• Dave Hansen's avatar
    x86: Require exact match for 'noxsave' command line option · 888e7ee2
    Dave Hansen authored
    commit 2cd3949f upstream.
    
    We have some very similarly named command-line options:
    
    arch/x86/kernel/cpu/common.c:__setup("noxsave", x86_xsave_setup);
    arch/x86/kernel/cpu/common.c:__setup("noxsaveopt", x86_xsaveopt_setup);
    arch/x86/kernel/cpu/common.c:__setup("noxsaves", x86_xsaves_setup);
    
    __setup() is designed to match options that take arguments, like
    "foo=bar" where you would have:
    
    	__setup("foo", x86_foo_func...);
    
    The problem is that "noxsave" actually _matches_ "noxsaves" in
    the same way that "foo" matches "foo=bar".  If you boot an old
    kernel that does not know about "noxsaves" with "noxsaves" on the
    command line, it will interpret the argument as "noxsave", which
    is not what you want at all.
    
    This makes the "noxsave" handler only return success when it finds
    an *exact* match.
    
    [ tglx: We really need to make __setup() more robust. ]
    Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
    Cc: Dave Hansen <dave@sr71.net>
    Cc: Fenghua Yu <fenghua.yu@intel.com>
    Cc: x86@kernel.org
    Link: http://lkml.kernel.org/r/20141111220133.FE053984@viggo.jf.intel.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
    888e7ee2
common.c 30.2 KB