1 files changed, 225 insertions, 0 deletions
diff --git a/thirdparty/pcre2/src/sljit/sljitWXExecAllocator.c b/thirdparty/pcre2/src/sljit/sljitWXExecAllocator.c
new file mode 100644
index 0000000000..6ef71f7d83
--- /dev/null
+++ b/thirdparty/pcre2/src/sljit/sljitWXExecAllocator.c
@@ -0,0 +1,225 @@
+/*
+ *    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 W^X executable memory allocator for POSIX
+   like systems and Windows
+
+   In *NIX, MAP_ANON is required (that is considered a feature) so make
+   sure to set the right availability macros for your system or the code
+   will fail to build.
+
+   If your system doesn't support mapping of anonymous pages (ex: IRIX) it
+   is also likely that it doesn't need this allocator and should be using
+   the standard one instead.
+
+   It allocates a separate map for each code block and may waste a lot of
+   memory, because whatever was requested, will be rounded up to the page
+   size (minimum 4KB, but could be even bigger).
+
+   It changes the page permissions (RW <-> RX) as needed and therefore, if you
+   will be updating the code after it has been generated, need to make sure to
+   block any concurrent execution, or could result in a SIGBUS, that could
+   even manifest itself at a different address than the one that was being
+   modified.
+
+   Only use if you are unable to use the regular allocator because of security
+   restrictions and adding exceptions to your application or the system are
+   not possible.
+*/
+
+#define SLJIT_UPDATE_WX_FLAGS(from, to, enable_exec) \
+	sljit_update_wx_flags((from), (to), (enable_exec))
+
+#ifndef _WIN32
+#include <sys/types.h>
+#include <sys/mman.h>
+
+#ifdef __NetBSD__
+#if defined(PROT_MPROTECT)
+#define check_se_protected(ptr, size) (0)
+#define SLJIT_PROT_WX PROT_MPROTECT(PROT_EXEC)
+#else /* !PROT_MPROTECT */
+#ifdef _NETBSD_SOURCE
+#include <sys/param.h>
+#else /* !_NETBSD_SOURCE */
+typedef unsigned int	u_int;
+#define devmajor_t sljit_s32
+#endif /* _NETBSD_SOURCE */
+#include <sys/sysctl.h>
+#include <unistd.h>
+
+#define check_se_protected(ptr, size) netbsd_se_protected()
+
+static SLJIT_INLINE int netbsd_se_protected(void)
+{
+	int mib[3];
+	int paxflags;
+	size_t len = sizeof(paxflags);
+
+	mib[0] = CTL_PROC;
+	mib[1] = getpid();
+	mib[2] = PROC_PID_PAXFLAGS;
+
+	if (SLJIT_UNLIKELY(sysctl(mib, 3, &paxflags, &len, NULL, 0) < 0))
+		return -1;
+
+	return (paxflags & CTL_PROC_PAXFLAGS_MPROTECT) ? -1 : 0;
+}
+#endif /* PROT_MPROTECT */
+#else /* POSIX */
+#define check_se_protected(ptr, size) generic_se_protected(ptr, size)
+
+static SLJIT_INLINE int generic_se_protected(void *ptr, sljit_uw size)
+{
+	if (SLJIT_LIKELY(!mprotect(ptr, size, PROT_EXEC)))
+		return mprotect(ptr, size, PROT_READ | PROT_WRITE);
+
+	return -1;
+}
+#endif /* NetBSD */
+
+#if defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED
+#define SLJIT_SE_LOCK()
+#define SLJIT_SE_UNLOCK()
+#else /* !SLJIT_SINGLE_THREADED */
+#include <pthread.h>
+#define SLJIT_SE_LOCK()	pthread_mutex_lock(&se_lock)
+#define SLJIT_SE_UNLOCK()	pthread_mutex_unlock(&se_lock)
+#endif /* SLJIT_SINGLE_THREADED */
+
+#ifndef SLJIT_PROT_WX
+#define SLJIT_PROT_WX 0
+#endif /* !SLJIT_PROT_WX */
+
+SLJIT_API_FUNC_ATTRIBUTE void* sljit_malloc_exec(sljit_uw size)
+{
+#if !(defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)
+	static pthread_mutex_t se_lock = PTHREAD_MUTEX_INITIALIZER;
+#endif
+	static int se_protected = !SLJIT_PROT_WX;
+	sljit_uw* ptr;
+
+	if (SLJIT_UNLIKELY(se_protected < 0))
+		return NULL;
+
+	size += sizeof(sljit_uw);
+	ptr = (sljit_uw*)mmap(NULL, size, PROT_READ | PROT_WRITE | SLJIT_PROT_WX,
+				MAP_PRIVATE | MAP_ANON, -1, 0);
+
+	if (ptr == MAP_FAILED)
+		return NULL;
+
+	if (SLJIT_UNLIKELY(se_protected > 0)) {
+		SLJIT_SE_LOCK();
+		se_protected = check_se_protected(ptr, size);
+		SLJIT_SE_UNLOCK();
+		if (SLJIT_UNLIKELY(se_protected < 0)) {
+			munmap((void *)ptr, size);
+			return NULL;
+		}
+	}
+
+	*ptr++ = size;
+	return ptr;
+}
+
+#undef SLJIT_PROT_WX
+#undef SLJIT_SE_UNLOCK
+#undef SLJIT_SE_LOCK
+
+SLJIT_API_FUNC_ATTRIBUTE void sljit_free_exec(void* ptr)
+{
+	sljit_uw *start_ptr = ((sljit_uw*)ptr) - 1;
+	munmap((void*)start_ptr, *start_ptr);
+}
+
+static void sljit_update_wx_flags(void *from, void *to, sljit_s32 enable_exec)
+{
+	sljit_uw page_mask = (sljit_uw)get_page_alignment();
+	sljit_uw start = (sljit_uw)from;
+	sljit_uw end = (sljit_uw)to;
+	int prot = PROT_READ | (enable_exec ? PROT_EXEC : PROT_WRITE);
+
+	SLJIT_ASSERT(start < end);
+
+	start &= ~page_mask;
+	end = (end + page_mask) & ~page_mask;
+
+	mprotect((void*)start, end - start, prot);
+}
+
+#else /* windows */
+
+SLJIT_API_FUNC_ATTRIBUTE void* sljit_malloc_exec(sljit_uw size)
+{
+	sljit_uw *ptr;
+
+	size += sizeof(sljit_uw);
+	ptr = (sljit_uw*)VirtualAlloc(NULL, size,
+				MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
+
+	if (!ptr)
+		return NULL;
+
+	*ptr++ = size;
+
+	return ptr;
+}
+
+SLJIT_API_FUNC_ATTRIBUTE void sljit_free_exec(void* ptr)
+{
+	sljit_uw start = (sljit_uw)ptr - sizeof(sljit_uw);
+#if defined(SLJIT_DEBUG) && SLJIT_DEBUG
+	sljit_uw page_mask = (sljit_uw)get_page_alignment();
+
+	SLJIT_ASSERT(!(start & page_mask));
+#endif
+	VirtualFree((void*)start, 0, MEM_RELEASE);
+}
+
+static void sljit_update_wx_flags(void *from, void *to, sljit_s32 enable_exec)
+{
+	DWORD oldprot;
+	sljit_uw page_mask = (sljit_uw)get_page_alignment();
+	sljit_uw start = (sljit_uw)from;
+	sljit_uw end = (sljit_uw)to;
+	DWORD prot = enable_exec ? PAGE_EXECUTE : PAGE_READWRITE;
+
+	SLJIT_ASSERT(start < end);
+
+	start &= ~page_mask;
+	end = (end + page_mask) & ~page_mask;
+
+	VirtualProtect((void*)start, end - start, prot, &oldprot);
+}
+
+#endif /* !windows */
+
+SLJIT_API_FUNC_ATTRIBUTE void sljit_free_unused_memory_exec(void)
+{
+	/* This allocator does not keep unused memory for future allocations. */
+}