• Ingo Molnar's avatar
    x86/asm/entry: Remove user_mode_ignore_vm86() · 55474c48
    Ingo Molnar authored
    user_mode_ignore_vm86() can be used instead of user_mode(), in
    places where we have already done a v8086_mode() security
    check of ptregs.
    
    But doing this check in the wrong place would be a bug that
    could result in security problems, and also the naming still
    isn't very clear.
    
    Furthermore, it only affects 32-bit kernels, while most
    development happens on 64-bit kernels.
    
    If we replace them with user_mode() checks then the cost is only
    a very minor increase in various slowpaths:
    
       text             data   bss     dec              hex    filename
       10573391         703562 1753042 13029995         c6d26b vmlinux.o.before
       10573423         703562 1753042 13030027         c6d28b vmlinux.o.after
    
    So lets get rid of this distinction once and for all.
    Acked-by: default avatarBorislav Petkov <bp@suse.de>
    Acked-by: default avatarAndy Lutomirski <luto@kernel.org>
    Cc: Andrew Lutomirski <luto@kernel.org>
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Brad Spengler <spender@grsecurity.net>
    Cc: Denys Vlasenko <dvlasenk@redhat.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Link: http://lkml.kernel.org/r/20150329090233.GA1963@gmail.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    55474c48
perf_event.c 50.3 KB