File not found: /sys/kernel/debug/tracing/events/syscalls

From: Naresh Kamboju
Date: Tue Nov 27 2018 - 10:22:17 EST


While debugging the selftests/bpf: get_cgroup_id_user test failure on arm64
where the test is expecting trace file
/sys/kernel/debug/tracing/events/syscalls/sys_enter_nanosleep/id
but this path not enabled after enabling required kernel configuration also.
CONFIG_FTRACE_SYSCALLS=y

strace output:
open(\"/sys/kernel/debug/tracing/events/syscalls/sys_enter_nanosleep/id\",
O_RDONLY) = -1 ENOENT (No such file or directory)

This problem noticed on Linux mainline kernel version 4.20.0-rc3.

Best regards
Naresh Kamboju