x86/fpu: Fix double-increment in setup_xstate_features()
I noticed that my MPX tracepoints were producing garbage for the lower and upper bounds: mpx_bounds_register_exception: address referenced: 0x00007fffffffccb7 bounds: lower: 0x0 ~upper: 0xffffffffffffffff mpx_bounds_register_exception: address referenced: 0x00007fffffffccbf bounds: lower: 0x0 ~upper: 0xffffffffffffffff This is, of course, bogus because 0x00007fffffffccbf is *within* the bounds. I assumed that my instruction decoder was bad and went looking at it. But I eventually realized that I was getting a '0' offset back from xstate_offsets[BNDREGS]. It was being skipped in the initialization, which is obviously bogus, so remove the extra leaf++. This also goes an initializes xstate_offsets/sizes[] to -1 so so that bugs like this will oops instead of silently failing in interesting ways. This was introduced by: 39f1acd2 ("x86/fpu/xstate: Don't assume the first zero xfeatures zero bit means the end") Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@sr71.net Link: http://lkml.kernel.org/r/20150611193400.2E0B00DB@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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