Enabling logs in Mbed TLS

RE: Enabling logs in Mbed TLS

Einar Thorsrud — Wed, 11 Dec 2024 09:00:22 GMT

Hi,

Yes, that is right. By default, heap is only included for debug builds, as discussed here (making a debug build will oveflow the flash with logging enabled so you will also need to adjust the parittion layout to allow a larger TF-M flash size).

RE: Enabling logs in Mbed TLS

MarkoSagadin — Mon, 09 Dec 2024 09:35:45 GMT

Hello!

I confirmed on my side that the with applied changes from the linked PR the serial_lte_modem with enabled Mbed TLS logs compiles.

The compile time issued related to the undefined reference to `end' still persists. (I know that wasn't expected from this PR.)

RE: Enabling logs in Mbed TLS

Einar Thorsrud — Tue, 03 Dec 2024 10:00:40 GMT

Hi,

I was mistaken earlier. This is a bug introduced in 2.8 due to a missing include folder. It is fixed in this pull request.

RE: Enabling logs in Mbed TLS

MarkoSagadin — Fri, 29 Nov 2024 10:20:39 GMT

Hello, thank you for your answer!

These configs are not relevant when using the nRF Connect SDK (there the mbed TLS that is used is the one in modules/crypto/mbedtls/).

Can you elaborate why they aren't relevant? I assumed that they are since CONFIG_MBEDTLS_MEMORY_DEBUG, CONFIG_MBEDTLS_DEBUG_C and CONFIG_MBEDTLS_DEBUG_LEVEL are present in the subsys/nrf_security/Kconfig.tls. The CONFIG_MBEDTLS_DEBUG is only present in the Zephyr.

Since someone took care to create KConfig symbols for defines that were present in the Mbed TLS and used them, it seems to me that this worked at some point.

Perhaps a differnt approach could be to modify nrf/subsys/nrf_security/src/zephyr/mbedtls_heap.c slightly to do the monitoring? If you just need to know the maximum heap usage, perhaps you can write a special pattern to mbedtls_heap and check with a debugger (in the same way as one traditionally check maximum stack usage)?

That is a possible strategy. Another one would be to use the monitoring infrastructure that is already in place by defining MEMORY_DEBUG at the top of the file and temporary remove all calls to mbed_printf (since they cause errors durring build).
Then I could inspect the max allocated usage with gdb.

I think that both of this approaches would work. But they are only workarounds for a thing that once did work. It would be nice if the root cause of this would be found and fixed.

RE: Enabling logs in Mbed TLS

Einar Thorsrud — Fri, 29 Nov 2024 09:32:44 GMT

Hi,

These configs are not relevant when using the nRF Connect SDK (there the mbed TLS that is used is the one in modules/crypto/mbedtls/). The heap is implemented in nrf/subsys/nrf_security/src/zephyr/mbedtls_heap.c. Perhaps a differnt approach could be to modify nrf/subsys/nrf_security/src/zephyr/mbedtls_heap.c slightly to do the monitoring? If you just need to know the maximum heap usage, perhaps you can write a special pattern to mbedtls_heap and check with a debugger (in the same way as one traditionally check maximum stack usage)?