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Posted to commits@nuttx.apache.org by GitBox <gi...@apache.org> on 2021/07/30 04:47:48 UTC

[GitHub] [incubator-nuttx] anchao opened a new pull request #4259: sched/backtrace: add support for printing the arbitrary thread stack in runtime

anchao opened a new pull request #4259:
URL: https://github.com/apache/incubator-nuttx/pull/4259


   ## Summary
   
   add support for printing the arbitrary thread stack in runtime to monitor the thread status
   ( only support cortex-m / cortex-a(thumb) )
   
   libs/libc: move the backtrace implement to sched
   arch/cortex-m: add arch backtrace support 
   sched/backtrace: add sched_backtrace support 
   
   ## Impact
   
   Depends on:
   https://github.com/apache/incubator-nuttx-apps/pull/817
   
   N/A, new feature
   
   ## Testing
   
   Running tasks:
   
   ```
   ap> ps
     PID GROUP PRI POLICY   TYPE    NPX STATE    EVENT     SIGMASK   STACK   USED  FILLED    CPU COMMAND
       0     0   0 FIFO     Kthread N-- Ready              00000000 003052 001044  34.2%   94.4% Idle Task
       1     1 253 RR       Kthread --- Waiting  Semaphore 00000000 003044 000344  11.3%    0.0% hpwork 0x2011dc34
       2     2 253 RR       Kthread --- Waiting  Semaphore 00000000 003044 000344  11.3%    0.0% hpwork 0x2011dc34
       3     3 253 RR       Kthread --- Waiting  Semaphore 00000000 003044 000344  11.3%    0.0% hpwork 0x2011dc34
       4     4 110 RR       Kthread --- Waiting  Semaphore 00000000 008164 000824  10.0%    1.6% lpwork 0x2011dc28
       5     5 110 RR       Kthread --- Waiting  Semaphore 00000000 008164 001592  19.5%    0.0% lpwork 0x2011dc28
       6     6 110 RR       Kthread --- Waiting  Semaphore 00000000 008164 001544  18.9%    0.5% lpwork 0x2011dc28
       8     8 101 RR       Kthread --- Waiting  Semaphore 00000000 004060 001896  46.6%    0.0% bes_main  0x34008650
       9     9 252 RR       Kthread --- Waiting  MQ empty  00000000 006108 000488   7.9%    0.0% app_thread  0x34007924
      10    10 253 RR       Kthread --- Waiting  Semaphore 00000000 008124 000504   6.2%    0.0% audio_flinger  0x20042968
      11    11 100 RR       Kthread --- Waiting  Signal    00000000 003028 000472  15.5%    0.0% apps_recover  0x34007944
      12    12 252 RR       Kthread --- Waiting  MQ empty  00000000 010180 000504   4.9%    0.0% net_wq  0x20044d60
      13    13 252 RR       Kthread --- Waiting  MQ empty  00000000 008132 000480   5.9%    0.0% net_tasklet  0x20044d28
      14    14 252 RR       Kthread --- Waiting  Semaphore 00000000 004036 000920  22.7%    0.0% cw1200_bh  0x20044e14
      15    15 224 RR       Kthread --- Waiting  Semaphore 00000000 004060 000636  15.6%    0.0% rptun audio 0x20147250
      16    16 100 RR       Task    --- Waiting  Semaphore 00000000 004060 000368   9.0%    0.0% rc_raw_event_thx 0x20148f70
      17    17 100 RR       Task    --- Running            00000000 004084 001824  44.6%    0.5% init
      18    18 100 RR       Task    --- Waiting  Semaphore 00000000 004084 002384  58.3%    0.0% kvdbd
      20    20 252 RR       Task    --- Waiting  Semaphore 00000000 004060 000536  13.2%    0.0% rpmsg-uorb-audio 0x20157650
      21    21 232 RR       Task    --- Waiting  Semaphore 00000000 006132 001808  29.4%    0.0% usrsock
      23    23 227 FIFO     Kthread --- Waiting  Semaphore 00000000 001984 000712  35.8%    0.0% BT TX  0x201575f0
      24    24 228 FIFO     Kthread --- Waiting  Semaphore 00000000 004032 000880  21.8%    0.5% BT RX  0x201575f0
      25    25 230 FIFO     Kthread --- Waiting  Semaphore 00000000 001984 000576  29.0%    0.0% BT ECC  0x201575f0
      26    26 228 FIFO     Kthread --- Waiting  Semaphore 00000000 004032 000944  23.4%    2.7% BT Driver  0x201575f0
      27    27 101 RR       Kthread --- Waiting  MQ empty  00000000 004060 000608  14.9%    0.0% wifi_event  0x34008524
      28    28 252 RR       Kthread --- Waiting  MQ empty  00000000 004052 000568  14.0%    0.0% bes_netdev_wq
      29    29 100 RR       Kthread --- Waiting  Signal    00000000 004052 000520  12.8%    0.0% trans_stat_task  0x34008504
      30    30 100 RR       Kthread --- Ready              00000000 003036 000552  18.1%    0.0% temp_main  0x34008630
   
   ```
   
   show task 1 hpwork:
   
   ```
   ap> dumpstack 1
   [06:14:18] [32] [BackTrace| 1|0]:   0xc0e635c   0x2111b6   0x2111d6  0xc0d7b06   0x2128a8
   ```
   
   check the backtrace:
   ```
   arm-none-eabi-addr2line -e nuttx 0xc0e635c   0x2111b6   0x2111d6  0xc0d7b06   0x2128a8
   /home/archer/code/m3/nuttx/arch/arm/src/armv8-m/arm_switchcontext.S:79
   /home/archer/code/m3/nuttx/sched/semaphore/sem_wait.c:153 (discriminator 2)
   /home/archer/code/m3/nuttx/sched/semaphore/sem_wait.c:222 (discriminator 1)
   /home/archer/code/m3/nuttx/sched/wqueue/kwork_thread.c:132
   /home/archer/code/m3/nuttx/sched/task/task_start.c:139
   ```
   
   dump stack in range 0 - 30:
   
   ```
   ap> dumpstack 0 30
   [06:14:27] [33] [BackTrace| 0|0]:    0x240420   0x240184 0x2400460b
   [06:14:27] [33] [BackTrace| 1|0]:   0xc0e635c   0x2111b6   0x2111d6  0xc0d7b06   0x2128a8
   [06:14:27] [33] [BackTrace| 2|0]:   0xc0e635c   0x2111b6   0x2111d6  0xc0d7b06   0x2128a8
   [06:14:27] [33] [BackTrace| 3|0]:   0xc0e635c   0x2111b6   0x2111d6  0xc0d7b06   0x2128a8
   [06:14:27] [33] [BackTrace| 4|0]:   0xc0e635c   0x2111b6   0x2111d6  0xc0d7b06   0x2128a8
   [06:14:27] [33] [BackTrace| 5|0]:   0xc0e635c   0x2111b6   0x2111d6  0xc0d7b06   0x2128a8
   [06:14:27] [33] [BackTrace| 6|0]:   0xc0e635c   0x2111b6   0x2111d6  0xc0d7b06   0x2128a8
   [06:14:27] [33] [BackTrace| 8|0]:   0xc0e635c   0x2111b6   0x2111d6   0x2103a4   0x210170   0x222556  0xc1ddad0   0x2128a8
   [06:14:27] [33] [BackTrace| 9|0]:   0xc0e635c   0x20f8b6   0x20f68e   0x222b1e  0xc1b066a  0xc1b0696   0x2128a8
   [06:14:27] [33] [BackTrace|10|0]:   0xc0e635c   0x2111b6   0x2111d6   0x2103a4   0x210170   0x222556   0x20df16   0x2128a8
   [06:14:27] [33] [BackTrace|11|0]:   0xc0e635c   0x211b6a   0x2121a8   0x212268  0xc0e5080  0xc1f6724   0x2128a8
   [06:14:27] [33] [BackTrace|12|0]:   0xc0e635c   0x20f8b6   0x20f68e   0x222b1e   0x22d968   0x2128a8
   [06:14:27] [33] [BackTrace|13|0]:   0xc0e635c   0x20f8b6   0x20f68e   0x2229ac   0x22e702   0x2128a8
   [06:14:27] [33] [BackTrace|14|0]:   0xc0e635c   0x2111b6   0x2111e2   0x222732   0x23e90e   0x2128a8
   [06:14:27] [33] [BackTrace|15|0]:   0xc0e635c   0x2111b6   0x2113a0   0x2113da  0xc0daa9c   0x2128a8
   [06:14:27] [33] [BackTrace|16|0]:   0xc0e635c   0x2111b6  0xc0e7b62  0xc0e07e4   0x2128bc
   [06:14:27] [33] [BackTrace|17|0]:   0xc0e635c   0x211bac   0x210d38   0x210d8e  0xc0fd872  0xc0fa42a  0xc0fd4e4  0xc0fe43c
   [06:14:27] [33] [BackTrace|17|1]:   0xc0fe912  0xc0e07e4   0x2128bc
   [06:14:27] [33] [BackTrace|18|0]:   0xc0e635c   0x2111b6  0xc196746  0xc1967b6  0xc134324  0xc1345dc  0xc0e07e4   0x2128bc
   [06:14:27] [33] [BackTrace|20|0]:   0xc0e635c   0x2111b6  0xc196746  0xc1967b6   0x2122fa  0xc108db4  0xc0e07e4   0x2128bc
   [06:14:27] [33] [BackTrace|21|0]:   0xc0e635c   0x2111b6  0xc196746  0xc1967b6  0xc103e1c 0xdeadbeec
   [06:14:27] [33] [BackTrace|23|0]:   0xc0e635c   0x2111b6   0x2111e2  0xc16f02e  0xc16ecee  0xc154a90  0xc16f36a   0x2128a8
   [06:14:27] [33] [BackTrace|24|0]:   0xc0e635c   0x2111b6   0x2111e2  0xc16f02e  0xc16ecee  0xc16f2c2  0xc16f5f0  0xc15494c
   [06:14:27] [33] [BackTrace|24|1]:   0xc16f36a   0x2128a8
   [06:14:27] [33] [BackTrace|25|0]:   0xc0e635c   0x2111b6   0x2111e2  0xc16f02e  0xc15381c  0xc16f36a   0x2128a8
   [06:14:27] [33] [BackTrace|26|0]:   0xc0e635c   0x2111b6   0x2111d6  0xc0e8d9e  0xc0dd790  0xc0dd82c  0xc16fb80  0xc16fbbe
   [06:14:27] [33] [BackTrace|26|1]:   0xc16f36a   0x2128a8
   [06:14:27] [33] [BackTrace|27|0]:   0xc0e635c   0x20f8b6   0x20f68e   0x222b1e  0xc1d4b3c   0x2128a8
   [06:14:27] [33] [BackTrace|28|0]:   0xc0e635c   0x20f8b6   0x20f68e   0x223b04   0x2128a8
   [06:14:27] [33] [BackTrace|29|0]:   0xc0e635c   0x211b6a   0x2121a8   0x212268  0xc0e5080  0xc1d419a   0x2128a8
   [06:14:27] [33] [BackTrace|30|0]:   0xc0e635c   0x211b6a   0x2121a8   0x212268  0xc0e5080  0xc1dd748   0x2128a8
   ```
   


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[GitHub] [incubator-nuttx] anchao commented on pull request #4259: sched/backtrace: add support for printing the arbitrary thread backtrace in runtime

Posted by GitBox <gi...@apache.org>.

anchao commented on pull request #4259:
URL: https://github.com/apache/incubator-nuttx/pull/4259#issuecomment-905479004


   let us close this PR since I have split the commit to other PR, please refer: 
   https://github.com/apache/incubator-nuttx/pull/4409 
   https://github.com/apache/incubator-nuttx/pull/4405


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[GitHub] [incubator-nuttx] anchao closed pull request #4259: sched/backtrace: add support for printing the arbitrary thread backtrace in runtime

Posted by GitBox <gi...@apache.org>.

anchao closed pull request #4259:
URL: https://github.com/apache/incubator-nuttx/pull/4259


   


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[GitHub] [incubator-nuttx] acassis commented on a change in pull request #4259: sched/backtrace: add support for printing the arbitrary thread backtrace in runtime

Posted by GitBox <gi...@apache.org>.

acassis commented on a change in pull request #4259:
URL: https://github.com/apache/incubator-nuttx/pull/4259#discussion_r680886726



##########
File path: arch/arm/src/arm/arm_backtrace.c
##########
@@ -0,0 +1,315 @@
+/****************************************************************************
+ * arch/arm/src/arm/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.
+ *
+ * Input Parameters:
+ *   lr    - Link register address
+ *
+ * Returned Value:
+ *   Link address offset, 0 is returned if the lr is invalid.
+ *
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ *
+ * Description:
+ *  backtrace_internal()  returns the currect link address from input program

Review comment:
       currect => current

##########
File path: arch/arm/src/armv6-m/arm_backtrace.c
##########
@@ -0,0 +1,313 @@
+/****************************************************************************
+ * arch/arm/src/armv6-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.

Review comment:
       currect => current

##########
File path: arch/arm/src/armv7-r/arm_backtrace.c
##########
@@ -0,0 +1,316 @@
+/****************************************************************************
+ * arch/arm/src/armv7-r/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.
+ *
+ * Input Parameters:
+ *   lr    - Link register address
+ *
+ * Returned Value:
+ *   Link address offset, 0 is returned if the lr is invalid.
+ *
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ *
+ * Description:
+ *  backtrace_internal()  returns the currect link address from input program

Review comment:
       ditto

##########
File path: arch/arm/src/armv8-m/arm_backtrace.c
##########
@@ -0,0 +1,313 @@
+/****************************************************************************
+ * arch/arm/src/armv8-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.
+ *
+ * Input Parameters:
+ *   lr    - Link register address
+ *
+ * Returned Value:
+ *   Link address offset, 0 is returned if the lr is invalid.
+ *
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ *
+ * Description:
+ *  backtrace_internal()  returns the currect link address from input program

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-a/arm_backtrace.c
##########
@@ -0,0 +1,315 @@
+/****************************************************************************
+ * arch/arm/src/armv7-a/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-r/arm_backtrace.c
##########
@@ -0,0 +1,316 @@
+/****************************************************************************
+ * arch/arm/src/armv7-r/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-a/arm_backtrace.c
##########
@@ -0,0 +1,315 @@
+/****************************************************************************
+ * arch/arm/src/armv7-a/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.
+ *
+ * Input Parameters:
+ *   lr    - Link register address
+ *
+ * Returned Value:
+ *   Link address offset, 0 is returned if the lr is invalid.
+ *
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ *
+ * Description:
+ *  backtrace_internal()  returns the currect link address from input program

Review comment:
       ditto

##########
File path: arch/arm/src/arm/arm_backtrace.c
##########
@@ -0,0 +1,315 @@
+/****************************************************************************
+ * arch/arm/src/arm/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-m/arm_backtrace.c
##########
@@ -0,0 +1,313 @@
+/****************************************************************************
+ * arch/arm/src/armv7-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.
+ *
+ * Input Parameters:
+ *   lr    - Link register address
+ *
+ * Returned Value:
+ *   Link address offset, 0 is returned if the lr is invalid.
+ *
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ *
+ * Description:
+ *  backtrace_internal()  returns the currect link address from input program

Review comment:
       ditto

##########
File path: arch/arm/src/armv8-m/arm_backtrace.c
##########
@@ -0,0 +1,313 @@
+/****************************************************************************
+ * arch/arm/src/armv8-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-m/arm_backtrace.c
##########
@@ -0,0 +1,313 @@
+/****************************************************************************
+ * arch/arm/src/armv7-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.

Review comment:
       ditto

##########
File path: arch/arm/src/armv6-m/arm_backtrace.c
##########
@@ -0,0 +1,313 @@
+/****************************************************************************
+ * arch/arm/src/armv6-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ *
+ * Description:
+ *  getlroffset()  returns the currect link address offset.
+ *
+ * Input Parameters:
+ *   lr    - Link register address
+ *
+ * Returned Value:
+ *   Link address offset, 0 is returned if the lr is invalid.
+ *
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ *
+ * Description:
+ *  backtrace_internal()  returns the currect link address from input program

Review comment:
       ditto




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[GitHub] [incubator-nuttx] anchao commented on pull request #4259: sched/backtrace: add support for printing the arbitrary thread backtrace in runtime

Posted by GitBox <gi...@apache.org>.

anchao commented on pull request #4259:
URL: https://github.com/apache/incubator-nuttx/pull/4259#issuecomment-890691789


   @acassis please review again, thank you!


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[GitHub] [incubator-nuttx] xiaoxiang781216 commented on pull request #4259: sched/backtrace: add support for printing the arbitrary thread backtrace in runtime

Posted by GitBox <gi...@apache.org>.

xiaoxiang781216 commented on pull request #4259:
URL: https://github.com/apache/incubator-nuttx/pull/4259#issuecomment-894602042


   @acassis could review again?


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[GitHub] [incubator-nuttx] acassis commented on a change in pull request #4259: sched/backtrace: add support for printing the arbitrary thread backtrace in runtime

Posted by GitBox <gi...@apache.org>.

acassis commented on a change in pull request #4259:
URL: https://github.com/apache/incubator-nuttx/pull/4259#discussion_r680093811



##########
File path: arch/arm/src/arm/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/arm/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ ****************************************************************************/

Review comment:
       Please include a complete Description of the function, including params and return

##########
File path: arch/arm/src/arm/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/arm/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ ****************************************************************************/
+
+static FAR void *backtrace_internal(FAR void **psp, FAR void **ppc,
+                                    FAR void *addr)
+{
+  FAR uint8_t *sp = *psp;
+  FAR uint8_t *pc = *ppc;
+  FAR uint8_t *base;
+  FAR uint8_t *lr;
+  uint32_t ins32;
+  uint16_t ins16;
+  int offset;
+  int frame;
+  int i;
+
+  if (*psp >= addr)
+    {
+      return NULL;
+    }
+
+  offset = 1;
+
+  for (i = 2; i < INSTR_LIMIT; i += 2)
+    {
+      ins16 = *(FAR uint16_t *)(pc - i);
+      if (INSTR_IS(ins16, T_PUSH))
+        {
+          frame = __builtin_popcount(ins16 & 0xff) + 1;
+          ins16 = *(FAR uint16_t *)(pc - i - 2);
+          if (INSTR_IS(ins16, T_PUSH_LO))
+            {
+              offset = __builtin_popcount(ins16 & 0xff);
+              frame += offset;
+            }
+
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(pc - i + 2);
+      if (INSTR_IS(ins32, T_STMDB))
+        {
+          frame = __builtin_popcount(ins32 & 0xfff) + 1;
+          break;
+        }
+    }
+
+  if (i >= INSTR_LIMIT)
+    {
+      return NULL;
+    }
+
+  base = pc - i;
+
+  i = 0;
+
+  while (i < INSTR_LIMIT && base + i < pc)
+    {
+      ins16 = *(FAR uint16_t *)(base + i);
+      if (INSTR_IS(ins16, T_SUB_SP_16))
+        {
+          frame += (ins16 & 0x7f);
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(base + i + 2);
+      if (INSTR_IS(ins32, T_SUB_SP_32))
+        {
+          uint32_t shift;
+          uint32_t sub;
+
+          sub    = (ins32 & 0x7f) + 0x80;
+          shift  = (ins32 >> 7) & 0x1;
+          shift += ((ins32 >> 12) & 0x7) << 1;
+          shift += ((ins32 >> 26) & 0x1) << 4;
+
+          frame += sub << (30 - shift);
+          break;
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_16))
+        {
+          frame += (ins32 & 0xff);
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_8))
+        {
+          frame += (ins32 & 0xff) / 2;
+        }
+
+      i += ((ins16 & 0xf800) >= 0xe800) ? 4 : 2;
+    }
+
+  lr = (FAR uint8_t *)*((FAR uint32_t *)sp + frame - offset);
+  if (lr == NULL)
+    {
+      return NULL;
+    }
+
+  offset = getlroffset(lr);
+  if (offset == 0)
+    {
+      return NULL;
+    }
+
+  *psp   = (FAR uint32_t *)sp + frame;
+  *ppc   = lr - offset;
+
+  return *ppc;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_backtrace
+ ****************************************************************************/
+
+int up_backtrace(FAR struct tcb_s *tcb, FAR void **buffer, int size)
+{
+  FAR struct tcb_s *rtcb;
+  irqstate_t flags;
+  FAR void *sp;
+  FAR void *lr;
+  int i;
+
+#ifdef CONFIG_ARM_THUMB
+  if (!tcb || size <= 0 || !buffer)
+#endif
+    {
+      return 0;
+    }
+
+  flags = enter_critical_section();
+
+  i = 0;
+
+  rtcb = this_task();
+
+  if (rtcb == tcb)
+    {
+      lr = (FAR uint8_t *)up_backtrace + 0x10;
+      sp = (FAR void *)arm_getsp();
+
+      buffer[i++] = up_backtrace;
+    }
+  else
+    {
+      lr = (FAR void *)tcb->xcp.regs[REG_LR];
+      sp = (FAR void *)tcb->xcp.regs[REG_SP];
+
+      buffer[i++] = (FAR void *)tcb->xcp.regs[REG_PC];
+    }
+
+  if (size == 1)
+    {
+      leave_critical_section(flags);
+      return size;
+    }
+
+  lr = (FAR uint8_t *)lr - getlroffset(lr);
+
+  if (rtcb != tcb)
+    {
+      buffer[i++] = lr;
+    }
+
+  for (; i < size; i++)
+    {
+      buffer[i] = backtrace_internal(&sp, &lr,
+                  tcb->stack_alloc_ptr + tcb->adj_stack_size);

Review comment:
       Please align this line to start after the "(" from previous line

##########
File path: arch/arm/src/armv7-r/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/armv7-r/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-r/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/armv7-r/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-a/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/armv7-a/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/

Review comment:
       ditto

##########
File path: arch/arm/src/armv6-m/arm_backtrace.c
##########
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * arch/arm/src/armv6-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ ****************************************************************************/
+
+static FAR void *backtrace_internal(FAR void **psp, FAR void **ppc,
+                                    FAR void *addr)
+{
+  FAR uint8_t *sp = *psp;
+  FAR uint8_t *pc = *ppc;
+  FAR uint8_t *base;
+  FAR uint8_t *lr;
+  uint32_t ins32;
+  uint16_t ins16;
+  int offset;
+  int frame;
+  int i;
+
+  if (*psp >= addr)
+    {
+      return NULL;
+    }
+
+  offset = 1;
+
+  for (i = 2; i < INSTR_LIMIT; i += 2)
+    {
+      ins16 = *(FAR uint16_t *)(pc - i);
+      if (INSTR_IS(ins16, T_PUSH))
+        {
+          frame = __builtin_popcount(ins16 & 0xff) + 1;
+          ins16 = *(FAR uint16_t *)(pc - i - 2);
+          if (INSTR_IS(ins16, T_PUSH_LO))
+            {
+              offset = __builtin_popcount(ins16 & 0xff);
+              frame += offset;
+            }
+
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(pc - i + 2);
+      if (INSTR_IS(ins32, T_STMDB))
+        {
+          frame = __builtin_popcount(ins32 & 0xfff) + 1;
+          break;
+        }
+    }
+
+  if (i >= INSTR_LIMIT)
+    {
+      return NULL;
+    }
+
+  base = pc - i;
+
+  i = 0;
+
+  while (i < INSTR_LIMIT && base + i < pc)
+    {
+      ins16 = *(FAR uint16_t *)(base + i);
+      if (INSTR_IS(ins16, T_SUB_SP_16))
+        {
+          frame += (ins16 & 0x7f);
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(base + i + 2);
+      if (INSTR_IS(ins32, T_SUB_SP_32))
+        {
+          uint32_t shift;
+          uint32_t sub;
+
+          sub    = (ins32 & 0x7f) + 0x80;
+          shift  = (ins32 >> 7) & 0x1;
+          shift += ((ins32 >> 12) & 0x7) << 1;
+          shift += ((ins32 >> 26) & 0x1) << 4;
+
+          frame += sub << (30 - shift);
+          break;
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_16))
+        {
+          frame += (ins32 & 0xff);
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_8))
+        {
+          frame += (ins32 & 0xff) / 2;
+        }
+
+      i += ((ins16 & 0xf800) >= 0xe800) ? 4 : 2;
+    }
+
+  lr = (FAR uint8_t *)*((FAR uint32_t *)sp + frame - offset);
+  if (lr == NULL)
+    {
+      return NULL;
+    }
+
+  offset = getlroffset(lr);
+  if (offset == 0)
+    {
+      return NULL;
+    }
+
+  *psp   = (FAR uint32_t *)sp + frame;
+  *ppc   = lr - offset;
+
+  return *ppc;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_backtrace
+ ****************************************************************************/

Review comment:
       ditto

##########
File path: arch/arm/src/armv6-m/arm_backtrace.c
##########
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * arch/arm/src/armv6-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-m/arm_backtrace.c
##########
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * arch/arm/src/armv7-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset

Review comment:
       ditto

##########
File path: arch/arm/src/armv6-m/arm_backtrace.c
##########
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * arch/arm/src/armv6-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ ****************************************************************************/

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-a/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/armv7-a/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal

Review comment:
       ditto

##########
File path: arch/arm/src/arm/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/arm/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ ****************************************************************************/
+
+static FAR void *backtrace_internal(FAR void **psp, FAR void **ppc,
+                                    FAR void *addr)
+{
+  FAR uint8_t *sp = *psp;
+  FAR uint8_t *pc = *ppc;
+  FAR uint8_t *base;
+  FAR uint8_t *lr;
+  uint32_t ins32;
+  uint16_t ins16;
+  int offset;
+  int frame;
+  int i;
+
+  if (*psp >= addr)
+    {
+      return NULL;
+    }
+
+  offset = 1;
+
+  for (i = 2; i < INSTR_LIMIT; i += 2)
+    {
+      ins16 = *(FAR uint16_t *)(pc - i);
+      if (INSTR_IS(ins16, T_PUSH))
+        {
+          frame = __builtin_popcount(ins16 & 0xff) + 1;
+          ins16 = *(FAR uint16_t *)(pc - i - 2);
+          if (INSTR_IS(ins16, T_PUSH_LO))
+            {
+              offset = __builtin_popcount(ins16 & 0xff);
+              frame += offset;
+            }
+
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(pc - i + 2);
+      if (INSTR_IS(ins32, T_STMDB))
+        {
+          frame = __builtin_popcount(ins32 & 0xfff) + 1;
+          break;
+        }
+    }
+
+  if (i >= INSTR_LIMIT)
+    {
+      return NULL;
+    }
+
+  base = pc - i;
+
+  i = 0;
+
+  while (i < INSTR_LIMIT && base + i < pc)
+    {
+      ins16 = *(FAR uint16_t *)(base + i);
+      if (INSTR_IS(ins16, T_SUB_SP_16))
+        {
+          frame += (ins16 & 0x7f);
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(base + i + 2);
+      if (INSTR_IS(ins32, T_SUB_SP_32))
+        {
+          uint32_t shift;
+          uint32_t sub;
+
+          sub    = (ins32 & 0x7f) + 0x80;
+          shift  = (ins32 >> 7) & 0x1;
+          shift += ((ins32 >> 12) & 0x7) << 1;
+          shift += ((ins32 >> 26) & 0x1) << 4;
+
+          frame += sub << (30 - shift);
+          break;
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_16))
+        {
+          frame += (ins32 & 0xff);
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_8))
+        {
+          frame += (ins32 & 0xff) / 2;
+        }
+
+      i += ((ins16 & 0xf800) >= 0xe800) ? 4 : 2;
+    }
+
+  lr = (FAR uint8_t *)*((FAR uint32_t *)sp + frame - offset);
+  if (lr == NULL)
+    {
+      return NULL;
+    }
+
+  offset = getlroffset(lr);
+  if (offset == 0)
+    {
+      return NULL;
+    }
+
+  *psp   = (FAR uint32_t *)sp + frame;
+  *ppc   = lr - offset;
+
+  return *ppc;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_backtrace
+ ****************************************************************************/

Review comment:
       Please include a complete Description of the function, including params and return

##########
File path: arch/arm/src/armv7-m/arm_backtrace.c
##########
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * arch/arm/src/armv7-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ ****************************************************************************/
+
+static FAR void *backtrace_internal(FAR void **psp, FAR void **ppc,
+                                    FAR void *addr)
+{
+  FAR uint8_t *sp = *psp;
+  FAR uint8_t *pc = *ppc;
+  FAR uint8_t *base;
+  FAR uint8_t *lr;
+  uint32_t ins32;
+  uint16_t ins16;
+  int offset;
+  int frame;
+  int i;
+
+  if (*psp >= addr)
+    {
+      return NULL;
+    }
+
+  offset = 1;
+
+  for (i = 2; i < INSTR_LIMIT; i += 2)
+    {
+      ins16 = *(FAR uint16_t *)(pc - i);
+      if (INSTR_IS(ins16, T_PUSH))
+        {
+          frame = __builtin_popcount(ins16 & 0xff) + 1;
+          ins16 = *(FAR uint16_t *)(pc - i - 2);
+          if (INSTR_IS(ins16, T_PUSH_LO))
+            {
+              offset = __builtin_popcount(ins16 & 0xff);
+              frame += offset;
+            }
+
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(pc - i + 2);
+      if (INSTR_IS(ins32, T_STMDB))
+        {
+          frame = __builtin_popcount(ins32 & 0xfff) + 1;
+          break;
+        }
+    }
+
+  if (i >= INSTR_LIMIT)
+    {
+      return NULL;
+    }
+
+  base = pc - i;
+
+  i = 0;
+
+  while (i < INSTR_LIMIT && base + i < pc)
+    {
+      ins16 = *(FAR uint16_t *)(base + i);
+      if (INSTR_IS(ins16, T_SUB_SP_16))
+        {
+          frame += (ins16 & 0x7f);
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(base + i + 2);
+      if (INSTR_IS(ins32, T_SUB_SP_32))
+        {
+          uint32_t shift;
+          uint32_t sub;
+
+          sub    = (ins32 & 0x7f) + 0x80;
+          shift  = (ins32 >> 7) & 0x1;
+          shift += ((ins32 >> 12) & 0x7) << 1;
+          shift += ((ins32 >> 26) & 0x1) << 4;
+
+          frame += sub << (30 - shift);
+          break;
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_16))
+        {
+          frame += (ins32 & 0xff);
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_8))
+        {
+          frame += (ins32 & 0xff) / 2;
+        }
+
+      i += ((ins16 & 0xf800) >= 0xe800) ? 4 : 2;
+    }
+
+  lr = (FAR uint8_t *)*((FAR uint32_t *)sp + frame - offset);
+  if (lr == NULL)
+    {
+      return NULL;
+    }
+
+  offset = getlroffset(lr);
+  if (offset == 0)
+    {
+      return NULL;
+    }
+
+  *psp   = (FAR uint32_t *)sp + frame;
+  *ppc   = lr - offset;
+
+  return *ppc;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_backtrace

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-a/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/armv7-a/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ ****************************************************************************/
+
+static FAR void *backtrace_internal(FAR void **psp, FAR void **ppc,
+                                    FAR void *addr)
+{
+  FAR uint8_t *sp = *psp;
+  FAR uint8_t *pc = *ppc;
+  FAR uint8_t *base;
+  FAR uint8_t *lr;
+  uint32_t ins32;
+  uint16_t ins16;
+  int offset;
+  int frame;
+  int i;
+
+  if (*psp >= addr)
+    {
+      return NULL;
+    }
+
+  offset = 1;
+
+  for (i = 2; i < INSTR_LIMIT; i += 2)
+    {
+      ins16 = *(FAR uint16_t *)(pc - i);
+      if (INSTR_IS(ins16, T_PUSH))
+        {
+          frame = __builtin_popcount(ins16 & 0xff) + 1;
+          ins16 = *(FAR uint16_t *)(pc - i - 2);
+          if (INSTR_IS(ins16, T_PUSH_LO))
+            {
+              offset = __builtin_popcount(ins16 & 0xff);
+              frame += offset;
+            }
+
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(pc - i + 2);
+      if (INSTR_IS(ins32, T_STMDB))
+        {
+          frame = __builtin_popcount(ins32 & 0xfff) + 1;
+          break;
+        }
+    }
+
+  if (i >= INSTR_LIMIT)
+    {
+      return NULL;
+    }
+
+  base = pc - i;
+
+  i = 0;
+
+  while (i < INSTR_LIMIT && base + i < pc)
+    {
+      ins16 = *(FAR uint16_t *)(base + i);
+      if (INSTR_IS(ins16, T_SUB_SP_16))
+        {
+          frame += (ins16 & 0x7f);
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(base + i + 2);
+      if (INSTR_IS(ins32, T_SUB_SP_32))
+        {
+          uint32_t shift;
+          uint32_t sub;
+
+          sub    = (ins32 & 0x7f) + 0x80;
+          shift  = (ins32 >> 7) & 0x1;
+          shift += ((ins32 >> 12) & 0x7) << 1;
+          shift += ((ins32 >> 26) & 0x1) << 4;
+
+          frame += sub << (30 - shift);
+          break;
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_16))
+        {
+          frame += (ins32 & 0xff);
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_8))
+        {
+          frame += (ins32 & 0xff) / 2;
+        }
+
+      i += ((ins16 & 0xf800) >= 0xe800) ? 4 : 2;
+    }
+
+  lr = (FAR uint8_t *)*((FAR uint32_t *)sp + frame - offset);
+  if (lr == NULL)
+    {
+      return NULL;
+    }
+
+  offset = getlroffset(lr);
+  if (offset == 0)
+    {
+      return NULL;
+    }
+
+  *psp   = (FAR uint32_t *)sp + frame;
+  *ppc   = lr - offset;
+
+  return *ppc;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_backtrace

Review comment:
       ditto

##########
File path: arch/arm/src/armv7-m/arm_backtrace.c
##########
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * arch/arm/src/armv7-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal

Review comment:
       ditto

##########
File path: arch/arm/src/armv8-m/arm_backtrace.c
##########
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * arch/arm/src/armv8-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions

Review comment:
       ditto

##########
File path: include/nuttx/arch.h
##########
@@ -493,6 +493,18 @@ void up_exit() noreturn_function;
 
 void up_assert(FAR const char *filename, int linenum);
 
+/****************************************************************************
+ * Name: up_backtrace
+ *
+ * Description:
+ *  Dump thread backtrace from specified tcb
+ *

Review comment:
       please include params info and return

##########
File path: arch/arm/src/armv8-m/arm_backtrace.c
##########
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * arch/arm/src/armv8-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset

Review comment:
       ditto

##########
File path: arch/arm/src/armv8-m/arm_backtrace.c
##########
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * arch/arm/src/armv8-m/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ ****************************************************************************/
+
+static FAR void *backtrace_internal(FAR void **psp, FAR void **ppc,
+                                    FAR void *addr)
+{
+  FAR uint8_t *sp = *psp;
+  FAR uint8_t *pc = *ppc;
+  FAR uint8_t *base;
+  FAR uint8_t *lr;
+  uint32_t ins32;
+  uint16_t ins16;
+  int offset;
+  int frame;
+  int i;
+
+  if (*psp >= addr)
+    {
+      return NULL;
+    }
+
+  offset = 1;
+
+  for (i = 2; i < INSTR_LIMIT; i += 2)
+    {
+      ins16 = *(FAR uint16_t *)(pc - i);
+      if (INSTR_IS(ins16, T_PUSH))
+        {
+          frame = __builtin_popcount(ins16 & 0xff) + 1;
+          ins16 = *(FAR uint16_t *)(pc - i - 2);
+          if (INSTR_IS(ins16, T_PUSH_LO))
+            {
+              offset = __builtin_popcount(ins16 & 0xff);
+              frame += offset;
+            }
+
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(pc - i + 2);
+      if (INSTR_IS(ins32, T_STMDB))
+        {
+          frame = __builtin_popcount(ins32 & 0xfff) + 1;
+          break;
+        }
+    }
+
+  if (i >= INSTR_LIMIT)
+    {
+      return NULL;
+    }
+
+  base = pc - i;
+
+  i = 0;
+
+  while (i < INSTR_LIMIT && base + i < pc)
+    {
+      ins16 = *(FAR uint16_t *)(base + i);
+      if (INSTR_IS(ins16, T_SUB_SP_16))
+        {
+          frame += (ins16 & 0x7f);
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(base + i + 2);
+      if (INSTR_IS(ins32, T_SUB_SP_32))
+        {
+          uint32_t shift;
+          uint32_t sub;
+
+          sub    = (ins32 & 0x7f) + 0x80;
+          shift  = (ins32 >> 7) & 0x1;
+          shift += ((ins32 >> 12) & 0x7) << 1;
+          shift += ((ins32 >> 26) & 0x1) << 4;
+
+          frame += sub << (30 - shift);
+          break;
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_16))
+        {
+          frame += (ins32 & 0xff);
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_8))
+        {
+          frame += (ins32 & 0xff) / 2;
+        }
+
+      i += ((ins16 & 0xf800) >= 0xe800) ? 4 : 2;
+    }
+
+  lr = (FAR uint8_t *)*((FAR uint32_t *)sp + frame - offset);
+  if (lr == NULL)
+    {
+      return NULL;
+    }
+
+  offset = getlroffset(lr);
+  if (offset == 0)
+    {
+      return NULL;
+    }
+
+  *psp   = (FAR uint32_t *)sp + frame;
+  *ppc   = lr - offset;
+
+  return *ppc;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_backtrace

Review comment:
       ditto

##########
File path: arch/arm/src/arm/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/arm/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset

Review comment:
       Please include a complete Description of the function, including params and return

##########
File path: arch/arm/src/armv7-r/arm_backtrace.c
##########
@@ -0,0 +1,268 @@
+/****************************************************************************
+ * arch/arm/src/armv7-r/arm_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"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macro and definitions for simple decoding of instuctions.
+ * To check an instruction, it is ANDed with the IMASK_ and
+ * the result is compared with the IOP_. The macro INSTR_IS
+ * does this and returns !0 to indicate a match.
+ */
+
+#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
+
+#define IMASK_T_STMDB     0xfffff000  /* stmdb sp!,{..lr} */
+#define IOP_T_STMDB       0xe92d4000
+
+#define IMASK_T_PUSH_LO   0xff00      /* push {reglist} (not LR) */
+#define IOP_T_PUSH_LO     0xb400
+
+#define IMASK_T_PUSH      0xff00      /* push {reglist} (inc LR) */
+#define IOP_T_PUSH        0xb500
+
+#define IMASK_T_VPUSH_16  0xffbf8f00  /* vpush d */
+#define IOP_T_VPUSH_16    0xed2d8b00
+
+#define IMASK_T_VPUSH_8   0xffbf8f00  /* vpush s */
+#define IOP_T_VPUSH_8     0xed2d8a00
+
+#define IMASK_T_SUB_SP_16 0xff80      /* sub sp, # */
+#define IOP_T_SUB_SP_16   0xb080
+
+#define IMASK_T_SUB_SP_32 0xfbff8f00  /* sub.w sp, sp, # */
+#define IOP_T_SUB_SP_32   0xf1ad0d00
+
+#define INSTR_LIMIT       0x2000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: getlroffset
+ ****************************************************************************/
+
+static int getlroffset(FAR uint8_t *lr)
+{
+  lr = (FAR uint8_t *)((uintptr_t)lr & 0xfffffffe);
+
+  if (((uintptr_t)lr & 0xffffffe0) == 0xffffffe0)
+    {
+      return 0;
+    }
+
+  return (*(FAR uint16_t *)(lr - 4) & 0xf000) == 0xf000 ? 5 : 3;
+}
+
+/****************************************************************************
+ * Name: backtrace_internal
+ ****************************************************************************/
+
+static FAR void *backtrace_internal(FAR void **psp, FAR void **ppc,
+                                    FAR void *addr)
+{
+  FAR uint8_t *sp = *psp;
+  FAR uint8_t *pc = *ppc;
+  FAR uint8_t *base;
+  FAR uint8_t *lr;
+  uint32_t ins32;
+  uint16_t ins16;
+  int offset;
+  int frame;
+  int i;
+
+  if (*psp >= addr)
+    {
+      return NULL;
+    }
+
+  offset = 1;
+
+  for (i = 2; i < INSTR_LIMIT; i += 2)
+    {
+      ins16 = *(FAR uint16_t *)(pc - i);
+      if (INSTR_IS(ins16, T_PUSH))
+        {
+          frame = __builtin_popcount(ins16 & 0xff) + 1;
+          ins16 = *(FAR uint16_t *)(pc - i - 2);
+          if (INSTR_IS(ins16, T_PUSH_LO))
+            {
+              offset = __builtin_popcount(ins16 & 0xff);
+              frame += offset;
+            }
+
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(pc - i + 2);
+      if (INSTR_IS(ins32, T_STMDB))
+        {
+          frame = __builtin_popcount(ins32 & 0xfff) + 1;
+          break;
+        }
+    }
+
+  if (i >= INSTR_LIMIT)
+    {
+      return NULL;
+    }
+
+  base = pc - i;
+
+  i = 0;
+
+  while (i < INSTR_LIMIT && base + i < pc)
+    {
+      ins16 = *(FAR uint16_t *)(base + i);
+      if (INSTR_IS(ins16, T_SUB_SP_16))
+        {
+          frame += (ins16 & 0x7f);
+          break;
+        }
+
+      ins32  = ins16 << 16;
+      ins32 |= *(FAR uint16_t *)(base + i + 2);
+      if (INSTR_IS(ins32, T_SUB_SP_32))
+        {
+          uint32_t shift;
+          uint32_t sub;
+
+          sub    = (ins32 & 0x7f) + 0x80;
+          shift  = (ins32 >> 7) & 0x1;
+          shift += ((ins32 >> 12) & 0x7) << 1;
+          shift += ((ins32 >> 26) & 0x1) << 4;
+
+          frame += sub << (30 - shift);
+          break;
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_16))
+        {
+          frame += (ins32 & 0xff);
+        }
+      else if (INSTR_IS(ins32, T_VPUSH_8))
+        {
+          frame += (ins32 & 0xff) / 2;
+        }
+
+      i += ((ins16 & 0xf800) >= 0xe800) ? 4 : 2;
+    }
+
+  lr = (FAR uint8_t *)*((FAR uint32_t *)sp + frame - offset);
+  if (lr == NULL)
+    {
+      return NULL;
+    }
+
+  offset = getlroffset(lr);
+  if (offset == 0)
+    {
+      return NULL;
+    }
+
+  *psp   = (FAR uint32_t *)sp + frame;
+  *ppc   = lr - offset;
+
+  return *ppc;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_backtrace

Review comment:
       ditto




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[GitHub] [incubator-nuttx] xiaoxiang781216 commented on pull request #4259: sched/backtrace: add support for printing the arbitrary thread backtrace in runtime

Posted by GitBox <gi...@apache.org>.

xiaoxiang781216 commented on pull request #4259:
URL: https://github.com/apache/incubator-nuttx/pull/4259#issuecomment-889669037


   Look good, please create a new patch to incoperate xtensa bracktrace to the new interface.


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