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* 9pnet: allow making incomplete read requestsSergey Alirzaev2020-03-271-61/+73
| | | | | | | | | | | | | A user doesn't necessarily want to wait for all the requested data to be available, since the waiting time for each request is unbounded. The new method permits sending one read request at a time and getting the response ASAP, allowing to use 9pnet with synthetic file systems representing arbitrary data streams. Link: http://lkml.kernel.org/r/20200205204053.12751-1-l29ah@cock.li Signed-off-by: Sergey Alirzaev <l29ah@cock.li> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* 9p: Transport error uninitializedLu Shuaibing2019-09-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The p9_tag_alloc() does not initialize the transport error t_err field. The struct p9_req_t *req is allocated and stored in a struct p9_client variable. The field t_err is never initialized before p9_conn_cancel() checks its value. KUMSAN(KernelUninitializedMemorySantizer, a new error detection tool) reports this bug. ================================================================== BUG: KUMSAN: use of uninitialized memory in p9_conn_cancel+0x2d9/0x3b0 Read of size 4 at addr ffff88805f9b600c by task kworker/1:2/1216 CPU: 1 PID: 1216 Comm: kworker/1:2 Not tainted 5.2.0-rc4+ #28 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Workqueue: events p9_write_work Call Trace: dump_stack+0x75/0xae __kumsan_report+0x17c/0x3e6 kumsan_report+0xe/0x20 p9_conn_cancel+0x2d9/0x3b0 p9_write_work+0x183/0x4a0 process_one_work+0x4d1/0x8c0 worker_thread+0x6e/0x780 kthread+0x1ca/0x1f0 ret_from_fork+0x35/0x40 Allocated by task 1979: save_stack+0x19/0x80 __kumsan_kmalloc.constprop.3+0xbc/0x120 kmem_cache_alloc+0xa7/0x170 p9_client_prepare_req.part.9+0x3b/0x380 p9_client_rpc+0x15e/0x880 p9_client_create+0x3d0/0xac0 v9fs_session_init+0x192/0xc80 v9fs_mount+0x67/0x470 legacy_get_tree+0x70/0xd0 vfs_get_tree+0x4a/0x1c0 do_mount+0xba9/0xf90 ksys_mount+0xa8/0x120 __x64_sys_mount+0x62/0x70 do_syscall_64+0x6d/0x1e0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff88805f9b6008 which belongs to the cache p9_req_t of size 144 The buggy address is located 4 bytes inside of 144-byte region [ffff88805f9b6008, ffff88805f9b6098) The buggy address belongs to the page: page:ffffea00017e6d80 refcount:1 mapcount:0 mapping:ffff888068b63740 index:0xffff88805f9b7d90 compound_mapcount: 0 flags: 0x100000000010200(slab|head) raw: 0100000000010200 ffff888068b66450 ffff888068b66450 ffff888068b63740 raw: ffff88805f9b7d90 0000000000100001 00000001ffffffff 0000000000000000 page dumped because: kumsan: bad access detected ================================================================== Link: http://lkml.kernel.org/r/20190613070854.10434-1-shuaibinglu@126.com Signed-off-by: Lu Shuaibing <shuaibinglu@126.com> [dominique.martinet@cea.fr: grouped the added init with the others] Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188Thomas Gleixner2019-05-301-16/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to free software foundation 51 franklin street fifth floor boston ma 02111 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 27 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528170026.981318839@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* 9p/net: fix memory leak in p9_client_createzhengbin2019-03-131-1/+1
| | | | | | | | | | | | If msize is less than 4096, we should close and put trans, destroy tagpool, not just free client. This patch fixes that. Link: http://lkml.kernel.org/m/1552464097-142659-1-git-send-email-zhengbin13@huawei.com Cc: stable@vger.kernel.org Fixes: 574d356b7a02 ("9p/net: put a lower bound on msize") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* 9p/net: put a lower bound on msizeDominique Martinet2018-12-251-0/+21
| | | | | | | | | | | | | | | | | | | | | If the requested msize is too small (either from command line argument or from the server version reply), we won't get any work done. If it's *really* too small, nothing will work, and this got caught by syzbot recently (on a new kmem_cache_create_usercopy() call) Just set a minimum msize to 4k in both code paths, until someone complains they have a use-case for a smaller msize. We need to check in both mount option and server reply individually because the msize for the first version request would be unchecked with just a global check on clnt->msize. Link: http://lkml.kernel.org/r/1541407968-31350-1-git-send-email-asmadeus@codewreck.org Reported-by: syzbot+0c1d61e4db7db94102ca@syzkaller.appspotmail.com Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: stable@vger.kernel.org
* Merge branch 'work.afs' of ↵Linus Torvalds2018-11-021-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull AFS updates from Al Viro: "AFS series, with some iov_iter bits included" * 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits) missing bits of "iov_iter: Separate type from direction and use accessor functions" afs: Probe multiple fileservers simultaneously afs: Fix callback handling afs: Eliminate the address pointer from the address list cursor afs: Allow dumping of server cursor on operation failure afs: Implement YFS support in the fs client afs: Expand data structure fields to support YFS afs: Get the target vnode in afs_rmdir() and get a callback on it afs: Calc callback expiry in op reply delivery afs: Fix FS.FetchStatus delivery from updating wrong vnode afs: Implement the YFS cache manager service afs: Remove callback details from afs_callback_break struct afs: Commit the status on a new file/dir/symlink afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS afs: Don't invoke the server to read data beyond EOF afs: Add a couple of tracepoints to log I/O errors afs: Handle EIO from delivery function afs: Fix TTL on VL server and address lists afs: Implement VL server rotation afs: Improve FS server rotation error handling ...
| * iov_iter: Separate type from direction and use accessor functionsDavid Howells2018-10-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the iov_iter struct, separate the iterator type from the iterator direction and use accessor functions to access them in most places. Convert a bunch of places to use switch-statements to access them rather then chains of bitwise-AND statements. This makes it easier to add further iterator types. Also, this can be more efficient as to implement a switch of small contiguous integers, the compiler can use ~50% fewer compare instructions than it has to use bitwise-and instructions. Further, cease passing the iterator type into the iterator setup function. The iterator function can set that itself. Only the direction is required. Signed-off-by: David Howells <dhowells@redhat.com>
* | 9p: potential NULL dereferenceDan Carpenter2018-10-101-1/+1
| | | | | | | | | | | | | | | | | | | | p9_tag_alloc() is supposed to return error pointers, but we accidentally return a NULL here. It would cause a NULL dereference in the caller. Link: http://lkml.kernel.org/m/20180926103934.GA14535@mwanda Fixes: 996d5b4db4b1 ("9p: Use a slab for allocating requests") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* | 9p: Add refcount to p9_req_tTomas Bortoli2018-09-071-7/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid use-after-free(s), use a refcount to keep track of the usable references to any instantiated struct p9_req_t. This commit adds p9_req_put(), p9_req_get() and p9_req_try_get() as wrappers to kref_put(), kref_get() and kref_get_unless_zero(). These are used by the client and the transports to keep track of valid requests' references. p9_free_req() is added back and used as callback by kref_put(). Add SLAB_TYPESAFE_BY_RCU as it ensures that the memory freed by kmem_cache_free() will not be reused for another type until the rcu synchronisation period is over, so an address gotten under rcu read lock is safe to inc_ref() without corrupting random memory while the lock is held. Link: http://lkml.kernel.org/r/1535626341-20693-1-git-send-email-asmadeus@codewreck.org Co-developed-by: Dominique Martinet <dominique.martinet@cea.fr> Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com> Reported-by: syzbot+467050c1ce275af2a5b8@syzkaller.appspotmail.com Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* | 9p: rename p9_free_req() functionTomas Bortoli2018-09-071-50/+50
| | | | | | | | | | | | | | | | | | | | | | | | In sight of the next patch to add a refcount in p9_req_t, rename the p9_free_req() function in p9_release_req(). In the next patch the actual kfree will be moved to another function. Link: http://lkml.kernel.org/r/20180811144254.23665-1-tomasbortoli@gmail.com Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com> Acked-by: Jun Piao <piaojun@huawei.com> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* | 9p: add a per-client fcall kmem_cacheDominique Martinet2018-09-071-5/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Having a specific cache for the fcall allocations helps speed up end-to-end latency. The caches will automatically be merged if there are multiple caches of items with the same size so we do not need to try to share a cache between different clients of the same size. Since the msize is negotiated with the server, only allocate the cache after that negotiation has happened - previous allocations or allocations of different sizes (e.g. zero-copy fcall) are made with kmalloc directly. Some figures on two beefy VMs with Connect-IB (sriov) / trans=rdma, with ior running 32 processes in parallel doing small 32 bytes IOs: - no alloc (4.18-rc7 request cache): 65.4k req/s - non-power of two alloc, no patch: 61.6k req/s - power of two alloc, no patch: 62.2k req/s - non-power of two alloc, with patch: 64.7k req/s - power of two alloc, with patch: 65.1k req/s Link: http://lkml.kernel.org/r/1532943263-24378-2-git-send-email-asmadeus@codewreck.org Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr> Acked-by: Jun Piao <piaojun@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Greg Kurz <groug@kaod.org>
* | 9p: embed fcall in req to round down buffer allocsDominique Martinet2018-09-071-81/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | 'msize' is often a power of two, or at least page-aligned, so avoiding an overhead of two dozen bytes for each allocation will help the allocator do its work and reduce memory fragmentation. Link: http://lkml.kernel.org/r/1533825236-22896-1-git-send-email-asmadeus@codewreck.org Suggested-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr> Reviewed-by: Greg Kurz <groug@kaod.org> Acked-by: Jun Piao <piaojun@huawei.com> Cc: Matthew Wilcox <willy@infradead.org>
* | 9p: Use a slab for allocating requestsMatthew Wilcox2018-08-291-153/+85
|/ | | | | | | | | | | | | | Replace the custom batch allocation with a slab. Use an IDR to store pointers to the active requests instead of an array. We don't try to handle P9_NOTAG specially; the IDR will happily shrink all the way back once the TVERSION call has completed. Link: http://lkml.kernel.org/r/20180711210225.19730-6-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* 9p: fix whitespace issuesStephen Hemminger2018-08-131-2/+2
| | | | | | | | Remove trailing whitespace and blank lines at EOF Link: http://lkml.kernel.org/m/20180724192918.31165-11-sthemmin@microsoft.com Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* 9p: validate PDU lengthTomas Bortoli2018-08-131-9/+16
| | | | | | | | | | | | | | | | | This commit adds length check for the PDU size. The size contained in the header has to match the actual size, except for TCP (trans_fd.c) where actual length is not known ahead and the header's length will be checked only against the validity range. Link: http://lkml.kernel.org/r/20180723154404.2406-1-tomasbortoli@gmail.com Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com> Reported-by: syzbot+65c6b72f284a39d416b4@syzkaller.appspotmail.com To: Eric Van Hensbergen <ericvh@gmail.com> To: Ron Minnich <rminnich@sandia.gov> To: Latchesar Ionkov <lucho@ionkov.net> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* 9p: Embed wait_queue_head into p9_req_tMatthew Wilcox2018-08-131-14/+5
| | | | | | | | | | | | | | On a 64-bit system, the wait_queue_head_t is 24 bytes while the pointer to it is 8 bytes. Growing the p9_req_t by 16 bytes is better than performing a 24-byte memory allocation. Link: http://lkml.kernel.org/r/20180711210225.19730-5-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Greg Kurz <groug@kaod.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* 9p: Replace the fidlist with an IDRMatthew Wilcox2018-08-131-28/+16
| | | | | | | | | | | | | | The p9_idpool being used to allocate the IDs uses an IDR to allocate the IDs ... which we then keep in a doubly-linked list, rather than in the IDR which allocated them. We can use an IDR directly which saves two pointers per p9_fid, and a tiny memory allocation per p9_client. Link: http://lkml.kernel.org/r/20180711210225.19730-4-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* 9p: Change p9_fid_create calling conventionMatthew Wilcox2018-08-131-14/+9
| | | | | | | | | | | | | | | | | | | | | Return NULL instead of ERR_PTR when we can't allocate a FID. The ENOSPC return value was getting all the way back to userspace, and that's confusing for a userspace program which isn't expecting read() to tell it there's no space left on the filesystem. The best error we can return to indicate a temporary failure caused by lack of client resources is ENOMEM. Maybe it would be better to sleep until a FID is available, but that's not a change I'm comfortable making. Link: http://lkml.kernel.org/r/20180711210225.19730-3-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Greg Kurz <groug@kaod.org> Reviewed-by: Yiwen Jiang <jiangyiwen@huwei.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* 9p: Fix comment on smp_wmbMatthew Wilcox2018-08-131-1/+1
| | | | | | | | | | | | | The previous comment misled me into thinking the barrier wasn't needed at all. Link: http://lkml.kernel.org/r/20180711210225.19730-2-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Greg Kurz <groug@kaod.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* net/9p/client.c: version pointer uninitializedTomas Bortoli2018-08-131-1/+1
| | | | | | | | | | | | | | | | | | | | The p9_client_version() does not initialize the version pointer. If the call to p9pdu_readf() returns an error and version has not been allocated in p9pdu_readf(), then the program will jump to the "error" label and will try to free the version pointer. If version is not initialized, free() will be called with uninitialized, garbage data and will provoke a crash. Link: http://lkml.kernel.org/r/20180709222943.19503-1-tomasbortoli@gmail.com Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com> Reported-by: syzbot+65c6b72f284a39d416b4@syzkaller.appspotmail.com Reviewed-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* net/9p/client.c: add missing '\n' at the end of p9_debug()piaojun2018-08-131-1/+1
| | | | | | | | | | | | | | In p9_client_getattr_dotl(), we should add '\n' at the end of printing log. Link: http://lkml.kernel.org/r/5B44589A.50302@huawei.com Signed-off-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* net/9p/client.c: put refcount of trans_mod in error case in parse_opts()piaojun2018-07-141-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In my testing, the second mount will fail after umounting successfully. The reason is that we put refcount of trans_mod in the correct case rather than the error case in parse_opts() at last. That will cause the refcount decrease to -1, and when we try to get trans_mod again in try_module_get(), we could only increase refcount to 0 which will cause failure as follows: parse_opts v9fs_get_trans_by_name try_module_get : return NULL to caller which cause error So we should put refcount of trans_mod in error case. Link: http://lkml.kernel.org/r/5B3F39A0.2030509@huawei.com Fixes: 9421c3e64137ec ("net/9p/client.c: fix potential refcnt problem of trans module") Signed-off-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com> Reviewed-by: Greg Kurz <groug@kaod.org> Reviewed-by: Dominique Martinet <dominique.martinet@cea.fr> Tested-by: Dominique Martinet <dominique.martinet@cea.fr> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* net/9p: detect invalid options as much as possibleChengguang Xu2018-06-081-8/+5
| | | | | | | | | | | | | | | | | | | Currently when detecting invalid options in option parsing, some options(e.g. msize) just set errno and allow to continuously validate other options so that it can detect invalid options as much as possible and give proper error messages together. This patch applies same rule to option 'trans' and 'version' when detecting -EINVAL. Link: http://lkml.kernel.org/r/1525340676-34072-1-git-send-email-cgxu519@gmx.com Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* net/9p/client.c: fix potential refcnt problem of trans moduleChengguang Xu2018-04-061-1/+4
| | | | | | | | | | | | | | | | | When specifying trans_mod multiple times in a mount, it will cause an inaccurate refcount of the trans module. Also, in the error case of option parsing, we should put the trans module if we have already got it. Link: http://lkml.kernel.org/r/1522154942-57339-1-git-send-email-cgxu519@gmx.com Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Miller <davem@davemloft.net> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* net/9p: avoid -ERESTARTSYS leak to userspaceGreg Kurz2018-04-061-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If it was interrupted by a signal, the 9p client may need to send some more requests to the server for cleanup before returning to userspace. To avoid such a last minute request to be interrupted right away, the client memorizes if a signal is pending, clears TIF_SIGPENDING, handles the request and calls recalc_sigpending() before returning. Unfortunately, if the transmission of this cleanup request fails for any reason, the transport returns an error and the client propagates it right away, without calling recalc_sigpending(). This ends up with -ERESTARTSYS from the initially interrupted request crawling up to syscall exit, with TIF_SIGPENDING cleared by the cleanup request. The specific signal handling code, which is responsible for converting -ERESTARTSYS to -EINTR is not called, and userspace receives the confusing errno value: open: Unknown error 512 (512) This is really hard to hit in real life. I discovered the issue while working on hot-unplug of a virtio-9p-pci device with an instrumented QEMU allowing to control request completion. Both p9_client_zc_rpc() and p9_client_rpc() functions have this buggy error path actually. Their code flow is a bit obscure and the best thing to do would probably be a full rewrite: to really ensure this situation of clearing TIF_SIGPENDING and returning -ERESTARTSYS can never happen. But given the general lack of interest for the 9p code, I won't risk breaking more things. So this patch simply fixes the buggy paths in both functions with a trivial label+goto. Thanks to Laurent Dufour for his help and suggestions on how to find the root cause and how to fix it. Link: http://lkml.kernel.org/r/152062809886.10599.7361006774123053312.stgit@bahia.lan Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: David Miller <davem@davemloft.net> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 9p: Fix missing commas in mount optionsTuomas Tynkkynen2017-11-191-1/+1
| | | | | | | | | | | | | | | Since commit c4fac9100456 ("9p: Implement show_options"), the mount options of 9p filesystems are printed out with some missing commas between the individual options: p9-scratch on /mnt/scratch type 9p (rw,dirsync,loose,access=clienttrans=virtio) Add them back. Cc: stable@vger.kernel.org # 4.13+ Fixes: c4fac9100456 ("9p: Implement show_options") Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* net/9p: Switch to wait_event_killable()Tuomas Tynkkynen2017-10-241-2/+1
| | | | | | | | | | | | | | | Because userspace gets Very Unhappy when calls like stat() and execve() return -EINTR on 9p filesystem mounts. For instance, when bash is looking in PATH for things to execute and some SIGCHLD interrupts stat(), bash can throw a spurious 'command not found' since it doesn't retry the stat(). In practice, hitting the problem is rare and needs a really slow/bogged down 9p server. Cc: stable@vger.kernel.org Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 9p: Implement show_optionsDavid Howells2017-07-111-0/+25
| | | | | | | | | | | | | | Implement the show_options superblock op for 9p as part of a bid to get rid of s_options and generic_show_options() to make it easier to implement a context-based mount where the mount options can be passed individually over a file descriptor. Signed-off-by: David Howells <dhowells@redhat.com> cc: Eric Van Hensbergen <ericvh@gmail.com> cc: Ron Minnich <rminnich@sandia.gov> cc: Latchesar Ionkov <lucho@ionkov.net> cc: v9fs-developer@lists.sourceforge.net Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* net/9p: switch to copy_from_iter_full()Al Viro2017-04-211-3/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* p9_client_readdir() fixAl Viro2017-04-171-0/+4
| | | | | | | | Don't assume that server is sane and won't return more data than asked for. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'work.misc' of ↵Linus Torvalds2017-03-041-9/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc final vfs updates from Al Viro: "A few unrelated patches that got beating in -next. Everything else will have to go into the next window ;-/" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: hfs: fix hfs_readdir() selftest for default_file_splice_read() infoleak 9p: constify ->d_name handling
| * 9p: constify ->d_name handlingAl Viro2017-01-121-9/+9
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-1/+1
|/ | | | | | | | | | | | | | | | | | | | <linux/sched/signal.h> We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/signal.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* remove lots of IS_ERR_VALUE abusesArnd Bergmann2016-05-281-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most users of IS_ERR_VALUE() in the kernel are wrong, as they pass an 'int' into a function that takes an 'unsigned long' argument. This happens to work because the type is sign-extended on 64-bit architectures before it gets converted into an unsigned type. However, anything that passes an 'unsigned short' or 'unsigned int' argument into IS_ERR_VALUE() is guaranteed to be broken, as are 8-bit integers and types that are wider than 'unsigned long'. Andrzej Hajda has already fixed a lot of the worst abusers that were causing actual bugs, but it would be nice to prevent any users that are not passing 'unsigned long' arguments. This patch changes all users of IS_ERR_VALUE() that I could find on 32-bit ARM randconfig builds and x86 allmodconfig. For the moment, this doesn't change the definition of IS_ERR_VALUE() because there are probably still architecture specific users elsewhere. Almost all the warnings I got are for files that are better off using 'if (err)' or 'if (err < 0)'. The only legitimate user I could find that we get a warning for is the (32-bit only) freescale fman driver, so I did not remove the IS_ERR_VALUE() there but changed the type to 'unsigned long'. For 9pfs, I just worked around one user whose calling conventions are so obscure that I did not dare change the behavior. I was using this definition for testing: #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \ unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO)) which ends up making all 16-bit or wider types work correctly with the most plausible interpretation of what IS_ERR_VALUE() was supposed to return according to its users, but also causes a compile-time warning for any users that do not pass an 'unsigned long' argument. I suggested this approach earlier this year, but back then we ended up deciding to just fix the users that are obviously broken. After the initial warning that caused me to get involved in the discussion (fs/gfs2/dir.c) showed up again in the mainline kernel, Linus asked me to send the whole thing again. [ Updated the 9p parts as per Al Viro - Linus ] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Andrzej Hajda <a.hajda@samsung.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.org/lkml/2016/1/7/363 Link: https://lkml.org/lkml/2016/5/27/486 Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 9p: ensure err is initialized to 0 in p9_client_read/writeVincent Bernat2015-08-231-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some use of those functions were providing unitialized values to those functions. Notably, when reading 0 bytes from an empty file on a 9P filesystem, the return code of read() was not 0. Tested with this simple program: #include <assert.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> int main(int argc, const char **argv) { assert(argc == 2); char buffer[256]; int fd = open(argv[1], O_RDONLY|O_NOCTTY); assert(fd >= 0); assert(read(fd, buffer, 0) == 0); return 0; } Cc: stable@vger.kernel.org # v4.1 Signed-off-by: Vincent Bernat <vincent@bernat.im> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 9p: cope with bogus responses from server in p9_client_{read,write}Al Viro2015-07-041-0/+8
| | | | | | if server claims to have written/read more than we'd told it to, warn and cap the claimed byte count to avoid advancing more than we are ready to.
* p9_client_write(): avoid double p9_free_req()Al Viro2015-07-041-0/+1
| | | | | | | | | Braino in "9p: switch p9_client_write() to passing it struct iov_iter *"; if response is impossible to parse and we discard the request, get the out of the loop right there. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 9p: forgetting to cancel request on interrupted zero-copy RPCAl Viro2015-07-041-1/+2
| | | | | | | | | | | If we'd already sent a request and decide to abort it, we *must* issue TFLUSH properly and not just blindly reuse the tag, or we'll get seriously screwed when response eventually arrives and we confuse it for response to later request that had reused the same tag. Cc: stable@vger.kernel.org # v3.2 and later Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* p9_client_attach(): set fid->uid correctlyAl Viro2015-04-121-0/+1
| | | | | | | | | | | | | it's almost always equal to current_fsuid(), but there's an exception - if the first writeback fid is opened by non-root *and* that happens before root has done any lookups in /, we end up doing attach for root. The current code leaves the resulting FID owned by root from the server POV and by non-root from the client one. Unfortunately, it means that e.g. massive dcache eviction will leave that user buggered - they'll end up redoing walks from / *and* picking that FID every time. As soon as they try to create something, the things will get nasty. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 9p: switch p9_client_read() to passing struct iov_iter *Al Viro2015-04-121-63/+61
| | | | | | ... and make it loop Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 9p: switch p9_client_write() to passing it struct iov_iter *Al Viro2015-04-121-57/+41
| | | | | | ... and make it loop until it's done Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* net/9p: switch the guts of p9_client_{read,write}() to iov_iterAl Viro2015-04-121-58/+59
| | | | | | | ... and have get_user_pages_fast() mapping fewer pages than requested to generate a short read/write. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 9P: remove unnecessary break after returnFabian Frederick2014-07-161-1/+0
| | | | | Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: David S. Miller <davem@davemloft.net>
* 9P: Get rid of REQ_STATUS_FLSHSimon Derr2014-03-251-1/+1
| | | | | | | | | | | | | | | | | This request state is mostly useless, and properly implementing it for RDMA would require an extra lock to be taken in handle_recv() and in rdma_cancel() to avoid this race: handle_recv() rdma_cancel() . . . if req->state == SENT req->state = RCVD . . req->state = FLSH So just get rid of it. Signed-off-by: Simon Derr <simon.derr@bull.net> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
* 9P: Add cancelled() to the transport functions.Simon Derr2014-03-251-6/+3
| | | | | | | And move transport-specific code out of net/9p/client.c Signed-off-by: Simon Derr <simon.derr@bull.net> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
* net: Mark function as static in 9p/client.cRashika2014-03-251-1/+1
| | | | | | | | | | | | Mark function as static in net/9p/client.c because it is not used outside this file. This eliminates the following warning in net/9p/client.c: net/9p/client.c:207:18: warning: no previous prototype for ‘p9_fcall_alloc’ [-Wmissing-prototypes] Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
* 9P: Add memory barriers to protect request fields over cb/rpc threads handoffDominique Martinet2014-03-251-1/+15
| | | | | | | | | | | | | We need barriers to guarantee this pattern works as intended: [w] req->rc, 1 [r] req->status, 1 wmb rmb [w] req->status, 1 [r] req->rc Where the wmb ensures that rc gets written before status, and the rmb ensures that if you observe status == 1, rc is the new value. Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
* net/9p: remove virtio default hack and set appropriate bits insteadEric Van Hensbergen2013-11-231-3/+0
| | | | | | | | | A few releases back a patch made virtio the default transport, however it was done in a way which side-stepped the mechanism put in place to allow for this selection. This patch cleans that up while maintaining virtio as the default transport. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
* Merge tag 'for-linus-3.12-merge' of ↵Linus Torvalds2013-09-111-0/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs Pull 9p updates from Eric Van Hensbergen: "Minor 9p fixes and tweaks for 3.12 merge window The first fixes namespace issues which causes a kernel NULL pointer dereference, the second fixes uevent handling to work better with udev, and the third switches some code to use srlcpy instead of strncpy in order to be safer. All changes have been baking in for-next for at least 2 weeks" * tag 'for-linus-3.12-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: fs/9p: avoid accessing utsname after namespace has been torn down 9p: send uevent after adding/removing mount_tag attribute fs: 9p: use strlcpy instead of strncpy
| * fs/9p: avoid accessing utsname after namespace has been torn downWill Deacon2013-08-261-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During trinity fuzzing in a kvmtool guest, I stumbled across the following: Unable to handle kernel NULL pointer dereference at virtual address 00000004 PC is at v9fs_file_do_lock+0xc8/0x1a0 LR is at v9fs_file_do_lock+0x48/0x1a0 [<c01e2ed0>] (v9fs_file_do_lock+0xc8/0x1a0) from [<c0119154>] (locks_remove_flock+0x8c/0x124) [<c0119154>] (locks_remove_flock+0x8c/0x124) from [<c00d9bf0>] (__fput+0x58/0x1e4) [<c00d9bf0>] (__fput+0x58/0x1e4) from [<c0044340>] (task_work_run+0xac/0xe8) [<c0044340>] (task_work_run+0xac/0xe8) from [<c002e36c>] (do_exit+0x6bc/0x8d8) [<c002e36c>] (do_exit+0x6bc/0x8d8) from [<c002e674>] (do_group_exit+0x3c/0xb0) [<c002e674>] (do_group_exit+0x3c/0xb0) from [<c002e6f8>] (__wake_up_parent+0x0/0x18) I believe this is due to an attempt to access utsname()->nodename, after exit_task_namespaces() has been called, leaving current->nsproxy->uts_ns as NULL and causing the above dereference. A similar issue was fixed for lockd in 9a1b6bf818e7 ("LOCKD: Don't call utsname()->nodename from nlmclnt_setlockargs"), so this patch attempts something similar for 9pfs. Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
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