Comments from the Linux kernel source code (edited for readability)
/* here be dragons and swear words */
/* WARNING: This routine is hairy and very complicated, but it must be as fast as possible as it handles the allocation of register windows to the user and kernel. If you touch this code be very careful as many other pieces of the kernel depend upon how this code behaves. You have been duly warned... */
https://github.com/torvalds/linux/blob/v6.18/arch/sparc/kernel/wof.S#L18-L24
/* Queue the unaccepted socket for death */
https://github.com/torvalds/linux/blob/v6.18/net/rose/af_rose.c#L372
/* I'm sure the JFFS2 code has done me permanent damage. I now think the following is normal */
https://github.com/torvalds/linux/blob/v6.18/drivers/mtd/parsers/redboot.c#L218-L220
/*
* "Define 'is'", Bill Clinton
* "Define 'if'", Steven Rostedt
*/
https://github.com/torvalds/linux/blob/v6.17/include/linux/compiler.h#L51-L54
/* This is ALPHA test software. This code may break your machine, randomly fail to work with new releases, misbehave and/or generally screw up. It might even work. */
https://github.com/torvalds/linux/blob/v6.17/net/x25/x25_route.c#L5-L7
/* And we do mean "weirdos" */
https://github.com/torvalds/linux/blob/v6.17/drivers/video/fbdev/macfb.c#L801-L803
/* BLACKLIST !!
*
* First blacklist any products that are egregiously nonconformant
* with the CDC Ethernet specs. Minor braindamage we cope with; when
* they're not even trying, needing a separate driver is only the first
* of the differences to show up.
*/
https://github.com/torvalds/linux/blob/v6.17/drivers/net/usb/cdc_ether.c#L575-L581
/* XXX This isn't really correct. XXX */
https://github.com/torvalds/linux/blob/v6.16/arch/sparc/include/asm/floppy_64.h#L272
/* Yes, Virginia, it had better be unsigned */
https://github.com/torvalds/linux/blob/v6.16/lib/string.c#L42
/* Don't you dare use this function. */
https://github.com/torvalds/linux/blob/v6.16/arch/x86/boot/string.c#L246
/* Guess, what 0x564c is :-) */
https://github.com/torvalds/linux/blob/v6.16/include/uapi/linux/magic.h#L50
/* we want to pad the sucker */
https://elixir.bootlin.com/linux/v6.16.6/source/lib/vsprintf.c#L617
/* Dear gcc, sg->page will be null from kzalloc. */
https://elixir.bootlin.com/linux/v6.16.4/source/net/rds/message.c#L431
/* Register the notifier if/when the first device type is registered, to prevent the link/init ordering from fucking us over. */
https://elixir.bootlin.com/linux/v6.16.3/source/drivers/mtd/mtd_blkdevs.c#L477-L479
/* BEWARE!!! Protocol handlers, mangling input packets, MUST BE last in hash buckets and checking protocol handlers MUST start from promiscuous ptype_all chain in net_bh. It is true now, do not change it. Explanation follows: if protocol handler, mangling packet, will be the first on list, it is not able to sense, that packet is cloned and should be copied-on-write, so that it will change it and subsequent readers will get broken packet. --ANK (980803) */
https://elixir.bootlin.com/linux/v6.16/source/net/core/dev.c#L564-L572
/* this may or may not crash, but who cares. it's a BUG. */
https://elixir.bootlin.com/linux/v6.16/source/fs/ocfs2/dlm/dlmmaster.c#L220-L221
/* only one ? nonsense! */
https://elixir.bootlin.com/linux/v6.16/source/sound/usb/mixer.c#L2755
/* kill the caller! */
https://elixir.bootlin.com/linux/v6.16/source/fs/ocfs2/dlm/dlmmaster.c#L2020
/* Calculate the boot block checksum on an ADFS drive. Note that this will appear to be correct if the sector contains all zeros, so also check that the disk size is non-zero!!! */
https://elixir.bootlin.com/linux/v6.15.6/source/include/linux/adfs_fs.h#L7-L11
/* ummm.. yes.. should really figure out wtf this is and why it's needed some day.. it's almost certainly wrong, but, it also somehow makes things work... */