- 15 2月, 2012 1 次提交
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由 Axel Lin 提交于
The first parameter should be "number of elements" and the second parameter should be "element size". Signed-off-by: NAxel Lin <axel.lin@gmail.com> Acked-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 20 12月, 2011 1 次提交
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由 Rusty Russell 提交于
DaveM said: Please, this kind of stuff rots forever and not using bool properly drives me crazy. Joe Perches <joe@perches.com> gave me the spatch script: @@ bool b; @@ -b = 0 +b = false @@ bool b; @@ -b = 1 +b = true I merely installed coccinelle, read the documentation and took credit. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 22 11月, 2011 1 次提交
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由 Thomas Meyer 提交于
The semantic patch that makes this change is available in scripts/coccinelle/api/memdup.cocci. Signed-off-by: NThomas Meyer <thomas@m3y3r.de> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 01 11月, 2011 1 次提交
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由 Paul Gortmaker 提交于
These files are non modular, but need to export symbols using the macros now living in export.h -- call out the include so that things won't break when we remove the implicit presence of module.h from everywhere. Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
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- 20 5月, 2011 5 次提交
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由 David S. Miller 提交于
This is identical to the case I fixed in rxrpc_get_peer() Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David S. Miller 提交于
I backed off from trying to just eliminate this variable, since transforming atomic_inc_return() into atomic_inc() takes away the memory barriers. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David S. Miller 提交于
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David S. Miller 提交于
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David S. Miller 提交于
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 04 5月, 2011 1 次提交
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由 David S. Miller 提交于
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 13 3月, 2011 1 次提交
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由 David S. Miller 提交于
The idea here is this minimizes the number of places one has to edit in order to make changes to how flows are defined and used. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 08 3月, 2011 1 次提交
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由 David Howells 提交于
Add a key type operation to permit the key type to vet the description of a new key that key_alloc() is about to allocate. The operation may reject the description if it wishes with an error of its choosing. If it does this, the key will not be allocated. Signed-off-by: NDavid Howells <dhowells@redhat.com> Reviewed-by: NMimi Zohar <zohar@us.ibm.com> Signed-off-by: NJames Morris <jmorris@namei.org>
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- 03 3月, 2011 2 次提交
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由 David Howells 提交于
The OpenAFS server is now sending ACKALL packets, so we need to handle them. Otherwise we report a protocol error and abort. Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David S. Miller 提交于
Instead of on the stack. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 26 2月, 2011 1 次提交
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由 Anton Blanchard 提交于
With slab poisoning enabled, I see the following oops: Unable to handle kernel paging request for data at address 0x6b6b6b6b6b6b6b73 ... NIP [c0000000006bc61c] .rxrpc_destroy+0x44/0x104 LR [c0000000006bc618] .rxrpc_destroy+0x40/0x104 Call Trace: [c0000000feb2bc00] [c0000000006bc618] .rxrpc_destroy+0x40/0x104 (unreliable) [c0000000feb2bc90] [c000000000349b2c] .key_cleanup+0x1a8/0x20c [c0000000feb2bd40] [c0000000000a2920] .process_one_work+0x2f4/0x4d0 [c0000000feb2be00] [c0000000000a2d50] .worker_thread+0x254/0x468 [c0000000feb2bec0] [c0000000000a868c] .kthread+0xbc/0xc8 [c0000000feb2bf90] [c000000000020e00] .kernel_thread+0x54/0x70 We aren't initialising token->next, but the code in destroy_context relies on the list being NULL terminated. Use kzalloc to zero out all the fields. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 15 1月, 2011 1 次提交
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由 Tejun Heo 提交于
rxrpc_workqueue isn't depended upon while reclaiming memory. Convert to alloc_workqueue() without WQ_MEM_RECLAIM. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NDavid Howells <dhowells@redhat.com> Cc: linux-afs@lists.infradead.org Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 23 11月, 2010 1 次提交
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由 Tracey Dent 提交于
Changed Makefile to use <modules>-y instead of <modules>-objs because -objs is deprecated and not mentioned in Documentation/kbuild/makefiles.txt. Signed-off-by: NTracey Dent <tdent48227@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 18 11月, 2010 1 次提交
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由 Changli Gao 提交于
Use the macros defined for the members of flowi to clean the code up. Signed-off-by: NChangli Gao <xiaosuo@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 13 8月, 2010 1 次提交
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由 David Howells 提交于
Add a dummy printk function for the maintenance of unused printks through gcc format checking, and also so that side-effect checking is maintained too. Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 05 8月, 2010 1 次提交
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由 David Howells 提交于
RxRPC can potentially deadlock as rxrpc_resend_time_expired() wants to get call->state_lock so that it can alter the state of an RxRPC call. However, its caller (call_timer_fn()) has an apparent lock on the timer struct. The problem is that rxrpc_resend_time_expired() isn't permitted to lock call->state_lock as this could cause a deadlock against rxrpc_send_abort() as that takes state_lock and then attempts to delete the resend timer by calling del_timer_sync(). The deadlock can occur because del_timer_sync() will sit there forever waiting for rxrpc_resend_time_expired() to return, but the latter may then wait for call->state_lock, which rxrpc_send_abort() holds around del_timer_sync()... This leads to a warning appearing in the kernel log that looks something like the attached. It should be sufficient to simply dispense with the locks. It doesn't matter if we set the resend timer expired event bit and queue the event processor whilst we're changing state to one where the resend timer is irrelevant as the event can just be ignored by the processor thereafter. ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.35-rc3-cachefs+ #115 ------------------------------------------------------- swapper/0 is trying to acquire lock: (&call->state_lock){++--..}, at: [<ffffffffa00200d4>] rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc] but task is already holding lock: (&call->resend_timer){+.-...}, at: [<ffffffff8103b675>] run_timer_softirq+0x182/0x2a5 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&call->resend_timer){+.-...}: [<ffffffff810560bc>] __lock_acquire+0x889/0x8fa [<ffffffff81056184>] lock_acquire+0x57/0x6d [<ffffffff8103bb9c>] del_timer_sync+0x3c/0x86 [<ffffffffa002bb7a>] rxrpc_send_abort+0x50/0x97 [af_rxrpc] [<ffffffffa002bdd9>] rxrpc_kernel_abort_call+0xa1/0xdd [af_rxrpc] [<ffffffffa0061588>] afs_deliver_to_call+0x129/0x368 [kafs] [<ffffffffa006181b>] afs_process_async_call+0x54/0xff [kafs] [<ffffffff8104261d>] worker_thread+0x1ef/0x2e2 [<ffffffff81045f47>] kthread+0x7a/0x82 [<ffffffff81002cd4>] kernel_thread_helper+0x4/0x10 -> #0 (&call->state_lock){++--..}: [<ffffffff81055237>] validate_chain+0x727/0xd23 [<ffffffff810560bc>] __lock_acquire+0x889/0x8fa [<ffffffff81056184>] lock_acquire+0x57/0x6d [<ffffffff813e6b69>] _raw_read_lock_bh+0x34/0x43 [<ffffffffa00200d4>] rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc] [<ffffffff8103b6e6>] run_timer_softirq+0x1f3/0x2a5 [<ffffffff81036828>] __do_softirq+0xa2/0x13e [<ffffffff81002dcc>] call_softirq+0x1c/0x28 [<ffffffff810049f0>] do_softirq+0x38/0x80 [<ffffffff810361a2>] irq_exit+0x45/0x47 [<ffffffff81018fb3>] smp_apic_timer_interrupt+0x88/0x96 [<ffffffff81002893>] apic_timer_interrupt+0x13/0x20 [<ffffffff810011ac>] cpu_idle+0x4d/0x83 [<ffffffff813e06f3>] start_secondary+0x1bd/0x1c1 other info that might help us debug this: 1 lock held by swapper/0: #0: (&call->resend_timer){+.-...}, at: [<ffffffff8103b675>] run_timer_softirq+0x182/0x2a5 stack backtrace: Pid: 0, comm: swapper Not tainted 2.6.35-rc3-cachefs+ #115 Call Trace: <IRQ> [<ffffffff81054414>] print_circular_bug+0xae/0xbd [<ffffffff81055237>] validate_chain+0x727/0xd23 [<ffffffff810560bc>] __lock_acquire+0x889/0x8fa [<ffffffff810539a7>] ? mark_lock+0x42f/0x51f [<ffffffff81056184>] lock_acquire+0x57/0x6d [<ffffffffa00200d4>] ? rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc] [<ffffffff813e6b69>] _raw_read_lock_bh+0x34/0x43 [<ffffffffa00200d4>] ? rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc] [<ffffffffa00200d4>] rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc] [<ffffffff8103b6e6>] run_timer_softirq+0x1f3/0x2a5 [<ffffffff8103b675>] ? run_timer_softirq+0x182/0x2a5 [<ffffffffa002007e>] ? rxrpc_resend_time_expired+0x0/0x96 [af_rxrpc] [<ffffffff810367ef>] ? __do_softirq+0x69/0x13e [<ffffffff81036828>] __do_softirq+0xa2/0x13e [<ffffffff81002dcc>] call_softirq+0x1c/0x28 [<ffffffff810049f0>] do_softirq+0x38/0x80 [<ffffffff810361a2>] irq_exit+0x45/0x47 [<ffffffff81018fb3>] smp_apic_timer_interrupt+0x88/0x96 [<ffffffff81002893>] apic_timer_interrupt+0x13/0x20 <EOI> [<ffffffff81049de1>] ? __atomic_notifier_call_chain+0x0/0x86 [<ffffffff8100955b>] ? mwait_idle+0x6e/0x78 [<ffffffff81009552>] ? mwait_idle+0x65/0x78 [<ffffffff810011ac>] cpu_idle+0x4d/0x83 [<ffffffff813e06f3>] start_secondary+0x1bd/0x1c1 Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 11 6月, 2010 1 次提交
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由 Changli Gao 提交于
remove useless union keyword in rtable, rt6_info and dn_route. Since there is only one member in a union, the union keyword isn't useful. Signed-off-by: NChangli Gao <xiaosuo@gmail.com> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 02 5月, 2010 1 次提交
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由 Eric Dumazet 提交于
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: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 27 4月, 2010 1 次提交
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由 Eric Dumazet 提交于
Commit aa395145 (net: sk_sleep() helper) missed three files in the conversion. Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 21 4月, 2010 1 次提交
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由 Eric Dumazet 提交于
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: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 30 3月, 2010 1 次提交
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由 Tejun Heo 提交于
include cleanup: Update gfp.h and slab.h includes to prepare for breaking 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: NTejun Heo <tj@kernel.org> Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
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- 23 3月, 2010 2 次提交
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由 Tetsuo Handa 提交于
alloc_skb() can return NULL. Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Tetsuo Handa 提交于
alloc_skb() can return NULL. Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 26 11月, 2009 1 次提交
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由 Octavian Purdila 提交于
Generated with the following semantic patch @@ struct net *n1; struct net *n2; @@ - n1 == n2 + net_eq(n1, n2) @@ struct net *n1; struct net *n2; @@ - n1 != n2 + !net_eq(n1, n2) applied over {include,net,drivers/net}. Signed-off-by: NOctavian Purdila <opurdila@ixiacom.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 06 11月, 2009 1 次提交
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由 Eric Paris 提交于
The generic __sock_create function has a kern argument which allows the security system to make decisions based on if a socket is being created by the kernel or by userspace. This patch passes that flag to the net_proto_family specific create function, so it can do the same thing. Signed-off-by: NEric Paris <eparis@redhat.com> Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 13 10月, 2009 1 次提交
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由 Neil Horman 提交于
Create a new socket level option to report number of queue overflows Recently I augmented the AF_PACKET protocol to report the number of frames lost on the socket receive queue between any two enqueued frames. This value was exported via a SOL_PACKET level cmsg. AFter I completed that work it was requested that this feature be generalized so that any datagram oriented socket could make use of this option. As such I've created this patch, It creates a new SOL_SOCKET level option called SO_RXQ_OVFL, which when enabled exports a SOL_SOCKET level cmsg that reports the nubmer of times the sk_receive_queue overflowed between any two given frames. It also augments the AF_PACKET protocol to take advantage of this new feature (as it previously did not touch sk->sk_drops, which this patch uses to record the overflow count). Tested successfully by me. Notes: 1) Unlike my previous patch, this patch simply records the sk_drops value, which is not a number of drops between packets, but rather a total number of drops. Deltas must be computed in user space. 2) While this patch currently works with datagram oriented protocols, it will also be accepted by non-datagram oriented protocols. I'm not sure if thats agreeable to everyone, but my argument in favor of doing so is that, for those protocols which aren't applicable to this option, sk_drops will always be zero, and reporting no drops on a receive queue that isn't used for those non-participating protocols seems reasonable to me. This also saves us having to code in a per-protocol opt in mechanism. 3) This applies cleanly to net-next assuming that commit 97775007 (my af packet cmsg patch) is reverted Signed-off-by: NNeil Horman <nhorman@tuxdriver.com> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 07 10月, 2009 1 次提交
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由 Stephen Hemminger 提交于
All usages of structure net_proto_ops should be declared const. Signed-off-by: NStephen Hemminger <shemminger@vyatta.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 01 10月, 2009 1 次提交
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由 David S. Miller 提交于
This provides safety against negative optlen at the type level instead of depending upon (sometimes non-trivial) checks against this sprinkled all over the the place, in each and every implementation. Based upon work done by Arjan van de Ven and feedback from Linus Torvalds. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 21 9月, 2009 1 次提交
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由 Anand Gadiyar 提交于
Signed-off-by: NAnand Gadiyar <gadiyar@ti.com> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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- 16 9月, 2009 1 次提交
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由 David Howells 提交于
Use uX rather than uintX_t types for consistency. Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 15 9月, 2009 4 次提交
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由 David Howells 提交于
Parse RxRPC security index 5 type keys (Kerberos 5 tokens). Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David Howells 提交于
Allow RxRPC keys to be read. This is to allow pioctl() to be implemented in userspace. RxRPC keys are read out in XDR format. Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David Howells 提交于
Allow add_key() and KEYCTL_INSTANTIATE to accept key payloads in XDR form as described by openafs-1.4.10/src/auth/afs_token.xg. This provides a way of passing kaserver, Kerberos 4, Kerberos 5 and GSSAPI keys from userspace, and allows for future expansion. Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David Howells 提交于
Declare the security index constants symbolically rather than just referring to them numerically. Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 06 8月, 2009 1 次提交
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由 Jan Engelhardt 提交于
String literals are constant, and usually, we can also tag the array of pointers const too, moving it to the .rodata section. Signed-off-by: NJan Engelhardt <jengelh@medozas.de> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 10 7月, 2009 1 次提交
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由 Jiri Olsa 提交于
Adding memory barrier after the poll_wait function, paired with receive callbacks. Adding fuctions sock_poll_wait and sk_has_sleeper to wrap the memory barrier. Without the memory barrier, following race can happen. The race fires, when following code paths meet, and the tp->rcv_nxt and __add_wait_queue updates stay in CPU caches. CPU1 CPU2 sys_select receive packet ... ... __add_wait_queue update tp->rcv_nxt ... ... tp->rcv_nxt check sock_def_readable ... { schedule ... if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) wake_up_interruptible(sk->sk_sleep) ... } If there was no cache the code would work ok, since the wait_queue and rcv_nxt are opposit to each other. Meaning that once tp->rcv_nxt is updated by CPU2, the CPU1 either already passed the tp->rcv_nxt check and sleeps, or will get the new value for tp->rcv_nxt and will return with new data mask. In both cases the process (CPU1) is being added to the wait queue, so the waitqueue_active (CPU2) call cannot miss and will wake up CPU1. The bad case is when the __add_wait_queue changes done by CPU1 stay in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 will then endup calling schedule and sleep forever if there are no more data on the socket. Calls to poll_wait in following modules were ommited: net/bluetooth/af_bluetooth.c net/irda/af_irda.c net/irda/irnet/irnet_ppp.c net/mac80211/rc80211_pid_debugfs.c net/phonet/socket.c net/rds/af_rds.c net/rfkill/core.c net/sunrpc/cache.c net/sunrpc/rpc_pipe.c net/tipc/socket.c Signed-off-by: NJiri Olsa <jolsa@redhat.com> Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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