ftrace_set_global_filter(9)

📦 version 7.3.1, in nixpkgs unstable

💅 ftrace_set_global_filter — the kernel API manual, bestie edition 🎀

okay so you're reading the Kernel API Manual page for ftrace_set_global_filter(9) and honestly? it's giving "small function, big vibes." let's get into it ✨

✨ NAME ✨

ftrace_set_global_filter — set a function to filter on with global tracers 🦋

like, it's the girl that tells the global tracers which functions they're allowed to look at. periodt.

🌸 SYNOPSIS 🌸

void ftrace_set_global_filter (unsigned char *buf , int len , int reset );

three args, no return value, no drama. she does the thing and leaves 💅

💖 ARGUMENTS 💖

  • buf — the string that holds the function filter text. this is the actual filter content, bestie, the main character of the call ✨
  • len — the length of the string. yes you have to tell her how long buf is, she's not psychic 😭
  • reset — non-zero to reset all filters before applying this filter. so if it's non-zero, everything gets wiped first and then your filter comes through, slay. if it's zero, no reset, we just vibe with what's there 🫶

🔥 DESCRIPTION 🔥

so, filters denote which functions should be enabled when tracing is enabled. that's the whole concept — filters are the vibe check for functions 👑

and here's the iconic part: if buf is NULL and reset is set, all functions will be enabled for tracing. all of them. every single one. not me clearing the whole guest list and letting everyone in 💀

🌈 SEE ALSO 🌈

okay this list is long but we do not skip. every single one of these, in order, no cap 🎀 — and the kernel file they live in is ./kernel/trace/ftrace.c:

like I said. long. but we ate and left no crumbs 🍓

and that's the page!! this little gem lives in ./kernel/trace and it's dated October 2026, footer name ftrace_set_global_filter(9) — mwah, iconic, no notes 💜🧚‍♀️

📦 where this page comes from