similar to: [Bridge] [PATCH] Remove rcu_assign_pointer() penalty for NULL pointers

From: "Paul E. McKenney" <paulmck at linux.vnet.ibm.com> The sparse checking for rcu_assign_pointer() was recently upgraded to reject non-__kernel address spaces. This also rejects __rcu, which is almost always the right thing to do. However, the uses in cfg80211_combine_bsses() and cfg80211_bss_update() are legitimate: They is assigning a pointer to an element from an

This is a repost of the RCU patch I have posted some time ago. The only change from the previous post, was to move it to a more recent version of xen-unstable (changeset 13386). I am planning to submit the following additional patches, after this one is accepted: 1) rename_find_domain.patch: Rename find_domain_by_id() to get_domain_by_id() 2) add_find_domain.patch: Add new

This is a repost of the RCU patch I have posted some time ago. The only change from the previous post, was to move it to a more recent version of xen-unstable (changeset 13386). I am planning to submit the following additional patches, after this one is accepted: 1) rename_find_domain.patch: Rename find_domain_by_id() to get_domain_by_id() 2) add_find_domain.patch: Add new

From: Matthew Wilcox <mawilcox at microsoft.com> The eXtensible Bitmap is a sparse bitmap representation which is efficient for set bits which tend to cluster. It supports up to 'unsigned long' worth of bits, and this commit adds the bare bones -- xb_set_bit(), xb_clear_bit() and xb_test_bit(). Signed-off-by: Matthew Wilcox <mawilcox at microsoft.com> Signed-off-by: Wei Wang

Asias He (4): vhost-net: Always access vq->private_data under vq mutex vhost-test: Always access vq->private_data under vq mutex vhost-scsi: Always access vq->private_data under vq mutex vhost: Remove custom vhost rcu usage drivers/vhost/net.c | 37 ++++++++++++++++--------------------- drivers/vhost/scsi.c | 17 ++++++----------- drivers/vhost/test.c | 20

Asias He (4): vhost-net: Always access vq->private_data under vq mutex vhost-test: Always access vq->private_data under vq mutex vhost-scsi: Always access vq->private_data under vq mutex vhost: Remove custom vhost rcu usage drivers/vhost/net.c | 37 ++++++++++++++++--------------------- drivers/vhost/scsi.c | 17 ++++++----------- drivers/vhost/test.c | 20

On Tue, Jul 23, 2019 at 03:57:17AM -0400, Jason Wang wrote: > We don't mark dirty pages if the map was teared down outside MMU > notifier. This will lead untracked dirty pages. Fixing by marking > dirty pages during map uninit. > > Reported-by: Michael S. Tsirkin <mst at redhat.com> > Fixes: 7f466032dc9e ("vhost: access vq metadata through kernel virtual

On Tue, Jul 23, 2019 at 03:57:17AM -0400, Jason Wang wrote: > We don't mark dirty pages if the map was teared down outside MMU > notifier. This will lead untracked dirty pages. Fixing by marking > dirty pages during map uninit. > > Reported-by: Michael S. Tsirkin <mst at redhat.com> > Fixes: 7f466032dc9e ("vhost: access vq metadata through kernel virtual

This implements a virtio simulator: - adds stubs for enough support functions to compile virtio ring in userspace. - Adds a stub vhost based module this can talk to. This should help us decide things like which ring layout works best. Communication is currently done using an eventfd descriptor. This means there's a shared spinlock there: what I would like to do in the future, is run

This implements a virtio simulator: - adds stubs for enough support functions to compile virtio ring in userspace. - Adds a stub vhost based module this can talk to. This should help us decide things like which ring layout works best. Communication is currently done using an eventfd descriptor. This means there's a shared spinlock there: what I would like to do in the future, is run

This hook is protected with the RCU, so simple if (br_should_route_hook) br_should_route_hook(...) is not enough on some architectures. Use the rcu_dereference/rcu_assign_pointer in this case. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> --- diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 3cedd4e..b42b192 100644 --- a/net/bridge/br_input.c +++

I'm commenting without understanding the logic. Wei Wang wrote: > + > +bool xb_preload(gfp_t gfp); > + Want __must_check annotation, for __radix_tree_preload() is marked with __must_check annotation. By error failing to check result of xb_preload() will lead to preemption kept disabled unexpectedly. > +int xb_set_bit(struct xb *xb, unsigned long bit) > +{ > + int err;

I'm commenting without understanding the logic. Wei Wang wrote: > + > +bool xb_preload(gfp_t gfp); > + Want __must_check annotation, for __radix_tree_preload() is marked with __must_check annotation. By error failing to check result of xb_preload() will lead to preemption kept disabled unexpectedly. > +int xb_set_bit(struct xb *xb, unsigned long bit) > +{ > + int err;

Hi, I got an optimization problem (O1, O2) regarding memory barrier “dmb ishld” I find in the test/CodeGen/AArch64/intrinsics-memory-barrier.ll , it’s stated that memory access around DMB should not be reordered, but when compiling the Linux kernel, I found load/store in static inline void hlist_add_before_rcu(struct hlist_node *n, struct hlist_node *next) { n->pprev

Patch 1 removes CONFIG_SMP Patch 2 removes separate smp_{,r,w}mb()s as a result of patch 1 Patch 4 removes __ia64__ defines from the x86 arch tree Patch 3 is related to patch 4 and changes the VIOAPIC to emulate version 0x20 as a performance gain. It preceeds Patch 4 so as to be more clear about the functional change. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

We flush under vq mutex when changing backends. This creates a deadlock as workqueue being flushed needs this lock as well. https://bugzilla.redhat.com/show_bug.cgi?id=612421 Drop the vq mutex before flush: we have the device mutex which is sufficient to prevent another ioctl from touching the vq. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/net.c | 5 +++++

We flush under vq mutex when changing backends. This creates a deadlock as workqueue being flushed needs this lock as well. https://bugzilla.redhat.com/show_bug.cgi?id=612421 Drop the vq mutex before flush: we have the device mutex which is sufficient to prevent another ioctl from touching the vq. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/net.c | 5 +++++

On 2019/6/28 ??8:36, Stefano Garzarella wrote: > Some callbacks used by the upper layers can run while we are in the > .remove(). A potential use-after-free can happen, because we free > the_virtio_vsock without knowing if the callbacks are over or not. > > To solve this issue we move the assignment of the_virtio_vsock at the > end of .probe(), when we finished all the

On 2019/6/28 ??8:36, Stefano Garzarella wrote: > Some callbacks used by the upper layers can run while we are in the > .remove(). A potential use-after-free can happen, because we free > the_virtio_vsock without knowing if the callbacks are over or not. > > To solve this issue we move the assignment of the_virtio_vsock at the > end of .probe(), when we finished all the

On 2019/7/3 ??6:41, Stefano Garzarella wrote: > On Wed, Jul 03, 2019 at 05:53:58PM +0800, Jason Wang wrote: >> On 2019/6/28 ??8:36, Stefano Garzarella wrote: >>> Some callbacks used by the upper layers can run while we are in the >>> .remove(). A potential use-after-free can happen, because we free >>> the_virtio_vsock without knowing if the callbacks are over