Commits
Andy Lutomirski committed 71d7244efb0
x86/entry/64: Stop initializing TSS.sp0 at boot commit 20bb83443ea79087b5e5f8dab4e9d80bb9bf7acb upstream. In my quest to get rid of thread_struct::sp0, I want to clean up or remove all of its readers. Two of them are in cpu_init() (32-bit and 64-bit), and they aren't needed. This is because we never enter userspace at all on the threads that CPUs are initialized in. Poison the initial TSS.sp0 and stop initializing it on CPU init. The comment text mostly comes from Dave Hansen. Thanks! Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/ee4a00540ad28c6cff475fbcc7769a4460acc861.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>