linux/arch
James Morse 7209c86860 arm64: mm: Set PSTATE.PAN from the cpu_enable_pan() call
Commit 338d4f49d6 ("arm64: kernel: Add support for Privileged Access
Never") enabled PAN by enabling the 'SPAN' feature-bit in SCTLR_EL1.
This means the PSTATE.PAN bit won't be set until the next return to the
kernel from userspace. On a preemptible kernel we may schedule work that
accesses userspace on a CPU before it has done this.

Now that cpufeature enable() calls are scheduled via stop_machine(), we
can set PSTATE.PAN from the cpu_enable_pan() call.

Add WARN_ON_ONCE(in_interrupt()) to check the PSTATE value we updated
is not immediately discarded.

Reported-by: Tony Thompson <anthony.thompson@arm.com>
Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
[will: fixed typo in comment]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 09:50:53 +01:00
..
alpha Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-14 18:19:05 -07:00
arc Merge branch 'work.uaccess' into for-linus 2016-10-14 20:42:44 -04:00
arm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-14 18:19:05 -07:00
arm64 arm64: mm: Set PSTATE.PAN from the cpu_enable_pan() call 2016-10-20 09:50:53 +01:00
avr32 Merge branch 'akpm' (patches from Andrew) 2016-10-07 21:38:00 -07:00
blackfin Merge branch 'work.uaccess' into for-linus 2016-10-14 20:42:44 -04:00
c6x nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
cris CRIS changes for 4.9 2016-10-10 11:28:35 -07:00
frv Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
h8300 nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
hexagon nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
ia64 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
m32r nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
m68k Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
metag Metag architecture fixes for v4.9-rc1 2016-10-14 11:11:39 -07:00
microblaze Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
mn10300 Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
nios2 nios2 update for v4.9-rc1 2016-10-10 11:31:19 -07:00
openrisc Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
parisc Merge branch 'parisc-4.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2016-10-11 23:59:07 -07:00
powerpc This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
s390 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
score Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-14 18:19:05 -07:00
sh Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
sparc Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
tile tile: use simpler API for random address requests 2016-10-11 15:06:32 -07:00
um nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
unicore32 unicore32: use simpler API for random address requests 2016-10-11 15:06:32 -07:00
x86 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
xtensa Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
.gitignore
Kconfig This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00