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netdev_warn_once()
We should warn user-space that it is doing something wrong when trying
to activate sessions with identical parameters but WARN_ON_ONCE macro
can not be used here as it serves a different purpose.
So it would be good to replace it with netdev_warn_once() message.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Fedor Pchelkin <[email protected]>
Signed-off-by: Alexey Khoroshilov <[email protected]>
Acked-by: Oleksij Rempel <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
[mkl: fix indention]
Signed-off-by: Marc Kleine-Budde <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth
Luiz Augusto von Dentz says:
====================
bluetooth pull request for net:
- Fixes various issues related to ISO channel/socket support
- Fixes issues when building with C=1
- Fix cancel uninitilized work which blocks syzbot to run
* tag 'for-net-2022-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
Bluetooth: ISO: Fix not using the correct QoS
Bluetooth: don't try to cancel uninitialized works at mgmt_index_removed()
Bluetooth: ISO: Fix iso_sock_getsockopt for BT_DEFER_SETUP
Bluetooth: MGMT: Fixes build warnings with C=1
Bluetooth: hci_event: Fix build warning with C=1
Bluetooth: ISO: Fix memory corruption
Bluetooth: Fix null pointer deref on unexpected status event
Bluetooth: ISO: Fix info leak in iso_sock_getsockopt()
Bluetooth: hci_conn: Fix updating ISO QoS PHY
Bluetooth: ISO: unlock on error path in iso_sock_setsockopt()
Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression
====================
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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Since
commit e6e771b3d897 ("s390/qeth: detach netdevice while card is offline")
there was a timing window during recovery, that qeth_query_card_info could
be sent to the card, even before it was ready for it, leading to a failing
card recovery. There is evidence that this window was hit, as not all
callers of get_link_ksettings() check for netif_device_present.
Use cached values in qeth_get_link_ksettings(), instead of calling
qeth_query_card_info() and falling back to default values in case it
fails. Link info is already updated when the card goes online, e.g. after
STARTLAN (physical link up). Set the link info to default values, when the
card goes offline or at STOPLAN (physical link down). A follow-on patch
will improve values reported for link down.
Fixes: e6e771b3d897 ("s390/qeth: detach netdevice while card is offline")
Signed-off-by: Alexandra Winter <[email protected]>
Reviewed-by: Thorsten Winkler <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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If CONFIG_NVMEM is not set of_nvmem_cell_get, of_nvmem_device_get
functions will return ERR_PTR(-EOPNOTSUPP) and "failed to get nvmem
cell io_impedance_ctrl" error would be reported despite "io_impedance_ctrl"
is completely missing in Device Tree and we should use default values.
Check -EOPNOTSUPP togather with -ENOENT to avoid this situation.
Fixes: 5c2d0a6a0701 ("net: phy: dp83867: implement support for io_impedance_ctrl nvmem cell")
Signed-off-by: Nikita Shubin <[email protected]>
Acked-by: Rasmus Villemoes <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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specified
In case master/slave clock role is not specified (which is default), the
aneg registers will not be written.
The visible impact of this is missing pause advertisement.
So, rework genphy_c45_baset1_an_config_aneg() to be able to write
advertisement registers even if clock role is unknown.
Fixes: 3da8ffd8545f ("net: phy: Add 10BASE-T1L support in phy-c45")
Signed-off-by: Oleksij Rempel <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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There are use-after-free bugs caused by tst_timer. The root cause
is that there are no functions to stop tst_timer in idt77252_exit().
One of the possible race conditions is shown below:
(thread 1) | (thread 2)
| idt77252_init_one
| init_card
| fill_tst
| mod_timer(&card->tst_timer, ...)
idt77252_exit | (wait a time)
| tst_timer
|
| ...
kfree(card) // FREE |
| card->soft_tst[e] // USE
The idt77252_dev is deallocated in idt77252_exit() and used in
timer handler.
This patch adds del_timer_sync() in idt77252_exit() in order that
the timer handler could be stopped before the idt77252_dev is
deallocated.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Duoming Zhou <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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closed
min_gate_len[tc] is supposed to track the shortest interval of
continuously open gates for a traffic class. For example, in the
following case:
TC 76543210
t0 00000001b 200000 ns
t1 00000010b 200000 ns
min_gate_len[0] and min_gate_len[1] should be 200000, while
min_gate_len[2-7] should be 0.
However what happens is that min_gate_len[0] is 200000, but
min_gate_len[1] ends up being 0 (despite gate_len[1] being 200000 at the
point where the logic detects the gate close event for TC 1).
The problem is that the code considers a "gate close" event whenever it
sees that there is a 0 for that TC (essentially it's level rather than
edge triggered). By doing that, any time a gate is seen as closed
without having been open prior, gate_len, which is 0, will be written
into min_gate_len. Once min_gate_len becomes 0, it's impossible for it
to track anything higher than that (the length of actually open
intervals).
To fix this, we make the writing to min_gate_len[tc] be edge-triggered,
which avoids writes for gates that are closed in consecutive intervals.
However what this does is it makes us need to special-case the
permanently closed gates at the end.
Fixes: 55a515b1f5a9 ("net: dsa: felix: drop oversized frames with tc-taprio instead of hanging the port")
Signed-off-by: Vladimir Oltean <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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When a userspace application starts a blocking connect(), a CALL REQUEST
is sent, the t21 timer is started and the connect is waiting in
x25_wait_for_connection_establishment(). If then for some reason the t21
timer expires before any reaction on the assigned logical channel (e.g.
CALL ACCEPT, CLEAR REQUEST), there is sent a CLEAR REQUEST and timer
t23 is started waiting for a CLEAR confirmation. If we now receive a
CLEAR CONFIRMATION from the peer, x25_disconnect() is called in
x25_state2_machine() with reason "0", which means "normal" call
clearing. This is ok, but the parameter "reason" is used as sk->sk_err
in x25_disconnect() and sock_error(sk) is evaluated in
x25_wait_for_connection_establishment() to check if the call is still
pending. As "0" is not rated as an error, the connect will stuck here
forever.
To fix this situation, also check if the sk->sk_state changed form
TCP_SYN_SENT to TCP_CLOSE in the meantime, which is also done by
x25_disconnect().
Signed-off-by: Martin Schiller <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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Gerhard Engleder says:
====================
tsnep: Two fixes for the driver
Two simple bugfixes for tsnep driver.
====================
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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If tsnep_tx_map() fails, then tsnep_tx_unmap() shall start at the write
index like tsnep_tx_map(). This is different to the normal operation.
Thus, add an additional parameter to tsnep_tx_unmap() to enable start at
different positions for successful TX and failed TX.
Fixes: 403f69bbdbad ("tsnep: Add TSN endpoint Ethernet MAC driver")
Signed-off-by: Gerhard Engleder <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
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Kernel test robot found the following warning:
drivers/net/ethernet/engleder/tsnep_main.c:1254:34: warning:
'tsnep_of_match' defined but not used [-Wunused-const-variable=]
of_match_ptr() compiles into NULL if CONFIG_OF is disabled.
tsnep_of_match exists always so use of of_match_ptr() is useless.
Fix warning by dropping of_match_ptr().
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Gerhard Engleder <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
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Pull ksmbd updates from Steve French:
- fixes for memory access bugs (out of bounds access, oops, leak)
- multichannel fixes
- session disconnect performance improvement, and session register
improvement
- cleanup
* tag '5.20-rc-ksmbd-server-fixes' of git://git.samba.org/ksmbd:
ksmbd: fix heap-based overflow in set_ntacl_dacl()
ksmbd: prevent out of bound read for SMB2_TREE_CONNNECT
ksmbd: prevent out of bound read for SMB2_WRITE
ksmbd: fix use-after-free bug in smb2_tree_disconect
ksmbd: fix memory leak in smb2_handle_negotiate
ksmbd: fix racy issue while destroying session on multichannel
ksmbd: use wait_event instead of schedule_timeout()
ksmbd: fix kernel oops from idr_remove()
ksmbd: add channel rwlock
ksmbd: replace sessions list in connection with xarray
MAINTAINERS: ksmbd: add entry for documentation
ksmbd: remove unused ksmbd_share_configs_cleanup function
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more iov_iter updates from Al Viro:
- more new_sync_{read,write}() speedups - ITER_UBUF introduction
- ITER_PIPE cleanups
- unification of iov_iter_get_pages/iov_iter_get_pages_alloc and
switching them to advancing semantics
- making ITER_PIPE take high-order pages without splitting them
- handling copy_page_from_iter() for high-order pages properly
* tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits)
fix copy_page_from_iter() for compound destinations
hugetlbfs: copy_page_to_iter() can deal with compound pages
copy_page_to_iter(): don't split high-order page in case of ITER_PIPE
expand those iov_iter_advance()...
pipe_get_pages(): switch to append_pipe()
get rid of non-advancing variants
ceph: switch the last caller of iov_iter_get_pages_alloc()
9p: convert to advancing variant of iov_iter_get_pages_alloc()
af_alg_make_sg(): switch to advancing variant of iov_iter_get_pages()
iter_to_pipe(): switch to advancing variant of iov_iter_get_pages()
block: convert to advancing variants of iov_iter_get_pages{,_alloc}()
iov_iter: advancing variants of iov_iter_get_pages{,_alloc}()
iov_iter: saner helper for page array allocation
fold __pipe_get_pages() into pipe_get_pages()
ITER_XARRAY: don't open-code DIV_ROUND_UP()
unify the rest of iov_iter_get_pages()/iov_iter_get_pages_alloc() guts
unify xarray_get_pages() and xarray_get_pages_alloc()
unify pipe_get_pages() and pipe_get_pages_alloc()
iov_iter_get_pages(): sanity-check arguments
iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper
...
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had been broken for ITER_BVEC et.al. since ever (OK, v3.17 when
ITER_BVEC had first appeared)...
Signed-off-by: Al Viro <[email protected]>
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... since April 2021
Signed-off-by: Al Viro <[email protected]>
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... just shove it into one pipe_buffer.
Signed-off-by: Al Viro <[email protected]>
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Signed-off-by: Al Viro <[email protected]>
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now that we are advancing the iterator, there's no need to
treat the first page separately - just call append_pipe()
in a loop.
Signed-off-by: Al Viro <[email protected]>
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mechanical change; will be further massaged in subsequent commits
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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here nothing even looks at the iov_iter after the call, so we couldn't
care less whether it advances or not.
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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that one is somewhat clumsier than usual and needs serious testing.
Signed-off-by: Al Viro <[email protected]>
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... and adjust the callers
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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... and untangle the cleanup on failure to add into pipe.
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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... doing revert if we end up not using some pages
Signed-off-by: Al Viro <[email protected]>
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Most of the users immediately follow successful iov_iter_get_pages()
with advancing by the amount it had returned.
Provide inline wrappers doing that, convert trivial open-coded
uses of those.
BTW, iov_iter_get_pages() never returns more than it had been asked
to; such checks in cifs ought to be removed someday...
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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All call sites of get_pages_array() are essenitally identical now.
Replace with common helper...
Returns number of slots available in resulting array or 0 on OOM;
it's up to the caller to make sure it doesn't ask to zero-entry
array (i.e. neither maxpages nor size are allowed to be zero).
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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... and don't mangle maxsize there - turn the loop into counting
one instead. Easier to see that we won't run out of array that
way. Note that special treatment of the partial buffer in that
thing is an artifact of the non-advancing semantics of
iov_iter_get_pages() - if not for that, it would be append_pipe(),
same as the body of the loop that follows it. IOW, once we make
iov_iter_get_pages() advancing, the whole thing will turn into
calculate how many pages do we want
allocate an array (if needed)
call append_pipe() that many times.
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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same as for pipes and xarrays; after that iov_iter_get_pages() becomes
a wrapper for __iov_iter_get_pages_alloc().
Signed-off-by: Al Viro <[email protected]>
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same as for pipes
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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The differences between those two are
* pipe_get_pages() gets a non-NULL struct page ** value pointing to
preallocated array + array size.
* pipe_get_pages_alloc() gets an address of struct page ** variable that
contains NULL, allocates the array and (on success) stores its address in
that variable.
Not hard to combine - always pass struct page ***, have
the previous pipe_get_pages_alloc() caller pass ~0U as cap for
array size.
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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zero maxpages is bogus, but best treated as "just return 0";
NULL pages, OTOH, should be treated as a hard bug.
get rid of now completely useless checks in xarray_get_pages{,_alloc}().
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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wrapper
Incidentally, ITER_XARRAY did *not* free the sucker in case when
iter_xarray_populate_pages() returned 0...
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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All their callers are next to each other; all of them
want the total amount of pages and, possibly, the
offset in the partial final buffer.
Combine into a new helper (pipe_npages()), fix the
bogosity in pipe_space_for_user(), while we are at it.
Signed-off-by: Al Viro <[email protected]>
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We often need to find whether the last buffer is anon or not, and
currently it's rather clumsy:
check if ->iov_offset is non-zero (i.e. that pipe is not empty)
if so, get the corresponding pipe_buffer and check its ->ops
if it's &default_pipe_buf_ops, we have an anon buffer.
Let's replace the use of ->iov_offset (which is nowhere near similar to
its role for other flavours) with signed field (->last_offset), with
the following rules:
empty, no buffers occupied: 0
anon, with bytes up to N-1 filled: N
zero-copy, with bytes up to N-1 filled: -N
That way abs(i->last_offset) is equal to what used to be in i->iov_offset
and empty vs. anon vs. zero-copy can be distinguished by the sign of
i->last_offset.
Checks for "should we extend the last buffer or should we start
a new one?" become easier to follow that way.
Note that most of the operations can only be done in a sane
state - i.e. when the pipe has nothing past the current position of
iterator. About the only thing that could be done outside of that
state is iov_iter_advance(), which transitions to the sane state by
truncating the pipe. There are only two cases where we leave the
sane state:
1) iov_iter_get_pages()/iov_iter_get_pages_alloc(). Will be
dealt with later, when we make get_pages advancing - the callers are
actually happier that way.
2) iov_iter copied, then something is put into the copy. Since
they share the underlying pipe, the original gets behind. When we
decide that we are done with the copy (original is not usable until then)
we advance the original. direct_io used to be done that way; nowadays
it operates on the original and we do iov_iter_revert() to discard
the excessive data. At the moment there's nothing in the kernel that
could do that to ITER_PIPE iterators, so this reason for insane state
is theoretical right now.
Signed-off-by: Al Viro <[email protected]>
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Fold pipe_truncate() into it, clean up. We can release buffers
in the same loop where we walk backwards to the iterator beginning
looking for the place where the new position will be.
Signed-off-by: Al Viro <[email protected]>
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instead of setting ->iov_offset for new position and calling
pipe_truncate() to adjust ->len of the last buffer and discard
everything after it, adjust ->len at the same time we set ->iov_offset
and use pipe_discard_from() to deal with buffers past that.
Signed-off-by: Al Viro <[email protected]>
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it's only used to get to the partial buffer we can add to,
and that's always the last one, i.e. pipe->head - 1.
Signed-off-by: Al Viro <[email protected]>
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Expand the only remaining call of push_pipe() (in
__pipe_get_pages()), combine it with the page-collecting loop there.
Note that the only reason it's not a loop doing append_pipe() is
that append_pipe() is advancing, while iov_iter_get_pages() is not.
As soon as it switches to saner semantics, this thing will switch
to using append_pipe().
Signed-off-by: Al Viro <[email protected]>
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New helper: append_pipe(). Extends the last buffer if possible,
allocates a new one otherwise. Returns page and offset in it
on success, NULL on failure. iov_iter is advanced past the
data we've got.
Use that instead of push_pipe() in copy-to-pipe primitives;
they get simpler that way. Handling of short copy (in "mc" one)
is done simply by iov_iter_revert() - iov_iter is in consistent
state after that one, so we can use that.
[Fix for braino caught by Liu Xinpeng <[email protected]> folded in]
[another braino fix, this time in copy_pipe_to_iter() and pipe_zero();
caught by testcase from Hugh Dickins]
Signed-off-by: Al Viro <[email protected]>
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There are only two kinds of pipe_buffer in the area used by ITER_PIPE.
1) anonymous - copy_to_iter() et.al. end up creating those and copying
data there. They have zero ->offset, and their ->ops points to
default_pipe_page_ops.
2) zero-copy ones - those come from copy_page_to_iter(), and page
comes from caller. ->offset is also caller-supplied - it might be
non-zero. ->ops points to page_cache_pipe_buf_ops.
Move creation and insertion of those into helpers - push_anon(pipe, size)
and push_page(pipe, page, offset, size) resp., separating them from
the "could we avoid creating a new buffer by merging with the current
head?" logics.
Acked-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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pipe_buffer instances of a pipe are organized as a ring buffer,
with power-of-2 size. Indices are kept *not* reduced modulo ring
size, so the buffer refered to by index N is
pipe->bufs[N & (pipe->ring_size - 1)].
Ring size can change over the lifetime of a pipe, but not while
the pipe is locked. So for any iov_iter primitives it's a constant.
Original conversion of pipes to this layout went overboard trying
to microoptimize that - calculating pipe->ring_size - 1, storing
it in a local variable and using through the function. In some
cases it might be warranted, but most of the times it only
obfuscates what's going on in there.
Introduce a helper (pipe_buf(pipe, N)) that would encapsulate
that and use it in the obvious cases. More will follow...
Reviewed-by: Jeff Layton <[email protected]>
Reviewed-by: Christian Brauner (Microsoft) <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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Use pipe_discard_from() explicitly in generic_file_read_iter(); don't bother
with rather non-obvious use of iov_iter_advance() in there.
Reviewed-by: Jeff Layton <[email protected]>
Reviewed-by: Christian Brauner (Microsoft) <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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Reviewed-by: Christian Brauner (Microsoft) <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(),
checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC
ones.
We are going to expose the things like ->write_iter() et.al. to those
in subsequent commits.
New predicate (user_backed_iter()) that is true for ITER_IOVEC and
ITER_UBUF; places like direct-IO handling should use that for
checking that pages we modify after getting them from iov_iter_get_pages()
would need to be dirtied.
DO NOT assume that replacing iter_is_iovec() with user_backed_iter()
will solve all problems - there's code that uses iter_is_iovec() to
decide how to poke around in iov_iter guts and for that the predicate
replacement obviously won't suffice.
Signed-off-by: Al Viro <[email protected]>
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What happens if a thread is preempted after mapping pages with
kmap_local_page() was questioned recently.[1]
Commit f3ba3c710ac5 ("mm/highmem: Provide kmap_local*") from Thomas
Gleixner explains clearly that on context switch, the maps of an outgoing
task are removed and the map of the incoming task are restored and that
kmap_local_page() can be invoked from both preemptible and atomic
contexts.[2]
Therefore, for the purpose to make it clearer that users can call
kmap_local_page() from contexts that allow preemption, rework a couple of
sentences and add further information in highmem.rst.
[1] https://lore.kernel.org/lkml/5303077.Sb9uPGUboI@opensuse/
[2] https://lore.kernel.org/all/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Fabio M. De Francesco <[email protected]>
Suggested-by: Ira Weiny <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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kmap_local_page() should always be preferred in place of kmap() and
kmap_atomic(). "Only use when really necessary." is not consistent with
the Documentation/mm/highmem.rst and these kdocs it embeds.
Therefore, delete the above-mentioned sentence from kdocs.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Fabio M. De Francesco <[email protected]>
Suggested-by: Ira Weiny <[email protected]>
Reviewed-by: Ira Weiny <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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The reasoning for converting kmap() to kmap_local_page() was questioned
recently.[1]
There are two main problems with kmap(): (1) It comes with an overhead as
mapping space is restricted and protected by a global lock for
synchronization and (2) kmap() also requires global TLB invalidation when
its pool wraps and it might block when the mapping space is fully utilized
until a slot becomes available.
Warn users to avoid the use of kmap() and instead use kmap_local_page(),
by designing their code to map pages in the same context the mapping will
be used.
[1] https://lore.kernel.org/lkml/1891319.taCxCBeP46@opensuse/
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Fabio M. De Francesco <[email protected]>
Suggested-by: Ira Weiny <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Users of kmap_local_page() must be absolutely sure to not hand kernel
virtual address obtained calling kmap_local_page() on highmem pages to
other contexts because those pointers are thread local, therefore, they
are no longer valid across different contexts.
Extend the documentation of kmap_local_page() to warn users about the
above-mentioned potential invalid use of pointers returned by
kmap_local_page().
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Fabio M. De Francesco <[email protected]>
Suggested-by: Ira Weiny <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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There is no need to kmap*() pages which are guaranteed to come from
ZONE_NORMAL (or lower). Linux has currently several call sites of
kmap{,_atomic,_local_page}() on pages which are clearly known which can't
come from ZONE_HIGHMEM.
Therefore, add a paragraph to highmem.rst, to explain better that a plain
page_address() may be used for getting the address of pages which cannot
come from ZONE_HIGHMEM, although it is always safe to use
kmap_local_page() / kunmap_local() also on those pages.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Fabio M. De Francesco <[email protected]>
Suggested-by: Ira Weiny <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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