update_ftrace_direct_add(9)

🦋 update_ftrace_direct_add(9) 🦋

okay bestie, this page is from the Kernel API Manual, and it's all about that ftrace direct-caller update life. No cap, it's giving kernel-internals main character energy. 💅

🌸 NAME 🌸

update_ftrace_direct_add — updates @ops by adding direct callers provided in @hash. ✨

✨ SYNOPSIS ✨

int update_ftrace_direct_add (struct ftrace_ops *ops , struct ftrace_hash *hash );

🎀 ARGUMENTS 🎀

• ops — the address of the struct ftrace_ops object. 👑
• hash — the address of the struct ftrace_hash object. 🫶

💖 DESCRIPTION 💖

This is the function you use to add custom direct callers (ip -> addr) to ops, specified in hash. The ops will be either registered or updated. That's it, that's the vibe. 🦋

🔥 RETURN 🔥

zero on success. Non zero on error, and that error list includes: -EINVAL — the hash is empty. 😭

🌈 SEE ALSO 🌈

Kernel file ./kernel/trace/ftrace.c — and here's the whole squad, no cap:

• ftrace_lookup_ip(9), ftrace_free_filter(9), ftrace_hash_move(9), ftrace_location_range(9), ftrace_location(9), ftrace_text_reserved(9), ftrace_bug(9)
• ftrace_update_record(9), ftrace_test_record(9), ftrace_get_addr_new(9), ftrace_get_addr_curr(9), ftrace_rec_iter_start(9), ftrace_rec_iter_next(9), ftrace_rec_iter_record(9)
• ftrace_run_stop_machine(9), arch_ftrace_update_code(9), ftrace_startup_subops(9), ftrace_shutdown_subops(9), ftrace_regex_open(9), allocate_ftrace_func_mapper(9)
• ftrace_func_mapper_find_ip(9), ftrace_func_mapper_add_ip(9), ftrace_func_mapper_remove_ip(9), free_ftrace_func_mapper(9), register_ftrace_direct(9), unregister_ftrace_direct(9)
• modify_ftrace_direct_nolock(9), modify_ftrace_direct(9), hash_add(9), hash_sub(9), update_ftrace_direct_del(9), update_ftrace_direct_mod(9)
• ftrace_set_filter_ip(9), ftrace_set_filter_ips(9), ftrace_ops_set_global_filter(9), ftrace_set_filter(9), ftrace_set_notrace(9), ftrace_set_global_filter(9)
• ftrace_set_global_notrace(9), ftrace_ops_get_func(9), ftrace_kill(9), ftrace_is_dead(9), register_ftrace_function(9), unregister_ftrace_function(9), ftrace_lookup_symbols(9)

xoxo 💋 — this page's source/version spot is ./kernel/trace, and it's dated October 2026; it's the Kernel API Manual, bestie. 🎀