tracepoint_string(9)

✨ tracepoint_string(9) ✨

ok so this is a page from the Kernel API Manual, bestie — yes, the actual kernel docs, and yes we're gonna make it make sense 🫶

💖 NAME 💖

tracepoint_string — register a constant persistent string to the trace system @str — a constant persistent string that will be referenced in tracepoints

🦋 SYNOPSIS 🦋

tracepoint_string (str );

🎀 ARGUMENTS 🎀

• str — okay so the original page literally just says -- undescribed -- here 💀 like bestie the docs said "figure it out." But from the NAME section we know what it is: the constant persistent string that's gonna be referenced in your tracepoints. That's all the page gives us, no cap.

🌸 DESCRIPTION 🌸

okay so picture this 💅 — you're using constant strings in tracepoints, right? Turns out it's faster and more efficient to just save the pointer to the string and reference that with a printf "s", instead of saving the whole string into the ring buffer and wasting space and time. lowkey iconic optimization, honestly.

But highkey there's a problem with that whole approach 😭 — the userspace tools that read the binary output of the trace buffers do not have access to the string. So instead they just show the address of the string, which is... not very useful to users. it's giving cryptic hex nonsense. not the vibe.

Enter tracepoint_string ✨ the string gets registered to the tracing system and exported to userspace via the debugfs/tracing/printk_formats file, which maps the string address to the string text. So now those userspace tools reading the binary buffers have a way to map the pointers back to the ASCII strings they actually represent. slay. the mystery address finally has a name 🔥

important caveat, bestie, don't skip this 🚨 the str used must be a constant string and persistent — it would not make sense to show a string that no longer exists. no dangling ghost strings in this house 🙈

But it's still totally fine to use with modules 💜 because when modules are unloaded, if they had tracepoints, the ring buffers are cleared too. So as long as the string does not change during the life of the module, it is fine to use tracepoint_string within a module. periodt.

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⭐ SEE ALSO ⭐

• Kernel file ./include/linux/tracepoint.h — go read it, iykyk 📖

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okay that's the whole page, bestie, you ate that 🍓💅 — this gem comes from ./include/linux, dated October 2026, and it's your girl tracepoint_string(9) signing off 🧚✨ mwah 💖