From patchwork Wed Nov 6 09:23:05 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 288804 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from fraxinus.osuosl.org (fraxinus.osuosl.org [140.211.166.137]) by ozlabs.org (Postfix) with ESMTP id 6EC862C00BE for ; Wed, 6 Nov 2013 20:23:41 +1100 (EST) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 55C3E8B127; Wed, 6 Nov 2013 09:23:40 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BlOs13xy-8co; Wed, 6 Nov 2013 09:23:39 +0000 (UTC) Received: from ash.osuosl.org (ash.osuosl.org [140.211.166.34]) by fraxinus.osuosl.org (Postfix) with ESMTP id 023168B122; Wed, 6 Nov 2013 09:23:39 +0000 (UTC) X-Original-To: uclibc@lists.busybox.net Delivered-To: uclibc@osuosl.org Received: from whitealder.osuosl.org (whitealder.osuosl.org [140.211.166.138]) by ash.osuosl.org (Postfix) with ESMTP id 51CD41BFA6A for ; Wed, 6 Nov 2013 09:23:38 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 4BC788AA85 for ; Wed, 6 Nov 2013 09:23:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id GbYvoNV-WSfl for ; Wed, 6 Nov 2013 09:23:35 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from tango.tkos.co.il (tango.tkos.co.il [62.219.50.35]) by whitealder.osuosl.org (Postfix) with ESMTPS id 66B718AA3A for ; Wed, 6 Nov 2013 09:23:34 +0000 (UTC) Received: from tarshish.tkos.co.il (80.179.12.157.static.012.net.il [80.179.12.157]) (authenticated bits=0) by tango.tkos.co.il (8.14.4/8.12.11) with ESMTP id rA69NPqf017685; Wed, 6 Nov 2013 11:23:29 +0200 From: Baruch Siach To: uclibc@uclibc.org Subject: [PATCH 1/2] ldso: move hashcode handling code to a separate header file Date: Wed, 6 Nov 2013 11:23:05 +0200 Message-Id: X-Mailer: git-send-email 1.8.4.rc3 X-Scanned-By: MIMEDefang 2.62 on 62.219.50.35 X-BeenThere: uclibc@uclibc.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Discussion and development of uClibc \(the embedded C library\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: uclibc-bounces@uclibc.org Sender: uclibc-bounces@uclibc.org Move the hashcode handling code inside the ldso/fdpic/dl-inlines.h to a header file (include/inline-hashtab.h), without any functional changes. This is in preparation for supporting TLS descriptors, which also uses that code. Signed-off-by: Chris Zankel Signed-off-by: Baruch Siach --- ldso/include/inline-hashtab.h | 270 ++++++++++++++++++++++++++++++++++++++++++ ldso/ldso/fdpic/dl-inlines.h | 267 +---------------------------------------- 2 files changed, 272 insertions(+), 265 deletions(-) create mode 100644 ldso/include/inline-hashtab.h diff --git a/ldso/include/inline-hashtab.h b/ldso/include/inline-hashtab.h new file mode 100644 index 0000000..5e82cc9 --- /dev/null +++ b/ldso/include/inline-hashtab.h @@ -0,0 +1,270 @@ +/* + * The hashcode handling code below is heavily inspired in libiberty's + * hashtab code, but with most adaptation points and support for + * deleting elements removed. + * + * Copyright (C) 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. + * Contributed by Vladimir Makarov (vmakarov@cygnus.com). + */ + +#ifndef INLINE_HASHTAB_H +# define INLINE_HASHTAB_H 1 + +static __always_inline unsigned long +higher_prime_number(unsigned long n) +{ + /* These are primes that are near, but slightly smaller than, a power of two. */ + static const unsigned long primes[] = { + 7, + 13, + 31, + 61, + 127, + 251, + 509, + 1021, + 2039, + 4093, + 8191, + 16381, + 32749, + 65521, + 131071, + 262139, + 524287, + 1048573, + 2097143, + 4194301, + 8388593, + 16777213, + 33554393, + 67108859, + 134217689, + 268435399, + 536870909, + 1073741789, + /* 4294967291 */ + ((unsigned long) 2147483647) + ((unsigned long) 2147483644), + }; + const unsigned long *low = &primes[0]; + const unsigned long *high = &primes[ARRAY_SIZE(primes)]; + + while (low != high) { + const unsigned long *mid = low + (high - low) / 2; + if (n > *mid) + low = mid + 1; + else + high = mid; + } + +#if 0 + /* If we've run out of primes, abort. */ + if (n > *low) { + fprintf(stderr, "Cannot find prime bigger than %lu\n", n); + abort(); + } +#endif + + return *low; +} + +struct funcdesc_ht +{ + /* Table itself */ + struct funcdesc_value **entries; + + /* Current size (in entries) of the hash table */ + size_t size; + + /* Current number of elements */ + size_t n_elements; +}; + +static __always_inline int +hash_pointer(const void *p) +{ + return (int) ((long)p >> 3); +} + +static __always_inline struct funcdesc_ht * +htab_create(void) +{ + struct funcdesc_ht *ht = _dl_malloc(sizeof(*ht)); + size_t ent_size; + + if (!ht) + return NULL; + ht->size = 3; + ent_size = sizeof(struct funcdesc_ht_value *) * ht->size; + ht->entries = _dl_malloc(ent_size); + if (!ht->entries) + return NULL; + + ht->n_elements = 0; + _dl_memset(ht->entries, 0, ent_size); + + return ht; +} + +/* + * This is only called from _dl_loadaddr_unmap, so it's safe to call + * _dl_free(). See the discussion below. + */ +static __always_inline void +htab_delete(struct funcdesc_ht *htab) +{ + size_t i; + + for (i = htab->size - 1; i >= 0; i--) + if (htab->entries[i]) + _dl_free(htab->entries[i]); + + _dl_free(htab->entries); + _dl_free(htab); +} + +/* + * Similar to htab_find_slot, but without several unwanted side effects: + * - Does not call htab->eq_f when it finds an existing entry. + * - Does not change the count of elements/searches/collisions in the + * hash table. + * This function also assumes there are no deleted entries in the table. + * HASH is the hash value for the element to be inserted. + */ +static __always_inline struct funcdesc_value ** +find_empty_slot_for_expand(struct funcdesc_ht *htab, int hash) +{ + size_t size = htab->size; + unsigned int index = hash % size; + struct funcdesc_value **slot = htab->entries + index; + int hash2; + + if (!*slot) + return slot; + + hash2 = 1 + hash % (size - 2); + for (;;) { + index += hash2; + if (index >= size) + index -= size; + + slot = htab->entries + index; + if (!*slot) + return slot; + } +} + +/* + * The following function changes size of memory allocated for the + * entries and repeatedly inserts the table elements. The occupancy + * of the table after the call will be about 50%. Naturally the hash + * table must already exist. Remember also that the place of the + * table entries is changed. If memory allocation failures are allowed, + * this function will return zero, indicating that the table could not be + * expanded. If all goes well, it will return a non-zero value. + */ +static __always_inline int +htab_expand(struct funcdesc_ht *htab) +{ + struct funcdesc_value **oentries; + struct funcdesc_value **olimit; + struct funcdesc_value **p; + struct funcdesc_value **nentries; + size_t nsize; + + oentries = htab->entries; + olimit = oentries + htab->size; + + /* + * Resize only when table after removal of unused elements is either + * too full or too empty. + */ + if (htab->n_elements * 2 > htab->size) + nsize = higher_prime_number(htab->n_elements * 2); + else + nsize = htab->size; + + nentries = _dl_malloc(sizeof(*nentries) * nsize); + _dl_memset(nentries, 0, sizeof(*nentries) * nsize); + if (nentries == NULL) + return 0; + htab->entries = nentries; + htab->size = nsize; + + p = oentries; + do { + if (*p) + *find_empty_slot_for_expand(htab, hash_pointer((*p)->entry_point)) = *p; + p++; + } while (p < olimit); + +#if 0 + /* + * We can't tell whether this was allocated by the _dl_malloc() + * built into ld.so or malloc() in the main executable or libc, + * and calling free() for something that wasn't malloc()ed could + * do Very Bad Things (TM). Take the conservative approach + * here, potentially wasting as much memory as actually used by + * the hash table, even if multiple growths occur. That's not + * so bad as to require some overengineered solution that would + * enable us to keep track of how it was allocated. + */ + _dl_free(oentries); +#endif + return 1; +} + +/* + * This function searches for a hash table slot containing an entry + * equal to the given element. To delete an entry, call this with + * INSERT = 0, then call htab_clear_slot on the slot returned (possibly + * after doing some checks). To insert an entry, call this with + * INSERT = 1, then write the value you want into the returned slot. + * When inserting an entry, NULL may be returned if memory allocation + * fails. + */ +static __always_inline struct funcdesc_value ** +htab_find_slot(struct funcdesc_ht *htab, void *ptr, int insert) +{ + unsigned int index; + int hash, hash2; + size_t size; + struct funcdesc_value **entry; + + if (htab->size * 3 <= htab->n_elements * 4 && + htab_expand(htab) == 0) + return NULL; + + hash = hash_pointer(ptr); + + size = htab->size; + index = hash % size; + + entry = &htab->entries[index]; + if (!*entry) + goto empty_entry; + else if ((*entry)->entry_point == ptr) + return entry; + + hash2 = 1 + hash % (size - 2); + for (;;) { + index += hash2; + if (index >= size) + index -= size; + + entry = &htab->entries[index]; + if (!*entry) + goto empty_entry; + else if ((*entry)->entry_point == ptr) + return entry; + } + + empty_entry: + if (!insert) + return NULL; + + htab->n_elements++; + return entry; +} + +#endif diff --git a/ldso/ldso/fdpic/dl-inlines.h b/ldso/ldso/fdpic/dl-inlines.h index 14a4916..46e4ba3 100644 --- a/ldso/ldso/fdpic/dl-inlines.h +++ b/ldso/ldso/fdpic/dl-inlines.h @@ -5,6 +5,8 @@ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball. */ +#include + /* Initialize a DL_LOADADDR_TYPE given a got pointer and a complete load map. */ static __always_inline void __dl_init_loadaddr_map(struct elf32_fdpic_loadaddr *loadaddr, Elf32_Addr dl_boot_got_pointer, @@ -143,271 +145,6 @@ __dl_addr_in_loadaddr(void *p, struct elf32_fdpic_loadaddr loadaddr) return 0; } -/* - * The hashcode handling code below is heavily inspired in libiberty's - * hashtab code, but with most adaptation points and support for - * deleting elements removed. - * - * Copyright (C) 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. - * Contributed by Vladimir Makarov (vmakarov@cygnus.com). - */ -static __always_inline unsigned long -higher_prime_number(unsigned long n) -{ - /* These are primes that are near, but slightly smaller than, a power of two. */ - static const unsigned long primes[] = { - 7, - 13, - 31, - 61, - 127, - 251, - 509, - 1021, - 2039, - 4093, - 8191, - 16381, - 32749, - 65521, - 131071, - 262139, - 524287, - 1048573, - 2097143, - 4194301, - 8388593, - 16777213, - 33554393, - 67108859, - 134217689, - 268435399, - 536870909, - 1073741789, - /* 4294967291 */ - ((unsigned long) 2147483647) + ((unsigned long) 2147483644), - }; - const unsigned long *low = &primes[0]; - const unsigned long *high = &primes[ARRAY_SIZE(primes)]; - - while (low != high) { - const unsigned long *mid = low + (high - low) / 2; - if (n > *mid) - low = mid + 1; - else - high = mid; - } - -#if 0 - /* If we've run out of primes, abort. */ - if (n > *low) { - fprintf(stderr, "Cannot find prime bigger than %lu\n", n); - abort(); - } -#endif - - return *low; -} - -struct funcdesc_ht -{ - /* Table itself */ - struct funcdesc_value **entries; - - /* Current size (in entries) of the hash table */ - size_t size; - - /* Current number of elements */ - size_t n_elements; -}; - -static __always_inline int -hash_pointer(const void *p) -{ - return (int) ((long)p >> 3); -} - -static __always_inline struct funcdesc_ht * -htab_create(void) -{ - struct funcdesc_ht *ht = _dl_malloc(sizeof(*ht)); - size_t ent_size; - - if (!ht) - return NULL; - ht->size = 3; - ent_size = sizeof(struct funcdesc_ht_value *) * ht->size; - ht->entries = _dl_malloc(ent_size); - if (!ht->entries) - return NULL; - - ht->n_elements = 0; - _dl_memset(ht->entries, 0, ent_size); - - return ht; -} - -/* - * This is only called from _dl_loadaddr_unmap, so it's safe to call - * _dl_free(). See the discussion below. - */ -static __always_inline void -htab_delete(struct funcdesc_ht *htab) -{ - size_t i; - - for (i = htab->size - 1; i >= 0; i--) - if (htab->entries[i]) - _dl_free(htab->entries[i]); - - _dl_free(htab->entries); - _dl_free(htab); -} - -/* - * Similar to htab_find_slot, but without several unwanted side effects: - * - Does not call htab->eq_f when it finds an existing entry. - * - Does not change the count of elements/searches/collisions in the - * hash table. - * This function also assumes there are no deleted entries in the table. - * HASH is the hash value for the element to be inserted. - */ -static __always_inline struct funcdesc_value ** -find_empty_slot_for_expand(struct funcdesc_ht *htab, int hash) -{ - size_t size = htab->size; - unsigned int index = hash % size; - struct funcdesc_value **slot = htab->entries + index; - int hash2; - - if (!*slot) - return slot; - - hash2 = 1 + hash % (size - 2); - for (;;) { - index += hash2; - if (index >= size) - index -= size; - - slot = htab->entries + index; - if (!*slot) - return slot; - } -} - -/* - * The following function changes size of memory allocated for the - * entries and repeatedly inserts the table elements. The occupancy - * of the table after the call will be about 50%. Naturally the hash - * table must already exist. Remember also that the place of the - * table entries is changed. If memory allocation failures are allowed, - * this function will return zero, indicating that the table could not be - * expanded. If all goes well, it will return a non-zero value. - */ -static __always_inline int -htab_expand(struct funcdesc_ht *htab) -{ - struct funcdesc_value **oentries; - struct funcdesc_value **olimit; - struct funcdesc_value **p; - struct funcdesc_value **nentries; - size_t nsize; - - oentries = htab->entries; - olimit = oentries + htab->size; - - /* - * Resize only when table after removal of unused elements is either - * too full or too empty. - */ - if (htab->n_elements * 2 > htab->size) - nsize = higher_prime_number(htab->n_elements * 2); - else - nsize = htab->size; - - nentries = _dl_malloc(sizeof(*nentries) * nsize); - _dl_memset(nentries, 0, sizeof(*nentries) * nsize); - if (nentries == NULL) - return 0; - htab->entries = nentries; - htab->size = nsize; - - p = oentries; - do { - if (*p) - *find_empty_slot_for_expand(htab, hash_pointer((*p)->entry_point)) = *p; - p++; - } while (p < olimit); - -#if 0 - /* - * We can't tell whether this was allocated by the _dl_malloc() - * built into ld.so or malloc() in the main executable or libc, - * and calling free() for something that wasn't malloc()ed could - * do Very Bad Things (TM). Take the conservative approach - * here, potentially wasting as much memory as actually used by - * the hash table, even if multiple growths occur. That's not - * so bad as to require some overengineered solution that would - * enable us to keep track of how it was allocated. - */ - _dl_free(oentries); -#endif - return 1; -} - -/* - * This function searches for a hash table slot containing an entry - * equal to the given element. To delete an entry, call this with - * INSERT = 0, then call htab_clear_slot on the slot returned (possibly - * after doing some checks). To insert an entry, call this with - * INSERT = 1, then write the value you want into the returned slot. - * When inserting an entry, NULL may be returned if memory allocation - * fails. - */ -static __always_inline struct funcdesc_value ** -htab_find_slot(struct funcdesc_ht *htab, void *ptr, int insert) -{ - unsigned int index; - int hash, hash2; - size_t size; - struct funcdesc_value **entry; - - if (htab->size * 3 <= htab->n_elements * 4 && - htab_expand(htab) == 0) - return NULL; - - hash = hash_pointer(ptr); - - size = htab->size; - index = hash % size; - - entry = &htab->entries[index]; - if (!*entry) - goto empty_entry; - else if ((*entry)->entry_point == ptr) - return entry; - - hash2 = 1 + hash % (size - 2); - for (;;) { - index += hash2; - if (index >= size) - index -= size; - - entry = &htab->entries[index]; - if (!*entry) - goto empty_entry; - else if ((*entry)->entry_point == ptr) - return entry; - } - - empty_entry: - if (!insert) - return NULL; - - htab->n_elements++; - return entry; -} - void * _dl_funcdesc_for (void *entry_point, void *got_value) {