Add guard page debug malloc.

libc/include/malloc.h

@@ -1,6 +1,6 @@
 /*******************************************************************************
 
-    Copyright(C) Jonas 'Sortie' Termansen 2012, 2013, 2014.
+    Copyright(C) Jonas 'Sortie' Termansen 2012, 2013, 2014, 2015.
 
     This file is part of the Sortix C Library.
 
@@ -79,6 +79,27 @@ int heap_get_paranoia(void);
 #endif
 #endif
 
+#if !defined(HEAP_GUARD_DEBUG) && \
+    defined(__is_sortix_kernel) && defined(HEAP_GUARD_DEBUG_KERNEL)
+#define HEAP_GUARD_DEBUG
+#endif
+
+#if !defined(MALLOC_GUARD_DEBUG) && \
+    __STDC_HOSTED__ && defined(HEAP_GUARD_DEBUG_USERLAND)
+#define HEAP_GUARD_DEBUG
+#endif
+
+#if defined(HEAP_GUARD_DEBUG) && !defined(__is_sortix_kernel)
+struct heap_alloc
+{
+	uintptr_t from;
+	size_t size;
+};
+#define HEAP_PAGE_SIZE 4096UL
+#define HEAP_ALIGN_PAGEDOWN(x) ((x) & ~(HEAP_PAGE_SIZE - 1))
+#define HEAP_ALIGN_PAGEUP(x) (-(-(x) & ~(HEAP_PAGE_SIZE - 1)))
+#endif
+
 /* A magic value to identify a heap part edge. The value is selected such
    that it is not appropriately aligned like a real heap chunk pointer, such
    that there are no ambiguous cases. */

libc/stdlib/free.cpp

@@ -1,6 +1,6 @@
 /*******************************************************************************
 
-    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014.
+    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014, 2015.
 
     This file is part of the Sortix C Library.
 
@@ -25,16 +25,14 @@
 #include <malloc.h>
 #include <stdlib.h>
 
-#if __is_sortix_kernel
-#include <sortix/kernel/kernel.h>
-#endif
-
 #if defined(HEAP_NO_ASSERT)
 #define __heap_verify() ((void) 0)
 #undef assert
 #define assert(x) do { ((void) 0); } while ( 0 )
 #endif
 
+#if !defined(HEAP_GUARD_DEBUG)
+
 extern "C" void free(void* addr)
 {
 	if ( !addr )
@@ -55,3 +53,33 @@ extern "C" void free(void* addr)
 	__heap_verify();
 	__heap_unlock();
 }
+
+#else
+
+#if defined(__is_sortix_kernel)
+#include <sortix/kernel/addralloc.h>
+#include <sortix/kernel/memorymanagement.h>
+#else
+#include <sys/mman.h>
+#endif
+
+extern "C" void free(void* addr)
+{
+	if ( !addr )
+		return;
+
+#if defined(__is_sortix_kernel)
+	using namespace Sortix;
+	addralloc_t* alloc_ptr = (addralloc_t*) Page::AlignDown((uintptr_t) addr - 16);
+	assert(alloc_ptr->from == (uintptr_t) alloc_ptr);
+	addralloc_t alloc = *alloc_ptr;
+	Memory::UnmapRange(alloc.from, alloc.size - Page::Size(), PAGE_USAGE_KERNEL_HEAP);
+	FreeKernelAddress(&alloc);
+#else
+	struct heap_alloc* alloc_ptr =
+		(struct heap_alloc*) HEAP_ALIGN_PAGEDOWN((uintptr_t) addr - 16);
+	munmap((void*) alloc_ptr->from, alloc_ptr->size);
+#endif
+}
+
+#endif

libc/stdlib/malloc.cpp

@@ -1,6 +1,6 @@
 /*******************************************************************************
 
-    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014.
+    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014, 2015.
 
     This file is part of the Sortix C Library.
 
@@ -28,16 +28,14 @@
 #include <stdlib.h>
 #include <string.h>
 
-#if __is_sortix_kernel
-#include <sortix/kernel/kernel.h>
-#endif
-
 #if defined(HEAP_NO_ASSERT)
 #define __heap_verify() ((void) 0)
 #undef assert
 #define assert(x) do { ((void) 0); } while ( 0 )
 #endif
 
+#if !defined(HEAP_GUARD_DEBUG)
+
 extern "C" void* malloc(size_t original_size)
 {
 	if ( !heap_size_has_bin(original_size) )
@@ -102,3 +100,55 @@ extern "C" void* malloc(size_t original_size)
 	// Return the inner data associated with the chunk to the caller.
 	return heap_chunk_to_data(result_chunk);
 }
+
+#else
+
+#if defined(__is_sortix_kernel)
+#include <sortix/mman.h>
+#include <sortix/kernel/addralloc.h>
+#include <sortix/kernel/memorymanagement.h>
+#else
+#include <sys/mman.h>
+#endif
+
+extern "C" void* malloc(size_t original_size)
+{
+	if ( !original_size )
+		original_size = 1;
+	size_t size = -(-original_size & ~15UL);
+	size_t needed = 16 + size;
+#if defined(__is_sortix_kernel)
+	using namespace Sortix;
+	needed = Page::AlignUp(needed);
+	size_t virtsize = needed + Page::Size();
+	addralloc_t addralloc;
+	if ( !AllocateKernelAddress(&addralloc, virtsize) )
+		return NULL;
+	if ( !Memory::MapRange(addralloc.from, addralloc.size - Page::Size(),
+	                       PROT_KREAD | PROT_KWRITE, PAGE_USAGE_KERNEL_HEAP) )
+	{
+		FreeKernelAddress(&addralloc);
+		return NULL;
+	}
+	Memory::Flush();
+	addralloc_t* addralloc_ptr = (addralloc_t*) (addralloc.from);
+	*addralloc_ptr = addralloc;
+#else
+	needed = HEAP_ALIGN_PAGEUP(needed);
+	size_t virtsize = needed + HEAP_PAGE_SIZE;
+	void* from = mmap(NULL, virtsize, PROT_READ | PROT_WRITE,
+	                  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if ( from == MAP_FAILED )
+		return NULL;
+	void* guard = (char*) from + needed;
+	if ( mprotect(guard, HEAP_PAGE_SIZE, PROT_NONE) < 0 )
+		return munmap(from, virtsize), (void*) NULL;
+	struct heap_alloc* addralloc_ptr = (struct heap_alloc*) from;
+	addralloc_ptr->from = (uintptr_t) from;
+	addralloc_ptr->size = virtsize;
+#endif
+	size_t offset = needed - size;
+	return (void*) (addralloc_ptr->from + offset);
+}
+
+#endif

libc/stdlib/realloc.cpp

@@ -1,6 +1,6 @@
 /*******************************************************************************
 
-    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014.
+    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014, 2015.
 
     This file is part of the Sortix C Library.
 
@@ -28,16 +28,14 @@
 #include <stdlib.h>
 #include <string.h>
 
-#if __is_sortix_kernel
-#include <sortix/kernel/kernel.h>
-#endif
-
 #if defined(HEAP_NO_ASSERT)
 #define __heap_verify() ((void) 0)
 #undef assert
 #define assert(x) do { ((void) 0); } while ( 0 )
 #endif
 
+#if !defined(HEAP_GUARD_DEBUG)
+
 extern "C" void* realloc(void* ptr, size_t requested_size)
 {
 	if ( !ptr )
@@ -125,3 +123,41 @@ extern "C" void* realloc(void* ptr, size_t requested_size)
 
 	return result;
 }
+
+#else
+
+#if defined(__is_sortix_kernel)
+#include <sortix/kernel/addralloc.h>
+#include <sortix/kernel/memorymanagement.h>
+#endif
+
+extern "C" void* realloc(void* ptr, size_t requested_size)
+{
+	if ( !ptr )
+		return malloc(requested_size);
+
+#if defined(__is_sortix_kernel)
+	using namespace Sortix;
+	addralloc_t* alloc_ptr =
+		(addralloc_t*) Page::AlignDown((uintptr_t) ptr - 16);
+	assert(alloc_ptr->from == (uintptr_t) alloc_ptr);
+	addralloc_t alloc = *alloc_ptr;
+	size_t size = (alloc.from + alloc.size - Page::Size()) - (uintptr_t) ptr;
+#else
+	struct heap_alloc* alloc_ptr =
+		(struct heap_alloc*) HEAP_ALIGN_PAGEDOWN((uintptr_t) ptr - 16);
+	assert(alloc_ptr->from == (uintptr_t) alloc_ptr);
+	struct heap_alloc alloc = *alloc_ptr;
+	size_t size = (alloc.from + alloc.size - HEAP_PAGE_SIZE) - (uintptr_t) ptr;
+#endif
+	if ( requested_size <= size )
+		return ptr;
+	void* replacement = malloc(requested_size);
+	if ( !replacement )
+		return NULL;
+	memcpy(replacement, ptr, size);
+	free(ptr);
+	return replacement;
+}
+
+#endif