[CONTENT WARNING] code gore

YOU HAVE BEEN WARNED!

This is real code, written by real programmers.

>   MUSL signal.h

typedef struct {
#ifdef __SI_SWAP_ERRNO_CODE
    int si_signo, si_code, si_errno;
#else
    int si_signo, si_errno, si_code;
#endif
    union {
        char __pad[128 - 2*sizeof(int) - sizeof(long)];
        struct {
            union {
                struct {
                    pid_t si_pid;
                    uid_t si_uid;
                } __piduid;
                struct {
                    int si_timerid;
                    int si_overrun;
                } __timer;
            } __first;
            union {
                union sigval si_value;
                struct {
                    int si_status;
                    clock_t si_utime, si_stime;
                } __sigchld;
            } __second;
        } __si_common;
        struct {
            void *si_addr;
            short si_addr_lsb;
            union {
                struct {
                    void *si_lower;
                    void *si_upper;
                } __addr_bnd;
                unsigned si_pkey;
            } __first; } __sigfault;
        struct {
            long si_band;
            int si_fd;
        } __sigpoll;
        struct {
            void *si_call_addr;
            int si_syscall;
            unsigned si_arch;
        } __sigsys;
    } __si_fields;
} siginfo_t;

>   Linux Kernel ABI hall of shame

#
# ABI hall of shame
#
config CLONE_BACKWARDS
      Architecture has tls passed as the 4th argument of clone(2),
      not the 5th one.

config CLONE_BACKWARDS2
      Architecture has the first two arguments of clone(2) swapped.

config CLONE_BACKWARDS3
      Architecture has tls passed as the 3rd argument of clone(2),
      not the 5th one.

config ODD_RT_SIGACTION
      Architecture has unusual rt_sigaction(2) arguments

config OLD_SIGSUSPEND
      Architecture has old sigsuspend(2) syscall, of one-argument variety

config OLD_SIGSUSPEND3
      Even weirder antique ABI - three-argument sigsuspend(2)

config OLD_SIGACTION
      Architecture has old sigaction(2) syscall.  Nope, not the same as
      OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2), but
      fairly different variant of sigaction(2), thanks to OSF/1
      compatibility...

>   grep fuck

$ grep -ri "fuck" linux

net/core/skbuff.c:
    Fuck, we are miserable poor guys...

arch/parisc/kernel/sys_parisc.c:
    Fucking broken ABI

lib/vsprintf.c: 
    Wirzenius wrote this portably, Torvalds fucked it up :-)

drivers/net/ethernet/sun/sunhme.c:
    Only Sun can take such nice parts and fuck up the programming interface
    like this.  Good job guys...
    ...
    ...
    This card is _fucking_ hot...

drivers/scsi/qlogicpti.h:
    Am I fucking pedantic or what?

fs/configfs/symlink.c:
     This is really sick.  What they wanted was a hybrid of link(2) and
     symlink(2) - they wanted the target resolved at syscall time (as
     link(2) would've done), be a directory (which link(2) would've
     refused to do) *AND* be a deep fucking magic, making the target
     busy from rmdir POV. symlink(2) is nothing of that sort, and the
     locking it gets matches the normal symlink(2) semantics.  Without
     attempts to resolve the target (which might very well not even
     exist yet) done prior to locking the parent directory.  This
     perversion, OTOH, needs to resolve the target, which would lead to
     obvious deadlocks if attempted with any directories locked.
     
     Unfortunately, that garbage is userland ABI and we should've said
     "no" back in 2005.  Too late now, so we get to play very ugly games
     with locking.
     
     Try *ANYTHING* of that sort in new code, and you will really regret
     it.  Just ask yourself - what could a BOFH do to me and do I want
     to find it out first-hand?
     
     AV, a thoroughly annoyed bastard.

kernel/irq/timings.c:
    The interval type is u64 in order to deal with the same type in our
    computation, that prevent mindfuck issues with overflow, sign and
    division.

drivers/gpu/drm/nouveau/nvkm/subdev/bios/init.c:
    This appears to be the behaviour of the VBIOS parser, and *is*
    important to cache the NV_PEXTDEV_BOOT0 on later chipsets to avoid
    fucking up the memory controller (somehow) by reading it on every
    INIT_RAM_RESTRICT_ZM_GROUP opcode.

drivers/gpu/drm/nouveau/nvkm/subdev/pmu/fuc/macros.fuc:
    #define NV_PPWR_INTR_EN_CLR_MASK /* fuck i hate envyas */ -1

drivers/cpufreq/powernow-k7.c:
    Some Athlon laptops have really fucked PST tables.

drivers/mtd/mtd_blkdevs.c:
    Register the notifier if/when the first device type is
    registered, to prevent the link/init ordering from fucking
    us over. */

include/linux/sysctl.h:
    @rcu: Delays the freeing of the inode. Introduced with
    "unfuck proc_sysctl ->d_compare()"

fs/notify/inotify/inotify_user.c:
    We found an mark in the idr at the right wd, but it's not the mark
    we were told to remove.  eparis seriously fucked up somewhere.
    
arch/m68k/include/asm/sun3ints.h:
    master list of VME vectors -- don't fuck with this

arch/mips/sgi-ip22/ip22-setup.c:
    Init the INDY HPC I/O controller.  Need to call this before fucking
    with the memory controller because it needs to know the boardID and
    whether this is a Guiness or a FullHouse machine.

>   No, this is not a railway system

taken from git log --oneline --graph. Commit messages are redacted.

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