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2022-08-08net: phy: c45 baset1: do not skip aneg configuration if clock role is not ↵Oleksij Rempel
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 <o.rempel@pengutronix.de> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20220805073159.908643-1-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-08atm: idt77252: fix use-after-free bugs caused by tst_timerDuoming Zhou
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 <duoming@zju.edu.cn> Link: https://lore.kernel.org/r/20220805070008.18007-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-08net: dsa: felix: fix min gate len calculation for tc when its first gate is ↵Vladimir Oltean
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 <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20220804202817.1677572-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-08net/x25: fix call timeouts in blocking connectsMartin Schiller
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 <ms@dev.tdt.de> Link: https://lore.kernel.org/r/20220805061810.10824-1-ms@dev.tdt.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-08Merge branch 'tsnep-two-fixes-for-the-driver'Jakub Kicinski
Gerhard Engleder says: ==================== tsnep: Two fixes for the driver Two simple bugfixes for tsnep driver. ==================== Link: https://lore.kernel.org/r/20220804183935.73763-1-gerhard@engleder-embedded.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-08tsnep: Fix tsnep_tx_unmap() error path usageGerhard Engleder
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 <gerhard@engleder-embedded.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-08tsnep: Fix unused warning for 'tsnep_of_match'Gerhard Engleder
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 <lkp@intel.com> Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-08Merge tag '5.20-rc-ksmbd-server-fixes' of git://git.samba.org/ksmbdLinus Torvalds
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
2022-08-08Merge tag 'pull-work.iov_iter-rebased' of ↵Linus Torvalds
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 ...
2022-08-08fix copy_page_from_iter() for compound destinationsAl Viro
had been broken for ITER_BVEC et.al. since ever (OK, v3.17 when ITER_BVEC had first appeared)... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08hugetlbfs: copy_page_to_iter() can deal with compound pagesAl Viro
... since April 2021 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08copy_page_to_iter(): don't split high-order page in case of ITER_PIPEAl Viro
... just shove it into one pipe_buffer. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08expand those iov_iter_advance()...Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08pipe_get_pages(): switch to append_pipe()Al Viro
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 <viro@zeniv.linux.org.uk>
2022-08-08get rid of non-advancing variantsAl Viro
mechanical change; will be further massaged in subsequent commits Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08ceph: switch the last caller of iov_iter_get_pages_alloc()Al Viro
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 <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-089p: convert to advancing variant of iov_iter_get_pages_alloc()Al Viro
that one is somewhat clumsier than usual and needs serious testing. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08af_alg_make_sg(): switch to advancing variant of iov_iter_get_pages()Al Viro
... and adjust the callers Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08iter_to_pipe(): switch to advancing variant of iov_iter_get_pages()Al Viro
... and untangle the cleanup on failure to add into pipe. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08block: convert to advancing variants of iov_iter_get_pages{,_alloc}()Al Viro
... doing revert if we end up not using some pages Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08iov_iter: advancing variants of iov_iter_get_pages{,_alloc}()Al Viro
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 <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08iov_iter: saner helper for page array allocationAl Viro
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 <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08fold __pipe_get_pages() into pipe_get_pages()Al Viro
... 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 <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08ITER_XARRAY: don't open-code DIV_ROUND_UP()Al Viro
Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08unify the rest of iov_iter_get_pages()/iov_iter_get_pages_alloc() gutsAl Viro
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 <viro@zeniv.linux.org.uk>
2022-08-08unify xarray_get_pages() and xarray_get_pages_alloc()Al Viro
same as for pipes Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08unify pipe_get_pages() and pipe_get_pages_alloc()Al Viro
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 <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08iov_iter_get_pages(): sanity-check argumentsAl Viro
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 <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into ↵Al Viro
wrapper Incidentally, ITER_XARRAY did *not* free the sucker in case when iter_xarray_populate_pages() returned 0... Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: fold data_start() and pipe_space_for_user() togetherAl Viro
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 <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: cache the type of last bufferAl Viro
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 <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: clean iov_iter_revert()Al Viro
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 <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: clean pipe_advance() upAl Viro
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 <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: lose iter_head argument of __pipe_get_pages()Al Viro
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 <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: fold push_pipe() into __pipe_get_pages()Al Viro
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 <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: allocate buffers as we go in copy-to-pipe primitivesAl Viro
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 <liuxp11@chinatelecom.cn> 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 <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: helpers for adding pipe buffersAl Viro
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 <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: helper for getting pipe buffer by indexAl Viro
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 <jlayton@kernel.org> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08splice: stop abusing iov_iter_advance() to flush a pipeAl Viro
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 <jlayton@kernel.org> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08switch new_sync_{read,write}() to ITER_UBUFAl Viro
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08new iov_iter flavour - ITER_UBUFAl Viro
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 <viro@zeniv.linux.org.uk>
2022-08-08Documentation/mm: add details about kmap_local_page() and preemptionFabio M. De Francesco
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/20201118204007.468533059@linutronix.de/ Link: https://lkml.kernel.org/r/20220728154844.10874-8-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08highmem: delete a sentence from kmap_local_page() kdocsFabio M. De Francesco
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/20220728154844.10874-7-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08Documentation/mm: rrefer kmap_local_page() and avoid kmap()Fabio M. De Francesco
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/20220728154844.10874-6-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08Documentation/mm: avoid invalid use of addresses from kmap_local_page()Fabio M. De Francesco
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/20220728154844.10874-5-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08Documentation/mm: don't kmap*() pages which can't come from HIGHMEMFabio M. De Francesco
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/20220728154844.10874-4-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08highmem: specify that kmap_local_page() is callable from interruptsFabio M. De Francesco
In a recent thread about converting kmap() to kmap_local_page(), the safety of calling kmap_local_page() was questioned.[1] "any context" should probably be enough detail for users who want to know whether or not kmap_local_page() can be called from interrupts. However, Linux still has kmap_atomic() which might make users think they must use the latter in interrupts. Add "including interrupts" for better clarity. [1] https://lore.kernel.org/lkml/3187836.aeNJFYEL58@opensuse/ Link: https://lkml.kernel.org/r/20220728154844.10874-3-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08highmem: remove unneeded spaces in kmap_local_page() kdocsFabio M. De Francesco
Patch series "highmem: Extend kmap_local_page() documentation", v2. The Highmem interface is evolving and the current documentation does not reflect the intended uses of each of the calls. Furthermore, after a recent series of reworks, the differences of the calls can still be confusing and may lead to the expanded use of calls which are deprecated. This series is the second round of changes towards an enhanced documentation of the Highmem's interface; at this stage the patches are only focused to kmap_local_page(). In addition it also contains some minor clean ups. This patch (of 7): In the kdocs of kmap_local_page(), the description of @page starts after several unnecessary spaces. Therefore, remove those spaces. Link: https://lkml.kernel.org/r/20220728154844.10874-1-fmdefrancesco@gmail.com Link: https://lkml.kernel.org/r/20220728154844.10874-2-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08mm, hwpoison: enable memory error handling on 1GB hugepageNaoya Horiguchi
Now error handling code is prepared, so remove the blocking code and enable memory error handling on 1GB hugepage. Link: https://lkml.kernel.org/r/20220714042420.1847125-9-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08mm, hwpoison: skip raw hwpoison page in freeing 1GB hugepageNaoya Horiguchi
Currently if memory_failure() (modified to remove blocking code with subsequent patch) is called on a page in some 1GB hugepage, memory error handling fails and the raw error page gets into leaked state. The impact is small in production systems (just leaked single 4kB page), but this limits the testability because unpoison doesn't work for it. We can no longer create 1GB hugepage on the 1GB physical address range with such leaked pages, that's not useful when testing on small systems. When a hwpoison page in a 1GB hugepage is handled, it's caught by the PageHWPoison check in free_pages_prepare() because the 1GB hugepage is broken down into raw error pages before coming to this point: if (unlikely(PageHWPoison(page)) && !order) { ... return false; } Then, the page is not sent to buddy and the page refcount is left 0. Originally this check is supposed to work when the error page is freed from page_handle_poison() (that is called from soft-offline), but now we are opening another path to call it, so the callers of __page_handle_poison() need to handle the case by considering the return value 0 as success. Then page refcount for hwpoison is properly incremented so unpoison works. Link: https://lkml.kernel.org/r/20220714042420.1847125-8-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>