vbox: provide initial memory buffer

broken due to changes of

libc: API transition
Issue #1987

For now provide a initial memory buffer for allocation of static
constructors and of malloc calls out of the libc during early
libc initialization until actual vbox code is executed having the Env
pointer.

repos/ports/src/virtualbox/libc.cc

@@ -28,6 +28,8 @@
 
 #include "libc_errno.h"
 
+/* Genode specific Vbox include */
+#include "vmm.h"
 
 /* libc memory allocator */
 #include <libc_mem_alloc.h>
@@ -38,14 +40,46 @@
 
 static const bool verbose = false;
 
+/*
+ * We need an initial buffer currently, since the libc issues during
+ * initialization malloc (dup) calls to the one defined below. At this
+ * point we have not any env pointer.
+ * Additionally static constructors are executed currently before the libc
+ * is done with initialization and so we also have no Env pointer here.
+ */
+static char     buffer[2048];
+static unsigned buffer_len = 0;
+
+static bool initial_memory(void * ptr)
+{
+	return buffer <= ptr && ptr < buffer + sizeof(buffer);
+}
+
 /*
  * We cannot use the libc's version of malloc because it does not satisfies
  * the alignment constraints asserted by 'Runtime/r3/alloc.cpp'.
  */
+static Libc::Mem_alloc_impl * memory()
+{
+	try { genode_env(); } catch (...) { return nullptr; }
+
+	static Libc::Mem_alloc_impl mem( genode_env().rm(), genode_env().ram());
+	return &mem;
+}
 
 extern "C" void *malloc(::size_t size)
 {
-	return Libc::mem_alloc()->alloc(size, Genode::log2(RTMEM_ALIGNMENT));
+	if (memory())
+		return memory()->alloc(size, Genode::log2(RTMEM_ALIGNMENT));
+
+	void * ret = buffer + buffer_len;
+	buffer_len += (size + RTMEM_ALIGNMENT - 1) & ~(0ULL + RTMEM_ALIGNMENT - 1);
+
+	if (buffer_len <= sizeof(buffer))
+		return ret;
+
+	struct Not_enough_initial_memory : Genode::Exception { };
+	throw Not_enough_initial_memory();
 }
 
 
@@ -60,7 +94,8 @@ extern "C" void *calloc(::size_t nmemb, ::size_t size)
 
 extern "C" void free(void *ptr)
 {
-	Libc::mem_alloc()->free(ptr);
+	if (!initial_memory(ptr))
+		memory()->free(ptr);
 }
 
 
@@ -74,12 +109,16 @@ extern "C" void *realloc(void *ptr, ::size_t size)
 		return 0;
 	}
 
-	/* determine size of old block content (without header) */
-	unsigned long old_size = Libc::mem_alloc()->size_at(ptr);
+	unsigned long old_size = size;
 
-	/* do not reallocate if new size is less than the current size */
-	if (size <= old_size)
-		return ptr;
+	if (!initial_memory(ptr)) {
+		/* determine size of old block content (without header) */
+		old_size = memory()->size_at(ptr);
+
+		/* do not reallocate if new size is less than the current size */
+		if (size <= old_size)
+			return ptr;
+	}
 
 	/* allocate new block */
 	void *new_addr = malloc(size);

repos/ports/src/virtualbox/sup.cc

@@ -25,9 +25,6 @@
 #include <iprt/uint128.h>
 #include <VBox/err.h>
 
-/* libc memory allocator */
-#include <libc_mem_alloc.h>
-
 
 struct Attached_gip : Genode::Attached_ram_dataspace
 {
@@ -283,7 +280,13 @@ void genode_VMMR0_DO_GVMM_CREATE_VM(PSUPVMMR0REQHDR pReqHdr)
 	 * PDMR3CritSectGetNop().
 	 */
 	size_t const cbVM = RT_UOFFSETOF(VM, aCpus[cCpus]);
-	VM *pVM = (VM *)Libc::mem_alloc()->alloc(cbVM, Genode::log2(PAGE_SIZE));
+
+	static Genode::Attached_ram_dataspace vm(genode_env().ram(),
+	                                         genode_env().rm(),
+	                                         cbVM);
+	Assert (vm.size() >= cbVM);
+
+	VM *pVM = vm.local_addr<VM>();
 	Genode::memset(pVM, 0, cbVM);
 
 	/*

repos/ports/src/virtualbox5/sup.cc

@@ -24,9 +24,6 @@
 #include <iprt/uint128.h>
 #include <VBox/err.h>
 
-/* libc memory allocator */
-#include <libc_mem_alloc.h>
-
 #include "vmm.h"
 
 enum {
@@ -286,7 +283,13 @@ void genode_VMMR0_DO_GVMM_CREATE_VM(PSUPVMMR0REQHDR pReqHdr)
 	 * PDMR3CritSectGetNop().
 	 */
 	size_t const cbVM = RT_UOFFSETOF(VM, aCpus[cCpus]);
-	VM *pVM = (VM *)Libc::mem_alloc()->alloc(cbVM, Genode::log2(PAGE_SIZE));
+
+	static Genode::Attached_ram_dataspace vm(genode_env().ram(),
+	                                         genode_env().rm(),
+	                                         cbVM);
+	Assert (vm.size() >= cbVM);
+
+	VM *pVM = vm.local_addr<VM>();
 	Genode::memset(pVM, 0, cbVM);
 
 	/*