How to include C backtrace in a kernel module code?

Question

So I am trying to find out what kernel processes are calling some functions in a block driver. I thought including backtrace() in the C library would make it easy. But I am havi

Answer 1

I know this question is about Linux, but since it's the first result for "backtrace kernel", here's a few more solutions:

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DragonFly BSD

It's print_backtrace(int count) from /sys/sys/systm.h. It's implemented in /sys/kern/kern_debug.c and/or /sys/platform/pc64/x86_64/db_trace.c. It can be found by searching for panic, which is implemented in /sys/kern/kern_shutdown.c, and calls print_backtrace(6) if DDB is defined and trace_on_panic is set, which are both defaults.

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FreeBSD

It's kdb_backtrace(void) from /sys/sys/kdb.h. Likewise, it's easy to find by looking into what the panic implementation calls when trace_on_panic is true.

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OpenBSD

Going the panic route, it appears to be db_stack_dump(), implemented in /sys/ddb/db_output.c. The only header mention is /sys/ddb/db_output.h.