Revision 510bb96fe5b3480b4b22d815786377e54cb701e7 authored by Thomas Gleixner on 15 April 2019, 08:46:07 UTC, committed by Ingo Molnar on 16 April 2019, 07:42:10 UTC
Xose Vazquez Perez reported boot warnings when NX is disabled on the kernel command line.

__early_set_fixmap() triggers this warning:

  attempted to set unsupported pgprot:    8000000000000163
			       bits:      8000000000000000
			       supported: 7fffffffffffffff

  WARNING: CPU: 0 PID: 0 at arch/x86/include/asm/pgtable.h:537
			    __early_set_fixmap+0xa2/0xff

because it uses __default_kernel_pte_mask to mask out unsupported bits.

Use __supported_pte_mask instead.

Disabling NX on the command line also triggers the NX warning in the page
table mapping check:

  WARNING: CPU: 1 PID: 1 at arch/x86/mm/dump_pagetables.c:262 note_page+0x2ae/0x650
  ....

Make the warning depend on NX set in __supported_pte_mask.

Reported-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Tested-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1904151037530.1729@nanos.tec.linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent 6a03469
Raw File
README
Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
back to top