• Linus Torvalds's avatar
    get rid of legacy 'get_ds()' function · 736706be
    Linus Torvalds authored
    Every in-kernel use of this function defined it to KERNEL_DS (either as
    an actual define, or as an inline function).  It's an entirely
    historical artifact, and long long long ago used to actually read the
    segment selector valueof '%ds' on x86.
    
    Which in the kernel is always KERNEL_DS.
    
    Inspired by a patch from Jann Horn that just did this for a very small
    subset of users (the ones in fs/), along with Al who suggested a script.
    I then just took it to the logical extreme and removed all the remaining
    gunk.
    
    Roughly scripted with
    
       git grep -l '(get_ds())' -- :^tools/ | xargs sed -i 's/(get_ds())/(KERNEL_DS)/'
       git grep -lw 'get_ds' -- :^tools/ | xargs sed -i '/^#define get_ds()/d'
    
    plus manual fixups to remove a few unusual usage patterns, the couple of
    inline function cases and to fix up a comment that had become stale.
    
    The 'get_ds()' function remains in an x86 kvm selftest, since in user
    space it actually does something relevant.
    Inspired-by: default avatarJann Horn <jannh@google.com>
    Inspired-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    736706be
segment.h 777 Bytes