linux/net/sctp/input.c

1272 lines
34 KiB

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: 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>
2010-03-24 17:04:11 +09:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
sctp: linearize early if it's not GSO Because otherwise when crc computation is still needed it's way more expensive than on a linear buffer to the point that it affects performance. It's so expensive that netperf test gives a perf output as below: Overhead Command Shared Object Symbol 18,62% netserver [kernel.vmlinux] [k] crc32_generic_shift 2,57% netserver [kernel.vmlinux] [k] __pskb_pull_tail 1,94% netserver [kernel.vmlinux] [k] fib_table_lookup 1,90% netserver [kernel.vmlinux] [k] copy_user_enhanced_fast_string 1,66% swapper [kernel.vmlinux] [k] intel_idle 1,63% netserver [kernel.vmlinux] [k] _raw_spin_lock 1,59% netserver [sctp] [k] sctp_packet_transmit 1,55% netserver [kernel.vmlinux] [k] memcpy_erms 1,42% netserver [sctp] [k] sctp_rcv # netperf -H 192.168.10.1 -l 10 -t SCTP_STREAM -cC -- -m 12000 SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.1 () port 0 AF_INET Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB 212992 212992 12000 10.00 3016.42 2.88 3.78 1.874 2.462 After patch: Overhead Command Shared Object Symbol 2,75% netserver [kernel.vmlinux] [k] memcpy_erms 2,63% netserver [kernel.vmlinux] [k] copy_user_enhanced_fast_string 2,39% netserver [kernel.vmlinux] [k] fib_table_lookup 2,04% netserver [kernel.vmlinux] [k] __pskb_pull_tail 1,91% netserver [kernel.vmlinux] [k] _raw_spin_lock 1,91% netserver [sctp] [k] sctp_packet_transmit 1,72% netserver [mlx4_en] [k] mlx4_en_process_rx_cq 1,68% netserver [sctp] [k] sctp_rcv # netperf -H 192.168.10.1 -l 10 -t SCTP_STREAM -cC -- -m 12000 SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.1 () port 0 AF_INET Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB 212992 212992 12000 10.00 3681.77 3.83 3.46 2.045 1.849 Fixes: 3acb50c18d8d ("sctp: delay as much as possible skb_linearize") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-18 14:58:35 -03:00
sctp: linearize early if it's not GSO Because otherwise when crc computation is still needed it's way more expensive than on a linear buffer to the point that it affects performance. It's so expensive that netperf test gives a perf output as below: Overhead Command Shared Object Symbol 18,62% netserver [kernel.vmlinux] [k] crc32_generic_shift 2,57% netserver [kernel.vmlinux] [k] __pskb_pull_tail 1,94% netserver [kernel.vmlinux] [k] fib_table_lookup 1,90% netserver [kernel.vmlinux] [k] copy_user_enhanced_fast_string 1,66% swapper [kernel.vmlinux] [k] intel_idle 1,63% netserver [kernel.vmlinux] [k] _raw_spin_lock 1,59% netserver [sctp] [k] sctp_packet_transmit 1,55% netserver [kernel.vmlinux] [k] memcpy_erms 1,42% netserver [sctp] [k] sctp_rcv # netperf -H 192.168.10.1 -l 10 -t SCTP_STREAM -cC -- -m 12000 SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.1 () port 0 AF_INET Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB 212992 212992 12000 10.00 3016.42 2.88 3.78 1.874 2.462 After patch: Overhead Command Shared Object Symbol 2,75% netserver [kernel.vmlinux] [k] memcpy_erms 2,63% netserver [kernel.vmlinux] [k] copy_user_enhanced_fast_string 2,39% netserver [kernel.vmlinux] [k] fib_table_lookup 2,04% netserver [kernel.vmlinux] [k] __pskb_pull_tail 1,91% netserver [kernel.vmlinux] [k] _raw_spin_lock 1,91% netserver [sctp] [k] sctp_packet_transmit 1,72% netserver [mlx4_en] [k] mlx4_en_process_rx_cq 1,68% netserver [sctp] [k] sctp_rcv # netperf -H 192.168.10.1 -l 10 -t SCTP_STREAM -cC -- -m 12000 SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.1 () port 0 AF_INET Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB 212992 212992 12000 10.00 3681.77 3.83 3.46 2.045 1.849 Fixes: 3acb50c18d8d ("sctp: delay as much as possible skb_linearize") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-18 14:58:35 -03:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
sctp: fix BH handling on socket backlog Now that the backlog processing is called with BH enabled, we have to disable BH before taking the socket lock via bh_lock_sock() otherwise it may dead lock: sctp_backlog_rcv() bh_lock_sock(sk); if (sock_owned_by_user(sk)) { if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) sctp_chunk_free(chunk); else backloged = 1; } else sctp_inq_push(inqueue, chunk); bh_unlock_sock(sk); while sctp_inq_push() was disabling/enabling BH, but enabling BH triggers pending softirq, which then may try to re-lock the socket in sctp_rcv(). [ 219.187215] <IRQ> [ 219.187217] [<ffffffff817ca3e0>] _raw_spin_lock+0x20/0x30 [ 219.187223] [<ffffffffa041888c>] sctp_rcv+0x48c/0xba0 [sctp] [ 219.187225] [<ffffffff816e7db2>] ? nf_iterate+0x62/0x80 [ 219.187226] [<ffffffff816f1b14>] ip_local_deliver_finish+0x94/0x1e0 [ 219.187228] [<ffffffff816f1e1f>] ip_local_deliver+0x6f/0xf0 [ 219.187229] [<ffffffff816f1a80>] ? ip_rcv_finish+0x3b0/0x3b0 [ 219.187230] [<ffffffff816f17a8>] ip_rcv_finish+0xd8/0x3b0 [ 219.187232] [<ffffffff816f2122>] ip_rcv+0x282/0x3a0 [ 219.187233] [<ffffffff810d8bb6>] ? update_curr+0x66/0x180 [ 219.187235] [<ffffffff816abac4>] __netif_receive_skb_core+0x524/0xa90 [ 219.187236] [<ffffffff810d8e00>] ? update_cfs_shares+0x30/0xf0 [ 219.187237] [<ffffffff810d557c>] ? __enqueue_entity+0x6c/0x70 [ 219.187239] [<ffffffff810dc454>] ? enqueue_entity+0x204/0xdf0 [ 219.187240] [<ffffffff816ac048>] __netif_receive_skb+0x18/0x60 [ 219.187242] [<ffffffff816ad1ce>] process_backlog+0x9e/0x140 [ 219.187243] [<ffffffff816ac8ec>] net_rx_action+0x22c/0x370 [ 219.187245] [<ffffffff817cd352>] __do_softirq+0x112/0x2e7 [ 219.187247] [<ffffffff817cc3bc>] do_softirq_own_stack+0x1c/0x30 [ 219.187247] <EOI> [ 219.187248] [<ffffffff810aa1c8>] do_softirq.part.14+0x38/0x40 [ 219.187249] [<ffffffff810aa24d>] __local_bh_enable_ip+0x7d/0x80 [ 219.187254] [<ffffffffa0408428>] sctp_inq_push+0x68/0x80 [sctp] [ 219.187258] [<ffffffffa04190f1>] sctp_backlog_rcv+0x151/0x1c0 [sctp] [ 219.187260] [<ffffffff81692b07>] __release_sock+0x87/0xf0 [ 219.187261] [<ffffffff81692ba0>] release_sock+0x30/0xa0 [ 219.187265] [<ffffffffa040e46d>] sctp_accept+0x17d/0x210 [sctp] [ 219.187266] [<ffffffff810e7510>] ? prepare_to_wait_event+0xf0/0xf0 [ 219.187268] [<ffffffff8172d52c>] inet_accept+0x3c/0x130 [ 219.187269] [<ffffffff8168d7a3>] SYSC_accept4+0x103/0x210 [ 219.187271] [<ffffffff817ca2ba>] ? _raw_spin_unlock_bh+0x1a/0x20 [ 219.187272] [<ffffffff81692bfc>] ? release_sock+0x8c/0xa0 [ 219.187276] [<ffffffffa0413e22>] ? sctp_inet_listen+0x62/0x1b0 [sctp] [ 219.187277] [<ffffffff8168f2d0>] SyS_accept+0x10/0x20 Fixes: 860fbbc343bf ("sctp: prepare for socket backlog behavior change") Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-23 00:32:48 -03:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
sctp: fix BH handling on socket backlog Now that the backlog processing is called with BH enabled, we have to disable BH before taking the socket lock via bh_lock_sock() otherwise it may dead lock: sctp_backlog_rcv() bh_lock_sock(sk); if (sock_owned_by_user(sk)) { if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) sctp_chunk_free(chunk); else backloged = 1; } else sctp_inq_push(inqueue, chunk); bh_unlock_sock(sk); while sctp_inq_push() was disabling/enabling BH, but enabling BH triggers pending softirq, which then may try to re-lock the socket in sctp_rcv(). [ 219.187215] <IRQ> [ 219.187217] [<ffffffff817ca3e0>] _raw_spin_lock+0x20/0x30 [ 219.187223] [<ffffffffa041888c>] sctp_rcv+0x48c/0xba0 [sctp] [ 219.187225] [<ffffffff816e7db2>] ? nf_iterate+0x62/0x80 [ 219.187226] [<ffffffff816f1b14>] ip_local_deliver_finish+0x94/0x1e0 [ 219.187228] [<ffffffff816f1e1f>] ip_local_deliver+0x6f/0xf0 [ 219.187229] [<ffffffff816f1a80>] ? ip_rcv_finish+0x3b0/0x3b0 [ 219.187230] [<ffffffff816f17a8>] ip_rcv_finish+0xd8/0x3b0 [ 219.187232] [<ffffffff816f2122>] ip_rcv+0x282/0x3a0 [ 219.187233] [<ffffffff810d8bb6>] ? update_curr+0x66/0x180 [ 219.187235] [<ffffffff816abac4>] __netif_receive_skb_core+0x524/0xa90 [ 219.187236] [<ffffffff810d8e00>] ? update_cfs_shares+0x30/0xf0 [ 219.187237] [<ffffffff810d557c>] ? __enqueue_entity+0x6c/0x70 [ 219.187239] [<ffffffff810dc454>] ? enqueue_entity+0x204/0xdf0 [ 219.187240] [<ffffffff816ac048>] __netif_receive_skb+0x18/0x60 [ 219.187242] [<ffffffff816ad1ce>] process_backlog+0x9e/0x140 [ 219.187243] [<ffffffff816ac8ec>] net_rx_action+0x22c/0x370 [ 219.187245] [<ffffffff817cd352>] __do_softirq+0x112/0x2e7 [ 219.187247] [<ffffffff817cc3bc>] do_softirq_own_stack+0x1c/0x30 [ 219.187247] <EOI> [ 219.187248] [<ffffffff810aa1c8>] do_softirq.part.14+0x38/0x40 [ 219.187249] [<ffffffff810aa24d>] __local_bh_enable_ip+0x7d/0x80 [ 219.187254] [<ffffffffa0408428>] sctp_inq_push+0x68/0x80 [sctp] [ 219.187258] [<ffffffffa04190f1>] sctp_backlog_rcv+0x151/0x1c0 [sctp] [ 219.187260] [<ffffffff81692b07>] __release_sock+0x87/0xf0 [ 219.187261] [<ffffffff81692ba0>] release_sock+0x30/0xa0 [ 219.187265] [<ffffffffa040e46d>] sctp_accept+0x17d/0x210 [sctp] [ 219.187266] [<ffffffff810e7510>] ? prepare_to_wait_event+0xf0/0xf0 [ 219.187268] [<ffffffff8172d52c>] inet_accept+0x3c/0x130 [ 219.187269] [<ffffffff8168d7a3>] SYSC_accept4+0x103/0x210 [ 219.187271] [<ffffffff817ca2ba>] ? _raw_spin_unlock_bh+0x1a/0x20 [ 219.187272] [<ffffffff81692bfc>] ? release_sock+0x8c/0xa0 [ 219.187276] [<ffffffffa0413e22>] ? sctp_inet_listen+0x62/0x1b0 [sctp] [ 219.187277] [<ffffffff8168f2d0>] SyS_accept+0x10/0x20 Fixes: 860fbbc343bf ("sctp: prepare for socket backlog behavior change") Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-23 00:32:48 -03:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
[SCTP]: A better solution to fix the race between sctp_peeloff() and sctp_rcv(). The goal is to hold the ref on the association/endpoint throughout the state-machine process. We accomplish like this: /* ref on the assoc/ep is taken during lookup */ if owned_by_user(sk) sctp_add_backlog(skb, sk); else inqueue_push(skb, sk); /* drop the ref on the assoc/ep */ However, in sctp_add_backlog() we take the ref on assoc/ep and hold it while the skb is on the backlog queue. This allows us to get rid of the sock_hold/sock_put in the lookup routines. Now sctp_backlog_rcv() needs to account for potential association move. In the unlikely event that association moved, we need to retest if the new socket is locked by user. If we don't this, we may have two packets racing up the stack toward the same socket and we can't deal with it. If the new socket is still locked, we'll just add the skb to its backlog continuing to hold the ref on the association. This get's rid of the need to move packets from one backlog to another and it also safe in case new packets arrive on the same backlog queue. The last step, is to lock the new socket when we are moving the association to it. This is needed in case any new packets arrive on the association when it moved. We want these to go to the backlog since we would like to avoid the race between this new packet and a packet that may be sitting on the backlog queue of the old socket toward the same association. Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
2006-05-19 11:01:18 -07:00
sctp: fix the handling of ICMP Frag Needed for too small MTUs syzbot reported a hang involving SCTP, on which it kept flooding dmesg with the message: [ 246.742374] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too low, using default minimum of 512 That happened because whenever SCTP hits an ICMP Frag Needed, it tries to adjust to the new MTU and triggers an immediate retransmission. But it didn't consider the fact that MTUs smaller than the SCTP minimum MTU allowed (512) would not cause the PMTU to change, and issued the retransmission anyway (thus leading to another ICMP Frag Needed, and so on). As IPv4 (ip_rt_min_pmtu=556) and IPv6 (IPV6_MIN_MTU=1280) minimum MTU are higher than that, sctp_transport_update_pmtu() is changed to re-fetch the PMTU that got set after our request, and with that, detect if there was an actual change or not. The fix, thus, skips the immediate retransmission if the received ICMP resulted in no change, in the hope that SCTP will select another path. Note: The value being used for the minimum MTU (512, SCTP_DEFAULT_MINSEGMENT) is not right and instead it should be (576, SCTP_MIN_PMTU), but such change belongs to another patch. Changes from v1: - do not disable PMTU discovery, in the light of commit 06ad391919b2 ("[SCTP] Don't disable PMTU discovery when mtu is small") and as suggested by Xin Long. - changed the way to break the rtx loop by detecting if the icmp resulted in a change or not Changes from v2: none See-also: https://lkml.org/lkml/2017/12/22/811 Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-05 11:17:18 -02:00
sctp: Fix a race between ICMP protocol unreachable and connect() ICMP protocol unreachable handling completely disregarded the fact that the user may have locked the socket. It proceeded to destroy the association, even though the user may have held the lock and had a ref on the association. This resulted in the following: Attempt to release alive inet socket f6afcc00 ========================= [ BUG: held lock freed! ] ------------------------- somenu/2672 is freeing memory f6afcc00-f6afcfff, with a lock still held there! (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c 1 lock held by somenu/2672: #0: (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c stack backtrace: Pid: 2672, comm: somenu Not tainted 2.6.32-telco #55 Call Trace: [<c1232266>] ? printk+0xf/0x11 [<c1038553>] debug_check_no_locks_freed+0xce/0xff [<c10620b4>] kmem_cache_free+0x21/0x66 [<c1185f25>] __sk_free+0x9d/0xab [<c1185f9c>] sk_free+0x1c/0x1e [<c1216e38>] sctp_association_put+0x32/0x89 [<c1220865>] __sctp_connect+0x36d/0x3f4 [<c122098a>] ? sctp_connect+0x13/0x4c [<c102d073>] ? autoremove_wake_function+0x0/0x33 [<c12209a8>] sctp_connect+0x31/0x4c [<c11d1e80>] inet_dgram_connect+0x4b/0x55 [<c11834fa>] sys_connect+0x54/0x71 [<c103a3a2>] ? lock_release_non_nested+0x88/0x239 [<c1054026>] ? might_fault+0x42/0x7c [<c1054026>] ? might_fault+0x42/0x7c [<c11847ab>] sys_socketcall+0x6d/0x178 [<c10da994>] ? trace_hardirqs_on_thunk+0xc/0x10 [<c1002959>] syscall_call+0x7/0xb This was because the sctp_wait_for_connect() would aqcure the socket lock and then proceed to release the last reference count on the association, thus cause the fully destruction path to finish freeing the socket. The simplest solution is to start a very short timer in case the socket is owned by user. When the timer expires, we can do some verification and be able to do the release properly. Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-06 00:56:07 -07:00
net: sctp: rework debugging framework to use pr_debug and friends We should get rid of all own SCTP debug printk macros and use the ones that the kernel offers anyway instead. This makes the code more readable and conform to the kernel code, and offers all the features of dynamic debbuging that pr_debug() et al has, such as only turning on/off portions of debug messages at runtime through debugfs. The runtime cost of having CONFIG_DYNAMIC_DEBUG enabled, but none of the debug statements printing, is negligible [1]. If kernel debugging is completly turned off, then these statements will also compile into "empty" functions. While we're at it, we also need to change the Kconfig option as it /now/ only refers to the ifdef'ed code portions in outqueue.c that enable further debugging/tracing of SCTP transaction fields. Also, since SCTP_ASSERT code was enabled with this Kconfig option and has now been removed, we transform those code parts into WARNs resp. where appropriate BUG_ONs so that those bugs can be more easily detected as probably not many people have SCTP debugging permanently turned on. To turn on all SCTP debugging, the following steps are needed: # mount -t debugfs none /sys/kernel/debug # echo -n 'module sctp +p' > /sys/kernel/debug/dynamic_debug/control This can be done more fine-grained on a per file, per line basis and others as described in [2]. [1] https://www.kernel.org/doc/ols/2009/ols2009-pages-39-46.pdf [2] Documentation/dynamic-debug-howto.txt Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-28 19:49:40 +02:00
sctp: Fix a race between ICMP protocol unreachable and connect() ICMP protocol unreachable handling completely disregarded the fact that the user may have locked the socket. It proceeded to destroy the association, even though the user may have held the lock and had a ref on the association. This resulted in the following: Attempt to release alive inet socket f6afcc00 ========================= [ BUG: held lock freed! ] ------------------------- somenu/2672 is freeing memory f6afcc00-f6afcfff, with a lock still held there! (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c 1 lock held by somenu/2672: #0: (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c stack backtrace: Pid: 2672, comm: somenu Not tainted 2.6.32-telco #55 Call Trace: [<c1232266>] ? printk+0xf/0x11 [<c1038553>] debug_check_no_locks_freed+0xce/0xff [<c10620b4>] kmem_cache_free+0x21/0x66 [<c1185f25>] __sk_free+0x9d/0xab [<c1185f9c>] sk_free+0x1c/0x1e [<c1216e38>] sctp_association_put+0x32/0x89 [<c1220865>] __sctp_connect+0x36d/0x3f4 [<c122098a>] ? sctp_connect+0x13/0x4c [<c102d073>] ? autoremove_wake_function+0x0/0x33 [<c12209a8>] sctp_connect+0x31/0x4c [<c11d1e80>] inet_dgram_connect+0x4b/0x55 [<c11834fa>] sys_connect+0x54/0x71 [<c103a3a2>] ? lock_release_non_nested+0x88/0x239 [<c1054026>] ? might_fault+0x42/0x7c [<c1054026>] ? might_fault+0x42/0x7c [<c11847ab>] sys_socketcall+0x6d/0x178 [<c10da994>] ? trace_hardirqs_on_thunk+0xc/0x10 [<c1002959>] syscall_call+0x7/0xb This was because the sctp_wait_for_connect() would aqcure the socket lock and then proceed to release the last reference count on the association, thus cause the fully destruction path to finish freeing the socket. The simplest solution is to start a very short timer in case the socket is owned by user. When the timer expires, we can do some verification and be able to do the release properly. Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-06 00:56:07 -07:00
sctp: Fix a race between ICMP protocol unreachable and connect() ICMP protocol unreachable handling completely disregarded the fact that the user may have locked the socket. It proceeded to destroy the association, even though the user may have held the lock and had a ref on the association. This resulted in the following: Attempt to release alive inet socket f6afcc00 ========================= [ BUG: held lock freed! ] ------------------------- somenu/2672 is freeing memory f6afcc00-f6afcfff, with a lock still held there! (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c 1 lock held by somenu/2672: #0: (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c stack backtrace: Pid: 2672, comm: somenu Not tainted 2.6.32-telco #55 Call Trace: [<c1232266>] ? printk+0xf/0x11 [<c1038553>] debug_check_no_locks_freed+0xce/0xff [<c10620b4>] kmem_cache_free+0x21/0x66 [<c1185f25>] __sk_free+0x9d/0xab [<c1185f9c>] sk_free+0x1c/0x1e [<c1216e38>] sctp_association_put+0x32/0x89 [<c1220865>] __sctp_connect+0x36d/0x3f4 [<c122098a>] ? sctp_connect+0x13/0x4c [<c102d073>] ? autoremove_wake_function+0x0/0x33 [<c12209a8>] sctp_connect+0x31/0x4c [<c11d1e80>] inet_dgram_connect+0x4b/0x55 [<c11834fa>] sys_connect+0x54/0x71 [<c103a3a2>] ? lock_release_non_nested+0x88/0x239 [<c1054026>] ? might_fault+0x42/0x7c [<c1054026>] ? might_fault+0x42/0x7c [<c11847ab>] sys_socketcall+0x6d/0x178 [<c10da994>] ? trace_hardirqs_on_thunk+0xc/0x10 [<c1002959>] syscall_call+0x7/0xb This was because the sctp_wait_for_connect() would aqcure the socket lock and then proceed to release the last reference count on the association, thus cause the fully destruction path to finish freeing the socket. The simplest solution is to start a very short timer in case the socket is owned by user. When the timer expires, we can do some verification and be able to do the release properly. Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-06 00:56:07 -07:00
[SK_BUFF]: Use offsets for skb->{mac,network,transport}_header on 64bit architectures With this we save 8 bytes per network packet, leaving a 4 bytes hole to be used in further shrinking work, likely with the offsetization of other pointers, such as ->{data,tail,end}, at the cost of adds, that were minimized by the usual practice of setting skb->{mac,nh,n}.raw to a local variable that is then accessed multiple times in each function, it also is not more expensive than before with regards to most of the handling of such headers, like setting one of these headers to another (transport to network, etc), or subtracting, adding to/from it, comparing them, etc. Now we have this layout for sk_buff on a x86_64 machine: [acme@mica net-2.6.22]$ pahole vmlinux sk_buff struct sk_buff { struct sk_buff * next; /* 0 8 */ struct sk_buff * prev; /* 8 8 */ struct rb_node rb; /* 16 24 */ struct sock * sk; /* 40 8 */ ktime_t tstamp; /* 48 8 */ struct net_device * dev; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ struct net_device * input_dev; /* 64 8 */ sk_buff_data_t transport_header; /* 72 4 */ sk_buff_data_t network_header; /* 76 4 */ sk_buff_data_t mac_header; /* 80 4 */ /* XXX 4 bytes hole, try to pack */ struct dst_entry * dst; /* 88 8 */ struct sec_path * sp; /* 96 8 */ char cb[48]; /* 104 48 */ /* cacheline 2 boundary (128 bytes) was 24 bytes ago*/ unsigned int len; /* 152 4 */ unsigned int data_len; /* 156 4 */ unsigned int mac_len; /* 160 4 */ union { __wsum csum; /* 4 */ __u32 csum_offset; /* 4 */ }; /* 164 4 */ __u32 priority; /* 168 4 */ __u8 local_df:1; /* 172 1 */ __u8 cloned:1; /* 172 1 */ __u8 ip_summed:2; /* 172 1 */ __u8 nohdr:1; /* 172 1 */ __u8 nfctinfo:3; /* 172 1 */ __u8 pkt_type:3; /* 173 1 */ __u8 fclone:2; /* 173 1 */ __u8 ipvs_property:1; /* 173 1 */ /* XXX 2 bits hole, try to pack */ __be16 protocol; /* 174 2 */ void (*destructor)(struct sk_buff *); /* 176 8 */ struct nf_conntrack * nfct; /* 184 8 */ /* --- cacheline 3 boundary (192 bytes) --- */ struct sk_buff * nfct_reasm; /* 192 8 */ struct nf_bridge_info *nf_bridge; /* 200 8 */ __u16 tc_index; /* 208 2 */ __u16 tc_verd; /* 210 2 */ dma_cookie_t dma_cookie; /* 212 4 */ __u32 secmark; /* 216 4 */ __u32 mark; /* 220 4 */ unsigned int truesize; /* 224 4 */ atomic_t users; /* 228 4 */ unsigned char * head; /* 232 8 */ unsigned char * data; /* 240 8 */ unsigned char * tail; /* 248 8 */ /* --- cacheline 4 boundary (256 bytes) --- */ unsigned char * end; /* 256 8 */ }; /* size: 264, cachelines: 5 */ /* sum members: 260, holes: 1, sum holes: 4 */ /* bit holes: 1, sum bit holes: 2 bits */ /* last cacheline: 8 bytes */ On 32 bits nothing changes, and pointers continue to be used with the compiler turning all this abstraction layer into dust. But there are some sk_buff validation tricks that are now possible, humm... :-) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-10 21:22:35 -07:00
sctp: Fix list corruption resulting from freeing an association on a list A few days ago Dave Jones reported this oops: [22766.294255] general protection fault: 0000 [#1] PREEMPT SMP [22766.295376] CPU 0 [22766.295384] Modules linked in: [22766.387137] ffffffffa169f292 6b6b6b6b6b6b6b6b ffff880147c03a90 ffff880147c03a74 [22766.387135] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000 [22766.387136] Process trinity-watchdo (pid: 10896, threadinfo ffff88013e7d2000, [22766.387137] Stack: [22766.387140] ffff880147c03a10 [22766.387140] ffffffffa169f2b6 [22766.387140] ffff88013ed95728 [22766.387143] 0000000000000002 [22766.387143] 0000000000000000 [22766.387143] ffff880003fad062 [22766.387144] ffff88013c120000 [22766.387144] [22766.387145] Call Trace: [22766.387145] <IRQ> [22766.387150] [<ffffffffa169f292>] ? __sctp_lookup_association+0x62/0xd0 [sctp] [22766.387154] [<ffffffffa169f2b6>] __sctp_lookup_association+0x86/0xd0 [sctp] [22766.387157] [<ffffffffa169f597>] sctp_rcv+0x207/0xbb0 [sctp] [22766.387161] [<ffffffff810d4da8>] ? trace_hardirqs_off_caller+0x28/0xd0 [22766.387163] [<ffffffff815827e3>] ? nf_hook_slow+0x133/0x210 [22766.387166] [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387168] [<ffffffff8159043d>] ip_local_deliver_finish+0x18d/0x4c0 [22766.387169] [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387171] [<ffffffff81590a07>] ip_local_deliver+0x47/0x80 [22766.387172] [<ffffffff8158fd80>] ip_rcv_finish+0x150/0x680 [22766.387174] [<ffffffff81590c54>] ip_rcv+0x214/0x320 [22766.387176] [<ffffffff81558c07>] __netif_receive_skb+0x7b7/0x910 [22766.387178] [<ffffffff8155856c>] ? __netif_receive_skb+0x11c/0x910 [22766.387180] [<ffffffff810d423e>] ? put_lock_stats.isra.25+0xe/0x40 [22766.387182] [<ffffffff81558f83>] netif_receive_skb+0x23/0x1f0 [22766.387183] [<ffffffff815596a9>] ? dev_gro_receive+0x139/0x440 [22766.387185] [<ffffffff81559280>] napi_skb_finish+0x70/0xa0 [22766.387187] [<ffffffff81559cb5>] napi_gro_receive+0xf5/0x130 [22766.387218] [<ffffffffa01c4679>] e1000_receive_skb+0x59/0x70 [e1000e] [22766.387242] [<ffffffffa01c5aab>] e1000_clean_rx_irq+0x28b/0x460 [e1000e] [22766.387266] [<ffffffffa01c9c18>] e1000e_poll+0x78/0x430 [e1000e] [22766.387268] [<ffffffff81559fea>] net_rx_action+0x1aa/0x3d0 [22766.387270] [<ffffffff810a495f>] ? account_system_vtime+0x10f/0x130 [22766.387273] [<ffffffff810734d0>] __do_softirq+0xe0/0x420 [22766.387275] [<ffffffff8169826c>] call_softirq+0x1c/0x30 [22766.387278] [<ffffffff8101db15>] do_softirq+0xd5/0x110 [22766.387279] [<ffffffff81073bc5>] irq_exit+0xd5/0xe0 [22766.387281] [<ffffffff81698b03>] do_IRQ+0x63/0xd0 [22766.387283] [<ffffffff8168ee2f>] common_interrupt+0x6f/0x6f [22766.387283] <EOI> [22766.387284] [22766.387285] [<ffffffff8168eed9>] ? retint_swapgs+0x13/0x1b [22766.387285] Code: c0 90 5d c3 66 0f 1f 44 00 00 4c 89 c8 5d c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89 5d e8 4c 89 65 f0 4c 89 6d f8 66 66 66 66 90 <0f> b7 87 98 00 00 00 48 89 fb 49 89 f5 66 c1 c0 08 66 39 46 02 [22766.387307] [22766.387307] RIP [22766.387311] [<ffffffffa168a2c9>] sctp_assoc_is_match+0x19/0x90 [sctp] [22766.387311] RSP <ffff880147c039b0> [22766.387142] ffffffffa16ab120 [22766.599537] ---[ end trace 3f6dae82e37b17f5 ]--- [22766.601221] Kernel panic - not syncing: Fatal exception in interrupt It appears from his analysis and some staring at the code that this is likely occuring because an association is getting freed while still on the sctp_assoc_hashtable. As a result, we get a gpf when traversing the hashtable while a freed node corrupts part of the list. Nominally I would think that an mibalanced refcount was responsible for this, but I can't seem to find any obvious imbalance. What I did note however was that the two places where we create an association using sctp_primitive_ASSOCIATE (__sctp_connect and sctp_sendmsg), have failure paths which free a newly created association after calling sctp_primitive_ASSOCIATE. sctp_primitive_ASSOCIATE brings us into the sctp_sf_do_prm_asoc path, which issues a SCTP_CMD_NEW_ASOC side effect, which in turn adds a new association to the aforementioned hash table. the sctp command interpreter that process side effects has not way to unwind previously processed commands, so freeing the association from the __sctp_connect or sctp_sendmsg error path would lead to a freed association remaining on this hash table. I've fixed this but modifying sctp_[un]hash_established to use hlist_del_init, which allows us to proerly use hlist_unhashed to check if the node is on a hashlist safely during a delete. That in turn alows us to safely call sctp_unhash_established in the __sctp_connect and sctp_sendmsg error paths before freeing them, regardles of what the associations state is on the hash list. I noted, while I was doing this, that the __sctp_unhash_endpoint was using hlist_unhsashed in a simmilar fashion, but never nullified any removed nodes pointers to make that function work properly, so I fixed that up in a simmilar fashion. I attempted to test this using a virtual guest running the SCTP_RR test from netperf in a loop while running the trinity fuzzer, both in a loop. I wasn't able to recreate the problem prior to this fix, nor was I able to trigger the failure after (neither of which I suppose is suprising). Given the trace above however, I think its likely that this is what we hit. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: davej@redhat.com CC: davej@redhat.com CC: "David S. Miller" <davem@davemloft.net> CC: Vlad Yasevich <vyasevich@gmail.com> CC: Sridhar Samudrala <sri@us.ibm.com> CC: linux-sctp@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-16 09:13:51 +00:00
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 17:06:00 -08:00