mm/mremap_pages: fix static key devmap_managed_key updates
commit 6f42193fd8
("memremap: don't use a separate devm action for
devmap_managed_enable_get") changed the static key updates such that we
now call devmap_managed_enable_put() without doing the equivalent
devmap_managed_enable_get().
devmap_managed_enable_get() is only called for MEMORY_DEVICE_PRIVATE and
MEMORY_DEVICE_FS_DAX, But memunmap_pages() get called for other pgmap
types too. This results in the below warning when switching between
system-ram and devdax mode for devdax namespace.
jump label: negative count!
WARNING: CPU: 52 PID: 1335 at kernel/jump_label.c:235 static_key_slow_try_dec+0x88/0xa0
Modules linked in:
....
NIP static_key_slow_try_dec+0x88/0xa0
LR static_key_slow_try_dec+0x84/0xa0
Call Trace:
static_key_slow_try_dec+0x84/0xa0
__static_key_slow_dec_cpuslocked+0x34/0xd0
static_key_slow_dec+0x54/0xf0
memunmap_pages+0x36c/0x500
devm_action_release+0x30/0x50
release_nodes+0x2f4/0x3e0
device_release_driver_internal+0x17c/0x280
bus_remove_device+0x124/0x210
device_del+0x1d4/0x530
unregister_dev_dax+0x48/0xe0
devm_action_release+0x30/0x50
release_nodes+0x2f4/0x3e0
device_release_driver_internal+0x17c/0x280
unbind_store+0x130/0x170
drv_attr_store+0x40/0x60
sysfs_kf_write+0x6c/0xb0
kernfs_fop_write+0x118/0x280
vfs_write+0xe8/0x2a0
ksys_write+0x84/0x140
system_call_exception+0x120/0x270
system_call_common+0xf0/0x27c
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Link: https://lkml.kernel.org/r/20201023183222.13186-1-rcampbell@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
3cea11cd5e
commit
46b1ee38b2
@ -41,28 +41,24 @@ EXPORT_SYMBOL_GPL(memremap_compat_align);
|
|||||||
DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
|
DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
|
||||||
EXPORT_SYMBOL(devmap_managed_key);
|
EXPORT_SYMBOL(devmap_managed_key);
|
||||||
|
|
||||||
static void devmap_managed_enable_put(void)
|
static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
|
||||||
{
|
{
|
||||||
static_branch_dec(&devmap_managed_key);
|
if (pgmap->type == MEMORY_DEVICE_PRIVATE ||
|
||||||
|
pgmap->type == MEMORY_DEVICE_FS_DAX)
|
||||||
|
static_branch_dec(&devmap_managed_key);
|
||||||
}
|
}
|
||||||
|
|
||||||
static int devmap_managed_enable_get(struct dev_pagemap *pgmap)
|
static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
|
||||||
{
|
{
|
||||||
if (pgmap->type == MEMORY_DEVICE_PRIVATE &&
|
if (pgmap->type == MEMORY_DEVICE_PRIVATE ||
|
||||||
(!pgmap->ops || !pgmap->ops->page_free)) {
|
pgmap->type == MEMORY_DEVICE_FS_DAX)
|
||||||
WARN(1, "Missing page_free method\n");
|
static_branch_inc(&devmap_managed_key);
|
||||||
return -EINVAL;
|
|
||||||
}
|
|
||||||
|
|
||||||
static_branch_inc(&devmap_managed_key);
|
|
||||||
return 0;
|
|
||||||
}
|
}
|
||||||
#else
|
#else
|
||||||
static int devmap_managed_enable_get(struct dev_pagemap *pgmap)
|
static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
|
||||||
{
|
{
|
||||||
return -EINVAL;
|
|
||||||
}
|
}
|
||||||
static void devmap_managed_enable_put(void)
|
static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
|
||||||
{
|
{
|
||||||
}
|
}
|
||||||
#endif /* CONFIG_DEV_PAGEMAP_OPS */
|
#endif /* CONFIG_DEV_PAGEMAP_OPS */
|
||||||
@ -169,7 +165,7 @@ void memunmap_pages(struct dev_pagemap *pgmap)
|
|||||||
pageunmap_range(pgmap, i);
|
pageunmap_range(pgmap, i);
|
||||||
|
|
||||||
WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");
|
WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");
|
||||||
devmap_managed_enable_put();
|
devmap_managed_enable_put(pgmap);
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL_GPL(memunmap_pages);
|
EXPORT_SYMBOL_GPL(memunmap_pages);
|
||||||
|
|
||||||
@ -307,7 +303,6 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
|
|||||||
.pgprot = PAGE_KERNEL,
|
.pgprot = PAGE_KERNEL,
|
||||||
};
|
};
|
||||||
const int nr_range = pgmap->nr_range;
|
const int nr_range = pgmap->nr_range;
|
||||||
bool need_devmap_managed = true;
|
|
||||||
int error, i;
|
int error, i;
|
||||||
|
|
||||||
if (WARN_ONCE(!nr_range, "nr_range must be specified\n"))
|
if (WARN_ONCE(!nr_range, "nr_range must be specified\n"))
|
||||||
@ -323,6 +318,10 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
|
|||||||
WARN(1, "Missing migrate_to_ram method\n");
|
WARN(1, "Missing migrate_to_ram method\n");
|
||||||
return ERR_PTR(-EINVAL);
|
return ERR_PTR(-EINVAL);
|
||||||
}
|
}
|
||||||
|
if (!pgmap->ops->page_free) {
|
||||||
|
WARN(1, "Missing page_free method\n");
|
||||||
|
return ERR_PTR(-EINVAL);
|
||||||
|
}
|
||||||
if (!pgmap->owner) {
|
if (!pgmap->owner) {
|
||||||
WARN(1, "Missing owner\n");
|
WARN(1, "Missing owner\n");
|
||||||
return ERR_PTR(-EINVAL);
|
return ERR_PTR(-EINVAL);
|
||||||
@ -336,11 +335,9 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
|
|||||||
}
|
}
|
||||||
break;
|
break;
|
||||||
case MEMORY_DEVICE_GENERIC:
|
case MEMORY_DEVICE_GENERIC:
|
||||||
need_devmap_managed = false;
|
|
||||||
break;
|
break;
|
||||||
case MEMORY_DEVICE_PCI_P2PDMA:
|
case MEMORY_DEVICE_PCI_P2PDMA:
|
||||||
params.pgprot = pgprot_noncached(params.pgprot);
|
params.pgprot = pgprot_noncached(params.pgprot);
|
||||||
need_devmap_managed = false;
|
|
||||||
break;
|
break;
|
||||||
default:
|
default:
|
||||||
WARN(1, "Invalid pgmap type %d\n", pgmap->type);
|
WARN(1, "Invalid pgmap type %d\n", pgmap->type);
|
||||||
@ -364,11 +361,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
|
|||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
if (need_devmap_managed) {
|
devmap_managed_enable_get(pgmap);
|
||||||
error = devmap_managed_enable_get(pgmap);
|
|
||||||
if (error)
|
|
||||||
return ERR_PTR(error);
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* Clear the pgmap nr_range as it will be incremented for each
|
* Clear the pgmap nr_range as it will be incremented for each
|
||||||
|
Loading…
Reference in New Issue
Block a user