ARM: Fix ioremap() of address zero

Murali Nalajala reports a regression that ioremapping address zero
results in an oops dump:

Unable to handle kernel paging request at virtual address fa200000
pgd = d4f80000
[fa200000] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0    Tainted: G        W (3.4.0-g3b5f728-00009-g638207a #13)
PC is at msm_pm_config_rst_vector_before_pc+0x8/0x30
LR is at msm_pm_boot_config_before_pc+0x18/0x20
pc : [<c0078f84>]    lr : [<c007903c>]    psr: a0000093
sp : c0837ef0  ip : cfe00000  fp : 0000000d
r10: da7efc17  r9 : 225c4278  r8 : 00000006
r7 : 0003c000  r6 : c085c824  r5 : 00000001  r4 : fa101000
r3 : fa200000  r2 : c095080c  r1 : 002250fc  r0 : 00000000
Flags: NzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM Segment kernel
Control: 10c5387d  Table: 25180059  DAC: 00000015
[<c0078f84>] (msm_pm_config_rst_vector_before_pc+0x8/0x30) from [<c007903c>] (msm_pm_boot_config_before_pc+0x18/0x20)
[<c007903c>] (msm_pm_boot_config_before_pc+0x18/0x20) from [<c007a55c>] (msm_pm_power_collapse+0x410/0xb04)
[<c007a55c>] (msm_pm_power_collapse+0x410/0xb04) from [<c007b17c>] (arch_idle+0x294/0x3e0)
[<c007b17c>] (arch_idle+0x294/0x3e0) from [<c000eed8>] (default_idle+0x18/0x2c)
[<c000eed8>] (default_idle+0x18/0x2c) from [<c000f254>] (cpu_idle+0x90/0xe4)
[<c000f254>] (cpu_idle+0x90/0xe4) from [<c057231c>] (rest_init+0x88/0xa0)
[<c057231c>] (rest_init+0x88/0xa0) from [<c07ff890>] (start_kernel+0x3a8/0x40c)
Code: c0704256 e12fff1e e59f2020 e5923000 (e5930000)

This is caused by the 'reserved' entries which we insert (see
19b52abe3c5d7 - ARM: 7438/1: fill possible PMD empty section gaps)
which get matched for physical address zero.

Resolve this by marking these reserved entries with a different flag.

Cc: <stable@vger.kernel.org>
Tested-by: Murali Nalajala <mnalajal@codeaurora.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7496/1: hw_breakpoint: don't rely on dfsr to show watchpoint access type

From ARM debug architecture v7.1 onwards, a watchpoint exception causes
the DFAR to be updated with the faulting data address. However, DFSR.WnR
takes an UNKNOWN value and therefore cannot be used in general to
determine the access type that triggered the watchpoint.

This patch forbids watchpoints without an overflow handler from
specifying a specific access type (load/store). Those with overflow
handlers must be able to handle false positives potentially triggered by
a watchpoint of a different access type on the same address. For
SIGTRAP-based handlers (i.e. ptrace), this should have no impact.

Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7497/1: hw_breakpoint: allow single-byte watchpoints on all addresses

Breakpoint validation currently fails for single-byte watchpoints on
addresses ending in 11b. There is no reason to forbid such a watchpoint,
so extend the validation code to allow it.

Cc: Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores

When enabling the MMU for ARMv7 CPUs, the decompressor does not touch
the ttbcr register, assuming that it will be zeroed (N == 0, EAE == 0).
Given that only EAE is defined as 0 for non-secure copies of the
register (and a bootloader such as kexec may leave it set to 1 anyway),
we should ensure that we reset the register ourselves before turning on
the MMU.

This patch zeroes TTBCR.EAE and TTBCR.N prior to enabling the MMU for
ARMv7 cores in the decompressor, configuring us exclusively for 32-bit
translation tables via TTBR0.

Cc: <stable@vger.kernel.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7502/1: contextidr: avoid using bfi instruction during notifier

The bfi instruction is not available on ARMv6, so instead use an and/orr
sequence in the contextidr_notifier. This gets rid of the assembler
error:

  Assembler messages:
  Error: selected processor does not support ARM mode `bfi r3,r2,#0,#8'

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7503/1: mm: only flush both pmd entries for classic MMU

LPAE does not use two pmd entries for a pte, so the additional tlb
flushing is not required.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7499/1: mm: Fix vmalloc overlap check for !HIGHMEM

With !HIGHMEM, sanity_check_meminfo checks for banks that completely or
partially overlap the vmalloc region. The test for partial overlap checks
__va(bank->start + bank->size) > vmalloc_min. This is not appropriate if
there is a non-linear translation between virtual and physical addresses,
as bank->start + bank->size is actually in the bank following the one being
interrogated.

In most cases, even when using SPARSEMEM, this is not problematic as the
subsequent bank will start at a higher va than the one in question. However
if the physical to virtual address conversion is not monotonic increasing,
the incorrect test could result in a bank not being truncated when it
should be.

This patch ensures we perform the va-pa conversion on memory from the
bank we are interested in, not the following one.

Reported-by: ??? (Steve) <zhanzhenbo@gmail.com>
Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
NFS: Fix the initialisation of the readdir 'cookieverf' array

When the NFS_COOKIEVERF helper macro was converted into a static
inline function in commit 99fadcd764 (nfs: convert NFS_*(inode)
helpers to static inline), we broke the initialisation of the
readdir cookies, since that depended on doing a memset with an
argument of 'sizeof(NFS_COOKIEVERF(inode))' which therefore
changed from sizeof(be32 cookieverf[2]) to sizeof(be32 *).

At this point, NFS_COOKIEVERF seems to be more of an obfuscation
than a helper, so the best thing would be to just get rid of it.

Also see: https://bugzilla.kernel.org/show_bug.cgi?id=46881

Reported-by: Andi Kleen <andi@firstfloor.org>
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
NFS: Fix a problem with the legacy binary mount code

Apparently, am-utils is still using the legacy binary mountdata interface,
and is having trouble parsing /proc/mounts due to the 'port=' field being
incorrectly set.

The following patch should fix up the regression.

Reported-by: Marius Tolzmann <tolzmann@molgen.mpg.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
NFSv4: Fix range checking in __nfs4_get_acl_uncached and __nfs4_proc_set_acl

Ensure that the user supplied buffer size doesn't cause us to overflow
the 'pages' array.

Also fix up some confusion between the use of PAGE_SIZE and
PAGE_CACHE_SIZE when calculating buffer sizes. We're not using
the page cache for anything here.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFSv4: Fix buffer overflow checking in __nfs4_get_acl_uncached

Pass the checks made by decode_getacl back to __nfs4_get_acl_uncached
so that it knows if the acl has been truncated.

The current overflow checking is broken, resulting in Oopses on
user-triggered nfs4_getfacl calls, and is opaque to the point
where several attempts at fixing it have failed.
This patch tries to clean up the code in addition to fixing the
Oopses by ensuring that the overflow checks are performed in
a single place (decode_getacl). If the overflow check failed,
we will still be able to report the acl length, but at least
we will no longer attempt to cache the acl or copy the
truncated contents to user space.

Reported-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Sachin Prabhu <sprabhu@redhat.com>
NFS: return error from decode_getfh in decode open

If decode_getfh failed, nfs4_xdr_dec_open would return 0 since the last
decode_* call must have succeeded.

Cc: stable@vger.kernel.org
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
SUNRPC: Fix a UDP transport regression

Commit 43cedbf0e8dfb9c5610eb7985d5f21263e313802 (SUNRPC: Ensure that
we grab the XPRT_LOCK before calling xprt_alloc_slot) is causing
hangs in the case of NFS over UDP mounts.

Since neither the UDP or the RDMA transport mechanism use dynamic slot
allocation, we can skip grabbing the socket lock for those transports.
Add a new rpc_xprt_op to allow switching between the TCP and UDP/RDMA
case.

Note that the NFSv4.1 back channel assigns the slot directly
through rpc_run_bc_task, so we can ignore that case.

Reported-by: Dick Streefland <dick.streefland@altium.nl>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>= 3.1]
ARM: 7512/1: Fix XIP build due to PHYS_OFFSET definition moving

During the p2v changes, the PHYS_OFFSET #define moved into a
!__ASSEMBLY__ section. This causes a XIP build to fail with

 arch/arm/kernel/head.o: In function 'stext':
 arch/arm/kernel/head.S:146: undefined reference to 'PHYS_OFFSET'

Momentarily leave the #ifndef __ASSEMBLY__ section so we can
define PHYS_OFFSET for all compilation units.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7513/1: Make sure dtc is built before running it

'make dtbs' in a clean tree will try running the dtc before actually
building it.  Make these rules depend upon the scripts to build it.

Cc: <stable@vger.kernel.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7521/1: Fix semihosting Kconfig text

It seems we were missing some text in the title for the
semihosting DEBUG_LL option. Add in the "/O" and fix up some
minor typos in the help text.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7526/1: traps: send SIGILL if get_user fails on undef handling path

get_user may fail to load from the provided __user address due to an
unhandled fault generated by the access.

In the case of the undefined instruction trap, this results in failure
to load the faulting instruction, in which case we should send SIGILL to
the task rather than continue with potentially uninitialised data.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINS

The {get,put}_user macros don't perform range checking on the provided
__user address when !CPU_HAS_DOMAINS.

This patch reworks the out-of-line assembly accessors to check the user
address against a specified limit, returning -EFAULT if is is out of
range.

[will: changed get_user register allocation to match put_user]
[rmk: fixed building on older ARM architectures]

Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7528/1: uaccess: annotate [__]{get,put}_user functions with might_fault()

The user access functions may generate a fault, resulting in invocation
of a handler that may sleep.

This patch annotates the accessors with might_fault() so that we print a
warning if they are invoked from atomic context and help lockdep keep
track of mmap_sem.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7529/1: delay: set loops_per_jiffy when moving to timer-based loop

The delay functions may be called by some platforms between switching to
the timer-based delay loop but before calibration. In this case, the
initial loops_per_jiffy may not be suitable for the timer (although a
compromise may be achievable) and delay times may be considered too
inaccurate.

This patch updates loops_per_jiffy when switching to the timer-based
delay loop so that delays are consistent prior to calibration.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>