• Ingo Molnar's avatar
    x86/boot: Add CONFIG_PARAVIRT_SPINLOCKS quirk to arch/x86/boot/compressed/misc.h · 927392d7
    Ingo Molnar authored
    Linus reported the following new warning on x86 allmodconfig with GCC 5.1:
    
      > ./arch/x86/include/asm/spinlock.h: In function ‘arch_spin_lock’:
      > ./arch/x86/include/asm/spinlock.h:119:3: warning: implicit declaration
      > of function ‘__ticket_lock_spinning’ [-Wimplicit-function-declaration]
      >    __ticket_lock_spinning(lock, inc.tail);
      >    ^
    
    This warning triggers because of these hacks in misc.h:
    
      /*
       * we have to be careful, because no indirections are allowed here, and
       * paravirt_ops is a kind of one. As it will only run in baremetal anyway,
       * we just keep it from happening
       */
      #undef CONFIG_PARAVIRT
      #undef CONFIG_KASAN
    
    But these hacks were not updated when CONFIG_PARAVIRT_SPINLOCKS was added,
    and eventually (with the introduction of queued paravirt spinlocks in
    recent kernels) this created an invalid Kconfig combination and broke
    the build.
    
    So add a CONFIG_PARAVIRT_SPINLOCKS #undef line as well.
    
    Also remove the _ASM_X86_DESC_H quirk: that undocumented quirk
    was originally added ages ago, in:
    
      099e1377 ("x86: use ELF format in compressed images.")
    
    and I went back to that kernel (and fixed up the main Makefile
    which didn't build anymore) and checked what failure it
    avoided: it avoided an include file dependencies related
    build failure related to our old x86-platforms code.
    
    That old code is long gone, the header dependencies got cleaned
    up, and the build does not fail anymore with the totality of
    asm/desc.h included - so remove the quirk.
    Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
    927392d7
misc.h 2.03 KB