linux-stable.git/arch/arm/include, branch v4.4.136

ARM: 8748/1: mm: Define vdso_start, vdso_end as array

2018-05-30T05:49:06+00:00

[ Upstream commit 73b9160d0dfe44dfdaffd6465dc1224c38a4a73c ]

Define vdso_start, vdso_end as array to avoid compile-time analysis error
for the case of built with CONFIG_FORTIFY_SOURCE.

and, since vdso_start, vdso_end are used in vdso.c only,
move extern-declaration from vdso.h to vdso.c.

If kernel is built with CONFIG_FORTIFY_SOURCE,
compile-time error happens at this code.
- if (memcmp(&vdso_start, "177ELF", 4))

The size of "&vdso_start" is recognized as 1 byte, but n is 4,
So that compile-time error is reported.

Acked-by: Kees Cook 
Signed-off-by: Jinbum Park 
Signed-off-by: Russell King 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARM: 8772/1: kprobes: Prohibit kprobes on get_user functions

2018-05-26T06:48:57+00:00

commit 0d73c3f8e7f6ee2aab1bb350f60c180f5ae21a2c upstream.

Since do_undefinstr() uses get_user to get the undefined
instruction, it can be called before kprobes processes
recursive check. This can cause an infinit recursive
exception.
Prohibit probing on get_user functions.

Fixes: 24ba613c9d6c ("ARM kprobes: core code")
Signed-off-by: Masami Hiramatsu 
Cc: stable@vger.kernel.org
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

futex: Remove duplicated code and fix undefined behaviour

2018-05-26T06:48:50+00:00

commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream.

There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.

Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.

This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.

And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.

Note that s390 removed access_ok check in d12a29703 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).

Signed-off-by: Jiri Slaby 
Signed-off-by: Thomas Gleixner 
Acked-by: Russell King 
Acked-by: Michael Ellerman  (powerpc)
Acked-by: Heiko Carstens  [s390]
Acked-by: Chris Metcalf  [for tile]
Reviewed-by: Darren Hart (VMware) 
Reviewed-by: Will Deacon  [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker 
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt 
Cc: Max Filippov 
Cc: Paul Mackerras 
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn 
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato 
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller 
Cc: "James E.J. Bottomley" 
Cc: Catalin Marinas 
Cc: Matt Turner 
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu 
Cc: Arnd Bergmann 
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson 
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky 
Cc: Stafford Horne 
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson 
Cc: Chris Zankel 
Cc: Michal Simek 
Cc: Tony Luck 
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta 
Cc: Ralf Baechle 
Cc: Richard Kuo 
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky 
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" 
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

xen: avoid type warning in xchg_xen_ulong

2018-04-13T17:50:20+00:00

[ Upstream commit 9cc91f212111cdcbefa02dcdb7dd443f224bf52c ]

The improved type-checking version of container_of() triggers a warning for
xchg_xen_ulong, pointing out that 'xen_ulong_t' is unsigned, but atomic64_t
contains a signed value:

drivers/xen/events/events_2l.c: In function 'evtchn_2l_handle_events':
drivers/xen/events/events_2l.c:187:1020: error: call to '__compiletime_assert_187' declared with attribute error: pointer type mismatch in container_of()

This adds a cast to work around the warning.

Cc: Ian Abbott 
Fixes: 85323a991d40 ("xen: arm: mandate EABI and use generic atomic operations.")
Fixes: daa2ac80834d ("kernel.h: handle pointers to arrays better in container_of()")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Stefano Stabellini 
Reviewed-by: Stefano Stabellini 
Acked-by: Ian Abbott 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARM: Hide finish_arch_post_lock_switch() from modules

2017-12-25T13:22:09+00:00

commit ef0491ea17f8019821c7e9c8e801184ecf17f85a upstream.

The introduction of switch_mm_irqs_off() brought back an old bug
regarding the use of preempt_enable_no_resched:

As part of:

  62b94a08da1b ("sched/preempt: Take away preempt_enable_no_resched() from modules")

the definition of preempt_enable_no_resched() is only available in
built-in code, not in loadable modules, so we can't generally use
it from header files.

However, the ARM version of finish_arch_post_lock_switch()
calls preempt_enable_no_resched() and is defined as a static
inline function in asm/mmu_context.h. This in turn means we cannot
include asm/mmu_context.h from modules.

With today's tip tree, asm/mmu_context.h gets included from
linux/mmu_context.h, which is normally the exact pattern one would
expect, but unfortunately, linux/mmu_context.h can be included from
the vhost driver that is a loadable module, now causing this compile
time error with modular configs:

  In file included from ../include/linux/mmu_context.h:4:0,
                   from ../drivers/vhost/vhost.c:18:
  ../arch/arm/include/asm/mmu_context.h: In function 'finish_arch_post_lock_switch':
  ../arch/arm/include/asm/mmu_context.h:88:3: error: implicit declaration of function 'preempt_enable_no_resched' [-Werror=implicit-function-declaration]
     preempt_enable_no_resched();

Andy already tried to fix the bug by including linux/preempt.h
from asm/mmu_context.h, but that didn't help. Arnd suggested reordering
the header files, which wasn't popular, so let's use this
workaround instead:

The finish_arch_post_lock_switch() definition is now also hidden
inside of #ifdef MODULE, so we don't see anything referencing
preempt_enable_no_resched() from a header file. I've built a
few hundred randconfig kernels with this, and did not see any
new problems.

Tested-by: Guenter Roeck 
Signed-off-by: Steven Rostedt 
Signed-off-by: Arnd Bergmann 
Acked-by: Russell King 
Cc: Alexander Shishkin 
Cc: Andy Lutomirski 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Arnaldo Carvalho de Melo 
Cc: Borislav Petkov 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Mel Gorman 
Cc: Peter Zijlstra 
Cc: Russell King - ARM Linux 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Cc: linux-arm-kernel@lists.infradead.org
Fixes: f98db6013c55 ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler")
Link: http://lkml.kernel.org/r/1463146234-161304-1-git-send-email-arnd@arndb.de
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one

2017-12-16T09:33:57+00:00

commit 5553b142be11e794ebc0805950b2e8313f93d718 upstream.

VTTBR_BADDR_MASK is used to sanity check the size and alignment of the
VTTBR address. It seems to currently be off by one, thereby only
allowing up to 39-bit addresses (instead of 40-bit) and also
insufficiently checking the alignment. This patch fixes it.

This patch is the 32bit pendent of Kristina's arm64 fix, and
she deserves the actual kudos for pinpointing that one.

Fixes: f7ed45be3ba52 ("KVM: ARM: World-switch implementation")
Cc:  # 3.9
Reported-by: Kristina Martsenko 
Reviewed-by: Christoffer Dall 
Signed-off-by: Marc Zyngier 
Signed-off-by: Christoffer Dall 
Signed-off-by: Greg Kroah-Hartman

arm: KVM: Survive unknown traps from guests

2017-12-16T09:33:52+00:00

[ Upstream commit f050fe7a9164945dd1c28be05bf00e8cfb082ccf ]

Currently we BUG() if we see a HSR.EC value we don't recognise. As
configurable disables/enables are added to the architecture (controlled
by RES1/RES0 bits respectively), with associated synchronous exceptions,
it may be possible for a guest to trigger exceptions with classes that
we don't recognise.

While we can't service these exceptions in a manner useful to the guest,
we can avoid bringing down the host. Per ARM DDI 0406C.c, all currently
unallocated HSR EC encodings are reserved, and per ARM DDI
0487A.k_iss10775, page G6-4395, EC values within the range 0x00 - 0x2c
are reserved for future use with synchronous exceptions, and EC values
within the range 0x2d - 0x3f may be used for either synchronous or
asynchronous exceptions.

The patch makes KVM handle any unknown EC by injecting an UNDEFINED
exception into the guest, with a corresponding (ratelimited) warning in
the host dmesg. We could later improve on this with with a new (opt-in)
exit to the host userspace.

Cc: Dave Martin 
Cc: Suzuki K Poulose 
Reviewed-by: Christoffer Dall 
Signed-off-by: Mark Rutland 
Signed-off-by: Marc Zyngier 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARM: BUG if jumping to usermode address in kernel mode

2017-12-16T09:33:50+00:00

commit 8bafae202c82dc257f649ea3c275a0f35ee15113 upstream.

Detect if we are returning to usermode via the normal kernel exit paths
but the saved PSR value indicates that we are in kernel mode.  This
could occur due to corrupted stack state, which has been observed with
"ftracetest".

This ensures that we catch the problem case before we get to user code.

Signed-off-by: Russell King 
Cc: Alex Shi 
Signed-off-by: Greg Kroah-Hartman

ARM: 8715/1: add a private asm/unaligned.h

2017-11-08T09:06:28+00:00

commit 1cce91dfc8f7990ca3aea896bfb148f240b12860 upstream.

The asm-generic/unaligned.h header provides two different implementations
for accessing unaligned variables: the access_ok.h version used when
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set pretends that all pointers
are in fact aligned, while the le_struct.h version convinces gcc that the
alignment of a pointer is '1', to make it issue the correct load/store
instructions depending on the architecture flags.

On ARMv5 and older, we always use the second version, to let the compiler
use byte accesses. On ARMv6 and newer, we currently use the access_ok.h
version, so the compiler can use any instruction including stm/ldm and
ldrd/strd that will cause an alignment trap. This trap can significantly
impact performance when we have to do a lot of fixups and, worse, has
led to crashes in the LZ4 decompressor code that does not have a trap
handler.

This adds an ARM specific version of asm/unaligned.h that uses the
le_struct.h/be_struct.h implementation unconditionally. This should lead
to essentially the same code on ARMv6+ as before, with the exception of
using regular load/store instructions instead of the trapping instructions
multi-register variants.

The crash in the LZ4 decompressor code was probably introduced by the
patch replacing the LZ4 implementation, commit 4e1a33b105dd ("lib: update
LZ4 compressor module"), so linux-4.11 and higher would be affected most.
However, we probably want to have this backported to all older stable
kernels as well, to help with the performance issues.

There are two follow-ups that I think we should also work on, but not
backport to stable kernels, first to change the asm-generic version of
the header to remove the ARM special case, and second to review all
other uses of CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to see if they
might be affected by the same problem on ARM.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

ARM: 8632/1: ftrace: fix syscall name matching

2017-08-11T16:08:58+00:00

[ Upstream commit 270c8cf1cacc69cb8d99dea812f06067a45e4609 ]

ARM has a few system calls (most notably mmap) for which the names of
the functions which are referenced in the syscall table do not match the
names of the syscall tracepoints.  As a consequence of this, these
tracepoints are not made available.  Implement
arch_syscall_match_sym_name to fix this and allow tracing even these
system calls.

Signed-off-by: Rabin Vincent 
Signed-off-by: Russell King 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman