Merge pull request #11998 from gschorcht/cpu/atmega_common/malloc-wrappers

cpu/atmega_common: wrappers for memory management function to avoid preemption

cpu/atmega_common/avr_libc_extra/posix_unistd.c

@@ -21,6 +21,7 @@
 
 #ifdef MODULE_VFS
 #include <fcntl.h>
+#include "irq.h"
 #include "vfs.h"
 #elif defined(MODULE_STDIO_UART)
 #include "stdio_uart.h"
@@ -175,4 +176,45 @@ ssize_t write(int fd, const void *src, size_t count)
 #endif
 }
 
+/*
+ * Following functions are wrappers around the according avr-libc system
+ * functions to avoid their preemption by disabling the interrupts for the
+ * time of their execution.
+ */
+extern void *__real_malloc(size_t size);
+extern void __real_free(void *ptr);
+extern void *__real_calloc(size_t nmemb, size_t size);
+extern void *__real_realloc(void *ptr, size_t size);
+
+void *__wrap_malloc(size_t size)
+{
+    unsigned state = irq_disable();
+    void *ptr = __real_malloc(size);
+    irq_restore(state);
+    return ptr;
+}
+
+void __wrap_free(void *ptr)
+{
+    unsigned state = irq_disable();
+    __real_free(ptr);
+    irq_restore(state);
+}
+
+void *__wrap_calloc(size_t nmemb, size_t size)
+{
+    unsigned state = irq_disable();
+    void *ptr = __real_calloc(nmemb, size);
+    irq_restore(state);
+    return ptr;
+}
+
+void *__wrap_realloc(void *ptr, size_t size)
+{
+    unsigned state = irq_disable();
+    void *new = __real_realloc(ptr, size);
+    irq_restore(state);
+    return new;
+}
+
 /** @} */

makefiles/arch/atmega.inc.mk

@@ -41,6 +41,9 @@ LDSCRIPT_COMPAT = $(if $(shell $(TARGET_ARCH)-ld --verbose | grep __TEXT_REGION_
                     -T$(RIOTCPU)/$(CPU)/ldscripts_compat/avr_2.26.ld)
 LINKFLAGS += $(LDSCRIPT_COMPAT)
 
+# use the wrapper functions for following avr-libc functions
+LINKFLAGS += -Wl,-wrap=malloc -Wl,-wrap=calloc -Wl,-wrap=realloc -Wl,-wrap=free
+
 ifeq ($(LTO),1)
   # avr-gcc <4.8.3 has a bug when using LTO which causes a warning to be printed always:
   # '_vector_25' appears to be a misspelled signal handler [enabled by default]