pcre2/pcre2-10.30-RC1-Distribute-forgotten-sljitProtExecAllocator.c.patch

From 953920c6fac83750ac8a4528672f1bd2c41d1fc6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>
Date: Thu, 20 Jul 2017 10:38:24 +0200
Subject: [PATCH] Distribute forgotten sljitProtExecAllocator.c
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Signed-off-by: Petr Písař <ppisar@redhat.com>
---
 Makefile.am                        |   1 +
 src/sljit/sljitProtExecAllocator.c | 421 +++++++++++++++++++++++++++++++++++++
 2 files changed, 422 insertions(+)
 create mode 100644 src/sljit/sljitProtExecAllocator.c

diff --git a/Makefile.am b/Makefile.am
index bbf23b8..7fa98c5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -442,6 +442,7 @@ EXTRA_DIST += \
   src/sljit/sljitNativeX86_32.c \
   src/sljit/sljitNativeX86_64.c \
   src/sljit/sljitNativeX86_common.c \
+  src/sljit/sljitProtExecAllocator.c \
   src/sljit/sljitUtils.c
 
 # Some of the JIT sources are also in separate files that are #included.
diff --git a/src/sljit/sljitProtExecAllocator.c b/src/sljit/sljitProtExecAllocator.c
new file mode 100644
index 0000000..8a5b2b3
--- /dev/null
+++ b/src/sljit/sljitProtExecAllocator.c
@@ -0,0 +1,421 @@
+/*
+ *    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	0x10000
+
+struct chunk_header {
+	void *executable;
+	int fd;
+};
+
+/*
+   alloc_chunk / free_chunk :
+     * allocate executable system memory chunks
+     * the size is always divisible by CHUNK_SIZE
+   allocator_grab_lock / allocator_release_lock :
+     * make the allocator thread safe
+     * can be empty if the OS (or the application) does not support threading
+     * only the allocator requires this lock, sljit is fully thread safe
+       as it only uses local variables
+*/
+
+#include <fcntl.h>
+
+#ifndef O_NOATIME
+#define O_NOATIME 0
+#endif
+
+#ifdef __O_TMPFILE
+#ifndef O_TMPFILE
+#define O_TMPFILE	(__O_TMPFILE | O_DIRECTORY)
+#endif
+#endif
+
+int mkostemp(char *template, int flags);
+char *secure_getenv(const char *name);
+
+static SLJIT_INLINE int create_tempfile(void)
+{
+	int fd;
+
+	char tmp_name[256];
+	size_t tmp_name_len;
+	char *dir;
+	size_t len;
+
+#ifdef P_tmpdir
+	len = (P_tmpdir != NULL) ? strlen(P_tmpdir) : 0;
+
+	if (len > 0 && len < sizeof(tmp_name)) {
+		strcpy(tmp_name, P_tmpdir);
+		tmp_name_len = len;
+	}
+	else {
+		strcpy(tmp_name, "/tmp");
+		tmp_name_len = 4;
+	}
+#else
+	strcpy(tmp_name, "/tmp");
+	tmp_name_len = 4;
+#endif
+
+	dir = secure_getenv("TMPDIR");
+	if (dir) {
+		len = strlen(dir);
+		if (len > 0 && len < sizeof(tmp_name)) {
+			strcpy(tmp_name, dir);
+			tmp_name_len = len;
+		}
+	}
+
+	SLJIT_ASSERT(tmp_name_len > 0 && tmp_name_len < sizeof(tmp_name));
+
+	while (tmp_name_len > 0 && tmp_name[tmp_name_len - 1] == '/') {
+		tmp_name_len--;
+		tmp_name[tmp_name_len] = '\0';
+	}
+
+#ifdef O_TMPFILE
+	fd = open(tmp_name, O_TMPFILE | O_EXCL | O_RDWR | O_NOATIME | O_CLOEXEC, S_IRUSR | S_IWUSR);
+	if (fd != -1)
+		return fd;
+#endif
+
+	if (tmp_name_len + 7 >= sizeof(tmp_name))
+	{
+		return -1;
+	}
+
+	strcpy(tmp_name + tmp_name_len, "/XXXXXX");
+	fd = mkostemp(tmp_name, O_CLOEXEC | O_NOATIME);
+
+	if (fd == -1)
+		return fd;
+
+	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, 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(retval, size);
+		close(fd);
+		return NULL;
+	}
+
+	retval->fd = fd;
+	return retval;
+}
+
+static SLJIT_INLINE void free_chunk(void *chunk, sljit_uw size)
+{
+	struct chunk_header *header = ((struct chunk_header *)chunk) - 1;
+
+	int fd = header->fd;
+	munmap(header->executable, size);
+	munmap(header, size);
+	close(fd);
+}
+
+/* --------------------------------------------------------------------- */
+/*  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) + 7) & ~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;
+
+	allocator_grab_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;
+			allocator_release_lock();
+			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) {
+		allocator_release_lock();
+		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;
+	allocator_release_lock();
+	return MEM_START(header);
+}
+
+SLJIT_API_FUNC_ATTRIBUTE void sljit_free_exec(void* ptr)
+{
+	struct block_header *header;
+	struct free_block* free_block;
+
+	allocator_grab_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 block_header));
+		}
+	}
+
+	allocator_release_lock();
+}
+
+SLJIT_API_FUNC_ATTRIBUTE void sljit_free_unused_memory_exec(void)
+{
+	struct free_block* free_block;
+	struct free_block* next_free_block;
+
+	allocator_grab_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 block_header));
+		}
+		free_block = next_free_block;
+	}
+
+	SLJIT_ASSERT((total_size && free_blocks) || (!total_size && !free_blocks));
+	allocator_release_lock();
+}
+
+SLJIT_API_FUNC_ATTRIBUTE sljit_sw sljit_exec_offset(void* ptr)
+{
+	return ((struct block_header *)(ptr))[-1].executable_offset;
+}
-- 
2.9.4