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Diffstat (limited to 'src/3rdparty/pcre2/src/sljit/sljitProtExecAllocator.c')
| -rw-r--r-- | src/3rdparty/pcre2/src/sljit/sljitProtExecAllocator.c | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/src/3rdparty/pcre2/src/sljit/sljitProtExecAllocator.c b/src/3rdparty/pcre2/src/sljit/sljitProtExecAllocator.c new file mode 100644 index 0000000000..915411fbed --- /dev/null +++ b/src/3rdparty/pcre2/src/sljit/sljitProtExecAllocator.c @@ -0,0 +1,474 @@ +/* + * Stack-less Just-In-Time compiler + * + * Copyright Zoltan Herczeg (hzmester@freemail.hu). All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, are + * permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this list of + * conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, this list + * of conditions and the following disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) AND CONTRIBUTORS ``AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE COPYRIGHT HOLDER(S) OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* + This file contains a simple executable memory allocator + + It is assumed, that executable code blocks are usually medium (or sometimes + large) memory blocks, and the allocator is not too frequently called (less + optimized than other allocators). Thus, using it as a generic allocator is + not suggested. + + How does it work: + Memory is allocated in continuous memory areas called chunks by alloc_chunk() + Chunk format: + [ block ][ block ] ... [ block ][ block terminator ] + + All blocks and the block terminator is started with block_header. The block + header contains the size of the previous and the next block. These sizes + can also contain special values. + Block size: + 0 - The block is a free_block, with a different size member. + 1 - The block is a block terminator. + n - The block is used at the moment, and the value contains its size. + Previous block size: + 0 - This is the first block of the memory chunk. + n - The size of the previous block. + + Using these size values we can go forward or backward on the block chain. + The unused blocks are stored in a chain list pointed by free_blocks. This + list is useful if we need to find a suitable memory area when the allocator + is called. + + When a block is freed, the new free block is connected to its adjacent free + blocks if possible. + + [ free block ][ used block ][ free block ] + and "used block" is freed, the three blocks are connected together: + [ one big free block ] +*/ + +/* --------------------------------------------------------------------- */ +/* System (OS) functions */ +/* --------------------------------------------------------------------- */ + +/* 64 KByte. */ +#define CHUNK_SIZE (sljit_uw)0x10000 + +struct chunk_header { + void *executable; +}; + +/* + alloc_chunk / free_chunk : + * allocate executable system memory chunks + * the size is always divisible by CHUNK_SIZE + SLJIT_ALLOCATOR_LOCK / SLJIT_ALLOCATOR_UNLOCK : + * provided as part of sljitUtils + * only the allocator requires this lock, sljit is fully thread safe + as it only uses local variables +*/ + +#ifndef __NetBSD__ +#include <sys/stat.h> +#include <fcntl.h> +#include <stdio.h> +#include <string.h> + +#ifndef O_NOATIME +#define O_NOATIME 0 +#endif + +/* this is a linux extension available since kernel 3.11 */ +#ifndef O_TMPFILE +#define O_TMPFILE 020200000 +#endif + +#ifndef _GNU_SOURCE +char *secure_getenv(const char *name); +int mkostemp(char *template, int flags); +#endif + +static SLJIT_INLINE int create_tempfile(void) +{ + int fd; + char tmp_name[256]; + size_t tmp_name_len = 0; + char *dir; + struct stat st; +#if defined(SLJIT_SINGLE_THREADED) && SLJIT_SINGLE_THREADED + mode_t mode; +#endif + +#ifdef HAVE_MEMFD_CREATE + /* this is a GNU extension, make sure to use -D_GNU_SOURCE */ + fd = memfd_create("sljit", MFD_CLOEXEC); + if (fd != -1) { + fchmod(fd, 0); + return fd; + } +#endif + + dir = secure_getenv("TMPDIR"); + + if (dir) { + tmp_name_len = strlen(dir); + if (tmp_name_len > 0 && tmp_name_len < sizeof(tmp_name)) { + if ((stat(dir, &st) == 0) && S_ISDIR(st.st_mode)) + strcpy(tmp_name, dir); + } + } + +#ifdef P_tmpdir + if (!tmp_name_len) { + tmp_name_len = strlen(P_tmpdir); + if (tmp_name_len > 0 && tmp_name_len < sizeof(tmp_name)) + strcpy(tmp_name, P_tmpdir); + } +#endif + if (!tmp_name_len) { + strcpy(tmp_name, "/tmp"); + tmp_name_len = 4; + } + + SLJIT_ASSERT(tmp_name_len > 0 && tmp_name_len < sizeof(tmp_name)); + + if (tmp_name[tmp_name_len - 1] == '/') + tmp_name[--tmp_name_len] = '\0'; + +#ifdef __linux__ + /* + * the previous trimming might had left an empty string if TMPDIR="/" + * so work around the problem below + */ + fd = open(tmp_name_len ? tmp_name : "/", + O_TMPFILE | O_EXCL | O_RDWR | O_NOATIME | O_CLOEXEC, 0); + if (fd != -1) + return fd; +#endif + + if (tmp_name_len + 7 >= sizeof(tmp_name)) + return -1; + + strcpy(tmp_name + tmp_name_len, "/XXXXXX"); +#if defined(SLJIT_SINGLE_THREADED) && SLJIT_SINGLE_THREADED + mode = umask(0777); +#endif + fd = mkostemp(tmp_name, O_CLOEXEC | O_NOATIME); +#if defined(SLJIT_SINGLE_THREADED) && SLJIT_SINGLE_THREADED + umask(mode); +#else + fchmod(fd, 0); +#endif + + if (fd == -1) + return -1; + + if (unlink(tmp_name)) { + close(fd); + return -1; + } + + return fd; +} + +static SLJIT_INLINE struct chunk_header* alloc_chunk(sljit_uw size) +{ + struct chunk_header *retval; + int fd; + + fd = create_tempfile(); + if (fd == -1) + return NULL; + + if (ftruncate(fd, (off_t)size)) { + close(fd); + return NULL; + } + + retval = (struct chunk_header *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + + if (retval == MAP_FAILED) { + close(fd); + return NULL; + } + + retval->executable = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_SHARED, fd, 0); + + if (retval->executable == MAP_FAILED) { + munmap((void *)retval, size); + close(fd); + return NULL; + } + + close(fd); + return retval; +} +#else +/* + * MAP_REMAPDUP is a NetBSD extension available sinde 8.0, make sure to + * adjust your feature macros (ex: -D_NETBSD_SOURCE) as needed + */ +static SLJIT_INLINE struct chunk_header* alloc_chunk(sljit_uw size) +{ + struct chunk_header *retval; + + retval = (struct chunk_header *)mmap(NULL, size, + PROT_READ | PROT_WRITE | PROT_MPROTECT(PROT_EXEC), + MAP_ANON | MAP_SHARED, -1, 0); + + if (retval == MAP_FAILED) + return NULL; + + retval->executable = mremap(retval, size, NULL, size, MAP_REMAPDUP); + if (retval->executable == MAP_FAILED) { + munmap((void *)retval, size); + return NULL; + } + + if (mprotect(retval->executable, size, PROT_READ | PROT_EXEC) == -1) { + munmap(retval->executable, size); + munmap((void *)retval, size); + return NULL; + } + + return retval; +} +#endif /* NetBSD */ + +static SLJIT_INLINE void free_chunk(void *chunk, sljit_uw size) +{ + struct chunk_header *header = ((struct chunk_header *)chunk) - 1; + + munmap(header->executable, size); + munmap((void *)header, size); +} + +/* --------------------------------------------------------------------- */ +/* Common functions */ +/* --------------------------------------------------------------------- */ + +#define CHUNK_MASK (~(CHUNK_SIZE - 1)) + +struct block_header { + sljit_uw size; + sljit_uw prev_size; + sljit_sw executable_offset; +}; + +struct free_block { + struct block_header header; + struct free_block *next; + struct free_block *prev; + sljit_uw size; +}; + +#define AS_BLOCK_HEADER(base, offset) \ + ((struct block_header*)(((sljit_u8*)base) + offset)) +#define AS_FREE_BLOCK(base, offset) \ + ((struct free_block*)(((sljit_u8*)base) + offset)) +#define MEM_START(base) ((void*)((base) + 1)) +#define ALIGN_SIZE(size) (((size) + sizeof(struct block_header) + 7u) & ~(sljit_uw)7) + +static struct free_block* free_blocks; +static sljit_uw allocated_size; +static sljit_uw total_size; + +static SLJIT_INLINE void sljit_insert_free_block(struct free_block *free_block, sljit_uw size) +{ + free_block->header.size = 0; + free_block->size = size; + + free_block->next = free_blocks; + free_block->prev = NULL; + if (free_blocks) + free_blocks->prev = free_block; + free_blocks = free_block; +} + +static SLJIT_INLINE void sljit_remove_free_block(struct free_block *free_block) +{ + if (free_block->next) + free_block->next->prev = free_block->prev; + + if (free_block->prev) + free_block->prev->next = free_block->next; + else { + SLJIT_ASSERT(free_blocks == free_block); + free_blocks = free_block->next; + } +} + +SLJIT_API_FUNC_ATTRIBUTE void* sljit_malloc_exec(sljit_uw size) +{ + struct chunk_header *chunk_header; + struct block_header *header; + struct block_header *next_header; + struct free_block *free_block; + sljit_uw chunk_size; + sljit_sw executable_offset; + + SLJIT_ALLOCATOR_LOCK(); + if (size < (64 - sizeof(struct block_header))) + size = (64 - sizeof(struct block_header)); + size = ALIGN_SIZE(size); + + free_block = free_blocks; + while (free_block) { + if (free_block->size >= size) { + chunk_size = free_block->size; + if (chunk_size > size + 64) { + /* We just cut a block from the end of the free block. */ + chunk_size -= size; + free_block->size = chunk_size; + header = AS_BLOCK_HEADER(free_block, chunk_size); + header->prev_size = chunk_size; + header->executable_offset = free_block->header.executable_offset; + AS_BLOCK_HEADER(header, size)->prev_size = size; + } + else { + sljit_remove_free_block(free_block); + header = (struct block_header*)free_block; + size = chunk_size; + } + allocated_size += size; + header->size = size; + SLJIT_ALLOCATOR_UNLOCK(); + return MEM_START(header); + } + free_block = free_block->next; + } + + chunk_size = sizeof(struct chunk_header) + sizeof(struct block_header); + chunk_size = (chunk_size + size + CHUNK_SIZE - 1) & CHUNK_MASK; + + chunk_header = alloc_chunk(chunk_size); + if (!chunk_header) { + SLJIT_ALLOCATOR_UNLOCK(); + return NULL; + } + + executable_offset = (sljit_sw)((sljit_u8*)chunk_header->executable - (sljit_u8*)chunk_header); + + chunk_size -= sizeof(struct chunk_header) + sizeof(struct block_header); + total_size += chunk_size; + + header = (struct block_header *)(chunk_header + 1); + + header->prev_size = 0; + header->executable_offset = executable_offset; + if (chunk_size > size + 64) { + /* Cut the allocated space into a free and a used block. */ + allocated_size += size; + header->size = size; + chunk_size -= size; + + free_block = AS_FREE_BLOCK(header, size); + free_block->header.prev_size = size; + free_block->header.executable_offset = executable_offset; + sljit_insert_free_block(free_block, chunk_size); + next_header = AS_BLOCK_HEADER(free_block, chunk_size); + } + else { + /* All space belongs to this allocation. */ + allocated_size += chunk_size; + header->size = chunk_size; + next_header = AS_BLOCK_HEADER(header, chunk_size); + } + next_header->size = 1; + next_header->prev_size = chunk_size; + next_header->executable_offset = executable_offset; + SLJIT_ALLOCATOR_UNLOCK(); + return MEM_START(header); +} + +SLJIT_API_FUNC_ATTRIBUTE void sljit_free_exec(void* ptr) +{ + struct block_header *header; + struct free_block* free_block; + + SLJIT_ALLOCATOR_LOCK(); + header = AS_BLOCK_HEADER(ptr, -(sljit_sw)sizeof(struct block_header)); + header = AS_BLOCK_HEADER(header, -header->executable_offset); + allocated_size -= header->size; + + /* Connecting free blocks together if possible. */ + + /* If header->prev_size == 0, free_block will equal to header. + In this case, free_block->header.size will be > 0. */ + free_block = AS_FREE_BLOCK(header, -(sljit_sw)header->prev_size); + if (SLJIT_UNLIKELY(!free_block->header.size)) { + free_block->size += header->size; + header = AS_BLOCK_HEADER(free_block, free_block->size); + header->prev_size = free_block->size; + } + else { + free_block = (struct free_block*)header; + sljit_insert_free_block(free_block, header->size); + } + + header = AS_BLOCK_HEADER(free_block, free_block->size); + if (SLJIT_UNLIKELY(!header->size)) { + free_block->size += ((struct free_block*)header)->size; + sljit_remove_free_block((struct free_block*)header); + header = AS_BLOCK_HEADER(free_block, free_block->size); + header->prev_size = free_block->size; + } + + /* The whole chunk is free. */ + if (SLJIT_UNLIKELY(!free_block->header.prev_size && header->size == 1)) { + /* If this block is freed, we still have (allocated_size / 2) free space. */ + if (total_size - free_block->size > (allocated_size * 3 / 2)) { + total_size -= free_block->size; + sljit_remove_free_block(free_block); + free_chunk(free_block, free_block->size + + sizeof(struct chunk_header) + + sizeof(struct block_header)); + } + } + + SLJIT_ALLOCATOR_UNLOCK(); +} + +SLJIT_API_FUNC_ATTRIBUTE void sljit_free_unused_memory_exec(void) +{ + struct free_block* free_block; + struct free_block* next_free_block; + + SLJIT_ALLOCATOR_LOCK(); + + free_block = free_blocks; + while (free_block) { + next_free_block = free_block->next; + if (!free_block->header.prev_size && + AS_BLOCK_HEADER(free_block, free_block->size)->size == 1) { + total_size -= free_block->size; + sljit_remove_free_block(free_block); + free_chunk(free_block, free_block->size + + sizeof(struct chunk_header) + + sizeof(struct block_header)); + } + free_block = next_free_block; + } + + SLJIT_ASSERT((total_size && free_blocks) || (!total_size && !free_blocks)); + SLJIT_ALLOCATOR_UNLOCK(); +} + +SLJIT_API_FUNC_ATTRIBUTE sljit_sw sljit_exec_offset(void* ptr) +{ + return ((struct block_header *)(ptr))[-1].executable_offset; +} |