riscv/backtrace: add up_backtrace support

Signed-off-by: chao.an <anchao@xiaomi.com>

arch/risc-v/src/common/riscv_backtrace.c

@@ -0,0 +1,178 @@
+/****************************************************************************
+ * arch/risc-v/src/common/riscv_backtrace.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/arch.h>
+#include "sched/sched.h"
+
+#include "riscv_internal.h"
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getfp
+ *
+ * Description:
+ *  getfp() returns current frame pointer
+ *
+ ****************************************************************************/
+
+static inline uintptr_t getfp(void)
+{
+  register uintptr_t fp;
+
+  __asm__
+  (
+    "\tadd  %0, x0, fp\n"
+    : "=r"(fp)
+  );
+
+  return fp;
+}
+
+/****************************************************************************
+ * Name: backtrace
+ *
+ * Description:
+ *  backtrace() parsing the return address through frame pointer
+ *
+ ****************************************************************************/
+
+static int backtrace(FAR uintptr_t *base, FAR uintptr_t *limit,
+                     FAR uintptr_t *fp, FAR uintptr_t *ra,
+                     FAR void **buffer, int size)
+{
+  int i = 0;
+
+  if (ra)
+    {
+      buffer[i++] = ra;
+    }
+
+  for (; i < size; fp = (FAR uintptr_t *)*(fp - 2), i++)
+    {
+      if (fp > limit || fp < base)
+        {
+          break;
+        }
+
+      ra = (FAR uintptr_t *)*(fp - 1);
+      if (ra == NULL)
+        {
+          break;
+        }
+
+      buffer[i] = ra;
+    }
+
+  return i;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_backtrace
+ *
+ * Description:
+ *  up_backtrace()  returns  a backtrace for the TCB, in the array
+ *  pointed to by buffer.  A backtrace is the series of currently active
+ *  function calls for the program.  Each item in the array pointed to by
+ *  buffer is of type void *, and is the return address from the
+ *  corresponding stack frame.  The size argument specifies the maximum
+ *  number of addresses that can be stored in buffer.   If  the backtrace is
+ *  larger than size, then the addresses corresponding to the size most
+ *  recent function calls are returned; to obtain the complete backtrace,
+ *  make sure that buffer and size are large enough.
+ *
+ * Input Parameters:
+ *   tcb    - Address of the task's TCB
+ *   buffer - Return address from the corresponding stack frame
+ *   size   - Maximum number of addresses that can be stored in buffer
+ *
+ * Returned Value:
+ *   up_backtrace() returns the number of addresses returned in buffer
+ *
+ ****************************************************************************/
+
+int up_backtrace(FAR struct tcb_s *tcb, FAR void **buffer, int size)
+{
+  FAR struct tcb_s *rtcb = running_task();
+  irqstate_t flags;
+  int ret;
+
+  if (size <= 0 || !buffer)
+    {
+      return 0;
+    }
+
+  if (tcb == NULL || tcb == rtcb)
+    {
+      if (up_interrupt_context())
+        {
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
+          ret = backtrace((FAR void *)&g_intstackalloc,
+                          (FAR void *)((uint32_t)&g_intstackalloc +
+                                       CONFIG_ARCH_INTERRUPTSTACK),
+                          (FAR void *)getfp(), NULL, buffer, size);
+#else
+          ret = backtrace(rtcb->stack_base_ptr,
+                          rtcb->stack_base_ptr + rtcb->adj_stack_size,
+                          (FAR void *)getfp(), NULL, buffer, size);
+#endif
+          if (ret < size)
+            {
+              ret += backtrace(rtcb->stack_base_ptr,
+                               rtcb->stack_base_ptr +
+                               rtcb->adj_stack_size,
+                               (FAR void *)CURRENT_REGS[REG_FP],
+                               (FAR void *)CURRENT_REGS[REG_EPC],
+                               &buffer[ret], size - ret);
+            }
+        }
+      else
+        {
+          ret = backtrace(rtcb->stack_base_ptr,
+                          rtcb->stack_base_ptr + rtcb->adj_stack_size,
+                          (FAR void *)getfp(), NULL, buffer, size);
+        }
+    }
+  else
+    {
+      flags = enter_critical_section();
+
+      ret = backtrace(tcb->stack_base_ptr,
+                      tcb->stack_base_ptr + tcb->adj_stack_size,
+                      (FAR void *)tcb->xcp.regs[REG_FP],
+                      (FAR void *)tcb->xcp.regs[REG_EPC],
+                      buffer, size);
+
+      leave_critical_section(flags);
+    }
+
+  return ret;
+}