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authorLinus Torvalds <torvalds@linux-foundation.org>2019-12-07 14:49:20 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-07 14:49:20 -0800
commitf74fd13f4585e418a3e630a82468be58bf1d98c1 (patch)
treec9738bc4729be166257a3cfd25a17cad049be314
parentMerge branch 'akpm' (patches from Andrew) (diff)
parentxen-blkback: allow module to be cleanly unloaded (diff)
downloadlinux-dev-f74fd13f4585e418a3e630a82468be58bf1d98c1.tar.xz
linux-dev-f74fd13f4585e418a3e630a82468be58bf1d98c1.zip
Merge tag 'for-linus-5.5b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull more xen updates from Juergen Gross: - a patch to fix a build warning - a cleanup of no longer needed code in the Xen event handling - a small series for the Xen grant driver avoiding high order allocations and replacing an insane global limit by a per-call one - a small series fixing Xen frontend/backend module referencing * tag 'for-linus-5.5b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen-blkback: allow module to be cleanly unloaded xen/xenbus: reference count registered modules xen/gntdev: switch from kcalloc() to kvcalloc() xen/gntdev: replace global limit of mapped pages by limit per call xen/gntdev: remove redundant non-zero check on ret xen/events: remove event handling recursion detection
-rw-r--r--drivers/block/xen-blkback/blkback.c8
-rw-r--r--drivers/block/xen-blkback/common.h3
-rw-r--r--drivers/block/xen-blkback/xenbus.c11
-rw-r--r--drivers/xen/events/events_base.c16
-rw-r--r--drivers/xen/gntdev-common.h2
-rw-r--r--drivers/xen/gntdev-dmabuf.c11
-rw-r--r--drivers/xen/gntdev.c64
-rw-r--r--drivers/xen/xenbus/xenbus_probe.c13
8 files changed, 66 insertions, 62 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 3666afa639d1..716b99aa2307 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -1506,5 +1506,13 @@ static int __init xen_blkif_init(void)
module_init(xen_blkif_init);
+static void __exit xen_blkif_fini(void)
+{
+ xen_blkif_xenbus_fini();
+ xen_blkif_interface_fini();
+}
+
+module_exit(xen_blkif_fini);
+
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS("xen-backend:vbd");
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index 1d3002d773f7..49132b0adbbe 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -375,9 +375,12 @@ struct phys_req {
struct block_device *bdev;
blkif_sector_t sector_number;
};
+
int xen_blkif_interface_init(void);
+void xen_blkif_interface_fini(void);
int xen_blkif_xenbus_init(void);
+void xen_blkif_xenbus_fini(void);
irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
int xen_blkif_schedule(void *arg);
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index b90dbcd99c03..e8c5c54e1d26 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -333,6 +333,12 @@ int __init xen_blkif_interface_init(void)
return 0;
}
+void xen_blkif_interface_fini(void)
+{
+ kmem_cache_destroy(xen_blkif_cachep);
+ xen_blkif_cachep = NULL;
+}
+
/*
* sysfs interface for VBD I/O requests
*/
@@ -1122,3 +1128,8 @@ int xen_blkif_xenbus_init(void)
{
return xenbus_register_backend(&xen_blkbk_driver);
}
+
+void xen_blkif_xenbus_fini(void)
+{
+ xenbus_unregister_driver(&xen_blkbk_driver);
+}
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 6c8843968a52..499eff7d3f65 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -1213,31 +1213,21 @@ void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
notify_remote_via_irq(irq);
}
-static DEFINE_PER_CPU(unsigned, xed_nesting_count);
-
static void __xen_evtchn_do_upcall(void)
{
struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
- int cpu = get_cpu();
- unsigned count;
+ int cpu = smp_processor_id();
do {
vcpu_info->evtchn_upcall_pending = 0;
- if (__this_cpu_inc_return(xed_nesting_count) - 1)
- goto out;
-
xen_evtchn_handle_events(cpu);
BUG_ON(!irqs_disabled());
- count = __this_cpu_read(xed_nesting_count);
- __this_cpu_write(xed_nesting_count, 0);
- } while (count != 1 || vcpu_info->evtchn_upcall_pending);
-
-out:
+ virt_rmb(); /* Hypervisor can set upcall pending. */
- put_cpu();
+ } while (vcpu_info->evtchn_upcall_pending);
}
void xen_evtchn_do_upcall(struct pt_regs *regs)
diff --git a/drivers/xen/gntdev-common.h b/drivers/xen/gntdev-common.h
index 91e44c04f787..9a3960ecff6c 100644
--- a/drivers/xen/gntdev-common.h
+++ b/drivers/xen/gntdev-common.h
@@ -81,7 +81,7 @@ void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add);
void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map);
-bool gntdev_account_mapped_pages(int count);
+bool gntdev_test_page_count(unsigned int count);
int gntdev_map_grant_pages(struct gntdev_grant_map *map);
diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c
index 2c4f324f8626..63f0857bf62d 100644
--- a/drivers/xen/gntdev-dmabuf.c
+++ b/drivers/xen/gntdev-dmabuf.c
@@ -446,7 +446,7 @@ dmabuf_exp_alloc_backing_storage(struct gntdev_priv *priv, int dmabuf_flags,
{
struct gntdev_grant_map *map;
- if (unlikely(count <= 0))
+ if (unlikely(gntdev_test_page_count(count)))
return ERR_PTR(-EINVAL);
if ((dmabuf_flags & GNTDEV_DMA_FLAG_WC) &&
@@ -459,11 +459,6 @@ dmabuf_exp_alloc_backing_storage(struct gntdev_priv *priv, int dmabuf_flags,
if (!map)
return ERR_PTR(-ENOMEM);
- if (unlikely(gntdev_account_mapped_pages(count))) {
- pr_debug("can't map %d pages: over limit\n", count);
- gntdev_put_map(NULL, map);
- return ERR_PTR(-ENOMEM);
- }
return map;
}
@@ -771,7 +766,7 @@ long gntdev_ioctl_dmabuf_exp_from_refs(struct gntdev_priv *priv, int use_ptemod,
if (copy_from_user(&op, u, sizeof(op)) != 0)
return -EFAULT;
- if (unlikely(op.count <= 0))
+ if (unlikely(gntdev_test_page_count(op.count)))
return -EINVAL;
refs = kcalloc(op.count, sizeof(*refs), GFP_KERNEL);
@@ -818,7 +813,7 @@ long gntdev_ioctl_dmabuf_imp_to_refs(struct gntdev_priv *priv,
if (copy_from_user(&op, u, sizeof(op)) != 0)
return -EFAULT;
- if (unlikely(op.count <= 0))
+ if (unlikely(gntdev_test_page_count(op.count)))
return -EINVAL;
gntdev_dmabuf = dmabuf_imp_to_refs(priv->dmabuf_priv,
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index a04ddf2a68af..4fc83e3f5ad3 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -55,12 +55,10 @@ MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
"Gerd Hoffmann <kraxel@redhat.com>");
MODULE_DESCRIPTION("User-space granted page access driver");
-static int limit = 1024*1024;
-module_param(limit, int, 0644);
-MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
- "the gntdev device");
-
-static atomic_t pages_mapped = ATOMIC_INIT(0);
+static unsigned int limit = 64*1024;
+module_param(limit, uint, 0644);
+MODULE_PARM_DESC(limit,
+ "Maximum number of grants that may be mapped by one mapping request");
static int use_ptemod;
@@ -71,9 +69,9 @@ static struct miscdevice gntdev_miscdev;
/* ------------------------------------------------------------------ */
-bool gntdev_account_mapped_pages(int count)
+bool gntdev_test_page_count(unsigned int count)
{
- return atomic_add_return(count, &pages_mapped) > limit;
+ return !count || count > limit;
}
static void gntdev_print_maps(struct gntdev_priv *priv,
@@ -114,14 +112,14 @@ static void gntdev_free_map(struct gntdev_grant_map *map)
gnttab_free_pages(map->count, map->pages);
#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
- kfree(map->frames);
+ kvfree(map->frames);
#endif
- kfree(map->pages);
- kfree(map->grants);
- kfree(map->map_ops);
- kfree(map->unmap_ops);
- kfree(map->kmap_ops);
- kfree(map->kunmap_ops);
+ kvfree(map->pages);
+ kvfree(map->grants);
+ kvfree(map->map_ops);
+ kvfree(map->unmap_ops);
+ kvfree(map->kmap_ops);
+ kvfree(map->kunmap_ops);
kfree(map);
}
@@ -135,12 +133,13 @@ struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
if (NULL == add)
return NULL;
- add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL);
- add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);
- add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);
- add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL);
- add->kunmap_ops = kcalloc(count, sizeof(add->kunmap_ops[0]), GFP_KERNEL);
- add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);
+ add->grants = kvcalloc(count, sizeof(add->grants[0]), GFP_KERNEL);
+ add->map_ops = kvcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);
+ add->unmap_ops = kvcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);
+ add->kmap_ops = kvcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL);
+ add->kunmap_ops = kvcalloc(count,
+ sizeof(add->kunmap_ops[0]), GFP_KERNEL);
+ add->pages = kvcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);
if (NULL == add->grants ||
NULL == add->map_ops ||
NULL == add->unmap_ops ||
@@ -159,8 +158,8 @@ struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
if (dma_flags & (GNTDEV_DMA_FLAG_WC | GNTDEV_DMA_FLAG_COHERENT)) {
struct gnttab_dma_alloc_args args;
- add->frames = kcalloc(count, sizeof(add->frames[0]),
- GFP_KERNEL);
+ add->frames = kvcalloc(count, sizeof(add->frames[0]),
+ GFP_KERNEL);
if (!add->frames)
goto err;
@@ -241,8 +240,6 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)
if (!refcount_dec_and_test(&map->users))
return;
- atomic_sub(map->count, &pages_mapped);
-
if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
notify_remote_via_evtchn(map->notify.event);
evtchn_put(map->notify.event);
@@ -506,7 +503,6 @@ static const struct mmu_interval_notifier_ops gntdev_mmu_ops = {
static int gntdev_open(struct inode *inode, struct file *flip)
{
struct gntdev_priv *priv;
- int ret = 0;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
@@ -518,16 +514,12 @@ static int gntdev_open(struct inode *inode, struct file *flip)
#ifdef CONFIG_XEN_GNTDEV_DMABUF
priv->dmabuf_priv = gntdev_dmabuf_init(flip);
if (IS_ERR(priv->dmabuf_priv)) {
- ret = PTR_ERR(priv->dmabuf_priv);
- kfree(priv);
- return ret;
- }
-#endif
+ int ret = PTR_ERR(priv->dmabuf_priv);
- if (ret) {
kfree(priv);
return ret;
}
+#endif
flip->private_data = priv;
#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
@@ -573,7 +565,7 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
if (copy_from_user(&op, u, sizeof(op)) != 0)
return -EFAULT;
pr_debug("priv %p, add %d\n", priv, op.count);
- if (unlikely(op.count <= 0))
+ if (unlikely(gntdev_test_page_count(op.count)))
return -EINVAL;
err = -ENOMEM;
@@ -581,12 +573,6 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
if (!map)
return err;
- if (unlikely(gntdev_account_mapped_pages(op.count))) {
- pr_debug("can't map: over limit\n");
- gntdev_put_map(NULL, map);
- return err;
- }
-
if (copy_from_user(map->grants, &u->refs,
sizeof(map->grants[0]) * op.count) != 0) {
gntdev_put_map(NULL, map);
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 5b471889d723..c21be6e9d38a 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -232,9 +232,16 @@ int xenbus_dev_probe(struct device *_dev)
return err;
}
+ if (!try_module_get(drv->driver.owner)) {
+ dev_warn(&dev->dev, "failed to acquire module reference on '%s'\n",
+ drv->driver.name);
+ err = -ESRCH;
+ goto fail;
+ }
+
err = drv->probe(dev, id);
if (err)
- goto fail;
+ goto fail_put;
err = watch_otherend(dev);
if (err) {
@@ -244,6 +251,8 @@ int xenbus_dev_probe(struct device *_dev)
}
return 0;
+fail_put:
+ module_put(drv->driver.owner);
fail:
xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename);
xenbus_switch_state(dev, XenbusStateClosed);
@@ -263,6 +272,8 @@ int xenbus_dev_remove(struct device *_dev)
if (drv->remove)
drv->remove(dev);
+ module_put(drv->driver.owner);
+
free_otherend_details(dev);
xenbus_switch_state(dev, XenbusStateClosed);