os: Precise data bus error with updatehub

[mtahirbutt]

Describe the bug
A clear and concise description of what the bug is.

When I run the updatehub app without DNS and without DHCP, it generates error right after probing. In other words, this error is generated after 1-2 minute right now but varies when updatehub lib is a bit played with.

updatehub: Probe metadata received
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: * BUS FAULT *[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: Precise data bus error[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: BFAR Address: 0x6f2e065[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: r0/a1: 0x06f2e065 r1/a2: 0x08039309 r2/a3: 0x00000031[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: r3/a4: 0x06f2e065 r12/ip: 0x20002c0e r14/lr: 0x08027e21[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: xpsr: 0x61000000[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: Faulting instruction address (r15/pc): 0x0802073e[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: Current thread: 0x20004f04 (unknown)[1B][0m
[1B][8D[1B][J[00:04:33.023,000] [1B][1;31m os: Halting system[1B][0m

What have you tried to diagnose or workaround this issue?

I removed the the recent enhancements (probe security, cleaning the code warnings etc.) made to updatehub lib and the app works fine at the moment. It is related to memory leak. So I tried to play around memory allocations in the updatehub lib and finally the code runs well.
Please see my branch
https://github.com/mtahirbutt/zephyr/tree/disco_l475_iot1

To Reproduce
Steps to reproduce the behavior:

1. mkdir build; cd build
2. cmake -DBOARD=disco_l475_iot1
3. make
4. See error

Expected behavior

The updatehub client should successfully download the image for updatehub-CE

Impact
What impact does this issue have on your progress (e.g., annoyance, showstopper)

Right now, I am successful in downloading the image and the framework works fine with older version of updatehub lib with some changings.

Screenshots or console output
If applicable, add a screenshot (drag-and-drop an image), or console logs
(cut-and-paste text and put a code fence (```) before and after, to help
explain the issue.

[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: * BUS FAULT *[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: Precise data bus error[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: BFAR Address: 0x6f2e065[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: r0/a1: 0x06f2e065 r1/a2: 0x08039309 r2/a3: 0x00000031[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: r3/a4: 0x06f2e065 r12/ip: 0x20002c0e r14/lr: 0x08027e21[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: xpsr: 0x61000000[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: Faulting instruction address (r15/pc): 0x0802073e[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0[1B][0m
[1B][8D[1B][J[00:04:32.948,000] [1B][1;31m os: Current thread: 0x20004f04 (unknown)[1B][0m
[1B][8D[1B][J[00:04:33.023,000] [1B][1;31m os: Halting system[1B][0m

Environment (please complete the following information):

• OS: (e.g. Ubuntu 18.04.4 LTS)
• Toolchain (e.g Zephyr 2.2.99 SDK-0.11.2, ...)
• Commit SHA: 3223c43

Additional context
I did not use DHCP and DNS.

[nandojve]

CC @otavio

[carlescufi]

@nandojve or @otavio any chance you can take a look at the branch and logs?
@mtahirbutt if you haven't tried that yet, please enable CONFIG_HW_STACK_PROTECTION and retry, in case it's a stack overflow.

[mtahirbutt]

I also reduced k_malloc (inside probe and install functions) assignments in the most recent updatehub lib code and used array variables, the issue also vanishes. will update but still facing some more issues. i can also try CONFIG_HW_STACK_PROTECTION by the way.

[nandojve]

Hi @carlescufi, we are looking at. I already self assigned myself the issue.
Thank you for reach us.

[nandojve]

@mtahirbutt We need that #25010 fixed to continue testing.

[mtahirbutt]

@nandojve I am experiencing some other error for zephyr master also "SHA256 size not valid etc." during Probe metadata also "could not parse jason etc." to the most recent zephyr so stopped at that and now working with my branch I mentioned. I have to make that work to another network interface. will look into zephyr master later. and as a general remark I am getting good results also with zephyr 2.2.99 regarding mcuboot stuff.

[otavio]

@mtahirbutt we apologize for the delay but we are on a dead-end as this is not reproducible here, so we foresee two possible scenarios:

1. we are missing something
2. your code/settings are different and it causes the side effect

On top of that, we found multiple issues with the ST MCUs and we've been reporting and fixing those issues as we can. Last is #25010 as @nandojve mentioned.

So, the bottom line is, we need to be using very same code/settings and reproduce the issue to be capable of debugging it.

[mtahirbutt]

@otavio thanks for your note. Yes there are still some side effects (retransmissions and in appropriate memory usage or something else) with my branch that I will take care later. right now I want to updatehub work quickly with another interface, will see zephyr master (about probe security and other enhancements made by you) later. Additionally, at first instance, I do not use DHCP and DNS, I am not sure about your setting.