eppp_link 1.0.1 with SPI has a task overflow in task ping (IDFGH-16304)

[bensuffolk]

Answers checklist.

• I have read the documentation for esp-protocols components and the issue is not addressed there.
• I have updated my esp-protocols branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

I find that the ping task overflows whenever I try to use the eppp with SPI using TUN mode.

My set up is 2 x esp32s3 connected via SPI. Initially I was using eppp_link 0.1.1 which just used the PPP method I believe and so had no problems.

I am using esp-idf 5.3.1 on one end and 5.3.0 on the other (and both ends have the same issue) and eppp_link 1.0.1

I (21:04:23.096) eppp_spi: EPPP SPI transport attached to EPPP netif pppos_server
I (21:04:23.102) eppp_tun_netif: Checking connection on EPPP interface #0
I (21:04:23.109) eppp_tun_netif: Ping started

***ERROR*** A stack overflow in task ping has been detected.


Backtrace: 0x40376a66:0x3fcc1d50 0x4037c7d5:0x3fcc1d70 0x4037e026:0x3fcc1d90 0x4037f3b7:0x3fcc1e10 0x4037e0ec:0x3fcc1e30 0x4037e0e2:0x00000000 |<-CORRUPTED

I have been able to fix the issue by adding

config.task_stack_size = 3072;

to eppp_check_connection in eppp_netif_tun.c, but that was an arbitrary amount (around 50% higher than the default). I have not done any investigation into how much actual space is required or why its passing the test cases and not in my real usage case.

[david-cermak]

Thanks for reporting, fixing in #872.
I assume you're using some debug logs, otherwise it seems like the default stack size was enough? Increased by 1K if verbosity >= debug.

[bensuffolk]

Thanks, I’m pretty sure my default log level was info, but I did have debug on a few items, but should not have been anything related to the ping task.

[david-cermak]

my default log level was info, but I did have debug on a few items

oh okay, the fix should still work (as the max level should've been debug or lower in that case)

esp-protocols/components/eppp_link/eppp_netif_tun.c

Lines 170 to 172 in cd57f1b

	#if CONFIG_LOG_MAXIMUM_LEVEL > 3
	config.task_stack_size += 1024; // Some additional stack needed for verbose logs
	#endif

[bensuffolk]

Yes all good, the fix works. Thanks