COREDUMP_WRITE(9)

✨ COREDUMP_WRITE(9) ✨

okay so bestie, welcome to the coredump_write era of the NetBSD Kernel Developer's Manual 🎀 (yes it's a section 9 page, yes we're reading it, yes we're thriving).

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💖 NAME 💖

coredump_write — the common coredump write routine, aka the little legend that actually puts your crash info onto disk 🫶

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🌸 SYNOPSIS 🌸

#include <sys/signalvar.h>

int
coredump_write(void *iocookie, enum uio_seg segflg, const void *data,
    size_t len);

literally just include the header and call it, iykyk ✨

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🦋 DESCRIPTION 🦋

so coredump_write() is the shared bestie used by both machine-dependent and machine-independent components to write information to a coredump 💅 no cap, both sides use the same routine.

let's break down the args, because we love a signature:

• iocookie — an opaque pointer that was supplied to the caller of coredump_write(). it's giving "don't look at me, i'm just the cookie" 🙈
• segflg — tells you where the data is located: system space or user space. vibe check on the memory region ✨
• data — points to the information to be written to the coredump 🍓
• len — the amount of data to be written. the length. the size. the moment 🔥

and the return? coredump_write() returns 0 on success and an appropriate error code on failure. periodt 💀

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👑 CODE REFERENCES 👑

where does the magic happen? bestie, i got you, here's the map 🗺️

• Process core dumps are initiated within the file sys/kern/kern_sig.c 🌈
• Process core dumps for ELF NetBSD binaries are performed within the files sys/kern/core_elf32.c or sys/kern/core_elf64.c ⭐
• Process core dumps for other NetBSD binaries are performed within the file sys/kern/core_netbsd.c 💜

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🧚 SEE ALSO 🧚

• cpu_coredump(9) — go read that one next, bestie, it's iconic 👑

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and that's the whole page, fr fr 💖 this was Debian, December 24, 2005 — happy holidays to this manpage specifically 🎀✨ slay, and good luck out there with your coredumps 🫶