[PATCH v6 0/6] Improved seccomp logging

This patch set aims to improve logging in seccomp by: 1) Empowering administrators to be able to permit or quiet logging of specific seccomp actions 2) Allowing applications to request logging of all actions, except for RET_ALLOW, in the filter being loaded (subject to the administrator's wishes in #1) 3) By making it possible for application developers to request logging of specific syscalls while developing filters for their application (subject to the administrator's wishes in #1) With this patch set applied, the logic for deciding if an action will be logged is as described in the commit message of the final patch. * Changes since v5: - Rebase onto https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/?h=seccomp... (kees) + Redefine the value of SECCOMP_FILTER_FLAG_LOG to account for the new SECCOMP_FILTER_FLAG_KILL_PROCESS + Add SECCOMP_FILTER_FLAG_KILL_PROCESS to the detect_seccomp_filter_flags selftest - Reorder patches to move SECCOMP_GET_ACTION_AVAIL patch behind actions_avail sysctl patch (kees) - Reorder patches to move the selftest to detect filter flag support before the patch that adds SECCOMP_FILTER_FLAG_LOG (kees) - Add psuedo code showing the high level logic of when and when not to log to the commit message of each patch that changes the logging behavior (inspired by kees) - Add Suggested-by to the SECCOMP_GET_ACTION_AVAIL patch to credit Andy for the idea (tyhicks) - Use sizeof(seccomp_actions_avail), instead of strlen(), to avoid variable length "names" array in seccomp_actions_logged_handler() (smatch) - Only check the actions_logged sysctl value for "kill" when first introducing the actions_logged sysctl since filters cannot yet set the FILTER_FLAG_LOG flag (kees) - Mention how the actions_logged sysctl could quiet SECCOMP_RET_LOG actions in seccomp_filter.rst documentation (kees) Tyler