Runtime dynamic memory tracing

This commit adds a dynamic memory tracer that calls a callback whenever
one of the basic memory allocation functions (malloc, realloc, calloc,
free) is called. The operation of the tracer is guarded by the
'MBED_MEM_TRACING_ENABLED` macro.

Author: Bogdan Marinescu

hal/api/mbed_mem_trace.h

@@ -0,0 +1,138 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2016 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __MBED_MEM_TRACE_H__
+#define __MBED_MEM_TRACE_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <sys/types.h>
+
+/* Masks for tracer */
+#define MBED_MEM_TRACE_MALLOC           (1 << 0)
+#define MBED_MEM_TRACE_REALLOC          (1 << 1)
+#define MBED_MEM_TRACE_CALLOC           (1 << 2)
+#define MBED_MEM_TRACE_FREE             (1 << 3)
+#define MBED_MEM_TRACE_ALL              (MBED_MEM_TRACE_MALLOC | MBED_MEM_TRACE_REALLOC | MBED_MEM_TRACE_CALLOC | MBED_MEM_TRACE_FREE)
+#define MBED_MEM_TRACE_DISABLE          (0)
+
+/* Prefix for the output of the default tracer */
+#define MBED_MEM_DEFAULT_TRACER_PREFIX  "#"
+
+/**
+ * Type of the callback used by the memory tracer. This callback is called when a memory
+ * allocation operation (malloc, realloc, calloc, free) is called and tracing is enabled
+ * for that memory allocation function.
+ *
+ * @param op the ID of the operation (MBED_MEM_TRACE_MALLOC, MBED_MEM_TRACE_REALLOC,
+ *           MBED_MEM_TRACE_CALLOC or MBED_MEM_TRACE_FREE).
+ * @param res the result that the memory operation returned (NULL for 'free').
+ * @param caller the caller of the memory operation. Note that the value of 'caller' might be
+ *               unreliable.
+ *
+ * The rest of the parameters passed 'mbed_mem_trace_cb_t' are the same as the memory operations
+ * that triggered its call (see 'man malloc' for details):
+ *
+ * - for malloc: cb(MBED_MEM_TRACE_MALLOC, res, caller, size).
+ * - for realloc: cb(MBED_MEM_TRACE_REALLOC, res, caller, ptr, size).
+ * - for calloc: cb(MBED_MEM_TRACE_CALLOC, res, caller, nmemb, size).
+ * - for free: cb(MBED_MEM_TRACE_FREE, NULL, caller, ptr).
+ */
+typedef void (*mbed_mem_trace_cb_t)(uint8_t op, void *res, void* caller, ...);
+
+/**
+ * Set up for the memory tracer. This function can be called more than one time
+ * to set up different masks and/or callbacks.
+ *
+ * @param mask the tracer mask. It can be a bitwise combination of MBED_MEM_TRACE_MALLOC,
+ *             MBED_MEM_TRACE_REALLOC, MBED_MEM_TRACE_CALLOC, MBED_MEM_TRACE_FREE, or
+ *             MBED_MEM_TRACE_ALL to trace all memory operations, or MBED_MEM_TRACE_DISABLE
+ *             to disable tracing.
+ * @param cb the callback to call on each enabled memory operation.
+ */
+void mbed_mem_trace_setup(uint8_t mask, mbed_mem_trace_cb_t cb);
+
+/**
+ * Trace a call to 'malloc'.
+ * @param res the result of running 'malloc'.
+ * @param size the 'size' argument given to 'malloc'.
+ * @return 'res' (the first argument).
+ */
+void* mbed_mem_trace_malloc(void *res, size_t size);
+
+/**
+ * Trace a call to 'realloc'.
+ * @param res the result of running 'realloc'.
+ * @param ptr the 'ptr' argument given to 'realloc'.
+ * @param size the 'size' argument given to 'realloc'.
+ * @return 'res' (the first argument).
+ */
+void* mbed_mem_trace_realloc(void *res, void *ptr, size_t size);
+
+/**
+ * Trace a call to 'calloc'.
+ * @param res the result of running 'calloc'.
+ * @param nmemb the 'nmemb' argument given to 'calloc'.
+ * @param size the 'size' argument given to 'calloc'.
+ * @Return 'res' (the first argument).
+ */
+void* mbed_mem_trace_calloc(void *res, size_t num, size_t size);
+
+/**
+ * Trace a call to 'free'.
+ * @param ptr the 'ptr' argument given to 'free'.
+ */
+void mbed_mem_trace_free(void *ptr);
+
+/**
+ * Default memory trace callback. DO NOT CALL DIRECTLY. It is meant to be used
+ * as the second argument of 'mbed_mem_trace_setup'.
+ *
+ * The default callback outputs trace data using 'printf', in a format that's
+ * easily parsable by an external tool. For each memory operation, the callback
+ * outputs a line that begins with '#<op>:<0xresult>;<0xcaller>-':
+ *
+ * - 'op' identifies the memory operation ('m' for 'malloc', 'r' for 'realloc',
+ *   'c' for 'calloc' and 'f' for 'free').
+ * - 'result' (base 16) is the result of the memor operation. This is always NULL
+ *   for 'free', since 'free' doesn't return anything.
+ * -'caller' (base 16) is the caller of the memory operation. Note that the value
+ *   of 'caller' might be unreliable.
+ *
+ * The rest of the output depends on the operation being traced:
+ *
+ * - for 'malloc': 'size', where 'size' is the original argument to 'malloc'.
+ * - for 'realloc': '0xptr;size', where 'ptr' (base 16) and 'size' are the original arguments to 'realloc'.
+ * - for 'calloc': 'nmemb;size', where 'nmemb' and 'size' are the original arguments to 'calloc'.
+ * - for 'free': '0xptr', where 'ptr' (base 16) is the original argument to 'free'.
+ *
+ * Examples:
+ *
+ * - '#m:0x20003240;0x600d-50' encodes a 'malloc' that returned 0x20003240, was called
+ *   by the instruction at 0x600D with a the 'size' argument equal to 50.
+ * - '#f:0x0;0x602f-0x20003240' encodes a 'free' that was called by the instruction at
+ *   0x602f with the 'ptr' argument equal to 0x20003240.
+ */
+void mbed_mem_default_callback(uint8_t op, void *res, void *caller, ...);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif// #ifndef __MBED_MEM_TRACE_H__
+

hal/api/toolchain.h

@@ -263,4 +263,17 @@ typedef int FILEHANDLE;
 #define EXTERN extern
 #endif
 
+/**
+ * Helper function that identifies the caller of a function
+ *
+ * @return Address of the calling function
+ */
+#if defined(TOOLCHAIN_ARM)
+    #define MBED_CALLER_ADDR() __builtin_return_address(0)
+#elif defined(TOOLCHAIN_GCC)
+    #define MBED_CALLER_ADDR() __builtin_extract_return_addr(__builtin_return_address(0))
+#else
+    #define MBED_CALLER_ADDR() (NULL)
+#endif
+
 #endif

hal/common/mbed_alloc_wrappers.c

@@ -0,0 +1,102 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2016 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "api/mbed_mem_trace.h"
+#include <stddef.h>
+#include <stdio.h>
+
+#if defined(TOOLCHAIN_GCC)
+
+#ifdef   FEATURE_UVISOR
+#include "uvisor-lib/uvisor-lib.h"
+#endif/* FEATURE_UVISOR */
+
+// TODO: memory tracing doesn't work with uVisor enabled.
+#if !defined(FEATURE_UVISOR)
+void * __wrap__malloc_r(struct _reent * r, size_t size) {
+    extern void * __real__malloc_r(struct _reent * r, size_t size);
+#ifdef MBED_MEM_TRACING_ENABLED
+    return mbed_mem_trace_malloc(__real__malloc_r(r, size), size);
+#else
+    return __real__malloc_r(r, size);
+#endif
+}
+void * __wrap__realloc_r(struct _reent * r, void * ptr, size_t size) {
+    extern void * __real__realloc_r(struct _reent * r, void * ptr, size_t size);
+#ifdef MBED_MEM_TRACING_ENABLED
+    return mbed_mem_trace_realloc(__real__realloc_r(r, ptr, size), ptr, size);
+#else
+    return __real__realloc_r(r, ptr, size);
+#endif
+}
+void __wrap__free_r(struct _reent * r, void * ptr) {
+    extern void __real__free_r(struct _reent * r, void * ptr);
+    __real__free_r(r, ptr);
+#ifdef MBED_MEM_TRACING_ENABLED
+    mbed_mem_trace_free(ptr);
+#endif
+}
+void * __wrap__calloc_r(struct _reent * r, size_t nmemb, size_t size) {
+    extern void* __real__calloc_r(struct _reent * r, size_t nmemb, size_t size);
+#ifdef MBED_MEM_TRACING_ENABLED
+    return mbed_mem_trace_calloc(__real__calloc_r(r, nmemb, size), nmemb, size);
+#else
+    return __real__calloc_r(r, nmemb, size);
+#endif
+}
+#endif // if !defined(FEATURE_UVISOR)
+
+#elif defined(TOOLCHAIN_ARM) // #if defined(TOOLCHAIN_GCC)
+
+void* $Sub$$malloc(size_t size) {
+#ifdef MBED_MEM_TRACING_ENABLED
+    return trace_malloc($Super$$malloc(size), size);
+#else
+    return $Super$$malloc(size);
+#endif
+}
+
+void* $Sub$$realloc(void *ptr, size_t size) {
+#ifdef MBED_MEM_TRACING_ENABLED
+    return trace_realloc($Super$$realloc(ptr, size), ptr, size);
+#else
+    return $Super$$realloc(ptr, size);
+#endif
+}
+
+void *$Sub$$calloc(size_t nmemb, size_t size) {
+#ifdef MBED_MEM_TRACING_ENABLED
+    return trace_calloc($Super$$calloc(nmemb, size), nmemb, size);
+#else
+    return $Super$$calloc(nmemb, size);
+#endif
+}
+
+void $Sub$$free(void *ptr) {
+    $Super$$free(ptr);
+#ifdef MBED_MEM_TRACING_ENABLED
+    trace_free(ptr);
+#endif
+}
+
+#else // #if defined(TOOLCHAIN_GCC)
+
+#ifdef MBED_MEM_TRACING_ENABLED
+#error Memory tracing not supported with the current toolchain.
+#endif
+
+#endif // #if defined(TOOLCHAIN_GCC)
+

hal/common/mbed_mem_trace.c

@@ -0,0 +1,127 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2016 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include "api/mbed_mem_trace.h"
+#include "api/critical.h"
+#include "api/toolchain.h"
+
+/******************************************************************************
+ * Internal variables, functions and helpers
+ *****************************************************************************/
+
+/* The current tracing mask (see mbed_mem_trace.h for details). */
+static uint8_t mem_trace_mask = MBED_MEM_TRACE_DISABLE;
+/* The callback function that will be called after a traced memory operations finishes. */
+static mbed_mem_trace_cb_t mem_trace_cb;
+/* 'already_tracing' guards "trace inside trace" situations (for example, the implementation
+ * of realloc() might call malloc() internally, and since malloc() is also traced, this could
+ * result in two calls to the callback function instead of one. */
+static uint8_t already_tracing;
+
+/******************************************************************************
+ * Public interface
+ *****************************************************************************/
+
+void mbed_mem_trace_setup(uint8_t mask, mbed_mem_trace_cb_t cb) {
+    mem_trace_mask = mask;
+    mem_trace_cb = cb;
+}
+
+void* mbed_mem_trace_malloc(void *res, size_t size) {
+    uint8_t expected = 0;
+
+    if (mem_trace_cb && (mem_trace_mask & MBED_MEM_TRACE_MALLOC)) {
+        if (core_util_atomic_cas_u8(&already_tracing, &expected, 1)) {
+            mem_trace_cb(MBED_MEM_TRACE_MALLOC, res, MBED_CALLER_ADDR(), size);
+            already_tracing = 0;
+        }
+    }
+    return res;
+}
+
+void* mbed_mem_trace_realloc(void *res, void *ptr, size_t size) {
+    uint8_t expected = 0;
+
+    if (mem_trace_cb && (mem_trace_mask & MBED_MEM_TRACE_REALLOC)) {
+        if (core_util_atomic_cas_u8(&already_tracing, &expected, 1)) {
+            mem_trace_cb(MBED_MEM_TRACE_REALLOC, res, MBED_CALLER_ADDR(), ptr, size);
+            already_tracing = 0;
+        }
+    }
+    return res;
+}
+
+void* mbed_mem_trace_calloc(void *res, size_t num, size_t size) {
+    uint8_t expected = 0;
+
+    if (mem_trace_cb && (mem_trace_mask & MBED_MEM_TRACE_CALLOC)) {
+        if (core_util_atomic_cas_u8(&already_tracing, &expected, 1)) {
+            mem_trace_cb(MBED_MEM_TRACE_CALLOC, res, MBED_CALLER_ADDR(), num, size);
+            already_tracing = 0;
+        }
+    }
+    return res;
+}
+
+void mbed_mem_trace_free(void *ptr) {
+    uint8_t expected = 0;
+
+    if (mem_trace_cb && (mem_trace_mask & MBED_MEM_TRACE_FREE)) {
+        if (core_util_atomic_cas_u8(&already_tracing, &expected, 1)) {
+            mem_trace_cb(MBED_MEM_TRACE_FREE, NULL, MBED_CALLER_ADDR(), ptr);
+            already_tracing = 0;
+        }
+    }
+}
+
+void mbed_mem_default_callback(uint8_t op, void *res, void *caller, ...) {
+    va_list va;
+    size_t temp_s1, temp_s2;
+    void *temp_ptr;
+
+    va_start(va, caller);
+    switch(op) {
+        case MBED_MEM_TRACE_MALLOC:
+            temp_s1 = va_arg(va, size_t);
+            printf(MBED_MEM_DEFAULT_TRACER_PREFIX "m:%p;%p-%u\n", res, caller, temp_s1);
+            break;
+
+        case MBED_MEM_TRACE_REALLOC:
+            temp_ptr = va_arg(va, void*);
+            temp_s1 = va_arg(va, size_t);
+            printf(MBED_MEM_DEFAULT_TRACER_PREFIX "r:%p;%p-%p;%u\n", res, caller, temp_ptr, temp_s1);
+            break;
+
+        case MBED_MEM_TRACE_CALLOC:
+            temp_s1 = va_arg(va, size_t);
+            temp_s2 = va_arg(va, size_t);
+            printf(MBED_MEM_DEFAULT_TRACER_PREFIX "c:%p;%p-%u;%u\n", res, caller, temp_s1, temp_s2);
+            break;
+
+        case MBED_MEM_TRACE_FREE:
+            temp_ptr = va_arg(va, void*);
+            printf(MBED_MEM_DEFAULT_TRACER_PREFIX "f:%p;%p-%p\n", res, caller, temp_ptr);
+            break;
+
+        default:
+            printf("?\n");
+    }
+    va_end(va);
+}
+