sandbox: add libc memory allocator

While we typically want to reuse as much barebox functionality as
possible in sandbox, using system malloc(3) instead can be very
useful when using external memory integrity tools. This is even
useful for AddressSanitizer, because the reports resulting from
the memory poisoning API are less detailed than the built-in
support for the libc malloc(3).

Note that a barebox "heap" is still allocated upfront. It's only
used for request_sdram_region now though. Whatever is allocated by
means of malloc and memalign will be ina disjunct heap.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 38 insertions, 0 deletions

diff --git a/arch/sandbox/Makefile b/arch/sandbox/Makefile
index c08ea0cf83..27021222dc 100644
--- a/arch/sandbox/Makefile
+++ b/arch/sandbox/Makefile
@@ -12,6 +12,7 @@ lds-y   := $(BOARD)/barebox.lds
 
 TEXT_BASE = $(CONFIG_TEXT_BASE)
 KBUILD_CFLAGS += -Dmalloc=barebox_malloc -Dcalloc=barebox_calloc \
+		-Dmalloc_stats=barebox_malloc_stats -Dmemalign=barebox_memalign \
 		-Dfree=barebox_free -Drealloc=barebox_realloc \
 		-Dread=barebox_read -Dwrite=barebox_write \
 		-Dopen=barebox_open -Dclose=barebox_close \
diff --git a/arch/sandbox/os/Makefile b/arch/sandbox/os/Makefile
index ed921443e0..df6d597e78 100644
--- a/arch/sandbox/os/Makefile
+++ b/arch/sandbox/os/Makefile
@@ -10,6 +10,7 @@ KBUILD_CFLAGS += -Wall
 NOSTDINC_FLAGS :=
 
 obj-y = common.o tap.o
+obj-$(CONFIG_MALLOC_LIBC) += libc_malloc.o
 
 CFLAGS_sdl.o = $(shell pkg-config sdl --cflags)
 obj-$(CONFIG_DRIVER_VIDEO_SDL) += sdl.o
diff --git a/arch/sandbox/os/libc_malloc.c b/arch/sandbox/os/libc_malloc.c
new file mode 100644
index 0000000000..74e3e26805
--- /dev/null
+++ b/arch/sandbox/os/libc_malloc.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 Ahmad Fatoum <a.fatoum@pengutronix.de>
+ */
+
+#include <stdlib.h>
+#include <malloc.h>
+
+void barebox_malloc_stats(void)
+{
+}
+
+void *barebox_memalign(size_t alignment, size_t bytes)
+{
+	return memalign(alignment, bytes);
+}
+
+void *barebox_malloc(size_t size)
+{
+	return malloc(size);
+}
+
+void barebox_free(void *ptr)
+{
+	free(ptr);
+}
+
+void *barebox_realloc(void *ptr, size_t size)
+{
+	return realloc(ptr, size);
+}
+
+void *barebox_calloc(size_t n, size_t elem_size)
+{
+	return calloc(n, elem_size);
+}