ERROR::INODE-UPROBES(7stap)

💅 error::inode-uprobes — the limitations era 🦋

okay bestie, welcome to the 7stap manual, section error::inode-uprobes. this is the page where we talk about what inode-uprobes cannot do, and ngl it's giving "we're working on it" energy. 🎀

😭 DESCRIPTION 😭

so, the uprobes kernel facility showed up in Linux 3.5 and its whole main character goal was to replace the older out-of-tree utrace patch so we could do user-space probing. slay concept! but the execution? there have been some functional limitations in inode-uprobes that straight-up preclude some systemtap constructs. 💀

and the devs are like "over time, we hope these regressions will be corrected" — which, periodt, we hope too. 🙏

🫶 function.return probes

process.function().return probes need "return-probes" or "uretprobes" functionality, and listen... that was just not implemented in the builtin inode-uprobes until kernel 3.10. not me showing up too early to the function's return party. 🙈

if you can't upgrade your kernel, bestie, here's the workaround: consider using process.statement() probes placed on source line numbers at the function's return statements. it's giving "we do a little improvising" but it works. ✨

💀 function.statement.absolute probes

back in the utrace-equipped kernels era, systemtap let you address probes by literal addresses in the process virtual memory address space. iconic, honestly. but the new inode-uprobes? does not have this capability. rip to that feature, you will be missed. 🕯️

🌈 SEE ALSO 🌈

• stap(1)
• http://kernelnewbies.org/Linux_3.5
• http://sourceware.org/systemtap/wiki/utrace
• error::reporting(7stap)

and that's the whole page, babe!! this was ERROR::INODE-UPROBES(7stap), part of the 7stap manual set — go read the others, they're lowkey iconic too. mwah, stay probing, and don't forget to upgrade your kernel if you can. 💖✨🦋👑