/* * benchmark.c: * Author: Konstantin Khlebnikov * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ #include #include #include #include #include "test.h" #define NSEC_PER_SEC 1000000000L static long long benchmark_iter(struct radix_tree_root *root, bool tagged) { volatile unsigned long sink = 0; struct radix_tree_iter iter; struct timespec start, finish; long long nsec; int l, loops = 1; void **slot; #ifdef BENCHMARK again: #endif clock_gettime(CLOCK_MONOTONIC, &start); for (l = 0; l < loops; l++) { if (tagged) { radix_tree_for_each_tagged(slot, root, &iter, 0, 0) sink ^= (unsigned long)slot; } else { radix_tree_for_each_slot(slot, root, &iter, 0) sink ^= (unsigned long)slot; } } clock_gettime(CLOCK_MONOTONIC, &finish); nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC + (finish.tv_nsec - start.tv_nsec); #ifdef BENCHMARK if (loops == 1 && nsec * 5 < NSEC_PER_SEC) { loops = NSEC_PER_SEC / nsec / 4 + 1; goto again; } #endif nsec /= loops; return nsec; } static void benchmark_size(unsigned long size, unsigned long step, int order) { RADIX_TREE(tree, GFP_KERNEL); long long normal, tagged; unsigned long index; for (index = 0 ; index < size ; index += step) { item_insert_order(&tree, index, order); radix_tree_tag_set(&tree, index, 0); } tagged = benchmark_iter(&tree, true); normal = benchmark_iter(&tree, false); printf("Size %ld, step %6ld, order %d tagged %10lld ns, normal %10lld ns\n", size, step, order, tagged, normal); item_kill_tree(&tree); rcu_barrier(); } void benchmark(void) { unsigned long size[] = {1 << 10, 1 << 20, 0}; unsigned long step[] = {1, 2, 7, 15, 63, 64, 65, 128, 256, 512, 12345, 0}; int c, s; printf("starting benchmarks\n"); printf("RADIX_TREE_MAP_SHIFT = %d\n", RADIX_TREE_MAP_SHIFT); for (c = 0; size[c]; c++) for (s = 0; step[s]; s++) benchmark_size(size[c], step[s], 0); for (c = 0; size[c]; c++) for (s = 0; step[s]; s++) benchmark_size(size[c], step[s] << 9, 9); } ='submit' value='search'/>
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authorEric Dumazet <edumazet@google.com>2017-01-27 08:11:44 -0800
committerDavid S. Miller <davem@davemloft.net>2017-01-29 18:30:56 -0500
commitf1712c73714088a7252d276a57126d56c7d37e64 (patch)
tree962ee49daf8d1cba8403fcf03b315d4a142ec944 /fs/xfs/libxfs
parentdc97a89e726c4e1830320d1db8215ef77ecebae0 (diff)
can: Fix kernel panic at security_sock_rcv_skb
Zhang Yanmin reported crashes [1] and provided a patch adding a synchronize_rcu() call in can_rx_unregister() The main problem seems that the sockets themselves are not RCU protected. If CAN uses RCU for delivery, then sockets should be freed only after one RCU grace period. Recent kernels could use sock_set_flag(sk, SOCK_RCU_FREE), but let's ease stable backports with the following fix instead. [1] BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81495e25>] selinux_socket_sock_rcv_skb+0x65/0x2a0 Call Trace: <IRQ> [<ffffffff81485d8c>] security_sock_rcv_skb+0x4c/0x60 [<ffffffff81d55771>] sk_filter+0x41/0x210 [<ffffffff81d12913>] sock_queue_rcv_skb+0x53/0x3a0 [<ffffffff81f0a2b3>] raw_rcv+0x2a3/0x3c0 [<ffffffff81f06eab>] can_rcv_filter+0x12b/0x370 [<ffffffff81f07af9>] can_receive+0xd9/0x120 [<ffffffff81f07beb>] can_rcv+0xab/0x100 [<ffffffff81d362ac>] __netif_receive_skb_core+0xd8c/0x11f0 [<ffffffff81d36734>] __netif_receive_skb+0x24/0xb0 [<ffffffff81d37f67>] process_backlog+0x127/0x280 [<ffffffff81d36f7b>] net_rx_action+0x33b/0x4f0 [<ffffffff810c88d4>] __do_softirq+0x184/0x440 [<ffffffff81f9e86c>] do_softirq_own_stack+0x1c/0x30 <EOI> [<ffffffff810c76fb>] do_softirq.part.18+0x3b/0x40 [<ffffffff810c8bed>] do_softirq+0x1d/0x20 [<ffffffff81d30085>] netif_rx_ni+0xe5/0x110 [<ffffffff8199cc87>] slcan_receive_buf+0x507/0x520 [<ffffffff8167ef7c>] flush_to_ldisc+0x21c/0x230 [<ffffffff810e3baf>] process_one_work+0x24f/0x670 [<ffffffff810e44ed>] worker_thread+0x9d/0x6f0 [<ffffffff810e4450>] ? rescuer_thread+0x480/0x480 [<ffffffff810ebafc>] kthread+0x12c/0x150 [<ffffffff81f9ccef>] ret_from_fork+0x3f/0x70 Reported-by: Zhang Yanmin <yanmin.zhang@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'fs/xfs/libxfs')