Add a note about the usage of the identity mapping; we do not support
accesses outside of the identity map region and kernel image while a
CPU is using the identity map. This is because the identity mapping
may overwrite vmalloc space, IO mappings, the vectors pages, etc.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On LPAE, each level 1 (pgd) page table entry maps 1GiB, and the level 2
(pmd) entries map 2MiB.
When the identity mapping is created on LPAE, the pgd pointers are copied
from the swapper_pg_dir. If we find that we need to modify the contents
of a pmd, we allocate a new empty pmd table and insert it into the
appropriate 1GB slot, before then filling it with the identity mapping.
However, if the 1GB slot covers the kernel lowmem mappings, we obliterate
those mappings.
When replacing a PMD, first copy the old PMD contents to the new PMD, so
that we preserve the existing mappings, particularly the mappings of the
kernel itself.
[rewrote commit message and added code comment -- rmk]
Fixes: ae2de10173 ("ARM: LPAE: Add identity mapping support for the 3-level page table format")
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If init_mm.brk is not section aligned, the LPAE fixup code will miss
updating the final PMD. Fix this by aligning map_end.
Fixes: a77e0c7b27 ("ARM: mm: Recreate kernel mappings in early_paging_init()")
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This fixes the following warning:
warning: (ARCH_MULTIPLATFORM && ARCH_INTEGRATOR && ARCH_SHMOBILE_LEGACY) selects ARM_PATCH_PHYS_VIRT which has unmet direct dependencies (!XIP_KERNEL && MMU && (!ARCH_REALVIEW || !SPARSEMEM))
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
commit 431a84b1a4
("ARM: 8034/1: Disable preemption in iwmmxt_task_enable()")
introduced macros {inc,dec}_preempt_count to iwmmxt_task_enable
to make it run with preemption disabled.
Unfortunately, other functions in iwmmxt.S also use concan_{save,dump,load}
sections located in iwmmxt_task_enable() to deal with iWMMXt coprocessor.
This causes an unbalanced preempt_count due to excessive dec_preempt_count
and destroyed return addresses in callers of concan_ labels due to a register
collision:
Linux version 3.16.0-rc3-00062-gd92a333-dirty (jef@armhf) (gcc version 4.8.3 (Debian 4.8.3-4) ) #5 PREEMPT Thu Jul 3 19:46:39 CEST 2014
CPU: ARMv7 Processor [560f5815] revision 5 (ARMv7), cr=10c5387d
CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache
Machine model: SolidRun CuBox
...
PJ4 iWMMXt v2 coprocessor enabled.
...
Unable to handle kernel paging request at virtual address fffffffe
pgd = bb25c000
[fffffffe] *pgd=3bfde821, *pte=00000000, *ppte=00000000
Internal error: Oops: 80000007 [#1] PREEMPT ARM
Modules linked in:
CPU: 0 PID: 62 Comm: startpar Not tainted 3.16.0-rc3-00062-gd92a333-dirty #5
task: bb230b80 ti: bb256000 task.ti: bb256000
PC is at 0xfffffffe
LR is at iwmmxt_task_copy+0x44/0x4c
pc : [<fffffffe>] lr : [<800130ac>] psr: 40000033
sp : bb257de8 ip : 00000013 fp : bb257ea4
r10: bb256000 r9 : fffffdfe r8 : 76e898e6
r7 : bb257ec8 r6 : bb256000 r5 : 7ea12760 r4 : 000000a0
r3 : ffffffff r2 : 00000003 r1 : bb257df8 r0 : 00000000
Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA Thumb Segment user
Control: 10c5387d Table: 3b25c019 DAC: 00000015
Process startpar (pid: 62, stack limit = 0xbb256248)
This patch fixes the issue by moving concan_{save,dump,load} into separate
code sections and make iwmmxt_task_enable() call them in the same way the
other functions use concan_ symbols. The test for valid ownership is moved
to concan_save and is safe for the other user of it, iwmmxt_task_disable().
The register collision is also resolved by moving concan_ symbols as
{inc,dec}_preempt_count are now local to iwmmxt_task_enable().
Fixes: 431a84b1a4 ("ARM: 8034/1: Disable preemption in iwmmxt_task_enable()")
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When setting up the CMA region, we must ensure that the old section
mappings are flushed from the TLB before replacing them with page
tables, otherwise we can suffer from mismatched aliases if the CPU
speculatively prefetches from these mappings at an inopportune time.
A mismatched alias can occur when the TLB contains a section mapping,
but a subsequent prefetch causes it to load a page table mapping,
resulting in the possibility of the TLB containing two matching
mappings for the same virtual address region.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The revision checking in l2c310_enable() was not correct; we were
masking the part number rather than the revision number. Fix this
to use the correct macro.
Fixes: 4374d64933 ("ARM: l2c: add automatic enable of early BRESP")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Conditionally compile kprobes test cases for ARMv5 instructions to avoid
compilation errors with ARMv4 targets like:
/tmp/cc7Tx8ST.s:16740: Error: selected processor does not support ARM mode `clz r0,r0'
Signed-off-by: Jon Medhurst <tixy@linaro.org>
ARM data processing instructions which have a register specified shift
are defined as UNPREDICTABLE if PC is used for any register, not just
the shift value as the code was previous assuming. This issue manifests
on A15 devices as either test case failures or undefined instructions
aborts.
Reported-by: David Long <dave.long@linaro.org>
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Due to a long-standing issue with Thumb symbol lookup [1] the jprobes
tests fail when built into a kernel compiled as Thumb mode. (They work
fine for ARM mode kernels or for Thumb when built as a loadable module.)
Rather than have this problem terminate testing prematurely lets instead
emit an error message and carry on with the main kprobes tests, delaying
the final failure report until the end.
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2011-August/063026.html
Signed-off-by: Jon Medhurst <tixy@linaro.org>
On the syscall tracing path, we call out to secure_computing() to allow
seccomp to check the syscall number being attempted. As part of this, a
SIGTRAP may be sent to the tracer and the syscall could be re-written by
a subsequent SET_SYSCALL ptrace request. Unfortunately, this new syscall
is ignored by the current code unless TIF_SYSCALL_TRACE is also set on
the current thread.
This patch slightly reworks the enter path of the syscall tracing code
so that we always reload the syscall number from
current_thread_info()->syscall after the potential ptrace traps.
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 1c2f87c (ARM: 8025/1: Get rid of meminfo) changed find_limits
to use memblock_get_current_limit for calculating the max_low pfn.
nommu targets never actually set a limit on memblock though which
means memblock_get_current_limit will just return the default
value. Set the memblock_limit to be the end of DDR to make sure
bounds are calculated correctly.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The CFI mapping is now perfect so we can expose the top block, read only.
There isn't much to read, though, just the sharpsl_params values.
Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reverts commit d26b17edaf
ARM: sa1100: collie.c: fall back to jedec_probe flash detection
Unfortunately the detection was challenged on the defective unit used for tests:
one of the NOR chips did not respond to the CFI query.
Moreover that bad device needed extra delays on erase-suspend/resume cycles.
Tested personally on 3 different units and with feedback of two other users.
Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The sync_phys variable has been replaced by link time computation in
mcpm_head.S before the code was submitted upstream.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When a PL310 cache is used on a system that provides hardware
coherency, the outer cache sync operation is useless, and can be
skipped. Moreover, on some systems, it is harmful as it causes
deadlocks between the Marvell coherency mechanism, the Marvell PCIe
controller and the Cortex-A9.
To avoid this, this commit introduces a new Device Tree property
'arm,io-coherent' for the L2 cache controller node, valid only for the
PL310 cache. It identifies the usage of the PL310 cache in an I/O
coherent configuration. Internally, it makes the driver disable the
outer cache sync operation.
Note that technically speaking, a fully coherent system wouldn't
require any of the other .outer_cache operations. However, in
practice, when booting secondary CPUs, these are not yet coherent, and
therefore a set of cache maintenance operations are necessary at this
point. This explains why we keep the other .outer_cache operations and
only ->sync is disabled.
While in theory any write to a PL310 register could cause the
deadlock, in practice, disabling ->sync is sufficient to workaround
the deadlock, since the other cache maintenance operations are only
used in very specific situations.
Contrary to previous versions of this patch, this new version does not
simply NULL-ify the ->sync member, because the l2c_init_data
structures are now 'const' and therefore cannot be modified, which is
a good thing. Therefore, this patch introduces a separate
l2c_init_data instance, called of_l2c310_coherent_data.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull i2c new drivers from Wolfram Sang:
"Here is a pull request from i2c hoping for the "new driver" rule.
Originally, I wanted to send this request during the merge window, but
code checkers with very recent additions complained, so a few fixups
were needed. So, some more time went by and I merged rc1 to get a
stable base"
So the "new driver" rule is really about drivers that people absolutely
need for the kernel to work on new hardware, which is not so much the
case for i2c. So I considered not pulling this, but eventually
relented.
Just for FYI: the whole (and only) point of "new drivers" is not that
new drivers cannot regress things (they can, and they have - by
triggering badly tested code on machines that never triggered that code
before), but because they can bring to life machines that otherwise
wouldn't be useful at all without the drivers.
So the new driver rule is for essential things that actual consumers
would care about, ie devices like networking or disk drivers that matter
to normal people (not server people - they run old kernels anyway, so
mainlining new drivers is irrelevant for them).
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: sun6-p2wi: fix call to snprintf
i2c: rk3x: add NULL entry to the end of_device_id array
i2c: sun6i-p2wi: use proper return value in probe
i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support
i2c: sunxi: add P2WI DT bindings documentation
i2c: rk3x: add driver for Rockchip RK3xxx SoC I2C adapter
Pull file locking fixes from Jeff Layton:
"File locking related bugfixes
Nothing too earth-shattering here. A fix for a potential regression
due to a patch in pile #1, and the addition of a memory barrier to
prevent a race condition between break_deleg and generic_add_lease"
* tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux:
locks: set fl_owner for leases back to current->files
locks: add missing memory barrier in break_deleg
Pull kbuild fixes from Michal Marek:
"There are three fixes for regressions caused by the relative paths
series: deb-pkg, tar-pkg and *docs did not work with O=.
Plus, there is a fix for the linux-headers deb package and a fixed
typo. These are not regression fixes but are safe enough"
* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: fix a typo in a kbuild document
builddeb: fix missing headers in linux-headers package
Documentation: Fix DocBook build with relative $(srctree)
kbuild: Fix tar-pkg with relative $(objtree)
deb-pkg: Fix for relative paths
Pull btrfs fixes from Chris Mason:
"This fixes some lockups in btrfs reported with rc1. It probably has
some performance impact because it is backing off our spinning locks
more often and switching to a blocking lock. I'll be able to nail
that down next week, but for now I want to get the lockups taken care
of.
Otherwise some more stack reduction and assorted fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix wrong error handle when the device is missing or is not writeable
Btrfs: fix deadlock when mounting a degraded fs
Btrfs: use bio_endio_nodec instead of open code
Btrfs: fix NULL pointer crash when running balance and scrub concurrently
btrfs: Skip scrubbing removed chunks to avoid -ENOENT.
Btrfs: fix broken free space cache after the system crashed
Btrfs: make free space cache write out functions more readable
Btrfs: remove unused wait queue in struct extent_buffer
Btrfs: fix deadlocks with trylock on tree nodes
Pull nfsd bugfixes from Bruce Fields:
"Fixes for a new regression from the xdr encoding rewrite, and a
delegation problem we've had for a while (made somewhat more annoying
by the vfs delegation support added in 3.13)"
* 'for-3.16' of git://linux-nfs.org/~bfields/linux:
NFSD: fix bug for readdir of pseudofs
NFSD: Don't hand out delegations for 30 seconds after recalling them.
Pull perf fixes from Ingo Molnar:
"This is larger than usual: the main reason are the ARM symbol lookup
speedups that came in late and were hard to resist.
There's also a kprobes fix and various tooling fixes, plus the minimal
re-enablement of the mmap2 support interface"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
x86/kprobes: Fix build errors and blacklist context_track_user
perf tests: Add test for closing dso objects on EMFILE error
perf tests: Add test for caching dso file descriptors
perf tests: Allow reuse of test_file function
perf tests: Spawn child for each test
perf tools: Add dso__data_* interface descriptons
perf tools: Allow to close dso fd in case of open failure
perf tools: Add file size check and factor dso__data_read_offset
perf tools: Cache dso data file descriptor
perf tools: Add global count of opened dso objects
perf tools: Add global list of opened dso objects
perf tools: Add data_fd into dso object
perf tools: Separate dso data related variables
perf tools: Cache register accesses for unwind processing
perf record: Fix to honor user freq/interval properly
perf timechart: Reflow documentation
perf probe: Improve error messages in --line option
perf probe: Improve an error message of perf probe --vars mode
perf probe: Show error code and description in verbose mode
perf probe: Improve error message for unknown member of data structure
...
Pull rtmutex fixes from Thomas Gleixner:
"Another three patches to make the rtmutex code more robust. That's
the last urgent fallout from the big futex/rtmutex investigation"
* 'locking-urgent-for-linus.patch' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rtmutex: Plug slow unlock race
rtmutex: Detect changes in the pi lock chain
rtmutex: Handle deadlock detection smarter
