Allow filter to be NULL when RESET flag is set, or to commit an already opened filter. Also add a "FUTURE" flag to match modules that have yet to be loaded. Starting in Linux v4.13, module functions can be added to the filter file before the module is loaded (and does not have any matching function). If the FUTURE flag is set, it will write the filter directly, and this only works for globs or direct function names. This patch set is based on top of: https://patchwork.kernel.org/project/linux-trace-devel/list/?series=457711 https://lore.kernel.org/linux-trace-devel/20210330005247.397966909@xxxxxxxxxxx/ Steven Rostedt (VMware) (4): libtracefs: Only allow RESET flag if file is not already opened libtracefs: Allow filter be NULL if RESET flag is set libtracefs: Allow filter to be NULL if module is set in tracefs_function_filter() libtracefs: Add TRACEFS_FL_FUTURE flag for future module filtering ---- Documentation/libtracefs-function-filter.txt | 52 +++++++++++++---- include/tracefs.h | 3 + src/tracefs-tools.c | 83 ++++++++++++++++++++++++---- 3 files changed, 114 insertions(+), 24 deletions(-)