Files
OpenCellular/extra/stack_analyzer
Che-yu Wu 816a8d87cd extra/stack_analyzer: Support to remove invalid paths.
Invalid paths (with arbitrary length) can be annotated and removed.
Report set of possible function cycles.
Sort the callsite outputs by filename and line number.

BUG=chromium:648840
BRANCH=none
TEST=extra/stack_analyzer/stack_analyzer_unittest.py
     make BOARD=elm && extra/stack_analyzer/stack_analyzer.py \
         --objdump=arm-none-eabi-objdump \
         --addr2line=arm-none-eabi-addr2line \
         --export_taskinfo=./build/elm/util/export_taskinfo.so \
         --section=RW \
         --annotation=./extra/stack_analyzer/example_annotation.yaml \
         ./build/elm/RW/ec.RW.elf
     make BOARD=elm SECTION=RW \
         ANNOTATION=./extra/stack_analyzer/example_annotation.yaml \
         analyzestack

Change-Id: I9d443df6439b55d5b92a7624bdd93cb6e18494e2
Signed-off-by: Che-yu Wu <cheyuw@google.com>
Reviewed-on: https://chromium-review.googlesource.com/640393
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
2017-09-01 00:44:32 -07:00
..

Stack Size Analysis Tool for EC Firmware

This tool does static analysis on EC firmwares to get the maximum stack usage of each function and task. The maximum stack usage of a function includes the stack used by itself and the functions it calls.

Usage

Make sure the firmware of your target board has been built.

In src/platform/ec, run

make BOARD=${BOARD} SECTION=${SECTION} ANNOTATION=${ANNOTATION} analyzestack

The ${SECTION} can be RO or RW. The ${ANNOTATION} is a optional annotation file, see the example_annotation.yaml.

Output

For each task, it will output the result like below,

Task: PD_C1, Max size: 1156 (932 + 224), Allocated size: 640
Call Trace:
    pd_task (160) [common/usb_pd_protocol.c:1644] 1008a6e8
        -> pd_task[common/usb_pd_protocol.c:1808] 1008ac8a
           - handle_request[common/usb_pd_protocol.c:1191]
             - handle_data_request[common/usb_pd_protocol.c:798]
        -> pd_task[common/usb_pd_protocol.c:2672] 1008c222
        -> [annotation]
    pd_send_request_msg.lto_priv.263 (56) [common/usb_pd_protocol.c:653] 1009a0b4
        -> pd_send_request_msg.lto_priv.263[common/usb_pd_protocol.c:712] 1009a22e0

The pd_task uses 160 bytes on the stack and calls pd_send_request_msg.lto_priv.263.

The callsites to the next function will be shown like below,

-> pd_task[common/usb_pd_protocol.c:1808] 1008ac8a
   - handle_request[common/usb_pd_protocol.c:1191]
     - handle_data_request[common/usb_pd_protocol.c:798]
-> pd_task[common/usb_pd_protocol.c:2672] 1008c222

This means one callsite to the next function is at usb_pd_protocol.c:798, but it is inlined to the current function and you can follow the trace: usb_pd_protocol.c:1808 -> usb_pd_protocol.c:1191 -> usb_pd_protocol.c:798 to find the callsite. The second callsite is at usb_pd_protocol.c:2672. And the third one is added by annotation.

The unresolved indirect callsites have the similar format to the above.

Annotating Indirect Call

To annotate an indirect call like this,

Unresolved indirect callsites:
    pd_transmit
        -> pd_transmit[common/usb_pd_protocol.c:407] 802c9c8
           - tcpm_transmit[driver/tcpm/tcpm.h:142]

It is an indirect call in the tcpm_transmit, which is inlined to the pd_transmit.

You can add a annotation like the below to eliminate it.

add:
  tcpm_transmit[driver/tcpm/tcpm.h:142]:
  - anx74xx_tcpm_transmit

The source tcpm_transmit[driver/tcpm/tcpm.h:142] must be a full signature (function_name[path:line number]). So the resolver can know which indirect call you want to annotate and eliminate (even if it is inlined).