From d18262da1f51ca933c774809f1a78e1e75ee0ee1 Mon Sep 17 00:00:00 2001
From: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Date: Wed, 18 Oct 2017 14:20:49 +0200
Subject: [PATCH] libc: add mempool for rwx memory

Issue #1723
---
 .../libports/src/lib/libc/file_operations.cc  | 12 +++++++---
 repos/libports/src/lib/libc/libc_mem_alloc.cc | 23 +++++++++++--------
 repos/libports/src/lib/libc/libc_mem_alloc.h  |  2 +-
 3 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/repos/libports/src/lib/libc/file_operations.cc b/repos/libports/src/lib/libc/file_operations.cc
index ffa7507775..a19818c814 100644
--- a/repos/libports/src/lib/libc/file_operations.cc
+++ b/repos/libports/src/lib/libc/file_operations.cc
@@ -29,6 +29,7 @@
 #include <fcntl.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
 #include <sys/types.h>
 #include <unistd.h>
 
@@ -427,7 +428,8 @@ extern "C" void *mmap(void *addr, ::size_t length, int prot, int flags,
 
 	/* handle requests for anonymous memory */
 	if (!addr && libc_fd == -1) {
-		void *start = Libc::mem_alloc()->alloc(length, PAGE_SHIFT);
+		bool const executable = prot & PROT_EXEC;
+		void *start = Libc::mem_alloc(executable)->alloc(length, PAGE_SHIFT);
 		mmap_registry()->insert(start, length, 0);
 		return start;
 	}
@@ -464,8 +466,12 @@ extern "C" int munmap(void *start, ::size_t length)
 	int ret = 0;
 	if (plugin)
 		ret = plugin->munmap(start, length);
-	else
-		Libc::mem_alloc()->free(start);
+	else {
+		bool const executable = true;
+		/* XXX another metadata handling required to track anonymous memory */
+		Libc::mem_alloc(!executable)->free(start);
+		Libc::mem_alloc(executable)->free(start);
+	}
 
 	mmap_registry()->remove(start);
 	return ret;
diff --git a/repos/libports/src/lib/libc/libc_mem_alloc.cc b/repos/libports/src/lib/libc/libc_mem_alloc.cc
index 45c2d6c9e4..22cdb9144f 100644
--- a/repos/libports/src/lib/libc/libc_mem_alloc.cc
+++ b/repos/libports/src/lib/libc/libc_mem_alloc.cc
@@ -16,7 +16,6 @@
 /* Genode includes */
 #include <base/env.h>
 #include <base/allocator_avl.h>
-#include <base/sleep.h>
 
 /* local includes */
 #include "libc_mem_alloc.h"
@@ -143,13 +142,19 @@ Genode::size_t Libc::Mem_alloc_impl::size_at(void const *addr) const
 }
 
 
-static Libc::Mem_alloc *_libc_mem_alloc;
+static Libc::Mem_alloc *_libc_mem_alloc_rw  = nullptr;
+static Libc::Mem_alloc *_libc_mem_alloc_rwx = nullptr;
 
 
 static void _init_mem_alloc(Genode::Region_map &rm, Genode::Ram_session &ram)
 {
-	static Libc::Mem_alloc_impl inst(rm, ram);
-	_libc_mem_alloc = &inst;
+	enum { MEMORY_EXECUTABLE = true };
+
+	static Libc::Mem_alloc_impl inst_rw(rm, ram, !MEMORY_EXECUTABLE);
+	static Libc::Mem_alloc_impl inst_rwx(rm, ram, MEMORY_EXECUTABLE);
+
+	_libc_mem_alloc_rw  = &inst_rw;
+	_libc_mem_alloc_rwx = &inst_rwx;
 }
 
 
@@ -162,12 +167,10 @@ namespace Libc {
 }
 
 
-Libc::Mem_alloc *Libc::mem_alloc()
+Libc::Mem_alloc *Libc::mem_alloc(bool executable)
 {
-	if (!_libc_mem_alloc) {
+	if (!_libc_mem_alloc_rw || !_libc_mem_alloc_rwx)
 		error("attempt to use 'Libc::mem_alloc' before call of 'init_mem_alloc'");
-		_init_mem_alloc(*env_deprecated()->rm_session(), *env_deprecated()->ram_session());
-	}
-	return _libc_mem_alloc;
-}
 
+	return executable ? _libc_mem_alloc_rwx : _libc_mem_alloc_rw;
+}
diff --git a/repos/libports/src/lib/libc/libc_mem_alloc.h b/repos/libports/src/lib/libc/libc_mem_alloc.h
index 7ea6f0a0d2..4e4ee80e23 100644
--- a/repos/libports/src/lib/libc/libc_mem_alloc.h
+++ b/repos/libports/src/lib/libc/libc_mem_alloc.h
@@ -27,7 +27,7 @@ namespace Libc {
 	/**
 	 * Return singleton instance of the memory allocator
 	 */
-	Mem_alloc *mem_alloc();
+	Mem_alloc *mem_alloc(bool executable = false);
 
 	class Mem_alloc_impl : public Mem_alloc
 	{