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2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<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>
2016-11-14net: fix sleeping for sk_wait_event()WANG Cong
Similar to commit 14135f30e33c ("inet: fix sleeping inside inet_wait_for_connect()"), sk_wait_event() needs to fix too, because release_sock() is blocking, it changes the process state back to running after sleep, which breaks the previous prepare_to_wait(). Switch to the new wait API. Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-28net: do not export sk_stream_write_spaceEric Dumazet
Since commit 900f65d361d3 ("tcp: move duplicate code from tcp_v4_init_sock()/tcp_v6_init_sock()") we no longer need to export sk_stream_write_space() From: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/renesas/ravb_main.c kernel/bpf/syscall.c net/ipv4/ipmr.c All three conflicts were cases of overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01net: fix sock_wake_async() rcu protectionEric Dumazet
Dmitry provided a syzkaller (http://github.com/google/syzkaller) triggering a fault in sock_wake_async() when async IO is requested. Said program stressed af_unix sockets, but the issue is generic and should be addressed in core networking stack. The problem is that by the time sock_wake_async() is called, we should not access the @flags field of 'struct socket', as the inode containing this socket might be freed without further notice, and without RCU grace period. We already maintain an RCU protected structure, "struct socket_wq" so moving SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA into it is the safe route. It also reduces number of cache lines needing dirtying, so might provide a performance improvement anyway. In followup patches, we might move remaining flags (SOCK_NOSPACE, SOCK_PASSCRED, SOCK_PASSSEC) to save 8 bytes and let 'struct socket' being mostly read and let it being shared between cpus. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATAEric Dumazet
This patch is a cleanup to make following patch easier to review. Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA from (struct socket)->flags to a (struct socket_wq)->flags to benefit from RCU protection in sock_wake_async() To ease backports, we rename both constants. Two new helpers, sk_set_bit(int nr, struct sock *sk) and sk_clear_bit(int net, struct sock *sk) are added so that following patch can change their implementation. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-30net: Generalise wq_has_sleeper helperHerbert Xu
The memory barrier in the helper wq_has_sleeper is needed by just about every user of waitqueue_active. This patch generalises it by making it take a wait_queue_head_t directly. The existing helper is renamed to skwq_has_sleeper. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09tcp: set SOCK_NOSPACE under memory pressureJason Baron
Under tcp memory pressure, calling epoll_wait() in edge triggered mode after -EAGAIN, can result in an indefinite hang in epoll_wait(), even when there is sufficient memory available to continue making progress. The problem is that when __sk_mem_schedule() returns 0 under memory pressure, we do not set the SOCK_NOSPACE flag in the tcp write paths (tcp_sendmsg() or do_tcp_sendpages()). Then, since SOCK_NOSPACE is used to trigger wakeups when incoming acks create sufficient new space in the write queue, all outstanding packets are acked, but we never wake up with the the EPOLLOUT that we are expecting from epoll_wait(). This issue is currently limited to epoll() when used in edge trigger mode, since 'tcp_poll()', does in fact currently set SOCK_NOSPACE. This is sufficient for poll()/select() and epoll() in level trigger mode. However, in edge trigger mode, epoll() is relying on the write path to set SOCK_NOSPACE. EPOLL(7) says that in edge-trigger mode we can only call epoll_wait() after read/write return -EAGAIN. Thus, in the case of the socket write, we are relying on the fact that tcp_sendmsg()/network write paths are going to issue a wakeup for us at some point in the future when we get -EAGAIN. Normally, epoll() edge trigger works fine when we've exceeded the sk->sndbuf because in that case we do set SOCK_NOSPACE. However, when we return -EAGAIN from the write path b/c we are over the tcp memory limits and not b/c we are over the sndbuf, we are never going to get another wakeup. I can reproduce this issue, using SO_SNDBUF, since __sk_mem_schedule() will return 0, or failure more readily with SO_SNDBUF: 1) create socket and set SO_SNDBUF to N 2) add socket as edge trigger 3) write to socket and block in epoll on -EAGAIN 4) cause tcp mem pressure via: echo "<small val>" > net.ipv4.tcp_mem The fix here is simply to set SOCK_NOSPACE in sk_stream_wait_memory() when the socket is non-blocking. Note that SOCK_NOSPACE, in addition to waking up outstanding waiters is also used to expand the size of the sk->sndbuf. However, we will not expand it by setting it in this case because tcp_should_expand_sndbuf(), ensures that no expansion occurs when we are under tcp memory pressure. Note that we could still hang if sk->sk_wmem_queue is 0, when we get the -EAGAIN. In this case the SOCK_NOSPACE bit will not help, since we are waiting for and event that will never happen. I believe that this case is harder to hit (and did not hit in my testing), in that over the tcp 'soft' memory limits, we continue to guarantee a minimum write buffer size. Perhaps, we could return -ENOSPC in this case, or maybe we simply issue a wakeup in this case, such that we keep retrying the write. Note that this case is not specific to epoll() ET, but rather would affect blocking sockets as well. So I view this patch as bringing epoll() edge-trigger into sync with the current poll()/select()/epoll() level trigger and blocking sockets behavior. Signed-off-by: Jason Baron <jbaron@akamai.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-14net: replace macros net_random and net_srandom with direct calls to prandomAruna-Hewapathirane
This patch removes the net_random and net_srandom macros and replaces them with direct calls to the prandom ones. As new commits only seem to use prandom_u32 there is no use to keep them around. This change makes it easier to grep for users of prandom_u32. Signed-off-by: Aruna-Hewapathirane <aruna.hewapathirane@gmail.com> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-24net: add sk_stream_is_writeable() helperEric Dumazet
Several call sites use the hardcoded following condition : sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) Lets use a helper because TCP_NOTSENT_LOWAT support will change this condition for TCP sockets. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-03net: Fix the condition passed to sk_wait_event()Nagendra Tomar
This patch fixes the condition (3rd arg) passed to sk_wait_event() in sk_stream_wait_memory(). The incorrect check in sk_stream_wait_memory() causes the following soft lockup in tcp_sendmsg() when the global tcp memory pool has exhausted. >>> snip <<< localhost kernel: BUG: soft lockup - CPU#3 stuck for 11s! [sshd:6429] localhost kernel: CPU 3: localhost kernel: RIP: 0010:[sk_stream_wait_memory+0xcd/0x200] [sk_stream_wait_memory+0xcd/0x200] sk_stream_wait_memory+0xcd/0x200 localhost kernel: localhost kernel: Call Trace: localhost kernel: [sk_stream_wait_memory+0x1b1/0x200] sk_stream_wait_memory+0x1b1/0x200 localhost kernel: [<ffffffff802557c0>] autoremove_wake_function+0x0/0x40 localhost kernel: [ipv6:tcp_sendmsg+0x6e6/0xe90] tcp_sendmsg+0x6e6/0xce0 localhost kernel: [sock_aio_write+0x126/0x140] sock_aio_write+0x126/0x140 localhost kernel: [xfs:do_sync_write+0xf1/0x130] do_sync_write+0xf1/0x130 localhost kernel: [<ffffffff802557c0>] autoremove_wake_function+0x0/0x40 localhost kernel: [hrtimer_start+0xe3/0x170] hrtimer_start+0xe3/0x170 localhost kernel: [vfs_write+0x185/0x190] vfs_write+0x185/0x190 localhost kernel: [sys_write+0x50/0x90] sys_write+0x50/0x90 localhost kernel: [system_call+0x7e/0x83] system_call+0x7e/0x83 >>> snip <<< What is happening is, that the sk_wait_event() condition passed from sk_stream_wait_memory() evaluates to true for the case of tcp global memory exhaustion. This is because both sk_stream_memory_free() and vm_wait are true which causes sk_wait_event() to *not* call schedule_timeout(). Hence sk_stream_wait_memory() returns immediately to the caller w/o sleeping. This causes the caller to again try allocation, which again fails and again calls sk_stream_wait_memory(), and so on. [ Bug introduced by commit c1cbe4b7ad0bc4b1d98ea708a3fecb7362aa4088 ("[NET]: Avoid atomic xchg() for non-error case") -DaveM ] Signed-off-by: Nagendra Singh Tomar <tomer_iisc@yahoo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-12net/core: EXPORT_SYMBOL cleanupsEric Dumazet
CodingStyle cleanups EXPORT_SYMBOL should immediately follow the symbol declaration. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-01net: sock_def_readable() and friends RCU conversionEric Dumazet
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we need two atomic operations (and associated dirtying) per incoming packet. RCU conversion is pretty much needed : 1) Add a new structure, called "struct socket_wq" to hold all fields that will need rcu_read_lock() protection (currently: a wait_queue_head_t and a struct fasync_struct pointer). [Future patch will add a list anchor for wakeup coalescing] 2) Attach one of such structure to each "struct socket" created in sock_alloc_inode(). 3) Respect RCU grace period when freeing a "struct socket_wq" 4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct socket_wq" 5) Change sk_sleep() function to use new sk->sk_wq instead of sk->sk_sleep 6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside a rcu_read_lock() section. 7) Change all sk_has_sleeper() callers to : - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock) - Use wq_has_sleeper() to eventually wakeup tasks. - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock) 8) sock_wake_async() is modified to use rcu protection as well. 9) Exceptions : macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq" instead of dynamically allocated ones. They dont need rcu freeing. Some cleanups or followups are probably needed, (possible sk_callback_lock conversion to a spinlock for example...). Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-20net: sk_sleep() helperEric Dumazet
Define a new function to return the waitqueue of a "struct sock". static inline wait_queue_head_t *sk_sleep(struct sock *sk) { return sk->sk_sleep; } Change all read occurrences of sk_sleep by a call to this function. Needed for a future RCU conversion. sk_sleep wont be a field directly available. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-17tcp: tcp_prequeue() can use keyed wakeupsJohn Dykstra
When TCP frees up write buffer space, avoid waking up tasks that have done a poll() or select() on the same socket specifying read-side events. This is an extension of a read-side patch by Eric Dumazet. Signed-off-by: John Dykstra <john.dykstra1@gmail.com> Acked-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-13net: Rationalise email address: Network Specific PartsAlan Cox
Clean up the various different email addresses of mine listed in the code to a single current and valid address. As Dave says his network merges for 2.6.28 are now done this seems a good point to send them in where they won't risk disrupting real changes. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-25net: convert BUG_TRAP to generic WARN_ONIlpo Järvinen
Removes legacy reinvent-the-wheel type thing. The generic machinery integrates much better to automated debugging aids such as kerneloops.org (and others), and is unambiguous due to better naming. Non-intuively BUG_TRAP() is actually equal to WARN_ON() rather than BUG_ON() though some might actually be promoted to BUG_ON() but I left that to future. I could make at least one BUILD_BUG_ON conversion. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET] CORE: Introducing new memory accounting interface.Hideo Aoki
This patch introduces new memory accounting functions for each network protocol. Most of them are renamed from memory accounting functions for stream protocols. At the same time, some stream memory accounting functions are removed since other functions do same thing. Renaming: sk_stream_free_skb() -> sk_wmem_free_skb() __sk_stream_mem_reclaim() -> __sk_mem_reclaim() sk_stream_mem_reclaim() -> sk_mem_reclaim() sk_stream_mem_schedule -> __sk_mem_schedule() sk_stream_pages() -> sk_mem_pages() sk_stream_rmem_schedule() -> sk_rmem_schedule() sk_stream_wmem_schedule() -> sk_wmem_schedule() sk_charge_skb() -> sk_mem_charge() Removeing sk_stream_rfree(): consolidates into sock_rfree() sk_stream_set_owner_r(): consolidates into skb_set_owner_r() sk_stream_mem_schedule() The following functions are added. sk_has_account(): check if the protocol supports accounting sk_mem_uncharge(): do the opposite of sk_mem_charge() In addition, to achieve consolidation, updating sk_wmem_queued is removed from sk_mem_charge(). Next, to consolidate memory accounting functions, this patch adds memory accounting calls to network core functions. Moreover, present memory accounting call is renamed to new accounting call. Finally we replace present memory accounting calls with new interface in TCP and SCTP. Signed-off-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Hideo Aoki <haoki@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[SOCK] Avoid divides in sk_stream_pages() and __sk_stream_mem_reclaim()Eric Dumazet
sk_forward_alloc being signed, we should take care of divides by SK_STREAM_MEM_QUANTUM we do in sk_stream_pages() and __sk_stream_mem_reclaim() This patchs introduces SK_STREAM_MEM_QUANTUM_SHIFT, defined as ilog2(SK_STREAM_MEM_QUANTUM), to be able to use right shifts instead of plain divides. This should help compiler to choose right shifts instead of expensive divides (as seen with CONFIG_CC_OPTIMIZE_FOR_SIZE=y on x86) Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET]: Name magic constants in sock_wake_async()Pavel Emelyanov
The sock_wake_async() performs a bit different actions depending on "how" argument. Unfortunately this argument ony has numerical magic values. I propose to give names to their constants to help people reading this function callers understand what's going on without looking into this function all the time. I suppose this is 2.6.25 material, but if it's not (or the naming seems poor/bad/awful), I can rework it against the current net-2.6 tree. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET]: Compact sk_stream_mem_schedule() codePavel Emelyanov
This function references sk->sk_prot->xxx for many times. It turned out, that there's so many code in it, that gcc cannot always optimize access to sk->sk_prot's fields. After saving the sk->sk_prot on the stack and comparing disassembled code, it turned out that the function became ~10 bytes shorter and made less dereferences (on i386 and x86_64). Stack consumption didn't grow. Besides, this patch drives most of this function into the 80 columns limit. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10[NET] CORE: Fix whitespace errors.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-12[NET]: fix __sk_stream_mem_reclaimIan McDonald
__sk_stream_mem_reclaim is only called by sk_stream_mem_reclaim. As such the check on sk->sk_forward_alloc is not needed and can be removed. Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-04-20[NET]: Add skb->truesize assertion checking.David S. Miller
Add some sanity checking. truesize should be at least sizeof(struct sk_buff) plus the current packet length. If not, then truesize is seriously mangled and deserves a kernel log message. Currently we'll do the check for release of stream socket buffers. But we can add checks to more spots over time. Incorporating ideas from Herbert Xu. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03[NET]: Avoid atomic xchg() for non-error caseBenjamin LaHaise
It also looks like there were 2 places where the test on sk_err was missing from the event wait logic (in sk_stream_wait_connect and sk_stream_wait_memory), while the rest of the sock_error() users look to be doing the right thing. This version of the patch fixes those, and cleans up a few places that were testing ->sk_err directly. Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-05[NET]: Fix race condition in sk_stream_wait_connectHerbert Xu
When sk_stream_wait_connect detects a state transition to ESTABLISHED or CLOSE_WAIT prior to it going to sleep, it will return without calling finish_wait and decrementing sk_write_pending. This may result in crashes and other unintended behaviour. The fix is to always call finish_wait and update sk_write_pending since it is safe to do so even if the wait entry is no longer on the queue. This bug was tracked down with the help of Alex Sidorenko and the fix is also based on his suggestion. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-05-01[PATCH] DocBook: changes and extensions to the kernel documentationPavel Pisa
I have recompiled Linux kernel 2.6.11.5 documentation for me and our university students again. The documentation could be extended for more sources which are equipped by structured comments for recent 2.6 kernels. I have tried to proceed with that task. I have done that more times from 2.6.0 time and it gets boring to do same changes again and again. Linux kernel compiles after changes for i386 and ARM targets. I have added references to some more files into kernel-api book, I have added some section names as well. So please, check that changes do not break something and that categories are not too much skewed. I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved by kernel convention. Most of the other changes are modifications in the comments to make kernel-doc happy, accept some parameters description and do not bail out on errors. Changed <pid> to @pid in the description, moved some #ifdef before comments to correct function to comments bindings, etc. You can see result of the modified documentation build at http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz Some more sources are ready to be included into kernel-doc generated documentation. Sources has been added into kernel-api for now. Some more section names added and probably some more chaos introduced as result of quick cleanup work. Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
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!