sljitExecAllocatorApple.c

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/*
 *    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.
 */
 
#include <sys/types.h>
#include <sys/mman.h>
/*
   On macOS systems, returns MAP_JIT if it is defined _and_ we're running on a
   version where it's OK to have more than one JIT block or where MAP_JIT is
   required.
   On non-macOS systems, returns MAP_JIT if it is defined.
*/
#include <TargetConditionals.h>
 
#if (defined(TARGET_OS_OSX) && TARGET_OS_OSX) || (TARGET_OS_MAC && !TARGET_OS_IPHONE)
 
#if defined(SLJIT_CONFIG_X86) && SLJIT_CONFIG_X86
 
#include <sys/utsname.h>
#include <stdlib.h>
 
#define SLJIT_UPDATE_WX_FLAGS(from, to, enable_exec)
 
#ifdef MAP_JIT
#define SLJIT_MAP_JIT   (get_map_jit_flag())
static SLJIT_INLINE int get_map_jit_flag(void)
{
    size_t page_size;
    void *ptr;
    struct utsname name;
    static int map_jit_flag = -1;
 
    if (map_jit_flag < 0) {
        map_jit_flag = 0;
        uname(&name);
 
        /* Kernel version for 10.14.0 (Mojave) or later */
        if (atoi(name.release) >= 18) {
            page_size = get_page_alignment() + 1;
            /* Only use MAP_JIT if a hardened runtime is used */
            ptr = mmap(NULL, page_size, PROT_WRITE | PROT_EXEC,
                    MAP_PRIVATE | MAP_ANON, -1, 0);
 
            if (ptr != MAP_FAILED)
                munmap(ptr, page_size);
            else
                map_jit_flag = MAP_JIT;
        }
    }
    return map_jit_flag;
}
#else /* !defined(MAP_JIT) */
#define SLJIT_MAP_JIT   (0)
#endif
 
#elif defined(SLJIT_CONFIG_ARM) && SLJIT_CONFIG_ARM
 
#include <AvailabilityMacros.h>
#include <pthread.h>
 
#define SLJIT_MAP_JIT   (MAP_JIT)
#define SLJIT_UPDATE_WX_FLAGS(from, to, enable_exec) \
        apple_update_wx_flags(enable_exec)
 
static SLJIT_INLINE void apple_update_wx_flags(sljit_s32 enable_exec)
{
#if MAC_OS_X_VERSION_MIN_REQUIRED < 110000
    if (__builtin_available(macos 11, *))
#endif /* BigSur */
    pthread_jit_write_protect_np(enable_exec);
}
 
#elif defined(SLJIT_CONFIG_PPC) && SLJIT_CONFIG_PPC
 
#define SLJIT_MAP_JIT   (0)
#define SLJIT_UPDATE_WX_FLAGS(from, to, enable_exec)
 
#else
#error "Unsupported architecture"
#endif /* SLJIT_CONFIG */
 
#else /* !TARGET_OS_OSX */
 
#ifdef MAP_JIT
#define SLJIT_MAP_JIT   (MAP_JIT)
#else
#define SLJIT_MAP_JIT   (0)
#endif
 
#endif /* TARGET_OS_OSX */
 
static SLJIT_INLINE void* alloc_chunk(sljit_uw size)
{
    void *retval;
    int prot = PROT_READ | PROT_WRITE | PROT_EXEC;
    int flags = MAP_PRIVATE;
    int fd = -1;
 
    flags |= MAP_ANON | SLJIT_MAP_JIT;
 
    retval = mmap(NULL, size, prot, flags, fd, 0);
    if (retval == MAP_FAILED)
        return NULL;
 
    SLJIT_UPDATE_WX_FLAGS(retval, (uint8_t *)retval + size, 0);
 
    return retval;
}
 
static SLJIT_INLINE void free_chunk(void *chunk, sljit_uw size)
{
    munmap(chunk, size);
}
 
#include "sljitExecAllocatorCore.c"