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2022-11-189p/fd: Use P9_HDRSZ for header sizeGUO Zihua1-3/+3
Cleanup hardcoded header sizes to use P9_HDRSZ instead of '7' Link: https://lkml.kernel.org/r/20221117091159.31533-4-guozihua@huawei.com Signed-off-by: GUO Zihua <guozihua@huawei.com> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> [Dominique: commit message adjusted to make sense after offset size adjustment got removed] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-11-189p/fd: Fix write overflow in p9_read_workGUO Zihua1-8/+8
This error was reported while fuzzing: BUG: KASAN: slab-out-of-bounds in _copy_to_iter+0xd35/0x1190 Write of size 4043 at addr ffff888008724eb1 by task kworker/1:1/24 CPU: 1 PID: 24 Comm: kworker/1:1 Not tainted 6.1.0-rc5-00002-g1adf73218daa-dirty #223 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 Workqueue: events p9_read_work Call Trace: <TASK> dump_stack_lvl+0x4c/0x64 print_report+0x178/0x4b0 kasan_report+0xae/0x130 kasan_check_range+0x179/0x1e0 memcpy+0x38/0x60 _copy_to_iter+0xd35/0x1190 copy_page_to_iter+0x1d5/0xb00 pipe_read+0x3a1/0xd90 __kernel_read+0x2a5/0x760 kernel_read+0x47/0x60 p9_read_work+0x463/0x780 process_one_work+0x91d/0x1300 worker_thread+0x8c/0x1210 kthread+0x280/0x330 ret_from_fork+0x22/0x30 </TASK> Allocated by task 457: kasan_save_stack+0x1c/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x7e/0x90 __kmalloc+0x59/0x140 p9_fcall_init.isra.11+0x5d/0x1c0 p9_tag_alloc+0x251/0x550 p9_client_prepare_req+0x162/0x350 p9_client_rpc+0x18d/0xa90 p9_client_create+0x670/0x14e0 v9fs_session_init+0x1fd/0x14f0 v9fs_mount+0xd7/0xaf0 legacy_get_tree+0xf3/0x1f0 vfs_get_tree+0x86/0x2c0 path_mount+0x885/0x1940 do_mount+0xec/0x100 __x64_sys_mount+0x1a0/0x1e0 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd This BUG pops up when trying to reproduce https://syzkaller.appspot.com/bug?id=6c7cd46c7bdd0e86f95d26ec3153208ad186f9fa The callstack is different but the issue is valid and re-producable with the same re-producer in the link. The root cause of this issue is that we check the size of the message received against the msize of the client in p9_read_work. However, it turns out that capacity is no longer consistent with msize. Thus, the message size should be checked against sdata capacity. As the msize is non-consistant with the capacity of the tag and as we are now checking message size against capacity directly, there is no point checking message size against msize. So remove it. Link: https://lkml.kernel.org/r/20221117091159.31533-2-guozihua@huawei.com Link: https://lkml.kernel.org/r/20221117091159.31533-3-guozihua@huawei.com Reported-by: syzbot+0f89bd13eaceccc0e126@syzkaller.appspotmail.com Fixes: 60ece0833b6c ("net/9p: allocate appropriate reduced message buffers") Signed-off-by: GUO Zihua <guozihua@huawei.com> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> [Dominique: squash patches 1 & 2 and fix size including header part] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-11-189p/fd: fix issue of list_del corruption in p9_fd_cancel()Zhengchao Shao1-0/+2
Syz reported the following issue: kernel BUG at lib/list_debug.c:53! invalid opcode: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:__list_del_entry_valid.cold+0x5c/0x72 Call Trace: <TASK> p9_fd_cancel+0xb1/0x270 p9_client_rpc+0x8ea/0xba0 p9_client_create+0x9c0/0xed0 v9fs_session_init+0x1e0/0x1620 v9fs_mount+0xba/0xb80 legacy_get_tree+0x103/0x200 vfs_get_tree+0x89/0x2d0 path_mount+0x4c0/0x1ac0 __x64_sys_mount+0x33b/0x430 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK> The process is as follows: Thread A: Thread B: p9_poll_workfn() p9_client_create() ... ... p9_conn_cancel() p9_fd_cancel() list_del() ... ... list_del() //list_del corruption There is no lock protection when deleting list in p9_conn_cancel(). After deleting list in Thread A, thread B will delete the same list again. It will cause issue of list_del corruption. Setting req->status to REQ_STATUS_ERROR under lock prevents other cleanup paths from trying to manipulate req_list. The other thread can safely check req->status because it still holds a reference to req at this point. Link: https://lkml.kernel.org/r/20221110122606.383352-1-shaozhengchao@huawei.com Fixes: 52f1c45dde91 ("9p: trans_fd/p9_conn_cancel: drop client lock earlier") Reported-by: syzbot+9b69b8d10ab4a7d88056@syzkaller.appspotmail.com Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> [Dominique: add description of the fix in commit message] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-10-07net/9p: clarify trans_fd parse_opt failure handlingLi Zhong1-1/+3
This parse_opts will set invalid opts.rfd/wfd in case of failure which we already check, but it is not clear for readers that parse_opts error are handled in p9_fd_create: clarify this by explicitely checking the return value. Link: https://lkml.kernel.org/r/20220921210921.1654735-1-floridsleeves@gmail.com Signed-off-by: Li Zhong <floridsleeves@gmail.com> [Dominique: reworded commit message to clarify this is NOOP] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-10-07net/9p: add __init/__exit annotations to module init/exit funcsXiu Jianfeng1-2/+2
xen transport was missing annotations Link: https://lkml.kernel.org/r/20220909103546.73015-1-xiujianfeng@huawei.com Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-10-07net/9p: use a dedicated spinlock for trans_fdDominique Martinet1-16/+25
Shamelessly copying the explanation from Tetsuo Handa's suggested patch[1] (slightly reworded): syzbot is reporting inconsistent lock state in p9_req_put()[2], for p9_tag_remove() from p9_req_put() from IRQ context is using spin_lock_irqsave() on "struct p9_client"->lock but trans_fd (not from IRQ context) is using spin_lock(). Since the locks actually protect different things in client.c and in trans_fd.c, just replace trans_fd.c's lock by a new one specific to the transport (client.c's protect the idr for fid/tag allocations, while trans_fd.c's protects its own req list and request status field that acts as the transport's state machine) Link: https://lore.kernel.org/r/20220904112928.1308799-1-asmadeus@codewreck.org Link: https://lkml.kernel.org/r/2470e028-9b05-2013-7198-1fdad071d999@I-love.SAKURA.ne.jp [1] Link: https://syzkaller.appspot.com/bug?extid=2f20b523930c32c160cc [2] Reported-by: syzbot <syzbot+2f20b523930c32c160cc@syzkaller.appspotmail.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-10-079p/trans_fd: always use O_NONBLOCK read/writeTetsuo Handa1-0/+3
syzbot is reporting hung task at p9_fd_close() [1], for p9_mux_poll_stop() from p9_conn_destroy() from p9_fd_close() is failing to interrupt already started kernel_read() from p9_fd_read() from p9_read_work() and/or kernel_write() from p9_fd_write() from p9_write_work() requests. Since p9_socket_open() sets O_NONBLOCK flag, p9_mux_poll_stop() does not need to interrupt kernel_read()/kernel_write(). However, since p9_fd_open() does not set O_NONBLOCK flag, but pipe blocks unless signal is pending, p9_mux_poll_stop() needs to interrupt kernel_read()/kernel_write() when the file descriptor refers to a pipe. In other words, pipe file descriptor needs to be handled as if socket file descriptor. We somehow need to interrupt kernel_read()/kernel_write() on pipes. A minimal change, which this patch is doing, is to set O_NONBLOCK flag from p9_fd_open(), for O_NONBLOCK flag does not affect reading/writing of regular files. But this approach changes O_NONBLOCK flag on userspace- supplied file descriptors (which might break userspace programs), and O_NONBLOCK flag could be changed by userspace. It would be possible to set O_NONBLOCK flag every time p9_fd_read()/p9_fd_write() is invoked, but still remains small race window for clearing O_NONBLOCK flag. If we don't want to manipulate O_NONBLOCK flag, we might be able to surround kernel_read()/kernel_write() with set_thread_flag(TIF_SIGPENDING) and recalc_sigpending(). Since p9_read_work()/p9_write_work() works are processed by kernel threads which process global system_wq workqueue, signals could not be delivered from remote threads when p9_mux_poll_stop() from p9_conn_destroy() from p9_fd_close() is called. Therefore, calling set_thread_flag(TIF_SIGPENDING)/recalc_sigpending() every time would be needed if we count on signals for making kernel_read()/kernel_write() non-blocking. Link: https://lkml.kernel.org/r/345de429-a88b-7097-d177-adecf9fed342@I-love.SAKURA.ne.jp Link: https://syzkaller.appspot.com/bug?extid=8b41a1365f1106fd0f33 [1] Reported-by: syzbot <syzbot+8b41a1365f1106fd0f33@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: syzbot <syzbot+8b41a1365f1106fd0f33@syzkaller.appspotmail.com> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> [Dominique: add comment at Christian's suggestion] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-10-05net/9p: allocate appropriate reduced message buffersChristian Schoenebeck1-7/+35
So far 'msize' was simply used for all 9p message types, which is far too much and slowed down performance tremendously with large values for user configurable 'msize' option. Let's stop this waste by using the new p9_msg_buf_size() function for allocating more appropriate, smaller buffers according to what is actually sent over the wire. Only exception: RDMA transport is currently excluded from this message size optimization - for its response buffers that is - as RDMA transport would not cope with it, due to its response buffers being pulled from a shared pool. [1] Link: https://lore.kernel.org/all/Ys3jjg52EIyITPua@codewreck.org/ [1] Link: https://lkml.kernel.org/r/3f51590535dc96ed0a165b8218c57639cfa5c36c.1657920926.git.linux_oss@crudebyte.com Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-10-05net/9p: add 'pooled_rbuffers' flag to struct p9_trans_moduleChristian Schoenebeck4-0/+4
This is a preparatory change for the subsequent patch: the RDMA transport pulls the buffers for its 9p response messages from a shared pool. [1] So this case has to be considered when choosing an appropriate response message size in the subsequent patch. Link: https://lore.kernel.org/all/Ys3jjg52EIyITPua@codewreck.org/ [1] Link: https://lkml.kernel.org/r/79d24310226bc4eb037892b5c097ec4ad4819a03.1657920926.git.linux_oss@crudebyte.com Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-10-05net/9p: add p9_msg_buf_size()Christian Schoenebeck2-0/+169
This new function calculates a buffer size suitable for holding the intended 9p request or response. For rather small message types (which applies to almost all 9p message types actually) simply use hard coded values. For some variable-length and potentially large message types calculate a more precise value according to what data is actually transmitted to avoid unnecessarily huge buffers. So p9_msg_buf_size() divides the individual 9p message types into 3 message size categories: - dynamically calculated message size (i.e. potentially large) - 8k hard coded message size - 4k hard coded message size As for the latter two hard coded message types: for most 9p message types it is pretty obvious whether they would always fit into 4k or 8k. But for some of them it depends on the maximum directory entry name length allowed by OS and filesystem for determining into which of the two size categories they would fit into. Currently Linux supports directory entry names up to NAME_MAX (255), however when comparing the limitation of individual filesystems, ReiserFS theoretically supports up to slightly below 4k long names. So in order to make this code more future proof, and as revisiting it later on is a bit tedious and has the potential to miss out details, the decision [1] was made to take 4k as basis as for max. name length. Link: https://lkml.kernel.org/r/bd6be891cf67e867688e8c8796d06408bfafa0d9.1657920926.git.linux_oss@crudebyte.com Link: https://lore.kernel.org/all/5564296.oo812IJUPE@silver/ [1] Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-10-05net/9p: split message size argument into 't_size' and 'r_size' pairChristian Schoenebeck1-9/+11
Refactor 'max_size' argument of p9_tag_alloc() and 'req_size' argument of p9_client_prepare_req() both into a pair of arguments 't_size' and 'r_size' respectively to allow handling the buffer size for request and reply separately from each other. Link: https://lkml.kernel.org/r/9431a25fe4b37fd12cecbd715c13af71f701f220.1657920926.git.linux_oss@crudebyte.com Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-10-059p: trans_fd/p9_conn_cancel: drop client lock earlierDominique Martinet1-1/+2
syzbot reported a double-lock here and we no longer need this lock after requests have been moved off to local list: just drop the lock earlier. Link: https://lkml.kernel.org/r/20220904064028.1305220-1-asmadeus@codewreck.org Reported-by: syzbot+50f7e8d06c3768dd97f3@syzkaller.appspotmail.com Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Tested-by: Schspa Shi <schspa@gmail.com>
2022-08-09Merge tag 'pull-work.iov_iter-rebased' of ↵Linus Torvalds3-19/+26
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 ...
2022-08-099p: convert to advancing variant of iov_iter_get_pages_alloc()Al Viro3-19/+26
that one is somewhat clumsier than usual and needs serious testing. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-07Merge tag '9p-for-5.20' of https://github.com/martinetd/linuxLinus Torvalds5-92/+97
Pull 9p updates from Dominique Martinet: - a couple of fixes - add a tracepoint for fid refcounting - some cleanup/followup on fid lookup - some cleanup around req refcounting * tag '9p-for-5.20' of https://github.com/martinetd/linux: net/9p: Initialize the iounit field during fid creation net: 9p: fix refcount leak in p9_read_work() error handling 9p: roll p9_tag_remove into p9_req_put 9p: Add client parameter to p9_req_put() 9p: Drop kref usage 9p: Fix some kernel-doc comments 9p fid refcount: cleanup p9_fid_put calls 9p fid refcount: add a 9p_fid_ref tracepoint 9p fid refcount: add p9_fid_get/put wrappers 9p: Fix minor typo in code comment 9p: Remove unnecessary variable for old fids while walking from d_parent 9p: Make the path walk logic more clear about when cloning is required 9p: Track the root fid with its own variable during lookups
2022-07-16net/9p: Initialize the iounit field during fid creationTyler Hicks1-4/+1
Ensure that the fid's iounit field is set to zero when a new fid is created. Certain 9P operations, such as OPEN and CREATE, allow the server to reply with an iounit size which the client code assigns to the p9_fid struct shortly after the fid is created by p9_fid_create(). On the other hand, an XATTRWALK operation doesn't allow for the server to specify an iounit value. The iounit field of the newly allocated p9_fid struct remained uninitialized in that case. Depending on allocation patterns, the iounit value could have been something reasonable that was carried over from previously freed fids or, in the worst case, could have been arbitrary values from non-fid related usages of the memory location. The bug was detected in the Windows Subsystem for Linux 2 (WSL2) kernel after the uninitialized iounit field resulted in the typical sequence of two getxattr(2) syscalls, one to get the size of an xattr and another after allocating a sufficiently sized buffer to fit the xattr value, to hit an unexpected ERANGE error in the second call to getxattr(2). An uninitialized iounit field would sometimes force rsize to be smaller than the xattr value size in p9_client_read_once() and the 9P server in WSL refused to chunk up the READ on the attr_fid and, instead, returned ERANGE to the client. The virtfs server in QEMU seems happy to chunk up the READ and this problem goes undetected there. Link: https://lkml.kernel.org/r/20220710141402.803295-1-tyhicks@linux.microsoft.com Fixes: ebf46264a004 ("fs/9p: Add support user. xattr") Cc: stable@vger.kernel.org Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-07-15net: 9p: fix refcount leak in p9_read_work() error handlingHangyu Hua1-0/+1
p9_req_put need to be called when m->rreq->rc.sdata is NULL to avoid temporary refcount leak. Link: https://lkml.kernel.org/r/20220712104438.30800-1-hbh25y@gmail.com Fixes: 728356dedeff ("9p: Add refcount to p9_req_t") Signed-off-by: Hangyu Hua <hbh25y@gmail.com> [Dominique: commit wording adjustments, p9_req_put argument fixes for rebase] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-07-159p: roll p9_tag_remove into p9_req_putDominique Martinet1-50/+51
mempool prep commit removed the awkward kref usage which didn't allow passing client pointer easily with the ref, so we no longer need a separate function to remove the tag from idr. This has the side benefit that it should be more robust in detecting leaks: umount will now properly catch unfreed requests as they still will be in the idr until the last ref is dropped Link: https://lkml.kernel.org/r/20220712060801.2487140-1-asmadeus@codewreck.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
2022-07-099p: Add client parameter to p9_req_put()Kent Overstreet5-16/+16
This is to aid in adding mempools, in the next patch. Link: https://lkml.kernel.org/r/20220704014243.153050-2-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-07-099p: Drop kref usageKent Overstreet1-11/+8
An upcoming patch is going to require passing the client through p9_req_put() -> p9_req_free(), but that's awkward with the kref indirection - so this patch switches to using refcount_t directly. Link: https://lkml.kernel.org/r/20220704014243.153050-1-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-07-029p fid refcount: add a 9p_fid_ref tracepointDominique Martinet1-1/+19
This adds a tracepoint event for 9p fid lifecycle tracing: when a fid is created, its reference count increased/decreased, and freed. The new 9p_fid_ref tracepoint should help anyone wishing to debug any fid problem such as missing clunk (destroy) or use-after-free. Link: https://lkml.kernel.org/r/20220612085330.1451496-6-asmadeus@codewreck.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-07-029p fid refcount: add p9_fid_get/put wrappersDominique Martinet1-12/+3
I was recently reminded that it is not clear that p9_client_clunk() was actually just decrementing refcount and clunking only when that reaches zero: make it clear through a set of helpers. This will also allow instrumenting refcounting better for debugging next patch Link: https://lkml.kernel.org/r/20220612085330.1451496-5-asmadeus@codewreck.org Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-06-099p: handling Rerror without copy_from_iter_full()Al Viro2-85/+35
p9_client_zc_rpc()/p9_check_zc_errors() are playing fast and loose with copy_from_iter_full(). Reading from file is done by sending Tread request. Response consists of fixed-sized header (including the amount of data actually read) followed by the data itself. For zero-copy case we arrange the things so that the first 11 bytes of reply go into the fixed-sized buffer, with the rest going straight into the pages we want to read into. What makes the things inconvenient is that sglist describing what should go where has to be set *before* the reply arrives. As the result, if reply is an error, the things get interesting. On success we get size[4] Rread tag[2] count[4] data[count] For error layout varies depending upon the protocol variant - in original 9P and 9P2000 it's size[4] Rerror tag[2] len[2] error[len] in 9P2000.U size[4] Rerror tag[2] len[2] error[len] errno[4] in 9P2000.L size[4] Rlerror tag[2] errno[4] The last case is nice and simple - we have an 11-byte response that fits into the fixed-sized buffer we hoped to get an Rread into. In other two, though, we get a variable-length string spill into the pages we'd prepared for the data to be read. Had that been in fixed-sized buffer (which is actually 4K), we would've dealt with that the same way we handle non-zerocopy case. However, for zerocopy it doesn't end up there, so we need to copy it from those pages. The trouble is, by the time we get around to that, the references to pages in question are already dropped. As the result, p9_zc_check_errors() tries to get the data using copy_from_iter_full(). Unfortunately, the iov_iter it's trying to read from might *NOT* be capable of that. It is, after all, a data destination, not data source. In particular, if it's an ITER_PIPE one, copy_from_iter_full() will simply fail. In ->zc_request() itself we do have those pages and dealing with the problem in there would be a simple matter of memcpy_from_page() into the fixed-sized buffer. Moreover, it isn't hard to recognize the (rare) case when such copying is needed. That way we get rid of p9_zc_check_errors() entirely - p9_check_errors() can be used instead both for zero-copy and non-zero-copy cases. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-05-27xen: switch gnttab_end_foreign_access() to take a struct page pointerJuergen Gross1-4/+4
Instead of a virtual kernel address use a pointer of the associated struct page as second parameter of gnttab_end_foreign_access(). Most users have that pointer available already and are creating the virtual address from it, risking problems in case the memory is located in highmem. gnttab_end_foreign_access() itself won't need to get the struct page from the address again. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2022-03-16xen/grant-table: remove readonly parameter from functionsJuergen Gross1-4/+4
The gnttab_end_foreign_access() family of functions is taking a "readonly" parameter, which isn't used. Remove it from the function parameters. Signed-off-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20220311103429.12845-3-jgross@suse.com Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2022-03-07xen/9p: use alloc/free_pages_exact()Juergen Gross1-8/+6
Instead of __get_free_pages() and free_pages() use alloc_pages_exact() and free_pages_exact(). This is in preparation of a change of gnttab_end_foreign_access() which will prohibit use of high-order pages. By using the local variable "order" instead of ring->intf->ring_order in the error path of xen_9pfs_front_alloc_dataring() another bug is fixed, as the error path can be entered before ring->intf->ring_order is being set. By using alloc_pages_exact() the size in bytes is specified for the allocation, which fixes another bug for the case of order < (PAGE_SHIFT - XEN_PAGE_SHIFT). This is part of CVE-2022-23041 / XSA-396. Reported-by: Simon Gaiser <simon@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> --- V4: - new patch
2022-01-18Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-1/+1
Pull virtio updates from Michael Tsirkin: "virtio,vdpa,qemu_fw_cfg: features, cleanups, and fixes. - partial support for < MAX_ORDER - 1 granularity for virtio-mem - driver_override for vdpa - sysfs ABI documentation for vdpa - multiqueue config support for mlx5 vdpa - and misc fixes, cleanups" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (42 commits) vdpa/mlx5: Fix tracking of current number of VQs vdpa/mlx5: Fix is_index_valid() to refer to features vdpa: Protect vdpa reset with cf_mutex vdpa: Avoid taking cf_mutex lock on get status vdpa/vdpa_sim_net: Report max device capabilities vdpa: Use BIT_ULL for bit operations vdpa/vdpa_sim: Configure max supported virtqueues vdpa/mlx5: Report max device capabilities vdpa: Support reporting max device capabilities vdpa/mlx5: Restore cur_num_vqs in case of failure in change_num_qps() vdpa: Add support for returning device configuration information vdpa/mlx5: Support configuring max data virtqueue vdpa/mlx5: Fix config_attr_mask assignment vdpa: Allow to configure max data virtqueues vdpa: Read device configuration only if FEATURES_OK vdpa: Sync calls set/get config/status with cf_mutex vdpa/mlx5: Distribute RX virtqueues in RQT object vdpa: Provide interface to read driver features vdpa: clean up get_config_size ret value handling virtio_ring: mark ring unused on error ...
2022-01-15virtio: wrap config->reset callsMichael S. Tsirkin1-1/+1
This will enable cleanups down the road. The idea is to disable cbs, then add "flush_queued_cbs" callback as a parameter, this way drivers can flush any work queued after callbacks have been disabled. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-10net/9p: show error message if user 'msize' cannot be satisfiedChristian Schoenebeck1-1/+6
If user supplied a large value with the 'msize' option, then client would silently limit that 'msize' value to the maximum value supported by transport. That's a bit confusing for users of not having any indication why the preferred 'msize' value could not be satisfied. Link: https://lkml.kernel.org/r/783ba37c1566dd715b9a67d437efa3b77e3cd1a7.1640870037.git.linux_oss@crudebyte.com Reported-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-01-10net/p9: load default transportsThomas Weißschuh1-2/+11
Now that all transports are split into modules it may happen that no transports are registered when v9fs_get_default_trans() is called. When that is the case try to load more transports from modules. Link: https://lkml.kernel.org/r/20211103193823.111007-5-linux@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> [Dominique: constify v9fs_get_trans_by_name argument as per patch1v2] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-01-109p/xen: autoload when xenbus service is availableThomas Weißschuh1-0/+1
Link: https://lkml.kernel.org/r/20211103193823.111007-4-linux@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-01-109p/trans_fd: split into dedicated moduleThomas Weißschuh4-5/+23
This allows these transports only to be used when needed. Link: https://lkml.kernel.org/r/20211103193823.111007-3-linux@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> [Dominique: Kconfig NET_9P_FD: -depends VIRTIO, +default NET_9P] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-12-189p/trans_virtio: Fix typo in the comment for p9_virtio_create()zhuxinran1-1/+1
couldlook ==> could look Link: https://lkml.kernel.org/r/20211216061439.4186-1-zhuran@mail.ustc.edu.cn Signed-off-by: zhuxinran <zhuran@mail.ustc.edu.cn> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-11-049p: fix a bunch of checkpatch warningsDominique Martinet6-246/+237
Sohaib Mohamed started a serie of tiny and incomplete checkpatch fixes but seemingly stopped halfway -- take over and do most of it. This is still missing net/9p/trans* and net/9p/protocol.c for a later time... Link: http://lkml.kernel.org/r/20211102134608.1588018-3-dominique.martinet@atmark-techno.com Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-11-039p: fix file headersDominique Martinet10-56/+3
- add missing SPDX-License-Identifier - remove (sometimes incorrect) file name from file header Link: http://lkml.kernel.org/r/20211102134608.1588018-2-dominique.martinet@atmark-techno.com Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-11-03net/9p: autoload transport modulesThomas Weißschuh4-6/+27
Automatically load transport modules based on the trans= parameter passed to mount. This removes the requirement for the user to know which module to use. Link: http://lkml.kernel.org/r/20211017134611.4330-1-linux@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-11-039p/net: fix missing error check in p9_check_errorsDominique Martinet1-0/+2
Link: https://lkml.kernel.org/r/99338965-d36c-886e-cd0e-1d8fff2b4746@gmail.com Reported-by: syzbot+06472778c97ed94af66d@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-09-05net/9p: increase default msize to 128kChristian Schoenebeck1-1/+1
Let's raise the default msize value to 128k. The 'msize' option defines the maximum message size allowed for any message being transmitted (in both directions) between 9p server and 9p client during a 9p session. Currently the default 'msize' is just 8k, which is way too conservative. Such a small 'msize' value has quite a negative performance impact, because individual 9p messages have to be split up far too often into numerous smaller messages to fit into this message size limitation. A default value of just 8k also has a much higher probablity of hitting short-read issues like: https://gitlab.com/qemu-project/qemu/-/issues/409 Unfortunately user feedback showed that many 9p users are not aware that this option even exists, nor the negative impact it might have if it is too low. Link: http://lkml.kernel.org/r/61ea0f0faaaaf26dd3c762eabe4420306ced21b9.1630770829.git.linux_oss@crudebyte.com Link: https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg01003.html Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-09-05net/9p: use macro to define default msizeChristian Schoenebeck1-2/+4
Use a macro to define the default value for the 'msize' option at one place instead of using two separate integer literals. Link: http://lkml.kernel.org/r/28bb651ae0349a7d57e8ddc92c1bd5e62924a912.1630770829.git.linux_oss@crudebyte.com Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-09-05net/9p: increase tcp max msize to 1MBDominique Martinet1-1/+1
Historically TCP has been limited to 64K buffers, but increasing msize provides huge performance benefits especially as latency increase so allow for bigger buffers. Ideally further improvements could change the allocation from the current contiguous chunk in slab (kmem_cache) to some scatter-gather compatible API... Note this only increases the max possible setting, not the default value. Link: http://lkml.kernel.org/r/YTQB5jCbvhmCWzNd@codewreck.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-07-279p/xen: Fix end of loop tests for list_for_each_entryHarshvardhan Jha1-2/+2
This patch addresses the following problems: - priv can never be NULL, so this part of the check is useless - if the loop ran through the whole list, priv->client is invalid and it is more appropriate and sufficient to check for the end of list_for_each_entry loop condition. Link: http://lkml.kernel.org/r/20210727000709.225032-1-harshvardhan.jha@oracle.com Signed-off-by: Harshvardhan Jha <harshvardhan.jha@oracle.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Tested-by: Stefano Stabellini <sstabellini@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-07-279p/trans_virtio: Remove sysfs file on probe failureXie Yongji1-1/+3
This ensures we don't leak the sysfs file if we failed to allocate chan->vc_wq during probe. Link: http://lkml.kernel.org/r/20210517083557.172-1-xieyongji@bytedance.com Fixes: 86c8437383ac ("net/9p: Add sysfs mount_tag file for virtio 9P device") Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-06-039p/trans_virtio: Fix spelling mistakesZheng Yongjun1-3/+3
reseting ==> resetting alloced ==> allocated accomodate ==> accommodate Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-29net: 9p: Correct function names in the kerneldoc commentsXiongfeng Wang1-2/+2
Fix the following W=1 kernel build warning(s): net/9p/client.c:133: warning: expecting prototype for parse_options(). Prototype was for parse_opts() instead net/9p/client.c:269: warning: expecting prototype for p9_req_alloc(). Prototype was for p9_tag_alloc() instead Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-299p/trans_fd: Correct function name p9_mux_destroy() in the kerneldocXiongfeng Wang1-1/+1
Fix the following W=1 kernel build warning(s): net/9p/trans_fd.c:881: warning: expecting prototype for p9_mux_destroy(). Prototype was for p9_conn_destroy() instead Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-29net: 9p: Correct function name errstr2errno() in the kerneldoc commentsXiongfeng Wang1-1/+1
Fix the following W=1 kernel build warning(s): net/9p/error.c:207: warning: expecting prototype for errstr2errno(). Prototype was for p9_errstr2errno() instead Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-04net: 9p: advance iov on empty readJisheng Zhang1-4/+0
I met below warning when cating a small size(about 80bytes) txt file on 9pfs(msize=2097152 is passed to 9p mount option), the reason is we miss iov_iter_advance() if the read count is 0 for zerocopy case, so we didn't truncate the pipe, then iov_iter_pipe() thinks the pipe is full. Fix it by removing the exception for 0 to ensure to call iov_iter_advance() even on empty read for zerocopy case. [ 8.279568] WARNING: CPU: 0 PID: 39 at lib/iov_iter.c:1203 iov_iter_pipe+0x31/0x40 [ 8.280028] Modules linked in: [ 8.280561] CPU: 0 PID: 39 Comm: cat Not tainted 5.11.0+ #6 [ 8.281260] RIP: 0010:iov_iter_pipe+0x31/0x40 [ 8.281974] Code: 2b 42 54 39 42 5c 76 22 c7 07 20 00 00 00 48 89 57 18 8b 42 50 48 c7 47 08 b [ 8.283169] RSP: 0018:ffff888000cbbd80 EFLAGS: 00000246 [ 8.283512] RAX: 0000000000000010 RBX: ffff888000117d00 RCX: 0000000000000000 [ 8.283876] RDX: ffff88800031d600 RSI: 0000000000000000 RDI: ffff888000cbbd90 [ 8.284244] RBP: ffff888000cbbe38 R08: 0000000000000000 R09: ffff8880008d2058 [ 8.284605] R10: 0000000000000002 R11: ffff888000375510 R12: 0000000000000050 [ 8.284964] R13: ffff888000cbbe80 R14: 0000000000000050 R15: ffff88800031d600 [ 8.285439] FS: 00007f24fd8af600(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000 [ 8.285844] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8.286150] CR2: 00007f24fd7d7b90 CR3: 0000000000c97000 CR4: 00000000000406b0 [ 8.286710] Call Trace: [ 8.288279] generic_file_splice_read+0x31/0x1a0 [ 8.289273] ? do_splice_to+0x2f/0x90 [ 8.289511] splice_direct_to_actor+0xcc/0x220 [ 8.289788] ? pipe_to_sendpage+0xa0/0xa0 [ 8.290052] do_splice_direct+0x8b/0xd0 [ 8.290314] do_sendfile+0x1ad/0x470 [ 8.290576] do_syscall_64+0x2d/0x40 [ 8.290818] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 8.291409] RIP: 0033:0x7f24fd7dca0a [ 8.292511] Code: c3 0f 1f 80 00 00 00 00 4c 89 d2 4c 89 c6 e9 bd fd ff ff 0f 1f 44 00 00 31 8 [ 8.293360] RSP: 002b:00007ffc20932818 EFLAGS: 00000206 ORIG_RAX: 0000000000000028 [ 8.293800] RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f24fd7dca0a [ 8.294153] RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000001 [ 8.294504] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 [ 8.294867] R10: 0000000001000000 R11: 0000000000000206 R12: 0000000000000003 [ 8.295217] R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000 [ 8.295782] ---[ end trace 63317af81b3ca24b ]--- Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-01-28net: remove redundant 'depends on NET'Masahiro Yamada1-1/+0
These Kconfig files are included from net/Kconfig, inside the if NET ... endif. Remove 'depends on NET', which we know it is already met. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20210125232026.106855-1-masahiroy@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-21Merge tag '9p-for-5.11-rc1' of git://github.com/martinetd/linuxLinus Torvalds1-5/+9
Pull 9p update from Dominique Martinet: - fix long-standing limitation on open-unlink-fop pattern - add refcount to p9_fid (fixes the above and will allow for more cleanups and simplifications in the future) * tag '9p-for-5.11-rc1' of git://github.com/martinetd/linux: 9p: Remove unnecessary IS_ERR() check 9p: Uninitialized variable in v9fs_writeback_fid() 9p: Fix writeback fid incorrectly being attached to dentry 9p: apply review requests for fid refcounting 9p: add refcount to p9_fid struct fs/9p: search open fids first fs/9p: track open fids fs/9p: fix create-unlink-getattr idiom
2020-11-199p: apply review requests for fid refcountingDominique Martinet1-2/+2
Fix style issues in parent commit ("apply review requests for fid refcounting"), no functional change. Link: http://lkml.kernel.org/r/1605802012-31133-2-git-send-email-asmadeus@codewreck.org Fixes: 6636b6dcc3db ("9p: add refcount to p9_fid struct") Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
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