x86/espfix: Document use of _PAGE_GLOBAL
authorDave Hansen <dave.hansen@linux.intel.com>
Fri, 6 Apr 2018 20:55:07 +0000 (13:55 -0700)
committerIngo Molnar <mingo@kernel.org>
Mon, 9 Apr 2018 16:27:33 +0000 (18:27 +0200)
commit6baf4bec02dbc41645c3a5130ee15a8e1d62b80f
tree8ebd462bb7ebff7d7db72e28a0bc8a405f2e1c1c
parent8a57f4849f4fa22ed18a941164a214083fc020a2
x86/espfix: Document use of _PAGE_GLOBAL

The "normal" kernel page table creation mechanisms using
PAGE_KERNEL_* page protections will never set _PAGE_GLOBAL with PTI.
The few places in the kernel that always want _PAGE_GLOBAL must
avoid using PAGE_KERNEL_*.

Document that we want it here and its use is not accidental.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180406205507.BCF4D4F0@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/kernel/espfix_64.c