This method is never actually called.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20220708080616.238833-2-hch@lst.deSigned-off-by: NJoerg Roedel <jroedel@suse.de>

This will provide a way for SMMU drivers to retrieve StreamIDs
associated with IORT RMR nodes and use that to set bypass settings
for those IDs.
Tested-by: NSteven Price <steven.price@arm.com>
Tested-by: NLaurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: NHanjun Guo <guohanjun@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220615101044.1972-6-shameerali.kolothum.thodi@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Parse through the IORT RMR nodes and populate the reserve region list
corresponding to a given IOMMU and device(optional). Also, go through
the ID mappings of the RMR node and retrieve all the SIDs associated
with it.
Reviewed-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: NSteven Price <steven.price@arm.com>
Tested-by: NLaurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: NHanjun Guo <guohanjun@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220615101044.1972-5-shameerali.kolothum.thodi@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Currently IORT provides a helper to retrieve HW MSI reserve regions.
Change this to a generic helper to retrieve any IORT related reserve
regions. This will be useful when we add support for RMR nodes in
subsequent patches.

[Lorenzo: For ACPI IORT]
Reviewed-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NSteven Price <steven.price@arm.com>
Tested-by: NLaurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: NHanjun Guo <guohanjun@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220615101044.1972-4-shameerali.kolothum.thodi@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

At present iort_iommu_msi_get_resv_regions() returns the number of
MSI reserved regions on success and there are no users for this.
The reserved region list will get populated anyway for platforms
that require the HW MSI region reservation. Hence, change the
function to return void instead.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NSteven Price <steven.price@arm.com>
Tested-by: NLaurentiu Tudor <laurentiu.tudor@nxp.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220615101044.1972-3-shameerali.kolothum.thodi@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

A callback is introduced to struct iommu_resv_region to free memory
allocations associated with the reserved region. This will be useful
when we introduce support for IORT RMR based reserved regions.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NSteven Price <steven.price@arm.com>
Tested-by: NLaurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220615101044.1972-2-shameerali.kolothum.thodi@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

q->elevator is referred in blk_mq_has_sqsched() without any protection,
no .q_usage_counter is held, no queue srcu and rcu read lock is held,
so potential use-after-free may be triggered.

Fix the issue by adding one queue flag for checking if the elevator
uses single queue style dispatch. Meantime the elevator feature flag
of ELEVATOR_F_MQ_AWARE isn't needed any more.

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220616014401.817001-3-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

This reverts:

commit d5a42de8 ("net: Add a second bind table hashed by port and address")
commit 538aaf9b ("selftests: Add test for timing a bind request to a port with a populated bhash entry")
Link: https://lore.kernel.org/netdev/20220520001834.2247810-1-kuba@kernel.org/

There are a few things that need to be fixed here:
* Updating bhash2 in cases where the socket's rcv saddr changes
* Adding bhash2 hashbucket locks

Links to syzbot reports:
https://lore.kernel.org/netdev/00000000000022208805e0df247a@google.com/
https://lore.kernel.org/netdev/0000000000003f33bc05dfaf44fe@google.com/

Fixes: d5a42de8 ("net: Add a second bind table hashed by port and address")
Reported-by: syzbot+015d756bbd1f8b5c8f09@syzkaller.appspotmail.com
Reported-by: syzbot+98fd2d1422063b0f8c44@syzkaller.appspotmail.com
Reported-by: syzbot+0a847a982613c6438fba@syzkaller.appspotmail.com
Signed-off-by: NJoanne Koong <joannelkoong@gmail.com>
Link: https://lore.kernel.org/r/20220615193213.2419568-1-joannelkoong@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

noop_backing_dev_info is used by superblocks of various
pseudofilesystems such as kdevtmpfs. After commit 10e14073
("writeback: Fix inode->i_io_list not be protected by inode->i_lock
error") this broke because __mark_inode_dirty() started to access more
fields from noop_backing_dev_info and this led to crashes inside
locked_inode_to_wb_and_lock_list() called from __mark_inode_dirty().
Fix the problem by initializing noop_backing_dev_info before the
filesystems get mounted.

Fixes: 10e14073 ("writeback: Fix inode->i_io_list not be protected by inode->i_lock error")
Reported-and-tested-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Reported-and-tested-by: NAlexandru Elisei <alexandru.elisei@arm.com>
Reported-and-tested-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

There are reports that the console kthreads block the global console
lock when the system is going down, for example, reboot, panic.

First part of the solution was to block kthreads in these problematic
system states so they stopped handling newly added messages.

Second part of the solution is to wait when for the kthreads when
they are actively printing. It solves the problem when a message
was printed before the system entered the problematic state and
the kthreads managed to step in.

A busy waiting has to be used because panic() can be called in any
context and in an unknown state of the scheduler.

There must be a timeout because the kthread might get stuck or sleeping
and never release the lock. The timeout 10s is an arbitrary value
inspired by the softlockup timeout.

Link: https://lore.kernel.org/r/20220610205038.GA3050413@paulmck-ThinkPad-P17-Gen-1
Link: https://lore.kernel.org/r/CAMdYzYpF4FNTBPZsEFeWRuEwSies36QM_As8osPWZSr2q-viEA@mail.gmail.comSigned-off-by: NPetr Mladek <pmladek@suse.com>
Tested-by: NPaul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20220615162805.27962-3-pmladek@suse.com

Commit e81fb419 ("netfs: Further cleanups after struct netfs_inode
wrapper introduced") changed the argument types and names, and actually
updated the comment too (although that was thanks to David Howells, not
me: my original patch only changed the code).

But the comment fixup didn't go quite far enough, and didn't change the
argument name in the comment, resulting in

  include/linux/netfs.h:314: warning: Function parameter or member 'ctx' not described in 'netfs_inode_init'
  include/linux/netfs.h:314: warning: Excess function parameter 'inode' description in 'netfs_inode_init'

during htmldoc generation.

Fixes: e81fb419 ("netfs: Further cleanups after struct netfs_inode wrapper introduced")
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This partially reverts a7c41b46

Even though IORING_CLOSE_FD_AND_FILE_SLOT might save cycles for some
users, but it tries to do two things at a time and it's not clear how to
handle errors and what to return in a single result field when one part
fails and another completes well. Kill it for now.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/837c745019b3795941eee4fcfd7de697886d645b.1655224415.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The resource must be on the LRU before ttm_lru_bulk_move_add() is called
and we need to check if the BO is pinned or not before adding it.

Additional to that we missed taking the LRU spinlock in ttm_bo_unpin().
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NArunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Acked-by: NLuben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220613080816.4965-1-christian.koenig@amd.com
Fixes: fee2ede1 ("drm/ttm: rework bulk move handling v5")

vmalloc does not allocate a vm_struct for vm_map_ram() areas.  That causes
us to deny usercopies from those areas.  This affects XFS which uses
vm_map_ram() for its directories.

Fix this by calling find_vmap_area() instead of find_vm_area().

Fixes: 0aef499f ("mm/usercopy: Detect vmalloc overruns")
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NUladzislau Rezki (Sony) <urezki@gmail.com>
Tested-by: NZorro Lang <zlang@redhat.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220612213227.3881769-2-willy@infradead.org

The syntax without dots is available since commit 43756e34
("scripts/kernel-doc: Add support for named variable macro arguments").

The same HTML output is produced with and without this patch.
Signed-off-by: NJonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NTejun Heo <tj@kernel.org>

The netfs_io_request cleanup op is now always in a position to be given a
pointer to a netfs_io_request struct, so this can be passed in instead of
the mapping and private data arguments (both of which are included in the
struct).

So rename the ->cleanup op to ->free_request (to match ->init_request) and
pass in the I/O pointer.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com

Change the signature of netfs helper functions to take a struct netfs_inode
pointer rather than a struct inode pointer where appropriate, thereby
relieving the need for the network filesystem to convert its internal inode
format down to the VFS inode only for netfslib to bounce it back up.  For
type safety, it's better not to do that (and it's less typing too).

Give netfs_write_begin() an extra argument to pass in a pointer to the
netfs_inode struct rather than deriving it internally from the file
pointer.  Note that the ->write_begin() and ->write_end() ops are intended
to be replaced in the future by netfslib code that manages this without the
need to call in twice for each page.

netfs_readpage() and similar are intended to be pointed at directly by the
address_space_operations table, so must stick to the signature dictated by
the function pointers there.

Changes
=======
- Updated the kerneldoc comments and documentation [DH].
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/CAHk-=wgkwKyNmNdKpQkqZ6DnmUL-x9hp0YBnUGjaPFEAdxDTbw@mail.gmail.com/

The commit that removed the Unisys s-Par and visorbus drivers
left around the include/linux/visorbus.h file mentioned in the
MAINTAINERS entry, we can also remove that too.

Fixes: e5f45b01 ("staging: Remove the drivers for the Unisys s-Par")
Reviewed-by: NFabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: NPeter Robinson <pbrobinson@gmail.com>
Link: https://lore.kernel.org/r/20220606132200.2873243-1-pbrobinson@gmail.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.

In suspend sequence there is a need to perform stop_rx during suspend
sequence to prevent any asynchronous data over rx line. However this
can cause problem to drivers which dont do re-start_rx during set_termios.

Add new callback start_rx and perform stop_rx only when implementation of
start_rx is present. Also add call to start_rx in resume sequence so that
drivers who come across this problem can make use of this framework.

Fixes: c9d2325c ("serial: core: Do stop_rx in suspend path for console if console_suspend is disabled")
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NVijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>
Link: https://lore.kernel.org/r/1654627965-1461-2-git-send-email-quic_vnivarth@quicinc.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With arch randomness being used by every distro and enabled in
defconfigs, the distinction between rng_has_arch_random() and
rng_is_initialized() is now rather small. In fact, the places where they
differ are now places where paranoid users and system builders really
don't want arch randomness to be used, in which case we should respect
that choice, or places where arch randomness is known to be broken, in
which case that choice is all the more important. So this commit just
removes the function and its one user.

Reviewed-by: Petr Mladek <pmladek@suse.com> # for vsprintf.c
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>

add_bootloader_randomness() and the variables it touches are only used
during __init and not after, so mark these as __init. At the same time,
unexport this, since it's only called by other __init code that's
built-in.

Cc: stable@vger.kernel.org
Fixes: 428826f5 ("fdt: add support for rng-seed")
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>

To embrace possible future optimizations of TLS, rename zerocopy
sendfile definitions to more generic ones:

* setsockopt: TLS_TX_ZEROCOPY_SENDFILE- > TLS_TX_ZEROCOPY_RO
* sock_diag: TLS_INFO_ZC_SENDFILE -> TLS_INFO_ZC_RO_TX

RO stands for readonly and emphasizes that the application shouldn't
modify the data being transmitted with zerocopy to avoid potential
disconnection.

Fixes: c1318b39 ("tls: Add opt-in zerocopy mode of sendfile()")
Signed-off-by: NMaxim Mikityanskiy <maximmi@nvidia.com>
Link: https://lore.kernel.org/r/20220608153425.3151146-1-maximmi@nvidia.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

While randstruct was satisfied with using an open-coded "void *" offset
cast for the netfs_i_context <-> inode casting, __builtin_object_size() as
used by FORTIFY_SOURCE was not as easily fooled.  This was causing the
following complaint[1] from gcc v12:

  In file included from include/linux/string.h:253,
                   from include/linux/ceph/ceph_debug.h:7,
                   from fs/ceph/inode.c:2:
  In function 'fortify_memset_chk',
      inlined from 'netfs_i_context_init' at include/linux/netfs.h:326:2,
      inlined from 'ceph_alloc_inode' at fs/ceph/inode.c:463:2:
  include/linux/fortify-string.h:242:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
    242 |                         __write_overflow_field(p_size_field, size);
        |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix this by embedding a struct inode into struct netfs_i_context (which
should perhaps be renamed to struct netfs_inode).  The struct inode
vfs_inode fields are then removed from the 9p, afs, ceph and cifs inode
structs and vfs_inode is then simply changed to "netfs.inode" in those
filesystems.

Further, rename netfs_i_context to netfs_inode, get rid of the
netfs_inode() function that converted a netfs_i_context pointer to an
inode pointer (that can now be done with &ctx->inode) and rename the
netfs_i_context() function to netfs_inode() (which is now a wrapper
around container_of()).

Most of the changes were done with:

  perl -p -i -e 's/vfs_inode/netfs.inode/'g \
        `git grep -l 'vfs_inode' -- fs/{9p,afs,ceph,cifs}/*.[ch]`

Kees suggested doing it with a pair structure[2] and a special
declarator to insert that into the network filesystem's inode
wrapper[3], but I think it's cleaner to embed it - and then it doesn't
matter if struct randomisation reorders things.

Dave Chinner suggested using a filesystem-specific VFS_I() function in
each filesystem to convert that filesystem's own inode wrapper struct
into the VFS inode struct[4].

Version #2:
 - Fix a couple of missed name changes due to a disabled cifs option.
 - Rename nfs_i_context to nfs_inode
 - Use "netfs" instead of "nic" as the member name in per-fs inode wrapper
   structs.

[ This also undoes commit 507160f4 ("netfs: gcc-12: temporarily
  disable '-Wattribute-warning' for now") that is no longer needed ]

Fixes: bc899ee1 ("netfs: Add a netfs inode context")
Reported-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NXiubo Li <xiubli@redhat.com>
cc: Jonathan Corbet <corbet@lwn.net>
cc: Eric Van Hensbergen <ericvh@gmail.com>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Steve French <smfrench@gmail.com>
cc: William Kucharski <william.kucharski@oracle.com>
cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
cc: Dave Chinner <david@fromorbit.com>
cc: linux-doc@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: samba-technical@lists.samba.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-hardening@vger.kernel.org
Link: https://lore.kernel.org/r/d2ad3a3d7bdd794c6efb562d2f2b655fb67756b9.camel@kernel.org/ [1]
Link: https://lore.kernel.org/r/20220517210230.864239-1-keescook@chromium.org/ [2]
Link: https://lore.kernel.org/r/20220518202212.2322058-1-keescook@chromium.org/ [3]
Link: https://lore.kernel.org/r/20220524101205.GI2306852@dread.disaster.area/ [4]
Link: https://lore.kernel.org/r/165296786831.3591209.12111293034669289733.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165305805651.4094995.7763502506786714216.stgit@warthog.procyon.org.uk # v2
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix "./include/linux/mm_types.h:279: warning: Function parameter or member
'mlock_count' not described in 'folio'".  Also neaten the html by hiding
the anon struct.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

If xas_split_alloc() fails to allocate the necessary nodes to complete the
xarray entry split, it sets the xa_state to -ENOMEM, which xas_nomem()
then interprets as "Please allocate more memory", not as "Please free
any unnecessary memory" (which was the intended outcome).  It's confusing
to use xas_nomem() to free memory in this context, so call xas_destroy()
instead.

Reported-by: syzbot+9e27a75a8c24f3fe75c1@syzkaller.appspotmail.com
Fixes: 6b24ca4a ("mm: Use multi-index entries in the page cache")
Cc: stable@vger.kernel.org
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

Fix the `unused-but-set-variable` warning as how other iteration
wrappers do.

Link: https://lore.kernel.org/all/202206071049.pofHsRih-lkp@intel.com/Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NGONG, Ruiqi <gongruiqi1@huawei.com>
Signed-off-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220607110848.941486-1-gongruiqi1@huawei.com

This patch makes get_vq_group and set_group_asid optional. This is
needed to unbreak the vDPA parent that doesn't support multiple
address spaces.

Cc: Gautam Dawar <gautam.dawar@xilinx.com>
Fixes: aaca8373 ("vhost-vdpa: support ASID based IOTLB API")
Signed-off-by: NJason Wang <jasowang@redhat.com>
Message-Id: <20220609041901.2029-1-jasowang@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Unused now, and the interface never really made a whole lot of sense to
start with.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMike Snitzer <snitzer@kernel.org>

Resurrect ubsan overflow checks and ubsan report this warning,
fix it by change the variable [length] type to size_t.

UBSAN: signed-integer-overflow in net/ipv6/ip6_output.c:1489:19
2147479552 + 8567 cannot be represented in type 'int'
CPU: 0 PID: 253 Comm: err Not tainted 5.16.0+ #1
Hardware name: linux,dummy-virt (DT)
Call trace:
  dump_backtrace+0x214/0x230
  show_stack+0x30/0x78
  dump_stack_lvl+0xf8/0x118
  dump_stack+0x18/0x30
  ubsan_epilogue+0x18/0x60
  handle_overflow+0xd0/0xf0
  __ubsan_handle_add_overflow+0x34/0x44
  __ip6_append_data.isra.48+0x1598/0x1688
  ip6_append_data+0x128/0x260
  udpv6_sendmsg+0x680/0xdd0
  inet6_sendmsg+0x54/0x90
  sock_sendmsg+0x70/0x88
  ____sys_sendmsg+0xe8/0x368
  ___sys_sendmsg+0x98/0xe0
  __sys_sendmmsg+0xf4/0x3b8
  __arm64_sys_sendmmsg+0x34/0x48
  invoke_syscall+0x64/0x160
  el0_svc_common.constprop.4+0x124/0x300
  do_el0_svc+0x44/0xc8
  el0_svc+0x3c/0x1e8
  el0t_64_sync_handler+0x88/0xb0
  el0t_64_sync+0x16c/0x170

Changes since v1:
-Change the variable [length] type to unsigned, as Eric Dumazet suggested.
Changes since v2:
-Don't change exthdrlen type in ip6_make_skb, as Paolo Abeni suggested.
Changes since v3:
-Don't change ulen type in udpv6_sendmsg and l2tp_ip6_sendmsg, as
Jakub Kicinski suggested.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NWang Yufen <wangyufen@huawei.com>
Link: https://lore.kernel.org/r/20220607120028.845916-1-wangyufen@huawei.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Transitioning between encode buffers is quite infrequent. It happens
about 1 time in 400 calls to xdr_reserve_space(), measured on NFSD
with a typical build/test workload.

Force the compiler to remove that code from xdr_reserve_space(),
which is a hot path on both the server and the client. This change
reduces the size of xdr_reserve_space() from 10 cache lines to 2
when compiled with -Os.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NJ. Bruce Fields <bfields@fieldses.org>

The trace event "workqueue_queue_work" use unsigned int type for
req_cpu, cpu. This casue confusing cpu number like below log.

$ cat /sys/kernel/debug/tracing/trace
cat-317  [001] ...: workqueue_queue_work: ... req_cpu=8192 cpu=4294967295

So, change unsigned type to signed type in the trace event. After
applying this patch, cpu number will be printed as -1 instead of
4294967295 as folllows.

$ cat /sys/kernel/debug/tracing/trace
cat-1338  [002] ...: workqueue_queue_work: ... req_cpu=8192 cpu=-1

Cc: Baik Song An <bsahn@etri.re.kr>
Cc: Hong Yeon Kim <kimhy@etri.re.kr>
Cc: Taeung Song <taeung@reallinux.co.kr>
Cc: linuxgeek@linuxgeek.io
Signed-off-by: NWonhyuk Yang <vvghjk1234@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Since flush operation synchronously waits for completion, flushing
system-wide WQs (e.g. system_wq) might introduce possibility of deadlock
due to unexpected locking dependency. Tejun Heo commented at [1] that it
makes no sense at all to call flush_workqueue() on the shared WQs as the
caller has no idea what it's gonna end up waiting for.

Although there is flush_scheduled_work() which flushes system_wq WQ with
"Think twice before calling this function! It's very easy to get into
trouble if you don't take great care." warning message, syzbot found a
circular locking dependency caused by flushing system_wq WQ [2].

Therefore, let's change the direction to that developers had better use
their local WQs if flush_scheduled_work()/flush_workqueue(system_*_wq) is
inevitable.

Steps for converting system-wide WQs into local WQs are explained at [3],
and a conversion to stop flushing system-wide WQs is in progress. Now we
want some mechanism for preventing developers who are not aware of this
conversion from again start flushing system-wide WQs.

Since I found that WARN_ON() is complete but awkward approach for teaching
developers about this problem, let's use __compiletime_warning() for
incomplete but handy approach. For completeness, we will also insert
WARN_ON() into __flush_workqueue() after all in-tree users stopped calling
flush_scheduled_work().

Link: https://lore.kernel.org/all/YgnQGZWT%2Fn3VAITX@slm.duckdns.org/ [1]
Link: https://syzkaller.appspot.com/bug?extid=bde0f89deacca7c765b8 [2]
Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp [3]
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NTejun Heo <tj@kernel.org>

The code comment says that the polynomial is x^16 + x^12 + x^15 + 1, but
the correct polynomial is x^16 + x^12 + x^5 + 1. Quoting from page 2 in
the ITU-T V.41 specification [1]:

  2 Encoding and checking process

  The service bits and information bits, taken in conjunction,
  correspond to the coefficients of a message polynomial having terms
  from x^(n-1) (n = total number of bits in a block or sequence) down to
  x^16. This polynomial is divided, modulo 2, by the generating
  polynomial x^16 + x^12 + x^5 + 1.

The hex (truncated) polynomial 0x1021 and CRC code implementation are
correct, however.

[1] https://www.itu.int/rec/T-REC-V.41-198811-I/enSigned-off-by: NRoger Knecht <roger@norberthealth.com>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>

The file-wide OBJECT_FILES_NON_STANDARD annotation is used with
CONFIG_FRAME_POINTER to tell objtool to skip the entire file when frame
pointers are enabled.  However that annotation is now deprecated because
it doesn't work with IBT, where objtool runs on vmlinux.o instead of
individual translation units.

Instead, use more fine-grained function-specific annotations:

- The 'save_mcount_regs' macro does funny things with the frame pointer.
  Use STACK_FRAME_NON_STANDARD_FP to tell objtool to ignore the
  functions using it.

- The return_to_handler() "function" isn't actually a callable function.
  Instead of being called, it's returned to.  The real return address
  isn't on the stack, so unwinding is already doomed no matter which
  unwinder is used.  So just remove the STT_FUNC annotation, telling
  objtool to ignore it.  That also removes the implicit
  ANNOTATE_NOENDBR, which now needs to be made explicit.

Fixes the following warning:

  vmlinux.o: warning: objtool: __fentry__+0x16: return with modified stack frame

Fixes: ed53a0d9 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NJosh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/b7a7a42fe306aca37826043dac89e113a1acdbac.1654268610.git.jpoimboe@kernel.org

If user requests for NFT_CHAIN_HW_OFFLOAD, then check if either device
provides the .ndo_setup_tc interface or there is an indirect flow block
that has been registered. Otherwise, bail out early from the preparation
phase. Moreover, validate that family == NFPROTO_NETDEV and hook is
NF_NETDEV_INGRESS.

Fixes: c9626a2c ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

By assigning xen-grant DMA ops we will restrict memory access for
passed device using Xen grant mappings. This is needed for using any
virtualized device (e.g. virtio) in Xen guests in a safe manner.

Please note, for the virtio devices the XEN_VIRTIO config should
be enabled (it forces ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS).
Signed-off-by: NOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/1654197833-25362-9-git-send-email-olekstysh@gmail.comSigned-off-by: NJuergen Gross <jgross@suse.com>

Use the presence of "iommus" property pointed to the IOMMU node with
recently introduced "xen,grant-dma" compatible as a clear indicator
of enabling Xen grant mappings scheme for that device and read the ID
of Xen domain where the corresponding backend is running. The domid
(domain ID) is used as an argument to the Xen grant mapping APIs.

To avoid the deferred probe timeout which takes place after reusing
generic IOMMU device tree bindings (because the IOMMU device never
becomes available) enable recently introduced stub IOMMU driver by
selecting XEN_GRANT_DMA_IOMMU.

Also introduce xen_is_grant_dma_device() to check whether xen-grant
DMA ops need to be set for a passed device.

Remove the hardcoded domid 0 in xen_grant_setup_dma_ops().
Signed-off-by: NOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/1654197833-25362-8-git-send-email-olekstysh@gmail.comSigned-off-by: NJuergen Gross <jgross@suse.com>

In order to support virtio in Xen guests add a config option XEN_VIRTIO
enabling the user to specify whether in all Xen guests virtio should
be able to access memory via Xen grant mappings only on the host side.

Also set PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS feature from the guest
initialization code on Arm and x86 if CONFIG_XEN_VIRTIO is enabled.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/1654197833-25362-5-git-send-email-olekstysh@gmail.comSigned-off-by: NJuergen Gross <jgross@suse.com>

Introduce Xen grant DMA-mapping layer which contains special DMA-mapping
routines for providing grant references as DMA addresses to be used by
frontends (e.g. virtio) in Xen guests.

Add the needed functionality by providing a special set of DMA ops
handling the needed grant operations for the I/O pages.

The subsequent commit will introduce the use case for xen-grant DMA ops
layer to enable using virtio devices in Xen guests in a safe manner.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/1654197833-25362-4-git-send-email-olekstysh@gmail.comSigned-off-by: NJuergen Gross <jgross@suse.com>

For support of virtio via grant mappings in rare cases larger mappings
using consecutive grants are needed. Support those by adding a bitmap
of free grants.

As consecutive grants will be needed only in very rare cases (e.g. when
configuring a virtio device with a multi-page ring), optimize for the
normal case of non-consecutive allocations.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/1654197833-25362-3-git-send-email-olekstysh@gmail.comSigned-off-by: NJuergen Gross <jgross@suse.com>