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2024-05-02af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc().Kuniyuki Iwashima1-1/+1
[ Upstream commit 1971d13ffa84a551d29a81fdf5b5ec5be166ac83 ] syzbot reported a lockdep splat regarding unix_gc_lock and unix_state_lock(). One is called from recvmsg() for a connected socket, and another is called from GC for TCP_LISTEN socket. So, the splat is false-positive. Let's add a dedicated lock class for the latter to suppress the splat. Note that this change is not necessary for net-next.git as the issue is only applied to the old GC impl. [0]: WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #0 Not tainted ----------------------------------------------------- kworker/u8:1/11 is trying to acquire lock: ffff88807cea4e70 (&u->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88807cea4e70 (&u->lock){+.+.}-{2:2}, at: __unix_gc+0x40e/0xf70 net/unix/garbage.c:302 but task is already holding lock: ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (unix_gc_lock){+.+.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] unix_notinflight+0x13d/0x390 net/unix/garbage.c:140 unix_detach_fds net/unix/af_unix.c:1819 [inline] unix_destruct_scm+0x221/0x350 net/unix/af_unix.c:1876 skb_release_head_state+0x100/0x250 net/core/skbuff.c:1188 skb_release_all net/core/skbuff.c:1200 [inline] __kfree_skb net/core/skbuff.c:1216 [inline] kfree_skb_reason+0x16d/0x3b0 net/core/skbuff.c:1252 kfree_skb include/linux/skbuff.h:1262 [inline] manage_oob net/unix/af_unix.c:2672 [inline] unix_stream_read_generic+0x1125/0x2700 net/unix/af_unix.c:2749 unix_stream_splice_read+0x239/0x320 net/unix/af_unix.c:2981 do_splice_read fs/splice.c:985 [inline] splice_file_to_pipe+0x299/0x500 fs/splice.c:1295 do_splice+0xf2d/0x1880 fs/splice.c:1379 __do_splice fs/splice.c:1436 [inline] __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice+0x331/0x4a0 fs/splice.c:1634 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&u->lock){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __unix_gc+0x40e/0xf70 net/unix/garbage.c:302 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(unix_gc_lock); lock(&u->lock); lock(unix_gc_lock); lock(&u->lock); *** DEADLOCK *** 3 locks held by kworker/u8:1/11: #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335 #1: ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335 #2: ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261 stack backtrace: CPU: 0 PID: 11 Comm: kworker/u8:1 Not tainted 6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: events_unbound __unix_gc Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __unix_gc+0x40e/0xf70 net/unix/garbage.c:302 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Fixes: 47d8ac011fe1 ("af_unix: Fix garbage collector racing against connect()") Reported-and-tested-by: syzbot+fa379358c28cc87cc307@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=fa379358c28cc87cc307 Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240424170443.9832-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-17af_unix: Fix garbage collector racing against connect()Michal Luczaj1-1/+17
[ Upstream commit 47d8ac011fe1c9251070e1bd64cb10b48193ec51 ] Garbage collector does not take into account the risk of embryo getting enqueued during the garbage collection. If such embryo has a peer that carries SCM_RIGHTS, two consecutive passes of scan_children() may see a different set of children. Leading to an incorrectly elevated inflight count, and then a dangling pointer within the gc_inflight_list. sockets are AF_UNIX/SOCK_STREAM S is an unconnected socket L is a listening in-flight socket bound to addr, not in fdtable V's fd will be passed via sendmsg(), gets inflight count bumped connect(S, addr) sendmsg(S, [V]); close(V) __unix_gc() ---------------- ------------------------- ----------- NS = unix_create1() skb1 = sock_wmalloc(NS) L = unix_find_other(addr) unix_state_lock(L) unix_peer(S) = NS // V count=1 inflight=0 NS = unix_peer(S) skb2 = sock_alloc() skb_queue_tail(NS, skb2[V]) // V became in-flight // V count=2 inflight=1 close(V) // V count=1 inflight=1 // GC candidate condition met for u in gc_inflight_list: if (total_refs == inflight_refs) add u to gc_candidates // gc_candidates={L, V} for u in gc_candidates: scan_children(u, dec_inflight) // embryo (skb1) was not // reachable from L yet, so V's // inflight remains unchanged __skb_queue_tail(L, skb1) unix_state_unlock(L) for u in gc_candidates: if (u.inflight) scan_children(u, inc_inflight_move_tail) // V count=1 inflight=2 (!) If there is a GC-candidate listening socket, lock/unlock its state. This makes GC wait until the end of any ongoing connect() to that socket. After flipping the lock, a possibly SCM-laden embryo is already enqueued. And if there is another embryo coming, it can not possibly carry SCM_RIGHTS. At this point, unix_inflight() can not happen because unix_gc_lock is already taken. Inflight graph remains unaffected. Fixes: 1fd05ba5a2f2 ("[AF_UNIX]: Rewrite garbage collector, fixes race.") Signed-off-by: Michal Luczaj <mhal@rbox.co> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240409201047.1032217-1-mhal@rbox.co Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-17af_unix: Do not use atomic ops for unix_sk(sk)->inflight.Kuniyuki Iwashima1-9/+8
[ Upstream commit 97af84a6bba2ab2b9c704c08e67de3b5ea551bb2 ] When touching unix_sk(sk)->inflight, we are always under spin_lock(&unix_gc_lock). Let's convert unix_sk(sk)->inflight to the normal unsigned long. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240123170856.41348-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 47d8ac011fe1 ("af_unix: Fix garbage collector racing against connect()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-27af_unix: Annotate data-race of gc_in_progress in wait_for_unix_gc().Kuniyuki Iwashima1-1/+1
[ Upstream commit 31e03207119a535d0b0e3b3a7f91983aeb2cb14d ] gc_in_progress is changed under spin_lock(&unix_gc_lock), but wait_for_unix_gc() reads it locklessly. Let's use READ_ONCE(). Fixes: 5f23b734963e ("net: Fix soft lockups/OOM issues w/ unix garbage collector") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240123170856.41348-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-06af_unix: Drop oob_skb ref before purging queue in GC.Kuniyuki Iwashima1-13/+9
commit aa82ac51d63328714645c827775d64dbfd9941f3 upstream. syzbot reported another task hung in __unix_gc(). [0] The current while loop assumes that all of the left candidates have oob_skb and calling kfree_skb(oob_skb) releases the remaining candidates. However, I missed a case that oob_skb has self-referencing fd and another fd and the latter sk is placed before the former in the candidate list. Then, the while loop never proceeds, resulting the task hung. __unix_gc() has the same loop just before purging the collected skb, so we can call kfree_skb(oob_skb) there and let __skb_queue_purge() release all inflight sockets. [0]: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2784 Comm: kworker/u4:8 Not tainted 6.8.0-rc4-syzkaller-01028-g71b605d32017 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: events_unbound __unix_gc RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:200 Code: 89 fb e8 23 00 00 00 48 8b 3d 84 f5 1a 0c 48 89 de 5b e9 43 26 57 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0d 90 52 70 7e 65 8b 15 91 52 70 RSP: 0018:ffffc9000a17fa78 EFLAGS: 00000287 RAX: ffffffff8a0a6108 RBX: ffff88802b6c2640 RCX: ffff88802c0b3b80 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc9000a17fbf0 R08: ffffffff89383f1d R09: 1ffff1100ee5ff84 R10: dffffc0000000000 R11: ffffed100ee5ff85 R12: 1ffff110056d84ee R13: ffffc9000a17fae0 R14: 0000000000000000 R15: ffffffff8f47b840 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffef5687ff8 CR3: 0000000029b34000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> __unix_gc+0xe69/0xf40 net/unix/garbage.c:343 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 </TASK> Reported-and-tested-by: syzbot+ecab4d36f920c3574bf9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=ecab4d36f920c3574bf9 Fixes: 25236c91b5ab ("af_unix: Fix task hung while purging oob_skb in GC.") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-06af_unix: Fix task hung while purging oob_skb in GC.Kuniyuki Iwashima1-3/+4
[ Upstream commit 25236c91b5ab4a26a56ba2e79b8060cf4e047839 ] syzbot reported a task hung; at the same time, GC was looping infinitely in list_for_each_entry_safe() for OOB skb. [0] syzbot demonstrated that the list_for_each_entry_safe() was not actually safe in this case. A single skb could have references for multiple sockets. If we free such a skb in the list_for_each_entry_safe(), the current and next sockets could be unlinked in a single iteration. unix_notinflight() uses list_del_init() to unlink the socket, so the prefetched next socket forms a loop itself and list_for_each_entry_safe() never stops. Here, we must use while() and make sure we always fetch the first socket. [0]: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5065 Comm: syz-executor236 Not tainted 6.8.0-rc3-syzkaller-00136-g1f719a2f3fa6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60 kernel/kcov.c:207 Code: cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 14 25 40 c2 03 00 <65> 8b 05 b4 7c 78 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 RSP: 0018:ffffc900033efa58 EFLAGS: 00000283 RAX: ffff88807b077800 RBX: ffff88807b077800 RCX: 1ffffffff27b1189 RDX: ffff88802a5a3b80 RSI: ffffffff8968488d RDI: ffff88807b077f70 RBP: ffffc900033efbb0 R08: 0000000000000001 R09: fffffbfff27a900c R10: ffffffff93d48067 R11: ffffffff8ae000eb R12: ffff88807b077800 R13: dffffc0000000000 R14: ffff88807b077e40 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564f4fc1e3a8 CR3: 000000000d57a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> unix_gc+0x563/0x13b0 net/unix/garbage.c:319 unix_release_sock+0xa93/0xf80 net/unix/af_unix.c:683 unix_release+0x91/0xf0 net/unix/af_unix.c:1064 __sock_release+0xb0/0x270 net/socket.c:659 sock_close+0x1c/0x30 net/socket.c:1421 __fput+0x270/0xb80 fs/file_table.c:376 task_work_run+0x14f/0x250 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa8a/0x2ad0 kernel/exit.c:871 do_group_exit+0xd4/0x2a0 kernel/exit.c:1020 __do_sys_exit_group kernel/exit.c:1031 [inline] __se_sys_exit_group kernel/exit.c:1029 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1029 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x270 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f9d6cbdac09 Code: Unable to access opcode bytes at 0x7f9d6cbdabdf. RSP: 002b:00007fff5952feb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9d6cbdac09 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 00007f9d6cc552b0 R08: ffffffffffffffb8 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 00007f9d6cc552b0 R13: 0000000000000000 R14: 00007f9d6cc55d00 R15: 00007f9d6cbabe70 </TASK> Reported-by: syzbot+4fa4a2d1f5a5ee06f006@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4fa4a2d1f5a5ee06f006 Fixes: 1279f9d9dec2 ("af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240209220453.96053-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-16af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.Kuniyuki Iwashima1-0/+11
[ Upstream commit 1279f9d9dec2d7462823a18c29ad61359e0a007d ] syzbot reported a warning [0] in __unix_gc() with a repro, which creates a socketpair and sends one socket's fd to itself using the peer. socketpair(AF_UNIX, SOCK_STREAM, 0, [3, 4]) = 0 sendmsg(4, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\360", iov_len=1}], msg_iovlen=1, msg_control=[{cmsg_len=20, cmsg_level=SOL_SOCKET, cmsg_type=SCM_RIGHTS, cmsg_data=[3]}], msg_controllen=24, msg_flags=0}, MSG_OOB|MSG_PROBE|MSG_DONTWAIT|MSG_ZEROCOPY) = 1 This forms a self-cyclic reference that GC should finally untangle but does not due to lack of MSG_OOB handling, resulting in memory leak. Recently, commit 11498715f266 ("af_unix: Remove io_uring code for GC.") removed io_uring's dead code in GC and revealed the problem. The code was executed at the final stage of GC and unconditionally moved all GC candidates from gc_candidates to gc_inflight_list. That papered over the reported problem by always making the following WARN_ON_ONCE(!list_empty(&gc_candidates)) false. The problem has been there since commit 2aab4b969002 ("af_unix: fix struct pid leaks in OOB support") added full scm support for MSG_OOB while fixing another bug. To fix this problem, we must call kfree_skb() for unix_sk(sk)->oob_skb if the socket still exists in gc_candidates after purging collected skb. Then, we need to set NULL to oob_skb before calling kfree_skb() because it calls last fput() and triggers unix_release_sock(), where we call duplicate kfree_skb(u->oob_skb) if not NULL. Note that the leaked socket remained being linked to a global list, so kmemleak also could not detect it. We need to check /proc/net/protocol to notice the unfreed socket. [0]: WARNING: CPU: 0 PID: 2863 at net/unix/garbage.c:345 __unix_gc+0xc74/0xe80 net/unix/garbage.c:345 Modules linked in: CPU: 0 PID: 2863 Comm: kworker/u4:11 Not tainted 6.8.0-rc1-syzkaller-00583-g1701940b1a02 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: events_unbound __unix_gc RIP: 0010:__unix_gc+0xc74/0xe80 net/unix/garbage.c:345 Code: 8b 5c 24 50 e9 86 f8 ff ff e8 f8 e4 22 f8 31 d2 48 c7 c6 30 6a 69 89 4c 89 ef e8 97 ef ff ff e9 80 f9 ff ff e8 dd e4 22 f8 90 <0f> 0b 90 e9 7b fd ff ff 48 89 df e8 5c e7 7c f8 e9 d3 f8 ff ff e8 RSP: 0018:ffffc9000b03fba0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffffc9000b03fc10 RCX: ffffffff816c493e RDX: ffff88802c02d940 RSI: ffffffff896982f3 RDI: ffffc9000b03fb30 RBP: ffffc9000b03fce0 R08: 0000000000000001 R09: fffff52001607f66 R10: 0000000000000003 R11: 0000000000000002 R12: dffffc0000000000 R13: ffffc9000b03fc10 R14: ffffc9000b03fc10 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005559c8677a60 CR3: 000000000d57a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> process_one_work+0x889/0x15e0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x12a0 kernel/workqueue.c:2787 kthread+0x2c6/0x3b0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 </TASK> Reported-by: syzbot+fa3ef895554bdbfd1183@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=fa3ef895554bdbfd1183 Fixes: 2aab4b969002 ("af_unix: fix struct pid leaks in OOB support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240203183149.63573-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-13io_uring/af_unix: defer registered files gc to io_uring releasePavel Begunkov1-0/+20
Instead of putting io_uring's registered files in unix_gc() we want it to be done by io_uring itself. The trick here is to consider io_uring registered files for cycle detection but not actually putting them down. Because io_uring can't register other ring instances, this will remove all refs to the ring file triggering the ->release path and clean up with io_ring_ctx_free(). Cc: stable@vger.kernel.org Fixes: 6b06314c47e1 ("io_uring: add file set registration") Reported-and-tested-by: David Bouman <dbouman03@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> [axboe: add kerneldoc comment to skb, fold in skb leak fix] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-01-15af_unix: annote lockless accesses to unix_tot_inflight & gc_in_progressEric Dumazet1-3/+11
wait_for_unix_gc() reads unix_tot_inflight & gc_in_progress without synchronization. Adds READ_ONCE()/WRITE_ONCE() and their associated comments to better document the intent. BUG: KCSAN: data-race in unix_inflight / wait_for_unix_gc write to 0xffffffff86e2b7c0 of 4 bytes by task 9380 on cpu 0: unix_inflight+0x1e8/0x260 net/unix/scm.c:63 unix_attach_fds+0x10c/0x1e0 net/unix/scm.c:121 unix_scm_to_skb net/unix/af_unix.c:1674 [inline] unix_dgram_sendmsg+0x679/0x16b0 net/unix/af_unix.c:1817 unix_seqpacket_sendmsg+0xcc/0x110 net/unix/af_unix.c:2258 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffffffff86e2b7c0 of 4 bytes by task 9375 on cpu 1: wait_for_unix_gc+0x24/0x160 net/unix/garbage.c:196 unix_dgram_sendmsg+0x8e/0x16b0 net/unix/af_unix.c:1772 unix_seqpacket_sendmsg+0xcc/0x110 net/unix/af_unix.c:2258 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00000002 -> 0x00000004 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 9375 Comm: syz-executor.1 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 9915672d4127 ("af_unix: limit unix_tot_inflight") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Link: https://lore.kernel.org/r/20220114164328.2038499-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 62Thomas Gleixner1-6/+1
Based on 1 normalized pattern(s): released under the gpl version 2 or later and 1 additional 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 as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520071858.828691433@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-28net: split out functions related to registering inflight socket filesJens Axboe1-69/+2
We need this functionality for the io_uring file registration, but we cannot rely on it since CONFIG_UNIX can be modular. Move the helpers to a separate file, that's always builtin to the kernel if CONFIG_UNIX is m/y. No functional changes in this patch, just moving code around. Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28Add io_uring IO interfaceJens Axboe1-0/+3
The submission queue (SQ) and completion queue (CQ) rings are shared between the application and the kernel. This eliminates the need to copy data back and forth to submit and complete IO. IO submissions use the io_uring_sqe data structure, and completions are generated in the form of io_uring_cqe data structures. The SQ ring is an index into the io_uring_sqe array, which makes it possible to submit a batch of IOs without them being contiguous in the ring. The CQ ring is always contiguous, as completion events are inherently unordered, and hence any io_uring_cqe entry can point back to an arbitrary submission. Two new system calls are added for this: io_uring_setup(entries, params) Sets up an io_uring instance for doing async IO. On success, returns a file descriptor that the application can mmap to gain access to the SQ ring, CQ ring, and io_uring_sqes. io_uring_enter(fd, to_submit, min_complete, flags, sigset, sigsetsize) Initiates IO against the rings mapped to this fd, or waits for them to complete, or both. The behavior is controlled by the parameters passed in. If 'to_submit' is non-zero, then we'll try and submit new IO. If IORING_ENTER_GETEVENTS is set, the kernel will wait for 'min_complete' events, if they aren't already available. It's valid to set IORING_ENTER_GETEVENTS and 'min_complete' == 0 at the same time, this allows the kernel to return already completed events without waiting for them. This is useful only for polling, as for IRQ driven IO, the application can just check the CQ ring without entering the kernel. With this setup, it's possible to do async IO with a single system call. Future developments will enable polled IO with this interface, and polled submission as well. The latter will enable an application to do IO without doing ANY system calls at all. For IRQ driven IO, an application only needs to enter the kernel for completions if it wants to wait for them to occur. Each io_uring is backed by a workqueue, to support buffered async IO as well. We will only punt to an async context if the command would need to wait for IO on the device side. Any data that can be accessed directly in the page cache is done inline. This avoids the slowness issue of usual threadpools, since cached data is accessed as quickly as a sync interface. Sample application: http://git.kernel.dk/cgit/fio/plain/t/io_uring.c Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-03-22net: unix: properly re-increment inflight counter of GC discarded candidatesAndrey Ulanov1-8/+9
Dmitry has reported that a BUG_ON() condition in unix_notinflight() may be triggered by a simple code that forwards unix socket in an SCM_RIGHTS message. That is caused by incorrect unix socket GC implementation in unix_gc(). The GC first collects list of candidates, then (a) decrements their "children's" inflight counter, (b) checks which inflight counters are now 0, and then (c) increments all inflight counters back. (a) and (c) are done by calling scan_children() with inc_inflight or dec_inflight as the second argument. Commit 6209344f5a37 ("net: unix: fix inflight counting bug in garbage collector") changed scan_children() such that it no longer considers sockets that do not have UNIX_GC_CANDIDATE flag. It also added a block of code that that unsets this flag _before_ invoking scan_children(, dec_iflight, ). This may lead to incorrect inflight counters for some sockets. This change fixes this bug by changing order of operations: UNIX_GC_CANDIDATE is now unset only after all inflight counters are restored to the original state. kernel BUG at net/unix/garbage.c:149! RIP: 0010:[<ffffffff8717ebf4>] [<ffffffff8717ebf4>] unix_notinflight+0x3b4/0x490 net/unix/garbage.c:149 Call Trace: [<ffffffff8716cfbf>] unix_detach_fds.isra.19+0xff/0x170 net/unix/af_unix.c:1487 [<ffffffff8716f6a9>] unix_destruct_scm+0xf9/0x210 net/unix/af_unix.c:1496 [<ffffffff86a90a01>] skb_release_head_state+0x101/0x200 net/core/skbuff.c:655 [<ffffffff86a9808a>] skb_release_all+0x1a/0x60 net/core/skbuff.c:668 [<ffffffff86a980ea>] __kfree_skb+0x1a/0x30 net/core/skbuff.c:684 [<ffffffff86a98284>] kfree_skb+0x184/0x570 net/core/skbuff.c:705 [<ffffffff871789d5>] unix_release_sock+0x5b5/0xbd0 net/unix/af_unix.c:559 [<ffffffff87179039>] unix_release+0x49/0x90 net/unix/af_unix.c:836 [<ffffffff86a694b2>] sock_release+0x92/0x1f0 net/socket.c:570 [<ffffffff86a6962b>] sock_close+0x1b/0x20 net/socket.c:1017 [<ffffffff81a76b8e>] __fput+0x34e/0x910 fs/file_table.c:208 [<ffffffff81a771da>] ____fput+0x1a/0x20 fs/file_table.c:244 [<ffffffff81483ab0>] task_work_run+0x1a0/0x280 kernel/task_work.c:116 [< inline >] exit_task_work include/linux/task_work.h:21 [<ffffffff8141287a>] do_exit+0x183a/0x2640 kernel/exit.c:828 [<ffffffff8141383e>] do_group_exit+0x14e/0x420 kernel/exit.c:931 [<ffffffff814429d3>] get_signal+0x663/0x1880 kernel/signal.c:2307 [<ffffffff81239b45>] do_signal+0xc5/0x2190 arch/x86/kernel/signal.c:807 [<ffffffff8100666a>] exit_to_usermode_loop+0x1ea/0x2d0 arch/x86/entry/common.c:156 [< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:190 [<ffffffff81009693>] syscall_return_slowpath+0x4d3/0x570 arch/x86/entry/common.c:259 [<ffffffff881478e6>] entry_SYSCALL_64_fastpath+0xc4/0xc6 Link: https://lkml.org/lkml/2017/3/6/252 Signed-off-by: Andrey Ulanov <andreyu@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 6209344 ("net: unix: fix inflight counting bug in garbage collector") Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-08unix: correctly track in-flight fds in sending process user_structHannes Frederic Sowa1-4/+4
The commit referenced in the Fixes tag incorrectly accounted the number of in-flight fds over a unix domain socket to the original opener of the file-descriptor. This allows another process to arbitrary deplete the original file-openers resource limit for the maximum of open files. Instead the sending processes and its struct cred should be credited. To do so, we add a reference counted struct user_struct pointer to the scm_fp_list and use it to account for the number of inflight unix fds. Fixes: 712f4aad406bb1 ("unix: properly account for FDs passed over unix sockets") Reported-by: David Herrmann <dh.herrmann@gmail.com> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-11unix: properly account for FDs passed over unix socketswilly tarreau1-5/+8
It is possible for a process to allocate and accumulate far more FDs than the process' limit by sending them over a unix socket then closing them to keep the process' fd count low. This change addresses this problem by keeping track of the number of FDs in flight per user and preventing non-privileged processes from having more FDs in flight than their configured FD limit. Reported-by: socketpair@gmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Mitigates: CVE-2013-4312 (Linux 2.0+) Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-23net: unix: garbage: fixed several comment and whitespace style issuesJason Eastman1-42/+28
fixed several comment and whitespace style issues Signed-off-by: Jason Eastman <eastman.jason.linux@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-08af_unix: remove 0 assignment on staticFabian Frederick1-1/+1
static values are automatically initialized to 0 Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-01af_unix: fix a fatal race with bit fieldsEric Dumazet1-6/+6
Using bit fields is dangerous on ppc64/sparc64, as the compiler [1] uses 64bit instructions to manipulate them. If the 64bit word includes any atomic_t or spinlock_t, we can lose critical concurrent changes. This is happening in af_unix, where unix_sk(sk)->gc_candidate/ gc_maybe_cycle/lock share the same 64bit word. This leads to fatal deadlock, as one/several cpus spin forever on a spinlock that will never be available again. A safer way would be to use a long to store flags. This way we are sure compiler/arch wont do bad things. As we own unix_gc_lock spinlock when clearing or setting bits, we can use the non atomic __set_bit()/__clear_bit(). recursion_level can share the same 64bit location with the spinlock, as it is set only with this spinlock held. [1] bug fixed in gcc-4.8.0 : http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52080 Reported-by: Ambrose Feinstein <ambrose@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-23new helper: file_inode(file)Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15Allow passing O_PATH descriptors via SCM_RIGHTS datagramsAl Viro1-1/+1
Just need to make sure that AF_UNIX garbage collector won't confuse O_PATHed socket on filesystem for real AF_UNIX opened socket. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-11-29af_unix: limit recursion levelEric Dumazet1-1/+1
Its easy to eat all kernel memory and trigger NMI watchdog, using an exploit program that queues unix sockets on top of others. lkml ref : http://lkml.org/lkml/2010/11/25/8 This mechanism is used in applications, one choice we have is to have a recursion limit. Other limits might be needed as well (if we queue other types of files), since the passfd mechanism is currently limited by socket receive queue sizes only. Add a recursion_level to unix socket, allowing up to 4 levels. Each time we send an unix socket through sendfd mechanism, we copy its recursion level (plus one) to receiver. This recursion level is cleared when socket receive queue is emptied. Reported-by: Марк Коренберг <socketpair@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-24af_unix: limit unix_tot_inflightEric Dumazet1-0/+7
Vegard Nossum found a unix socket OOM was possible, posting an exploit program. My analysis is we can eat all LOWMEM memory before unix_gc() being called from unix_release_sock(). Moreover, the thread blocked in unix_gc() can consume huge amount of time to perform cleanup because of huge working set. One way to handle this is to have a sensible limit on unix_tot_inflight, tested from wait_for_unix_gc() and to force a call to unix_gc() if this limit is hit. This solves the OOM and also reduce overall latencies, and should not slowdown normal workloads. Reported-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-04unix/garbage: kill copy of the skb queue walkerIlpo Järvinen1-11/+2
Worse yet, it seems that its arguments were in reverse order. Also remove one related helper which seems hardly worth keeping. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo1-1/+0
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2008-12-03Merge branch 'master' of ↵David S. Miller1-3/+10
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/ixgbe/ixgbe_main.c drivers/net/smc91x.c
2008-11-27net: Fix soft lockups/OOM issues w/ unix garbage collectordann frazier1-3/+10
This is an implementation of David Miller's suggested fix in: https://bugzilla.redhat.com/show_bug.cgi?id=470201 It has been updated to use wait_event() instead of wait_event_interruptible(). Paraphrasing the description from the above report, it makes sendmsg() block while UNIX garbage collection is in progress. This avoids a situation where child processes continue to queue new FDs over a AF_UNIX socket to a parent which is in the exit path and running garbage collection on these FDs. This contention can result in soft lockups and oom-killing of unrelated processes. Signed-off-by: dann frazier <dannf@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-12Merge branch 'master' of ↵David S. Miller1-12/+37
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/message/fusion/mptlan.c drivers/net/sfc/ethtool.c net/mac80211/debugfs_sta.c
2008-11-09net: unix: fix inflight counting bug in garbage collectorMiklos Szeredi1-12/+37
Previously I assumed that the receive queues of candidates don't change during the GC. This is only half true, nothing can be received from the queues (see comment in unix_gc()), but buffers could be added through the other half of the socket pair, which may still have file descriptors referring to it. This can result in inc_inflight_move_tail() erronously increasing the "inflight" counter for a unix socket for which dec_inflight() wasn't previously called. This in turn can trigger the "BUG_ON(total_refs < inflight_refs)" in a later garbage collection run. Fix this by only manipulating the "inflight" counter for sockets which are candidates themselves. Duplicating the file references in unix_attach_fds() is also needed to prevent a socket becoming a candidate for GC while the skb that contains it is not yet queued. Reported-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-02af_unix: clean up net/unix/af_unix.c garbage.c sysctl_net_unix.cJianjun Kong1-6/+6
clean up net/unix/af_unix.c garbage.c sysctl_net_unix.c Signed-off-by: Jianjun Kong <jianjun@zeuux.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-27[PATCH] f_count may wrap aroundAl Viro1-9/+9
make it atomic_long_t; while we are at it, get rid of useless checks in affs, hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-11-11[AF_UNIX]: Convert socks to unix_socks in scan_inflight, not in callbacksPavel Emelyanov1-11/+9
The scan_inflight() routine scans through the unix sockets and calls some passed callback. The fact is that all these callbacks work with the unix_sock objects, not the sock ones, so make this conversion in the scan_inflight() before calling the callbacks. This removes one unneeded variable from the inc_inflight_move_tail(). Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-11[AF_UNIX]: Make unix_tot_inflight counter non-atomicPavel Emelyanov1-3/+3
This counter is _always_ modified under the unix_gc_lock spinlock, so its atomicity can be provided w/o additional efforts. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-12[AF_UNIX]: Rewrite garbage collector, fixes race.Miklos Szeredi1-139/+186
Throw out the old mark & sweep garbage collector and put in a refcounting cycle detecting one. The old one had a race with recvmsg, that resulted in false positives and hence data loss. The old algorithm operated on all unix sockets in the system, so any additional locking would have meant performance problems for all users of these. The new algorithm instead only operates on "in flight" sockets, which are very rare, and the additional locking for these doesn't negatively impact the vast majority of users. In fact it's probable, that there weren't *any* heavy senders of sockets over sockets, otherwise the above race would have been discovered long ago. The patch works OK with the app that exposed the race with the old code. The garbage collection has also been verified to work in a few simple cases. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-14[PATCH] remove many unneeded #includes of sched.hTim Schmielau1-1/+0
After Al Viro (finally) succeeded in removing the sched.h #include in module.h recently, it makes sense again to remove other superfluous sched.h includes. There are quite a lot of files which include it but don't actually need anything defined in there. Presumably these includes were once needed for macros that used to live in sched.h, but moved to other header files in the course of cleaning it up. To ease the pain, this time I did not fiddle with any header files and only removed #includes from .c-files, which tend to cause less trouble. Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha, arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig, allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all configs in arch/arm/configs on arm. I also checked that no new warnings were introduced by the patch (actually, some warnings are removed that were emitted by unnecessarily included header files). Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[NET] UNIX: Fix whitespace errors.YOSHIFUJI Hideaki1-7/+7
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-08[PATCH] struct path: convert unixJosef Sipek1-1/+1
Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-21[NET] sem2mutex: net/Arjan van de Ven1-3/+4
Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-04[AF_UNIX]: Use spinlock for unix_table_lockDavid S. Miller1-2/+2
This lock is actually taken mostly as a writer, so using a rwlock actually just makes performance worse especially on chips like the Intel P4. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-30[TCP]: Move the tcp sock states to net/tcp_states.hArnaldo Carvalho de Melo1-1/+1
Lots of places just needs the states, not even linux/tcp.h, where this enum was, needs it. This speeds up development of the refactorings as less sources are rebuilt when things get moved from net/tcp.h. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-30[NET]: Kill skb->listDavid S. Miller1-6/+6
Remove the "list" member of struct sk_buff, as it is entirely redundant. All SKB list removal callers know which list the SKB is on, so storing this in sk_buff does nothing other than taking up some space. Two tricky bits were SCTP, which I took care of, and two ATM drivers which Francois Romieu <romieu@fr.zoreil.com> fixed up. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
2005-04-17Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds1-0/+312
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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