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Jiri Kosina 87df26175e x86/mm: Unbreak modules that rely on external PAGE_KERNEL availability
Commit 7744ccdbc1 ("x86/mm: Add Secure Memory Encryption (SME)
support") as a side-effect made PAGE_KERNEL all of a sudden unavailable
to modules which can't make use of EXPORT_SYMBOL_GPL() symbols.

This is because once SME is enabled, sme_me_mask (which is introduced as
EXPORT_SYMBOL_GPL) makes its way to PAGE_KERNEL through _PAGE_ENC,
causing imminent build failure for all the modules which make use of all
the EXPORT-SYMBOL()-exported API (such as vmap(), __vmalloc(),
remap_pfn_range(), ...).

Exporting (as EXPORT_SYMBOL()) interfaces (and having done so for ages)
that take pgprot_t argument, while making it impossible to -- all of a
sudden -- pass PAGE_KERNEL to it, feels rather incosistent.

Restore the original behavior and make it possible to pass PAGE_KERNEL
to all its EXPORT_SYMBOL() consumers.

[ This is all so not wonderful. We shouldn't need that "sme_me_mask"
  access at all in all those places that really don't care about that
  level of detail, and just want _PAGE_KERNEL or whatever.

  We have some similar issues with _PAGE_CACHE_WP and _PAGE_NOCACHE,
  both of which hide a "cachemode2protval()" call, and which also ends
  up using another EXPORT_SYMBOL(), but at least that only triggers for
  the much more rare cases.

  Maybe we could move these dynamic page table bits to be generated much
  deeper down in the VM layer, instead of hiding them in the macros that
  everybody uses.

  So this all would merit some cleanup. But not today.   - Linus ]

Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Despised-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-08 13:52:36 -08:00
..
alpha License cleanup: add SPDX license identifiers to some files 2017-11-02 10:04:46 -07:00
arc License cleanup: add SPDX license identifiers to some files 2017-11-02 10:04:46 -07:00
arm Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-04 14:26:30 -07:00
arm64 Fixes for interrupt controller emulation in ARM/ARM64 and x86, plus a one-liner 2017-11-04 11:44:55 -07:00
blackfin License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
c6x License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
cris License cleanup: add SPDX license identifier to uapi header files with no license 2017-11-02 11:19:54 +01:00
frv License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
h8300 License cleanup: add SPDX license identifier to uapi header files with no license 2017-11-02 11:19:54 +01:00
hexagon License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
ia64 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-05 12:14:50 -08:00
m32r License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
m68k License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
metag License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
microblaze License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
mips MIPS fixes for 4.14 2017-11-04 11:31:02 -07:00
mn10300 License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
nios2 License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
openrisc License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
parisc License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
powerpc powerpc fixes for 4.14 #6 2017-11-03 09:25:53 -07:00
s390 License cleanup: add SPDX license identifiers to some files 2017-11-02 10:04:46 -07:00
score License cleanup: add SPDX license identifier to uapi header files with no license 2017-11-02 11:19:54 +01:00
sh License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
sparc License cleanup: add SPDX license identifier to uapi header files with no license 2017-11-02 11:19:54 +01:00
tile Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2017-11-03 10:36:43 -07:00
um License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
unicore32 License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
x86 x86/mm: Unbreak modules that rely on external PAGE_KERNEL availability 2017-11-08 13:52:36 -08:00
xtensa License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
.gitignore
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00