On 01/05/2016 10:35 AM, Borislav Petkov wrote: > On Tue, Dec 22, 2015 at 02:52:38PM -0800, Dave Hansen wrote: >> From: Dave Hansen <[email protected]> >> The x86 early command line parsing in cmdline_find_option_bool() >> is buggy. If it matches a specified 'option' all the way to >> the end of the command-line, it will consider it a match. >> >> For instance, >> >> cmdline = "foo"; >> cmdline_find_option_bool(cmdline, "fool"); >> >> will return 1. This is particularly annoying since we have >> actual FPU options like "noxsave" and "noxsaves" So, >> command-line "foo bar noxsave" will match *BOTH* a "noxsave" and >> "noxsaves". (This turns out not to be an actual problem because >> "noxsave" implies "noxsaves", but it's still confusing.) > > So I booted a guest with this command line: > > [ 0.000000] Kernel command line: root=/dev/sda1 resume=/dev/sdb1 debug > ignore_loglevel log_buf_len=16M earlyprintk=ttyS0,115200 console=ttyS0,115200 > console=tty0 noxsave > > after applying the debug hunk below. However, the only debug output I > got is this: > > [ 0.000000] x86_noxsave_setup > > If I supply "noxsaves", I get, as expected > > [ 0.000000] x86_noxsaves_setup > > only. Ditto for "noxsaveopt". > > So what am I missing?
The current code uses __setup() which uses different parsing than cmdline_find_option_bool(). We're going to have to move the noxsave* ones over to cmdline_find_option_bool() since we need the parsing earlier than __setup() works. The changelog should have been more clear on this, though. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
