This is part of the effort to remove the empty element of the ctl_table structures (used to calculate size) and replace it with an ARRAY_SIZE call. By replacing the child element in struct ctl_table with a flags element we make sure that there are no forward recursions on child nodes and therefore set ourselves up for just using an ARRAY_SIZE. We also added some self tests to make sure that we do not break anything. Patchset is separated in 4: parport fixes, selftests fixes, selftests additions and replacement of child element. Tested everything with sysctl self tests and everything seems "ok". 1. parport fixes: This is related to my previous series and it plugs a sysct table leak in the parport driver. @mcgrof: I'm just leaving this here so we don't have to retest the parport stuff 2. Selftests fixes: Remove the prefixed zeros when passing a awk field to the awk print command because it was causing $0009 to be interpreted as $0. Replaced continue with return in sysctl.sh(test_case) so the test actually gets skipped. The skip decision is now in sysctl.sh(skip_test). 3. Selftest additions: New test to confirm that unregister actually removes targets. New test to confirm that permanently empty targets are indeed created and that no other targets can be created "on top". 4. Replaced the child pointer in struct ctl_table with an enum which is used to differentiate between permanently empty targets and non-empty ones. V2: Replaced the u8 flag with an enumeration. Comments/feedback greatly appreciated Best Joel Joel Granados (8): parport: plug a sysctl register leak test_sysctl: Fix test metadata getters test_sysctl: Group node sysctl test under one func test_sysctl: Add an unregister sysctl test test_sysctl: Add an option to prevent test skip test_sysclt: Test for registering a mount point sysctl: Remove debugging dump_stack sysctl: replace child with an enumeration drivers/parport/procfs.c | 23 ++--- fs/proc/proc_sysctl.c | 82 ++++------------ include/linux/sysctl.h | 14 ++- lib/test_sysctl.c | 91 ++++++++++++++++-- tools/testing/selftests/sysctl/sysctl.sh | 115 +++++++++++++++++------ 5 files changed, 214 insertions(+), 111 deletions(-) -- 2.30.2