r--r--drivers/xen/manage.c18
-rw-r--r--drivers/xen/privcmd-buf.c210
-rw-r--r--drivers/xen/privcmd.c9
-rw-r--r--drivers/xen/privcmd.h3
-rw-r--r--drivers/xen/xen-scsiback.c16
9 files changed, 279 insertions, 18 deletions
diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
index 36f59a1be7e9..61389bdc7926 100644
--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -654,10 +654,17 @@ static int scsifront_dev_reset_handler(struct scsi_cmnd *sc)
static int scsifront_sdev_configure(struct scsi_device *sdev)
{
struct vscsifrnt_info *info = shost_priv(sdev->host);
+ int err;
- if (info && current == info->curr)
- xenbus_printf(XBT_NIL, info->dev->nodename,
+ if (info && current == info->curr) {
+ err = xenbus_printf(XBT_NIL, info->dev->nodename,
info->dev_state_path, "%d", XenbusStateConnected);
+ if (err) {
+ xenbus_dev_error(info->dev, err,
+ "%s: writing dev_state_path", __func__);
+ return err;
+ }
+ }
return 0;
}
@@ -665,10 +672,15 @@ static int scsifront_sdev_configure(struct scsi_device *sdev)
static void scsifront_sdev_destroy(struct scsi_device *sdev)
{
struct vscsifrnt_info *info = shost_priv(sdev->host);
+ int err;
- if (info && current == info->curr)
- xenbus_printf(XBT_NIL, info->dev->nodename,
+ if (info && current == info->curr) {
+ err = xenbus_printf(XBT_NIL, info->dev->nodename,
info->dev_state_path, "%d", XenbusStateClosed);
+ if (err)
+ xenbus_dev_error(info->dev, err,
+ "%s: writing dev_state_path", __func__);
+ }
}
static struct scsi_host_template scsifront_sht = {
@@ -1003,9 +1015,12 @@ static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op)
if (scsi_add_device(info->host, chn, tgt, lun)) {
dev_err(&dev->dev, "scsi_add_device\n");
- xenbus_printf(XBT_NIL, dev->nodename,
+ err = xenbus_printf(XBT_NIL, dev->nodename,
info->dev_state_path,
"%d", XenbusStateClosed);
+ if (err)
+ xenbus_dev_error(dev, err,
+ "%s: writing dev_state_path", __func__);
}
break;
case VSCSIFRONT_OP_DEL_LUN:
@@ -1019,10 +1034,14 @@ static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op)
}
break;
case VSCSIFRONT_OP_READD_LUN:
- if (device_state == XenbusStateConnected)
- xenbus_printf(XBT_NIL, dev->nodename,
+ if (device_state == XenbusStateConnected) {
+ err = xenbus_printf(XBT_NIL, dev->nodename,
info->dev_state_path,
"%d", XenbusStateConnected);
+ if (err)
+ xenbus_dev_error(dev, err,
+ "%s: writing dev_state_path", __func__);
+ }
break;
default:
break;
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 451e833f5931..48b154276179 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -41,4 +41,4 @@ obj-$(CONFIG_XEN_PVCALLS_FRONTEND) += pvcalls-front.o
xen-evtchn-y := evtchn.o
xen-gntdev-y := gntdev.o
xen-gntalloc-y := gntalloc.o
-xen-privcmd-y := privcmd.o
+xen-privcmd-y := privcmd.o privcmd-buf.o
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 762378f1811c..08e4af04d6f2 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -628,8 +628,6 @@ static void __unbind_from_irq(unsigned int irq)
xen_irq_info_cleanup(info);
}
- BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
-
xen_free_irq(irq);
}
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 2473b0a9e6e4..ba9f3eec2bd0 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -799,7 +799,7 @@ int gnttab_alloc_pages(int nr_pages, struct page **pages)
return 0;
}
-EXPORT_SYMBOL(gnttab_alloc_pages);
+EXPORT_SYMBOL_GPL(gnttab_alloc_pages);
/**
* gnttab_free_pages - free pages allocated by gnttab_alloc_pages()
@@ -820,7 +820,7 @@ void gnttab_free_pages(int nr_pages, struct page **pages)
}
free_xenballooned_pages(nr_pages, pages);
}
-EXPORT_SYMBOL(gnttab_free_pages);
+EXPORT_SYMBOL_GPL(gnttab_free_pages);
/* Handling of paged out grant targets (GNTST_eagain) */
#define MAX_DELAY 256
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 8835065029d3..c93d8ef8df34 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -289,8 +289,15 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path,
return;
}
- if (sysrq_key != '\0')
- xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
+ if (sysrq_key != '\0') {
+ err = xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
+ if (err) {
+ pr_err("%s: Error %d writing sysrq in control/sysrq\n",
+ __func__, err);
+ xenbus_transaction_end(xbt, 1);
+ return;
+ }
+ }
err = xenbus_transaction_end(xbt, 0);
if (err == -EAGAIN)
@@ -342,7 +349,12 @@ static int setup_shutdown_watcher(void)
continue;
snprintf(node, FEATURE_PATH_SIZE, "feature-%s",
shutdown_handlers[idx].command);
- xenbus_printf(XBT_NIL, "control", node, "%u", 1);
+ err = xenbus_printf(XBT_NIL, "control", node, "%u", 1);
+ if (err) {
+ pr_err("%s: Error %d writing %s\n", __func__,
+ err, node);
+ return err;
+ }
}
return 0;
diff --git a/drivers/xen/privcmd-buf.c b/drivers/xen/privcmd-buf.c
new file mode 100644
index 000000000000..df1ed37c3269
--- /dev/null
+++ b/drivers/xen/privcmd-buf.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+/******************************************************************************
+ * privcmd-buf.c
+ *
+ * Mmap of hypercall buffers.
+ *
+ * Copyright (c) 2018 Juergen Gross
+ */
+
+#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+
+#include "privcmd.h"
+
+MODULE_LICENSE("GPL");
+
+static unsigned int limit = 64;
+module_param(limit, uint, 0644);
+MODULE_PARM_DESC(limit, "Maximum number of pages that may be allocated by "
+ "the privcmd-buf device per open file");
+
+struct privcmd_buf_private {
+ struct mutex lock;
+ struct list_head list;
+ unsigned int allocated;
+};
+
+struct privcmd_buf_vma_private {
+ struct privcmd_buf_private *file_priv;
+ struct list_head list;
+ unsigned int users;
+ unsigned int n_pages;
+ struct page *pages[];
+};
+
+static int privcmd_buf_open(struct inode *ino, struct file *file)
+{
+ struct privcmd_buf_private *file_priv;
+
+ file_priv = kzalloc(sizeof(*file_priv), GFP_KERNEL);
+ if (!file_priv)
+ return -ENOMEM;
+
+ mutex_init(&file_priv->lock);
+ INIT_LIST_HEAD(&file_priv->list);
+
+ file->private_data = file_priv;
+
+ return 0;
+}
+
+static void privcmd_buf_vmapriv_free(struct privcmd_buf_vma_private *vma_priv)
+{
+ unsigned int i;
+
+ vma_priv->file_priv->allocated -= vma_priv->n_pages;
+
+ list_del(&vma_priv->list);
+
+ for (i = 0; i < vma_priv->n_pages; i++)
+ if (vma_priv->pages[i])
+ __free_page(vma_priv->pages[i]);
+
+ kfree(vma_priv);
+}
+
+static int privcmd_buf_release(struct inode *ino, struct file *file)
+{
+ struct privcmd_buf_private *file_priv = file->private_data;
+ struct privcmd_buf_vma_private *vma_priv;
+
+ mutex_lock(&file_priv->lock);
+
+ while (!list_empty(&file_priv->list)) {
+ vma_priv = list_first_entry(&file_priv->list,
+ struct privcmd_buf_vma_private,
+ list);
+ privcmd_buf_vmapriv_free(vma_priv);
+ }
+
+ mutex_unlock(&file_priv->lock);
+
+ kfree(file_priv);
+
+ return 0;
+}
+
+static void privcmd_buf_vma_open(struct vm_area_struct *vma)
+{
+ struct privcmd_buf_vma_private *vma_priv = vma->vm_private_data;
+
+ if (!vma_priv)
+ return;
+
+ mutex_lock(&vma_priv->file_priv->lock);
+ vma_priv->users++;
+ mutex_unlock(&vma_priv->file_priv->lock);
+}
+
+static void privcmd_buf_vma_close(struct vm_area_struct *vma)
+{
+ struct privcmd_buf_vma_private *vma_priv = vma->vm_private_data;
+ struct privcmd_buf_private *file_priv;
+
+ if (!vma_priv)
+ return;
+
+ file_priv = vma_priv->file_priv;
+
+ mutex_lock(&file_priv->lock);
+
+ vma_priv->users--;
+ if (!vma_priv->users)
+ privcmd_buf_vmapriv_free(vma_priv);
+
+ mutex_unlock(&file_priv->lock);
+}
+
+static vm_fault_t privcmd_buf_vma_fault(struct vm_fault *vmf)
+{
+ pr_debug("fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
+ vmf->vma, vmf->vma->vm_start, vmf->vma->vm_end,
+ vmf->pgoff, (void *)vmf->address);
+
+ return VM_FAULT_SIGBUS;
+}
+
+static const struct vm_operations_struct privcmd_buf_vm_ops = {
+ .open = privcmd_buf_vma_open,
+ .close = privcmd_buf_vma_close,
+ .fault = privcmd_buf_vma_fault,
+};
+
+static int privcmd_buf_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct privcmd_buf_private *file_priv = file->private_data;
+ struct privcmd_buf_vma_private *vma_priv;
+ unsigned long count = vma_pages(vma);
+ unsigned int i;
+ int ret = 0;
+
+ if (!(vma->vm_flags & VM_SHARED) || count > limit ||
+ file_priv->allocated + count > limit)
+ return -EINVAL;
+
+ vma_priv = kzalloc(sizeof(*vma_priv) + count * sizeof(void *),
+ GFP_KERNEL);
+ if (!vma_priv)
+ return -ENOMEM;
+
+ vma_priv->n_pages = count;
+ count = 0;
+ for (i = 0; i < vma_priv->n_pages; i++) {
+ vma_priv->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!vma_priv->pages[i])
+ break;
+ count++;
+ }
+
+ mutex_lock(&file_priv->lock);
+
+ file_priv->allocated += count;
+
+ vma_priv->file_priv = file_priv;
+ vma_priv->users = 1;
+
+ vma->vm_flags |= VM_IO | VM_DONTEXPAND;
+ vma->vm_ops = &privcmd_buf_vm_ops;
+ vma->vm_private_data = vma_priv;
+
+ list_add(&vma_priv->list, &file_priv->list);
+
+ if (vma_priv->n_pages != count)
+ ret = -ENOMEM;
+ else
+ for (i = 0; i < vma_priv->n_pages; i++) {
+ ret = vm_insert_page(vma, vma->vm_start + i * PAGE_SIZE,
+ vma_priv->pages[i]);
+ if (ret)
+ break;
+ }
+
+ if (ret)
+ privcmd_buf_vmapriv_free(vma_priv);
+
+ mutex_unlock(&file_priv->lock);
+
+ return ret;
+}
+
+const struct file_operations xen_privcmdbuf_fops = {
+ .owner = THIS_MODULE,
+ .open = privcmd_buf_open,
+ .release = privcmd_buf_release,
+ .mmap = privcmd_buf_mmap,
+};
+EXPORT_SYMBOL_GPL(xen_privcmdbuf_fops);
+
+struct miscdevice xen_privcmdbuf_dev = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "xen/hypercall",
+ .fops = &xen_privcmdbuf_fops,
+};
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 8ae0349d9f0a..7e6e682104dc 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -1007,12 +1007,21 @@ static int __init privcmd_init(void)
pr_err("Could not register Xen privcmd device\n");
return err;
}
+
+ err = misc_register(&xen_privcmdbuf_dev);
+ if (err != 0) {
+ pr_err("Could not register Xen hypercall-buf device\n");
+ misc_deregister(&privcmd_dev);
+ return err;
+ }
+
return 0;
}
static void __exit privcmd_exit(void)
{
misc_deregister(&privcmd_dev);
+ misc_deregister(&xen_privcmdbuf_dev);
}
module_init(privcmd_init);
diff --git a/drivers/xen/privcmd.h b/drivers/xen/privcmd.h
index 14facaeed36f..0dd9f8f67ee3 100644
--- a/drivers/xen/privcmd.h
+++ b/drivers/xen/privcmd.h
@@ -1,3 +1,6 @@
#include <linux/fs.h>
extern const struct file_operations xen_privcmd_fops;
+extern const struct file_operations xen_privcmdbuf_fops;
+
+extern struct miscdevice xen_privcmdbuf_dev;
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 7bc88fd43cfc..e2f3e8b0fba9 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -1012,6 +1012,7 @@ static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
{
struct v2p_entry *entry;
unsigned long flags;
+ int err;
if (try) {
spin_lock_irqsave(&info->v2p_lock, flags);
@@ -1027,8 +1028,11 @@ static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
scsiback_del_translation_entry(info, vir);
}
} else if (!try) {
- xenbus_printf(XBT_NIL, info->dev->nodename, state,
+ err = xenbus_printf(XBT_NIL, info->dev->nodename, state,
"%d", XenbusStateClosed);
+ if (err)
+ xenbus_dev_error(info->dev, err,
+ "%s: writing %s", __func__, state);
}
}
@@ -1067,8 +1071,11 @@ static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
if (IS_ERR(val)) {
- xenbus_printf(XBT_NIL, dev->nodename, state,
+ err = xenbus_printf(XBT_NIL, dev->nodename, state,
"%d", XenbusStateClosed);
+ if (err)
+ xenbus_dev_error(info->dev, err,
+ "%s: writing %s", __func__, state);
return;
}
strlcpy(phy, val, VSCSI_NAMELEN);
@@ -1079,8 +1086,11 @@ static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
&vir.hst, &vir.chn, &vir.tgt, &vir.lun);
if (XENBUS_EXIST_ERR(err)) {
- xenbus_printf(XBT_NIL, dev->nodename, state,
+ err = xenbus_printf(XBT_NIL, dev->nodename, state,
"%d", XenbusStateClosed);
+ if (err)
+ xenbus_dev_error(info->dev, err,
+ "%s: writing %s", __func__, state);
return;
}