Interesting, when writing to 2 different files, I get the same crashes. Will test with only one task/fd.
> In fact, my last crash report did contain a difference with yours:
> ROOT task was at priority 0
> main was at 1
> task0 was at 30 timeout 3.7ms
> task1 was at 29 timeout 4.9 ms
> Does this mean that both tasks were actually not even inside the critical
> section ?
Yep, and this clearly indicates that there is no issue with mutexes,
semaphores, or whatever. Please try to capture the full trace and post
it to the list. As I said, this kind of topic here is not my home domain...