/* * A fast, small, non-recursive O(nlog n) sort for the Linux kernel * * Jan 23 2005 Matt Mackall */ #include #include #include static int alignment_ok(const void *base, int align) { return IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) || ((unsigned long)base & (align - 1)) == 0; } static void u32_swap(void *a, void *b, int size) { u32 t = *(u32 *)a; *(u32 *)a = *(u32 *)b; *(u32 *)b = t; } static void u64_swap(void *a, void *b, int size) { u64 t = *(u64 *)a; *(u64 *)a = *(u64 *)b; *(u64 *)b = t; } static void generic_swap(void *a, void *b, int size) { char t; do { t = *(char *)a; *(char *)a++ = *(char *)b; *(char *)b++ = t; } while (--size > 0); } /** * sort - sort an array of elements * @base: pointer to data to sort * @num: number of elements * @size: size of each element * @cmp_func: pointer to comparison function * @swap_func: pointer to swap function or NULL * * This function does a heapsort on the given array. You may provide a * swap_func function optimized to your element type. * * Sorting time is O(n log n) both on average and worst-case. While * qsort is about 20% faster on average, it suffers from exploitable * O(n*n) worst-case behavior and extra memory requirements that make * it less suitable for kernel use. */ void sort(void *base, size_t num, size_t size, int (*cmp_func)(const void *, const void *), void (*swap_func)(void *, void *, int size)) { /* pre-scale counters for performance */ int i = (num/2 - 1) * size, n = num * size, c, r; if (!swap_func) { if (size == 4 && alignment_ok(base, 4)) swap_func = u32_swap; else if (size == 8 && alignment_ok(base, 8)) swap_func = u64_swap; else swap_func = generic_swap; } /* heapify */ for ( ; i >= 0; i -= size) { for (r = i; r * 2 + size < n; r = c) { c = r * 2 + size; if (c < n - size && cmp_func(base + c, base + c + size) < 0) c += size; if (cmp_func(base + r, base + c) >= 0) break; swap_func(base + r, base + c, size); } } /* sort */ for (i = n - size; i > 0; i -= size) { swap_func(base, base + i, size); for (r = 0; r * 2 + size < i; r = c) { c = r * 2 + size; if (c < i - size && cmp_func(base + c, base + c + size) < 0) c += size; if (cmp_func(base + r, base + c) >= 0) break; swap_func(base + r, base + c, size); } } } EXPORT_SYMBOL(sort); #if 0 #include /* a simple boot-time regression test */ int cmpint(const void *a, const void *b) { return *(int *)a - *(int *)b; } static int sort_test(void) { int *a, i, r = 1; a = kmalloc(1000 * sizeof(int), GFP_KERNEL); BUG_ON(!a); printk("testing sort()\n"); for (i = 0; i < 1000; i++) { r = (r * 725861) % 6599; a[i] = r; } sort(a, 1000, sizeof(int), cmpint, NULL); for (i = 0; i < 999; i++) if (a[i] > a[i+1]) { printk("sort() failed!\n"); break; } kfree(a); return 0; } module_init(sort_test); #endif xt.git/log/net/ipv4?id=5f4492493e75dafc5cbb96eabe0f146c2ffb1e3d&showmsg=1'>Expand)AuthorFilesLines 2017-02-07net: use dst_confirm_neigh for UDP, RAW, ICMP, L2TPJulian Anastasov4-3/+15 2017-02-07net: add confirm_neigh method to dst_opsJulian Anastasov1-0/+19 2017-02-07tcp: replace dst_confirm with sk_dst_confirmJulian Anastasov3-14/+7 2017-02-07net: add dst_pending_confirm flag to skbuffJulian Anastasov1-1/+4 2017-02-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller9-47/+31 2017-02-03tcp: clear pfmemalloc on outgoing skbEric Dumazet1-0/+7 2017-02-03tcp: add tcp_mss_clamp() helperEric Dumazet3-19/+7 2017-02-02net: add LINUX_MIB_PFMEMALLOCDROP counterEric Dumazet1-0/+1 2017-02-02net: ipv4: remove fib_lookup.h from devinet.c include listDavid Ahern1-2/+0 2017-02-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+4 2017-02-02netfilter: allow logging from non-init namespacesMichal Kubeček2-2/+2 2017-02-02netfilter: add and use nf_ct_set helperFlorian Westphal3-6/+3 2017-02-02skbuff: add and use skb_nfct helperFlorian Westphal4-8/+8 2017-02-02netfilter: reset netfilter state when duplicating packetFlorian Westphal1-1/+1 2017-02-02netfilter: conntrack: no need to pass ctinfo to error handlerFlorian Westphal1-6/+6