mirror of
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183733f882
memset() is used by CRYPTO_secure_zalloc(), which isn't hidden away behind IMPLEMENTED. Reviewed-by: Rich Salz <rsalz@openssl.org>
571 lines
14 KiB
C
571 lines
14 KiB
C
/*
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* Copyright 2004-2014, Akamai Technologies. All Rights Reserved.
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* This file is distributed under the terms of the OpenSSL license.
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*/
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/*
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* This file is in two halves. The first half implements the public API
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* to be used by external consumers, and to be used by OpenSSL to store
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* data in a "secure arena." The second half implements the secure arena.
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* For details on that implementation, see below (look for uppercase
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* "SECURE HEAP IMPLEMENTATION").
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*/
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#include <openssl/crypto.h>
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#include <e_os.h>
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#include <string.h>
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#if defined(OPENSSL_SYS_LINUX) || defined(OPENSSL_SYS_UNIX)
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# define IMPLEMENTED
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# include <stdlib.h>
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# include <assert.h>
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# include <unistd.h>
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# include <sys/types.h>
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# include <sys/mman.h>
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# include <sys/param.h>
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# include <sys/stat.h>
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# include <fcntl.h>
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#endif
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#define LOCK() CRYPTO_w_lock(CRYPTO_LOCK_MALLOC)
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#define UNLOCK() CRYPTO_w_unlock(CRYPTO_LOCK_MALLOC)
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#define CLEAR(p, s) OPENSSL_cleanse(p, s)
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#ifndef PAGE_SIZE
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# define PAGE_SIZE 4096
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#endif
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#ifdef IMPLEMENTED
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static size_t secure_mem_used;
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static int secure_mem_initialized;
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static int too_late;
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/*
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* These are the functions that must be implemented by a secure heap (sh).
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*/
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static int sh_init(size_t size, int minsize);
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static char *sh_malloc(size_t size);
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static void sh_free(char *ptr);
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static void sh_done(void);
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static int sh_actual_size(char *ptr);
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static int sh_allocated(const char *ptr);
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#endif
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int CRYPTO_secure_malloc_init(size_t size, int minsize)
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{
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#ifdef IMPLEMENTED
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int ret = 0;
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if (too_late)
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return ret;
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LOCK();
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OPENSSL_assert(!secure_mem_initialized);
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if (!secure_mem_initialized) {
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ret = sh_init(size, minsize);
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secure_mem_initialized = 1;
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}
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UNLOCK();
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return ret;
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#else
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return 0;
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#endif /* IMPLEMENTED */
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}
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void CRYPTO_secure_malloc_done()
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{
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#ifdef IMPLEMENTED
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LOCK();
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sh_done();
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secure_mem_initialized = 0;
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UNLOCK();
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#endif /* IMPLEMENTED */
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}
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int CRYPTO_secure_malloc_initialized()
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{
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#ifdef IMPLEMENTED
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return secure_mem_initialized;
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#else
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return 0;
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#endif /* IMPLEMENTED */
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}
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void *CRYPTO_secure_malloc(size_t num, const char *file, int line)
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{
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#ifdef IMPLEMENTED
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void *ret;
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size_t actual_size;
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if (!secure_mem_initialized) {
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too_late = 1;
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return CRYPTO_malloc(num, file, line);
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}
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LOCK();
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ret = sh_malloc(num);
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actual_size = ret ? sh_actual_size(ret) : 0;
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secure_mem_used += actual_size;
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UNLOCK();
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return ret;
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#else
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return CRYPTO_malloc(num, file, line);
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#endif /* IMPLEMENTED */
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}
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void *CRYPTO_secure_zalloc(size_t num, const char *file, int line)
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{
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void *ret = CRYPTO_secure_malloc(num, file, line);
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if (ret != NULL)
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memset(ret, 0, num);
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return ret;
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}
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void CRYPTO_secure_free(void *ptr)
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{
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#ifdef IMPLEMENTED
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size_t actual_size;
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if (ptr == NULL)
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return;
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if (!secure_mem_initialized) {
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CRYPTO_free(ptr);
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return;
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}
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LOCK();
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actual_size = sh_actual_size(ptr);
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CLEAR(ptr, actual_size);
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secure_mem_used -= actual_size;
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sh_free(ptr);
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UNLOCK();
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#else
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CRYPTO_free(ptr);
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#endif /* IMPLEMENTED */
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}
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int CRYPTO_secure_allocated(const void *ptr)
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{
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#ifdef IMPLEMENTED
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int ret;
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if (!secure_mem_initialized)
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return 0;
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LOCK();
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ret = sh_allocated(ptr);
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UNLOCK();
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return ret;
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#else
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return 0;
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#endif /* IMPLEMENTED */
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}
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size_t CRYPTO_secure_used()
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{
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#ifdef IMPLEMENTED
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return secure_mem_used;
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#else
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return 0;
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#endif /* IMPLEMENTED */
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}
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size_t CRYPTO_secure_actual_size(void *ptr)
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{
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#ifdef IMPLEMENTED
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size_t actual_size;
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LOCK();
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actual_size = sh_actual_size(ptr);
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UNLOCK();
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return actual_size;
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#else
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return 0;
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#endif
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}
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/* END OF PAGE ...
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... START OF PAGE */
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/*
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* SECURE HEAP IMPLEMENTATION
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*/
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#ifdef IMPLEMENTED
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/*
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* The implementation provided here uses a fixed-sized mmap() heap,
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* which is locked into memory, not written to core files, and protected
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* on either side by an unmapped page, which will catch pointer overruns
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* (or underruns) and an attempt to read data out of the secure heap.
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* Free'd memory is zero'd or otherwise cleansed.
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*
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* This is a pretty standard buddy allocator. We keep areas in a multiple
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* of "sh.minsize" units. The freelist and bitmaps are kept separately,
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* so all (and only) data is kept in the mmap'd heap.
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*
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* This code assumes eight-bit bytes. The numbers 3 and 7 are all over the
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* place.
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*/
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# define TESTBIT(t, b) (t[(b) >> 3] & (1 << ((b) & 7)))
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# define SETBIT(t, b) (t[(b) >> 3] |= (1 << ((b) & 7)))
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# define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(1 << ((b) & 7))))
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#define WITHIN_ARENA(p) \
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((char*)(p) >= sh.arena && (char*)(p) < &sh.arena[sh.arena_size])
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#define WITHIN_FREELIST(p) \
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((char*)(p) >= (char*)sh.freelist && (char*)(p) < (char*)&sh.freelist[sh.freelist_size])
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typedef struct sh_list_st
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{
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struct sh_list_st *next;
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struct sh_list_st **p_next;
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} SH_LIST;
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typedef struct sh_st
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{
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char* map_result;
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size_t map_size;
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char *arena;
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int arena_size;
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char **freelist;
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int freelist_size;
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int minsize;
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unsigned char *bittable;
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unsigned char *bitmalloc;
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int bittable_size; /* size in bits */
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} SH;
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static SH sh;
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static int sh_getlist(char *ptr)
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{
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int list = sh.freelist_size - 1;
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int bit = (sh.arena_size + ptr - sh.arena) / sh.minsize;
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for (; bit; bit >>= 1, list--) {
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if (TESTBIT(sh.bittable, bit))
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break;
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OPENSSL_assert((bit & 1) == 0);
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}
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return list;
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}
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static int sh_testbit(char *ptr, int list, unsigned char *table)
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{
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int bit;
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OPENSSL_assert(list >= 0 && list < sh.freelist_size);
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OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
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bit = (1 << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
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OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
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return TESTBIT(table, bit);
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}
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static void sh_clearbit(char *ptr, int list, unsigned char *table)
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{
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int bit;
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OPENSSL_assert(list >= 0 && list < sh.freelist_size);
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OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
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bit = (1 << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
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OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
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OPENSSL_assert(TESTBIT(table, bit));
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CLEARBIT(table, bit);
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}
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static void sh_setbit(char *ptr, int list, unsigned char *table)
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{
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int bit;
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OPENSSL_assert(list >= 0 && list < sh.freelist_size);
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OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
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bit = (1 << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
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OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
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OPENSSL_assert(!TESTBIT(table, bit));
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SETBIT(table, bit);
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}
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static void sh_add_to_list(char **list, char *ptr)
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{
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SH_LIST *temp;
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OPENSSL_assert(WITHIN_FREELIST(list));
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OPENSSL_assert(WITHIN_ARENA(ptr));
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temp = (SH_LIST *)ptr;
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temp->next = *(SH_LIST **)list;
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OPENSSL_assert(temp->next == NULL || WITHIN_ARENA(temp->next));
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temp->p_next = (SH_LIST **)list;
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if (temp->next != NULL) {
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OPENSSL_assert((char **)temp->next->p_next == list);
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temp->next->p_next = &(temp->next);
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}
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*list = ptr;
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}
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static void sh_remove_from_list(char *ptr, char *list)
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{
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SH_LIST *temp, *temp2;
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temp = (SH_LIST *)ptr;
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if (temp->next != NULL)
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temp->next->p_next = temp->p_next;
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*temp->p_next = temp->next;
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if (temp->next == NULL)
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return;
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temp2 = temp->next;
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OPENSSL_assert(WITHIN_FREELIST(temp2->p_next) || WITHIN_ARENA(temp2->p_next));
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}
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static int sh_init(size_t size, int minsize)
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{
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int i, ret;
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size_t pgsize;
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size_t aligned;
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memset(&sh, 0, sizeof sh);
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/* make sure size and minsize are powers of 2 */
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OPENSSL_assert(size > 0);
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OPENSSL_assert((size & (size - 1)) == 0);
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OPENSSL_assert(minsize > 0);
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OPENSSL_assert((minsize & (minsize - 1)) == 0);
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if (size <= 0 || (size & (size - 1)) != 0)
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goto err;
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if (minsize <= 0 || (minsize & (minsize - 1)) != 0)
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goto err;
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sh.arena_size = size;
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sh.minsize = minsize;
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sh.bittable_size = (sh.arena_size / sh.minsize) * 2;
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sh.freelist_size = -1;
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for (i = sh.bittable_size; i; i >>= 1)
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sh.freelist_size++;
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sh.freelist = OPENSSL_zalloc(sh.freelist_size * sizeof (char *));
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OPENSSL_assert(sh.freelist != NULL);
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if (sh.freelist == NULL)
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goto err;
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sh.bittable = OPENSSL_zalloc(sh.bittable_size >> 3);
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OPENSSL_assert(sh.bittable != NULL);
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if (sh.bittable == NULL)
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goto err;
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sh.bitmalloc = OPENSSL_zalloc(sh.bittable_size >> 3);
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OPENSSL_assert(sh.bitmalloc != NULL);
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if (sh.bitmalloc == NULL)
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goto err;
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/* Allocate space for heap, and two extra pages as guards */
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#if defined(_SC_PAGE_SIZE) || defined (_SC_PAGESIZE)
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{
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# if defined(_SC_PAGE_SIZE)
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long tmppgsize = sysconf(_SC_PAGE_SIZE);
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# else
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long tmppgsize = sysconf(_SC_PAGESIZE);
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# endif
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if (tmppgsize < 1)
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pgsize = PAGE_SIZE;
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else
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pgsize = (size_t)tmppgsize;
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}
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#else
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pgsize = PAGE_SIZE;
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#endif
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sh.map_size = pgsize + sh.arena_size + pgsize;
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if (1) {
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#ifdef MAP_ANON
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sh.map_result = mmap(NULL, sh.map_size,
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PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
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} else {
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#endif
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int fd;
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sh.map_result = MAP_FAILED;
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if ((fd = open("/dev/zero", O_RDWR)) >= 0) {
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sh.map_result = mmap(NULL, sh.map_size,
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PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
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close(fd);
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}
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}
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OPENSSL_assert(sh.map_result != MAP_FAILED);
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if (sh.map_result == MAP_FAILED)
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goto err;
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sh.arena = (char *)(sh.map_result + pgsize);
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sh_setbit(sh.arena, 0, sh.bittable);
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sh_add_to_list(&sh.freelist[0], sh.arena);
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/* Now try to add guard pages and lock into memory. */
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ret = 1;
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/* Starting guard is already aligned from mmap. */
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if (mprotect(sh.map_result, pgsize, PROT_NONE) < 0)
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ret = 2;
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/* Ending guard page - need to round up to page boundary */
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aligned = (pgsize + sh.arena_size + (pgsize - 1)) & ~(pgsize - 1);
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if (mprotect(sh.map_result + aligned, pgsize, PROT_NONE) < 0)
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ret = 2;
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if (mlock(sh.arena, sh.arena_size) < 0)
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ret = 2;
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#ifdef MADV_DONTDUMP
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if (madvise(sh.arena, sh.arena_size, MADV_DONTDUMP) < 0)
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ret = 2;
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#endif
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return ret;
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err:
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sh_done();
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return 0;
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}
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static void sh_done()
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{
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OPENSSL_free(sh.freelist);
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OPENSSL_free(sh.bittable);
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OPENSSL_free(sh.bitmalloc);
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if (sh.map_result != NULL && sh.map_size)
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munmap(sh.map_result, sh.map_size);
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memset(&sh, 0, sizeof sh);
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}
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static int sh_allocated(const char *ptr)
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{
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return WITHIN_ARENA(ptr) ? 1 : 0;
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}
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static char *sh_find_my_buddy(char *ptr, int list)
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{
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int bit;
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char *chunk = NULL;
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bit = (1 << list) + (ptr - sh.arena) / (sh.arena_size >> list);
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bit ^= 1;
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if (TESTBIT(sh.bittable, bit) && !TESTBIT(sh.bitmalloc, bit))
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chunk = sh.arena + ((bit & ((1 << list) - 1)) * (sh.arena_size >> list));
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return chunk;
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}
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static char *sh_malloc(size_t size)
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{
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int list, slist;
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size_t i;
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char *chunk;
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list = sh.freelist_size - 1;
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for (i = sh.minsize; i < size; i <<= 1)
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list--;
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if (list < 0)
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return NULL;
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/* try to find a larger entry to split */
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for (slist = list; slist >= 0; slist--)
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if (sh.freelist[slist] != NULL)
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break;
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if (slist < 0)
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return NULL;
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/* split larger entry */
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while (slist != list) {
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char *temp = sh.freelist[slist];
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/* remove from bigger list */
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OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
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sh_clearbit(temp, slist, sh.bittable);
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sh_remove_from_list(temp, sh.freelist[slist]);
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OPENSSL_assert(temp != sh.freelist[slist]);
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/* done with bigger list */
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slist++;
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/* add to smaller list */
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OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
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sh_setbit(temp, slist, sh.bittable);
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sh_add_to_list(&sh.freelist[slist], temp);
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OPENSSL_assert(sh.freelist[slist] == temp);
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/* split in 2 */
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temp += sh.arena_size >> slist;
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OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
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sh_setbit(temp, slist, sh.bittable);
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sh_add_to_list(&sh.freelist[slist], temp);
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OPENSSL_assert(sh.freelist[slist] == temp);
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OPENSSL_assert(temp-(sh.arena_size >> slist) == sh_find_my_buddy(temp, slist));
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}
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/* peel off memory to hand back */
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chunk = sh.freelist[list];
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OPENSSL_assert(sh_testbit(chunk, list, sh.bittable));
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sh_setbit(chunk, list, sh.bitmalloc);
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sh_remove_from_list(chunk, sh.freelist[list]);
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OPENSSL_assert(WITHIN_ARENA(chunk));
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return chunk;
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}
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static void sh_free(char *ptr)
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{
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int list;
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char *buddy;
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if (ptr == NULL)
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return;
|
|
OPENSSL_assert(WITHIN_ARENA(ptr));
|
|
if (!WITHIN_ARENA(ptr))
|
|
return;
|
|
|
|
list = sh_getlist(ptr);
|
|
OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
|
|
sh_clearbit(ptr, list, sh.bitmalloc);
|
|
sh_add_to_list(&sh.freelist[list], ptr);
|
|
|
|
/* Try to coalesce two adjacent free areas. */
|
|
while ((buddy = sh_find_my_buddy(ptr, list)) != NULL) {
|
|
OPENSSL_assert(ptr == sh_find_my_buddy(buddy, list));
|
|
OPENSSL_assert(ptr != NULL);
|
|
OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
|
|
sh_clearbit(ptr, list, sh.bittable);
|
|
sh_remove_from_list(ptr, sh.freelist[list]);
|
|
OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
|
|
sh_clearbit(buddy, list, sh.bittable);
|
|
sh_remove_from_list(buddy, sh.freelist[list]);
|
|
|
|
list--;
|
|
|
|
if (ptr > buddy)
|
|
ptr = buddy;
|
|
|
|
OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
|
|
sh_setbit(ptr, list, sh.bittable);
|
|
sh_add_to_list(&sh.freelist[list], ptr);
|
|
OPENSSL_assert(sh.freelist[list] == ptr);
|
|
}
|
|
}
|
|
|
|
static int sh_actual_size(char *ptr)
|
|
{
|
|
int list;
|
|
|
|
OPENSSL_assert(WITHIN_ARENA(ptr));
|
|
if (!WITHIN_ARENA(ptr))
|
|
return 0;
|
|
list = sh_getlist(ptr);
|
|
OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
|
|
return sh.arena_size / (1 << list);
|
|
}
|
|
#endif /* IMPLEMENTED */
|