diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Kconfig.debug | 8 | ||||
-rw-r--r-- | lib/Makefile | 2 | ||||
-rw-r--r-- | lib/crc32.c | 153 | ||||
-rw-r--r-- | lib/dynamic_debug.c | 8 | ||||
-rw-r--r-- | lib/iovec.c | 4 | ||||
-rw-r--r-- | lib/net_utils.c | 10 | ||||
-rw-r--r-- | lib/random32.c | 49 | ||||
-rw-r--r-- | lib/rhashtable.c | 797 | ||||
-rw-r--r-- | lib/test_bpf.c | 28 |
9 files changed, 935 insertions, 124 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1f630ad..cfe7df8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1536,6 +1536,14 @@ config TEST_STRING_HELPERS config TEST_KSTRTOX tristate "Test kstrto*() family of functions at runtime" +config TEST_RHASHTABLE + bool "Perform selftest on resizable hash table" + default n + help + Enable this option to test the rhashtable functions at boot. + + If unsure, say N. + endmenu # runtime tests config PROVIDE_OHCI1394_DMA_INIT diff --git a/lib/Makefile b/lib/Makefile index 230b4b1..8427df9 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -26,7 +26,7 @@ obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ gcd.o lcm.o list_sort.o uuid.o flex_array.o iovec.o clz_ctz.o \ bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o \ - percpu-refcount.o percpu_ida.o hash.o + percpu-refcount.o percpu_ida.o hash.o rhashtable.o obj-y += string_helpers.o obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o obj-y += kstrtox.o diff --git a/lib/crc32.c b/lib/crc32.c index 21a7b2135..9a907d4 100644 --- a/lib/crc32.c +++ b/lib/crc32.c @@ -50,34 +50,10 @@ MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>"); MODULE_DESCRIPTION("Various CRC32 calculations"); MODULE_LICENSE("GPL"); -#define GF2_DIM 32 - -static u32 gf2_matrix_times(u32 *mat, u32 vec) -{ - u32 sum = 0; - - while (vec) { - if (vec & 1) - sum ^= *mat; - vec >>= 1; - mat++; - } - - return sum; -} - -static void gf2_matrix_square(u32 *square, u32 *mat) -{ - int i; - - for (i = 0; i < GF2_DIM; i++) - square[i] = gf2_matrix_times(mat, mat[i]); -} - #if CRC_LE_BITS > 8 || CRC_BE_BITS > 8 /* implements slicing-by-4 or slicing-by-8 algorithm */ -static inline u32 +static inline u32 __pure crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 (*tab)[256]) { # ifdef __LITTLE_ENDIAN @@ -155,51 +131,6 @@ crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 (*tab)[256]) } #endif -/* For conditions of distribution and use, see copyright notice in zlib.h */ -static u32 crc32_generic_combine(u32 crc1, u32 crc2, size_t len2, - u32 polynomial) -{ - u32 even[GF2_DIM]; /* Even-power-of-two zeros operator */ - u32 odd[GF2_DIM]; /* Odd-power-of-two zeros operator */ - u32 row; - int i; - - if (len2 <= 0) - return crc1; - - /* Put operator for one zero bit in odd */ - odd[0] = polynomial; - row = 1; - for (i = 1; i < GF2_DIM; i++) { - odd[i] = row; - row <<= 1; - } - - gf2_matrix_square(even, odd); /* Put operator for two zero bits in even */ - gf2_matrix_square(odd, even); /* Put operator for four zero bits in odd */ - - /* Apply len2 zeros to crc1 (first square will put the operator for one - * zero byte, eight zero bits, in even). - */ - do { - /* Apply zeros operator for this bit of len2 */ - gf2_matrix_square(even, odd); - if (len2 & 1) - crc1 = gf2_matrix_times(even, crc1); - len2 >>= 1; - /* If no more bits set, then done */ - if (len2 == 0) - break; - /* Another iteration of the loop with odd and even swapped */ - gf2_matrix_square(odd, even); - if (len2 & 1) - crc1 = gf2_matrix_times(odd, crc1); - len2 >>= 1; - } while (len2 != 0); - - crc1 ^= crc2; - return crc1; -} /** * crc32_le_generic() - Calculate bitwise little-endian Ethernet AUTODIN II @@ -271,19 +202,81 @@ u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len) (const u32 (*)[256])crc32ctable_le, CRC32C_POLY_LE); } #endif -u32 __pure crc32_le_combine(u32 crc1, u32 crc2, size_t len2) +EXPORT_SYMBOL(crc32_le); +EXPORT_SYMBOL(__crc32c_le); + +/* + * This multiplies the polynomials x and y modulo the given modulus. + * This follows the "little-endian" CRC convention that the lsbit + * represents the highest power of x, and the msbit represents x^0. + */ +static u32 __attribute_const__ gf2_multiply(u32 x, u32 y, u32 modulus) { - return crc32_generic_combine(crc1, crc2, len2, CRCPOLY_LE); + u32 product = x & 1 ? y : 0; + int i; + + for (i = 0; i < 31; i++) { + product = (product >> 1) ^ (product & 1 ? modulus : 0); + x >>= 1; + product ^= x & 1 ? y : 0; + } + + return product; } -u32 __pure __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2) +/** + * crc32_generic_shift - Append len 0 bytes to crc, in logarithmic time + * @crc: The original little-endian CRC (i.e. lsbit is x^31 coefficient) + * @len: The number of bytes. @crc is multiplied by x^(8*@len) + * @polynomial: The modulus used to reduce the result to 32 bits. + * + * It's possible to parallelize CRC computations by computing a CRC + * over separate ranges of a buffer, then summing them. + * This shifts the given CRC by 8*len bits (i.e. produces the same effect + * as appending len bytes of zero to the data), in time proportional + * to log(len). + */ +static u32 __attribute_const__ crc32_generic_shift(u32 crc, size_t len, + u32 polynomial) { - return crc32_generic_combine(crc1, crc2, len2, CRC32C_POLY_LE); + u32 power = polynomial; /* CRC of x^32 */ + int i; + + /* Shift up to 32 bits in the simple linear way */ + for (i = 0; i < 8 * (int)(len & 3); i++) + crc = (crc >> 1) ^ (crc & 1 ? polynomial : 0); + + len >>= 2; + if (!len) + return crc; + + for (;;) { + /* "power" is x^(2^i), modulo the polynomial */ + if (len & 1) + crc = gf2_multiply(crc, power, polynomial); + + len >>= 1; + if (!len) + break; + + /* Square power, advancing to x^(2^(i+1)) */ + power = gf2_multiply(power, power, polynomial); + } + + return crc; } -EXPORT_SYMBOL(crc32_le); -EXPORT_SYMBOL(crc32_le_combine); -EXPORT_SYMBOL(__crc32c_le); -EXPORT_SYMBOL(__crc32c_le_combine); + +u32 __attribute_const__ crc32_le_shift(u32 crc, size_t len) +{ + return crc32_generic_shift(crc, len, CRCPOLY_LE); +} + +u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len) +{ + return crc32_generic_shift(crc, len, CRC32C_POLY_LE); +} +EXPORT_SYMBOL(crc32_le_shift); +EXPORT_SYMBOL(__crc32c_le_shift); /** * crc32_be_generic() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32 @@ -351,7 +344,7 @@ EXPORT_SYMBOL(crc32_be); #ifdef CONFIG_CRC32_SELFTEST /* 4096 random bytes */ -static u8 __attribute__((__aligned__(8))) test_buf[] = +static u8 const __aligned(8) test_buf[] __initconst = { 0x5b, 0x85, 0x21, 0xcb, 0x09, 0x68, 0x7d, 0x30, 0xc7, 0x69, 0xd7, 0x30, 0x92, 0xde, 0x59, 0xe4, @@ -875,7 +868,7 @@ static struct crc_test { u32 crc_le; /* expected crc32_le result */ u32 crc_be; /* expected crc32_be result */ u32 crc32c_le; /* expected crc32c_le result */ -} test[] = +} const test[] __initconst = { {0x674bf11d, 0x00000038, 0x00000542, 0x0af6d466, 0xd8b6e4c1, 0xf6e93d6c}, {0x35c672c6, 0x0000003a, 0x000001aa, 0xc6d3dfba, 0x28aaf3ad, 0x0fe92aca}, diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 7288e38..c9afbe2 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -614,13 +614,15 @@ int __dynamic_netdev_dbg(struct _ddebug *descriptor, char buf[PREFIX_SIZE]; res = dev_printk_emit(7, dev->dev.parent, - "%s%s %s %s: %pV", + "%s%s %s %s%s: %pV", dynamic_emit_prefix(descriptor, buf), dev_driver_string(dev->dev.parent), dev_name(dev->dev.parent), - netdev_name(dev), &vaf); + netdev_name(dev), netdev_reg_state(dev), + &vaf); } else if (dev) { - res = printk(KERN_DEBUG "%s: %pV", netdev_name(dev), &vaf); + res = printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev), + netdev_reg_state(dev), &vaf); } else { res = printk(KERN_DEBUG "(NULL net_device): %pV", &vaf); } diff --git a/lib/iovec.c b/lib/iovec.c index 7a7c2da..df3abd1 100644 --- a/lib/iovec.c +++ b/lib/iovec.c @@ -85,6 +85,10 @@ EXPORT_SYMBOL(memcpy_toiovecend); int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, int offset, int len) { + /* No data? Done! */ + if (len == 0) + return 0; + /* Skip over the finished iovecs */ while (offset >= iov->iov_len) { offset -= iov->iov_len; diff --git a/lib/net_utils.c b/lib/net_utils.c index 2e3c52c..148fc6e 100644 --- a/lib/net_utils.c +++ b/lib/net_utils.c @@ -3,24 +3,24 @@ #include <linux/ctype.h> #include <linux/kernel.h> -int mac_pton(const char *s, u8 *mac) +bool mac_pton(const char *s, u8 *mac) { int i; /* XX:XX:XX:XX:XX:XX */ if (strlen(s) < 3 * ETH_ALEN - 1) - return 0; + return false; /* Don't dirty result unless string is valid MAC. */ for (i = 0; i < ETH_ALEN; i++) { if (!isxdigit(s[i * 3]) || !isxdigit(s[i * 3 + 1])) - return 0; + return false; if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':') - return 0; + return false; } for (i = 0; i < ETH_ALEN; i++) { mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]); } - return 1; + return true; } EXPORT_SYMBOL(mac_pton); diff --git a/lib/random32.c b/lib/random32.c index fa5da61..c9b6bf3 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -40,6 +40,10 @@ #ifdef CONFIG_RANDOM32_SELFTEST static void __init prandom_state_selftest(void); +#else +static inline void prandom_state_selftest(void) +{ +} #endif static DEFINE_PER_CPU(struct rnd_state, net_rand_state); @@ -53,8 +57,7 @@ static DEFINE_PER_CPU(struct rnd_state, net_rand_state); */ u32 prandom_u32_state(struct rnd_state *state) { -#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b) - +#define TAUSWORTHE(s, a, b, c, d) ((s & c) << d) ^ (((s << a) ^ s) >> b) state->s1 = TAUSWORTHE(state->s1, 6U, 13U, 4294967294U, 18U); state->s2 = TAUSWORTHE(state->s2, 2U, 27U, 4294967288U, 2U); state->s3 = TAUSWORTHE(state->s3, 13U, 21U, 4294967280U, 7U); @@ -147,21 +150,25 @@ static void prandom_warmup(struct rnd_state *state) prandom_u32_state(state); } -static void prandom_seed_very_weak(struct rnd_state *state, u32 seed) +static u32 __extract_hwseed(void) { - /* Note: This sort of seeding is ONLY used in test cases and - * during boot at the time from core_initcall until late_initcall - * as we don't have a stronger entropy source available yet. - * After late_initcall, we reseed entire state, we have to (!), - * otherwise an attacker just needs to search 32 bit space to - * probe for our internal 128 bit state if he knows a couple - * of prandom32 outputs! - */ -#define LCG(x) ((x) * 69069U) /* super-duper LCG */ - state->s1 = __seed(LCG(seed), 2U); - state->s2 = __seed(LCG(state->s1), 8U); - state->s3 = __seed(LCG(state->s2), 16U); - state->s4 = __seed(LCG(state->s3), 128U); + u32 val = 0; + + (void)(arch_get_random_seed_int(&val) || + arch_get_random_int(&val)); + + return val; +} + +static void prandom_seed_early(struct rnd_state *state, u32 seed, + bool mix_with_hwseed) +{ +#define LCG(x) ((x) * 69069U) /* super-duper LCG */ +#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) + state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); + state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); + state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); + state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); } /** @@ -194,14 +201,13 @@ static int __init prandom_init(void) { int i; -#ifdef CONFIG_RANDOM32_SELFTEST prandom_state_selftest(); -#endif for_each_possible_cpu(i) { struct rnd_state *state = &per_cpu(net_rand_state,i); + u32 weak_seed = (i + jiffies) ^ random_get_entropy(); - prandom_seed_very_weak(state, (i + jiffies) ^ random_get_entropy()); + prandom_seed_early(state, weak_seed, true); prandom_warmup(state); } @@ -210,6 +216,7 @@ static int __init prandom_init(void) core_initcall(prandom_init); static void __prandom_timer(unsigned long dontcare); + static DEFINE_TIMER(seed_timer, __prandom_timer, 0, 0); static void __prandom_timer(unsigned long dontcare) @@ -419,7 +426,7 @@ static void __init prandom_state_selftest(void) for (i = 0; i < ARRAY_SIZE(test1); i++) { struct rnd_state state; - prandom_seed_very_weak(&state, test1[i].seed); + prandom_seed_early(&state, test1[i].seed, false); prandom_warmup(&state); if (test1[i].result != prandom_u32_state(&state)) @@ -434,7 +441,7 @@ static void __init prandom_state_selftest(void) for (i = 0; i < ARRAY_SIZE(test2); i++) { struct rnd_state state; - prandom_seed_very_weak(&state, test2[i].seed); + prandom_seed_early(&state, test2[i].seed, false); prandom_warmup(&state); for (j = 0; j < test2[i].iteration - 1; j++) diff --git a/lib/rhashtable.c b/lib/rhashtable.c new file mode 100644 index 0000000..e6940cf --- /dev/null +++ b/lib/rhashtable.c @@ -0,0 +1,797 @@ +/* + * Resizable, Scalable, Concurrent Hash Table + * + * Copyright (c) 2014 Thomas Graf <tgraf@suug.ch> + * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net> + * + * Based on the following paper: + * https://www.usenix.org/legacy/event/atc11/tech/final_files/Triplett.pdf + * + * Code partially derived from nft_hash + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/log2.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <linux/hash.h> +#include <linux/random.h> +#include <linux/rhashtable.h> +#include <linux/log2.h> + +#define HASH_DEFAULT_SIZE 64UL +#define HASH_MIN_SIZE 4UL + +#define ASSERT_RHT_MUTEX(HT) BUG_ON(!lockdep_rht_mutex_is_held(HT)) + +#ifdef CONFIG_PROVE_LOCKING +int lockdep_rht_mutex_is_held(const struct rhashtable *ht) +{ + return ht->p.mutex_is_held(); +} +EXPORT_SYMBOL_GPL(lockdep_rht_mutex_is_held); +#endif + +/** + * rht_obj - cast hash head to outer object + * @ht: hash table + * @he: hashed node + */ +void *rht_obj(const struct rhashtable *ht, const struct rhash_head *he) +{ + return (void *) he - ht->p.head_offset; +} +EXPORT_SYMBOL_GPL(rht_obj); + +static u32 __hashfn(const struct rhashtable *ht, const void *key, + u32 len, u32 hsize) +{ + u32 h; + + h = ht->p.hashfn(key, len, ht->p.hash_rnd); + + return h & (hsize - 1); +} + +/** + * rhashtable_hashfn - compute hash for key of given length + * @ht: hash table to compuate for + * @key: pointer to key + * @len: length of key + * + * Computes the hash value using the hash function provided in the 'hashfn' + * of struct rhashtable_params. The returned value is guaranteed to be + * smaller than the number of buckets in the hash table. + */ +u32 rhashtable_hashfn(const struct rhashtable *ht, const void *key, u32 len) +{ + struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); + + return __hashfn(ht, key, len, tbl->size); +} +EXPORT_SYMBOL_GPL(rhashtable_hashfn); + +static u32 obj_hashfn(const struct rhashtable *ht, const void *ptr, u32 hsize) +{ + if (unlikely(!ht->p.key_len)) { + u32 h; + + h = ht->p.obj_hashfn(ptr, ht->p.hash_rnd); + + return h & (hsize - 1); + } + + return __hashfn(ht, ptr + ht->p.key_offset, ht->p.key_len, hsize); +} + +/** + * rhashtable_obj_hashfn - compute hash for hashed object + * @ht: hash table to compuate for + * @ptr: pointer to hashed object + * + * Computes the hash value using the hash function `hashfn` respectively + * 'obj_hashfn' depending on whether the hash table is set up to work with + * a fixed length key. The returned value is guaranteed to be smaller than + * the number of buckets in the hash table. + */ +u32 rhashtable_obj_hashfn(const struct rhashtable *ht, void *ptr) +{ + struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); + + return obj_hashfn(ht, ptr, tbl->size); +} +EXPORT_SYMBOL_GPL(rhashtable_obj_hashfn); + +static u32 head_hashfn(const struct rhashtable *ht, + const struct rhash_head *he, u32 hsize) +{ + return obj_hashfn(ht, rht_obj(ht, he), hsize); +} + +static struct bucket_table *bucket_table_alloc(size_t nbuckets, gfp_t flags) +{ + struct bucket_table *tbl; + size_t size; + + size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]); + tbl = kzalloc(size, flags); + if (tbl == NULL) + tbl = vzalloc(size); + + if (tbl == NULL) + return NULL; + + tbl->size = nbuckets; + + return tbl; +} + +static void bucket_table_free(const struct bucket_table *tbl) +{ + kvfree(tbl); +} + +/** + * rht_grow_above_75 - returns true if nelems > 0.75 * table-size + * @ht: hash table + * @new_size: new table size + */ +bool rht_grow_above_75(const struct rhashtable *ht, size_t new_size) +{ + /* Expand table when exceeding 75% load */ + return ht->nelems > (new_size / 4 * 3); +} +EXPORT_SYMBOL_GPL(rht_grow_above_75); + +/** + * rht_shrink_below_30 - returns true if nelems < 0.3 * table-size + * @ht: hash table + * @new_size: new table size + */ +bool rht_shrink_below_30(const struct rhashtable *ht, size_t new_size) +{ + /* Shrink table beneath 30% load */ + return ht->nelems < (new_size * 3 / 10); +} +EXPORT_SYMBOL_GPL(rht_shrink_below_30); + +static void hashtable_chain_unzip(const struct rhashtable *ht, + const struct bucket_table *new_tbl, + struct bucket_table *old_tbl, size_t n) +{ + struct rhash_head *he, *p, *next; + unsigned int h; + + /* Old bucket empty, no work needed. */ + p = rht_dereference(old_tbl->buckets[n], ht); + if (!p) + return; + + /* Advance the old bucket pointer one or more times until it + * reaches a node that doesn't hash to the same bucket as the + * previous node p. Call the previous node p; + */ + h = head_hashfn(ht, p, new_tbl->size); + rht_for_each(he, p->next, ht) { + if (head_hashfn(ht, he, new_tbl->size) != h) + break; + p = he; + } + RCU_INIT_POINTER(old_tbl->buckets[n], p->next); + + /* Find the subsequent node which does hash to the same + * bucket as node P, or NULL if no such node exists. + */ + next = NULL; + if (he) { + rht_for_each(he, he->next, ht) { + if (head_hashfn(ht, he, new_tbl->size) == h) { + next = he; + break; + } + } + } + + /* Set p's next pointer to that subsequent node pointer, + * bypassing the nodes which do not hash to p's bucket + */ + RCU_INIT_POINTER(p->next, next); +} + +/** + * rhashtable_expand - Expand hash table while allowing concurrent lookups + * @ht: the hash table to expand + * @flags: allocation flags + * + * A secondary bucket array is allocated and the hash entries are migrated + * while keeping them on both lists until the end of the RCU grace period. + * + * This function may only be called in a context where it is safe to call + * synchronize_rcu(), e.g. not within a rcu_read_lock() section. + * + * The caller must ensure that no concurrent table mutations take place. + * It is however valid to have concurrent lookups if they are RCU protected. + */ +int rhashtable_expand(struct rhashtable *ht, gfp_t flags) +{ + struct bucket_table *new_tbl, *old_tbl = rht_dereference(ht->tbl, ht); + struct rhash_head *he; + unsigned int i, h; + bool complete; + + ASSERT_RHT_MUTEX(ht); + + if (ht->p.max_shift && ht->shift >= ht->p.max_shift) + return 0; + + new_tbl = bucket_table_alloc(old_tbl->size * 2, flags); + if (new_tbl == NULL) + return -ENOMEM; + + ht->shift++; + + /* For each new bucket, search the corresponding old bucket + * for the first entry that hashes to the new bucket, and + * link the new bucket to that entry. Since all the entries + * which will end up in the new bucket appear in the same + * old bucket, this constructs an entirely valid new hash + * table, but with multiple buckets "zipped" together into a + * single imprecise chain. + */ + for (i = 0; i < new_tbl->size; i++) { + h = i & (old_tbl->size - 1); + rht_for_each(he, old_tbl->buckets[h], ht) { + if (head_hashfn(ht, he, new_tbl->size) == i) { + RCU_INIT_POINTER(new_tbl->buckets[i], he); + break; + } + } + } + + /* Publish the new table pointer. Lookups may now traverse + * the new table, but they will not benefit from any + * additional efficiency until later steps unzip the buckets. + */ + rcu_assign_pointer(ht->tbl, new_tbl); + + /* Unzip interleaved hash chains */ + do { + /* Wait for readers. All new readers will see the new + * table, and thus no references to the old table will + * remain. + */ + synchronize_rcu(); + + /* For each bucket in the old table (each of which + * contains items from multiple buckets of the new + * table): ... + */ + complete = true; + for (i = 0; i < old_tbl->size; i++) { + hashtable_chain_unzip(ht, new_tbl, old_tbl, i); + if (old_tbl->buckets[i] != NULL) + complete = false; + } + } while (!complete); + + bucket_table_free(old_tbl); + return 0; +} +EXPORT_SYMBOL_GPL(rhashtable_expand); + +/** + * rhashtable_shrink - Shrink hash table while allowing concurrent lookups + * @ht: the hash table to shrink + * @flags: allocation flags + * + * This function may only be called in a context where it is safe to call + * synchronize_rcu(), e.g. not within a rcu_read_lock() section. + * + * The caller must ensure that no concurrent table mutations take place. + * It is however valid to have concurrent lookups if they are RCU protected. + */ +int rhashtable_shrink(struct rhashtable *ht, gfp_t flags) +{ + struct bucket_table *ntbl, *tbl = rht_dereference(ht->tbl, ht); + struct rhash_head __rcu **pprev; + unsigned int i; + + ASSERT_RHT_MUTEX(ht); + + if (tbl->size <= HASH_MIN_SIZE) + return 0; + + ntbl = bucket_table_alloc(tbl->size / 2, flags); + if (ntbl == NULL) + return -ENOMEM; + + ht->shift--; + + /* Link each bucket in the new table to the first bucket + * in the old table that contains entries which will hash + * to the new bucket. + */ + for (i = 0; i < ntbl->size; i++) { + ntbl->buckets[i] = tbl->buckets[i]; + + /* Link each bucket in the new table to the first bucket + * in the old table that contains entries which will hash + * to the new bucket. + */ + for (pprev = &ntbl->buckets[i]; *pprev != NULL; + pprev = &rht_dereference(*pprev, ht)->next) + ; + RCU_INIT_POINTER(*pprev, tbl->buckets[i + ntbl->size]); + } + + /* Publish the new, valid hash table */ + rcu_assign_pointer(ht->tbl, ntbl); + + /* Wait for readers. No new readers will have references to the + * old hash table. + */ + synchronize_rcu(); + + bucket_table_free(tbl); + + return 0; +} +EXPORT_SYMBOL_GPL(rhashtable_shrink); + +/** + * rhashtable_insert - insert object into hash hash table + * @ht: hash table + * @obj: pointer to hash head inside object + * @flags: allocation flags (table expansion) + * + * Will automatically grow the table via rhashtable_expand() if the the + * grow_decision function specified at rhashtable_init() returns true. + * + * The caller must ensure that no concurrent table mutations occur. It is + * however valid to have concurrent lookups if they are RCU protected. + */ +void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj, + gfp_t flags) +{ + struct bucket_table *tbl = rht_dereference(ht->tbl, ht); + u32 hash; + + ASSERT_RHT_MUTEX(ht); + + hash = head_hashfn(ht, obj, tbl->size); + RCU_INIT_POINTER(obj->next, tbl->buckets[hash]); + rcu_assign_pointer(tbl->buckets[hash], obj); + ht->nelems++; + + if (ht->p.grow_decision && ht->p.grow_decision(ht, tbl->size)) + rhashtable_expand(ht, flags); +} +EXPORT_SYMBOL_GPL(rhashtable_insert); + +/** + * rhashtable_remove_pprev - remove object from hash table given previous element + * @ht: hash table + * @obj: pointer to hash head inside object + * @pprev: pointer to previous element + * @flags: allocation flags (table expansion) + * + * Identical to rhashtable_remove() but caller is alreayd aware of the element + * in front of the element to be deleted. This is in particular useful for + * deletion when combined with walking or lookup. + */ +void rhashtable_remove_pprev(struct rhashtable *ht, struct rhash_head *obj, + struct rhash_head **pprev, gfp_t flags) +{ + struct bucket_table *tbl = rht_dereference(ht->tbl, ht); + + ASSERT_RHT_MUTEX(ht); + + RCU_INIT_POINTER(*pprev, obj->next); + ht->nelems--; + + if (ht->p.shrink_decision && + ht->p.shrink_decision(ht, tbl->size)) + rhashtable_shrink(ht, flags); +} +EXPORT_SYMBOL_GPL(rhashtable_remove_pprev); + +/** + * rhashtable_remove - remove object from hash table + * @ht: hash table + * @obj: pointer to hash head inside object + * @flags: allocation flags (table expansion) + * + * Since the hash chain is single linked, the removal operation needs to + * walk the bucket chain upon removal. The removal operation is thus + * considerable slow if the hash table is not correctly sized. + * + * Will automatically shrink the table via rhashtable_expand() if the the + * shrink_decision function specified at rhashtable_init() returns true. + * + * The caller must ensure that no concurrent table mutations occur. It is + * however valid to have concurrent lookups if they are RCU protected. + */ +bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj, + gfp_t flags) +{ + struct bucket_table *tbl = rht_dereference(ht->tbl, ht); + struct rhash_head __rcu **pprev; + struct rhash_head *he; + u32 h; + + ASSERT_RHT_MUTEX(ht); + + h = head_hashfn(ht, obj, tbl->size); + + pprev = &tbl->buckets[h]; + rht_for_each(he, tbl->buckets[h], ht) { + if (he != obj) { + pprev = &he->next; + continue; + } + + rhashtable_remove_pprev(ht, he, pprev, flags); + return true; + } + + return false; +} +EXPORT_SYMBOL_GPL(rhashtable_remove); + +/** + * rhashtable_lookup - lookup key in hash table + * @ht: hash table + * @key: pointer to key + * + * Computes the hash value for the key and traverses the bucket chain looking + * for a entry with an identical key. The first matching entry is returned. + * + * This lookup function may only be used for fixed key hash table (key_len + * paramter set). It will BUG() if used inappropriately. + * + * Lookups may occur in parallel with hash mutations as long as the lookup is + * guarded by rcu_read_lock(). The caller must take care of this. + */ +void *rhashtable_lookup(const struct rhashtable *ht, const void *key) +{ + const struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); + struct rhash_head *he; + u32 h; + + BUG_ON(!ht->p.key_len); + + h = __hashfn(ht, key, ht->p.key_len, tbl->size); + rht_for_each_rcu(he, tbl->buckets[h], ht) { + if (memcmp(rht_obj(ht, he) + ht->p.key_offset, key, + ht->p.key_len)) + continue; + return (void *) he - ht->p.head_offset; + } + + return NULL; +} +EXPORT_SYMBOL_GPL(rhashtable_lookup); + +/** + * rhashtable_lookup_compare - search hash table with compare function + * @ht: hash table + * @hash: hash value of desired entry + * @compare: compare function, must return true on match + * @arg: argument passed on to compare function + * + * Traverses the bucket chain behind the provided hash value and calls the + * specified compare function for each entry. + * + * Lookups may occur in parallel with hash mutations as long as the lookup is + * guarded by rcu_read_lock(). The caller must take care of this. + * + * Returns the first entry on which the compare function returned true. + */ +void *rhashtable_lookup_compare(const struct rhashtable *ht, u32 hash, + bool (*compare)(void *, void *), void *arg) +{ + const struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); + struct rhash_head *he; + + if (unlikely(hash >= tbl->size)) + return NULL; + + rht_for_each_rcu(he, tbl->buckets[hash], ht) { + if (!compare(rht_obj(ht, he), arg)) + continue; + return (void *) he - ht->p.head_offset; + } + + return NULL; +} +EXPORT_SYMBOL_GPL(rhashtable_lookup_compare); + +static size_t rounded_hashtable_size(unsigned int nelem) +{ + return max(roundup_pow_of_two(nelem * 4 / 3), HASH_MIN_SIZE); +} + +/** + * rhashtable_init - initialize a new hash table + * @ht: hash table to be initialized + * @params: configuration parameters + * + * Initializes a new hash table based on the provided configuration + * parameters. A table can be configured either with a variable or + * fixed length key: + * + * Configuration Example 1: Fixed length keys + * struct test_obj { + * int key; + * void * my_member; + * struct rhash_head node; + * }; + * + * struct rhashtable_params params = { + * .head_offset = offsetof(struct test_obj, node), + * .key_offset = offsetof(struct test_obj, key), + * .key_len = sizeof(int), + * .hashfn = arch_fast_hash, + * .mutex_is_held = &my_mutex_is_held, + * }; + * + * Configuration Example 2: Variable length keys + * struct test_obj { + * [...] + * struct rhash_head node; + * }; + * + * u32 my_hash_fn(const void *data, u32 seed) + * { + * struct test_obj *obj = data; + * + * return [... hash ...]; + * } + * + * struct rhashtable_params params = { + * .head_offset = offsetof(struct test_obj, node), + * .hashfn = arch_fast_hash, + * .obj_hashfn = my_hash_fn, + * .mutex_is_held = &my_mutex_is_held, + * }; + */ +int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params) +{ + struct bucket_table *tbl; + size_t size; + + size = HASH_DEFAULT_SIZE; + + if ((params->key_len && !params->hashfn) || + (!params->key_len && !params->obj_hashfn)) + return -EINVAL; + + if (params->nelem_hint) + size = rounded_hashtable_size(params->nelem_hint); + + tbl = bucket_table_alloc(size, GFP_KERNEL); + if (tbl == NULL) + return -ENOMEM; + + memset(ht, 0, sizeof(*ht)); + ht->shift = ilog2(tbl->size); + memcpy(&ht->p, params, sizeof(*params)); + RCU_INIT_POINTER(ht->tbl, tbl); + + if (!ht->p.hash_rnd) + get_random_bytes(&ht->p.hash_rnd, sizeof(ht->p.hash_rnd)); + + return 0; +} +EXPORT_SYMBOL_GPL(rhashtable_init); + +/** + * rhashtable_destroy - destroy hash table + * @ht: the hash table to destroy + * + * Frees the bucket array. + */ +void rhashtable_destroy(const struct rhashtable *ht) +{ + const struct bucket_table *tbl = rht_dereference(ht->tbl, ht); + + bucket_table_free(tbl); +} +EXPORT_SYMBOL_GPL(rhashtable_destroy); + +/************************************************************************** + * Self Test + **************************************************************************/ + +#ifdef CONFIG_TEST_RHASHTABLE + +#define TEST_HT_SIZE 8 +#define TEST_ENTRIES 2048 +#define TEST_PTR ((void *) 0xdeadbeef) +#define TEST_NEXPANDS 4 + +static int test_mutex_is_held(void) +{ + return 1; +} + +struct test_obj { + void *ptr; + int value; + struct rhash_head node; +}; + +static int __init test_rht_lookup(struct rhashtable *ht) +{ + unsigned int i; + + for (i = 0; i < TEST_ENTRIES * 2; i++) { + struct test_obj *obj; + bool expected = !(i % 2); + u32 key = i; + + obj = rhashtable_lookup(ht, &key); + + if (expected && !obj) { + pr_warn("Test failed: Could not find key %u\n", key); + return -ENOENT; + } else if (!expected && obj) { + pr_warn("Test failed: Unexpected entry found for key %u\n", + key); + return -EEXIST; + } else if (expected && obj) { + if (obj->ptr != TEST_PTR || obj->value != i) { + pr_warn("Test failed: Lookup value mismatch %p!=%p, %u!=%u\n", + obj->ptr, TEST_PTR, obj->value, i); + return -EINVAL; + } + } + } + + return 0; +} + +static void test_bucket_stats(struct rhashtable *ht, + struct bucket_table *tbl, + bool quiet) +{ + unsigned int cnt, i, total = 0; + struct test_obj *obj; + + for (i = 0; i < tbl->size; i++) { + cnt = 0; + + if (!quiet) + pr_info(" [%#4x/%zu]", i, tbl->size); + + rht_for_each_entry_rcu(obj, tbl->buckets[i], node) { + cnt++; + total++; + if (!quiet) + pr_cont(" [%p],", obj); + } + + if (!quiet) + pr_cont("\n [%#x] first element: %p, chain length: %u\n", + i, tbl->buckets[i], cnt); + } + + pr_info(" Traversal complete: counted=%u, nelems=%zu, entries=%d\n", + total, ht->nelems, TEST_ENTRIES); +} + +static int __init test_rhashtable(struct rhashtable *ht) +{ + struct bucket_table *tbl; + struct test_obj *obj, *next; + int err; + unsigned int i; + + /* + * Insertion Test: + * Insert TEST_ENTRIES into table with all keys even numbers + */ + pr_info(" Adding %d keys\n", TEST_ENTRIES); + for (i = 0; i < TEST_ENTRIES; i++) { + struct test_obj *obj; + + obj = kzalloc(sizeof(*obj), GFP_KERNEL); + if (!obj) { + err = -ENOMEM; + goto error; + } + + obj->ptr = TEST_PTR; + obj->value = i * 2; + + rhashtable_insert(ht, &obj->node, GFP_KERNEL); + } + + rcu_read_lock(); + tbl = rht_dereference_rcu(ht->tbl, ht); + test_bucket_stats(ht, tbl, true); + test_rht_lookup(ht); + rcu_read_unlock(); + + for (i = 0; i < TEST_NEXPANDS; i++) { + pr_info(" Table expansion iteration %u...\n", i); + rhashtable_expand(ht, GFP_KERNEL); + + rcu_read_lock(); + pr_info(" Verifying lookups...\n"); + test_rht_lookup(ht); + rcu_read_unlock(); + } + + for (i = 0; i < TEST_NEXPANDS; i++) { + pr_info(" Table shrinkage iteration %u...\n", i); + rhashtable_shrink(ht, GFP_KERNEL); + + rcu_read_lock(); + pr_info(" Verifying lookups...\n"); + test_rht_lookup(ht); + rcu_read_unlock(); + } + + pr_info(" Deleting %d keys\n", TEST_ENTRIES); + for (i = 0; i < TEST_ENTRIES; i++) { + u32 key = i * 2; + + obj = rhashtable_lookup(ht, &key); + BUG_ON(!obj); + + rhashtable_remove(ht, &obj->node, GFP_KERNEL); + kfree(obj); + } + + return 0; + +error: + tbl = rht_dereference_rcu(ht->tbl, ht); + for (i = 0; i < tbl->size; i++) + rht_for_each_entry_safe(obj, next, tbl->buckets[i], ht, node) + kfree(obj); + + return err; +} + +static int __init test_rht_init(void) +{ + struct rhashtable ht; + struct rhashtable_params params = { + .nelem_hint = TEST_HT_SIZE, + .head_offset = offsetof(struct test_obj, node), + .key_offset = offsetof(struct test_obj, value), + .key_len = sizeof(int), + .hashfn = arch_fast_hash, + .mutex_is_held = &test_mutex_is_held, + .grow_decision = rht_grow_above_75, + .shrink_decision = rht_shrink_below_30, + }; + int err; + + pr_info("Running resizable hashtable tests...\n"); + + err = rhashtable_init(&ht, ¶ms); + if (err < 0) { + pr_warn("Test failed: Unable to initialize hashtable: %d\n", + err); + return err; + } + + err = test_rhashtable(&ht); + + rhashtable_destroy(&ht); + + return err; +} + +subsys_initcall(test_rht_init); + +#endif /* CONFIG_TEST_RHASHTABLE */ diff --git a/lib/test_bpf.c b/lib/test_bpf.c index c579e0f..89e0345 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -66,7 +66,7 @@ struct bpf_test { const char *descr; union { struct sock_filter insns[MAX_INSNS]; - struct sock_filter_int insns_int[MAX_INSNS]; + struct bpf_insn insns_int[MAX_INSNS]; } u; __u8 aux; __u8 data[MAX_DATA]; @@ -1761,9 +1761,9 @@ static int probe_filter_length(struct sock_filter *fp) return len + 1; } -static struct sk_filter *generate_filter(int which, int *err) +static struct bpf_prog *generate_filter(int which, int *err) { - struct sk_filter *fp; + struct bpf_prog *fp; struct sock_fprog_kern fprog; unsigned int flen = probe_filter_length(tests[which].u.insns); __u8 test_type = tests[which].aux & TEST_TYPE_MASK; @@ -1773,7 +1773,7 @@ static struct sk_filter *generate_filter(int which, int *err) fprog.filter = tests[which].u.insns; fprog.len = flen; - *err = sk_unattached_filter_create(&fp, &fprog); + *err = bpf_prog_create(&fp, &fprog); if (tests[which].aux & FLAG_EXPECTED_FAIL) { if (*err == -EINVAL) { pr_cont("PASS\n"); @@ -1798,7 +1798,7 @@ static struct sk_filter *generate_filter(int which, int *err) break; case INTERNAL: - fp = kzalloc(sk_filter_size(flen), GFP_KERNEL); + fp = kzalloc(bpf_prog_size(flen), GFP_KERNEL); if (fp == NULL) { pr_cont("UNEXPECTED_FAIL no memory left\n"); *err = -ENOMEM; @@ -1807,9 +1807,9 @@ static struct sk_filter *generate_filter(int which, int *err) fp->len = flen; memcpy(fp->insnsi, tests[which].u.insns_int, - fp->len * sizeof(struct sock_filter_int)); + fp->len * sizeof(struct bpf_insn)); - sk_filter_select_runtime(fp); + bpf_prog_select_runtime(fp); break; } @@ -1817,21 +1817,21 @@ static struct sk_filter *generate_filter(int which, int *err) return fp; } -static void release_filter(struct sk_filter *fp, int which) +static void release_filter(struct bpf_prog *fp, int which) { __u8 test_type = tests[which].aux & TEST_TYPE_MASK; switch (test_type) { case CLASSIC: - sk_unattached_filter_destroy(fp); + bpf_prog_destroy(fp); break; case INTERNAL: - sk_filter_free(fp); + bpf_prog_free(fp); break; } } -static int __run_one(const struct sk_filter *fp, const void *data, +static int __run_one(const struct bpf_prog *fp, const void *data, int runs, u64 *duration) { u64 start, finish; @@ -1840,7 +1840,7 @@ static int __run_one(const struct sk_filter *fp, const void *data, start = ktime_to_us(ktime_get()); for (i = 0; i < runs; i++) - ret = SK_RUN_FILTER(fp, data); + ret = BPF_PROG_RUN(fp, data); finish = ktime_to_us(ktime_get()); @@ -1850,7 +1850,7 @@ static int __run_one(const struct sk_filter *fp, const void *data, return ret; } -static int run_one(const struct sk_filter *fp, struct bpf_test *test) +static int run_one(const struct bpf_prog *fp, struct bpf_test *test) { int err_cnt = 0, i, runs = MAX_TESTRUNS; @@ -1884,7 +1884,7 @@ static __init int test_bpf(void) int i, err_cnt = 0, pass_cnt = 0; for (i = 0; i < ARRAY_SIZE(tests); i++) { - struct sk_filter *fp; + struct bpf_prog *fp; int err; pr_info("#%d %s ", i, tests[i].descr); |