syscall_trace_exit is currently doing things back-to-front; invoking
the audit hook *after* signalling the debugger, which presents an
opportunity for the registers to be re-written by userspace in order to
bypass auditing constaints.
This patch fixes the ordering by moving the audit code first and the
tracehook code last. On the face of it, it looks like
current_thread_info()->syscall may be incorrect for the sys_exit
tracepoint, but that's actually not an issue because it will have been
set during syscall entry and cannot have changed since then.
Reported-by: Andrew Gabbasov <Andrew_Gabbasov@mentor.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch keeps disabled the strict alignment CP15 bit for
all armv6 and armv7 processor without the mmu. This behaviour
is now same as in the mmu case.
Signed-off-by: Armando Visconti <armando.visconti@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This is what is done for the regular interrupts in kernel/irqs/proc.c
already, before calling arch_show_interrupts(). Not doing so for the
IPIs causes the column headers not to match with the content whenever
some CPUs are offline.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Use the previously unused TPIDRPRW register to store percpu offsets.
TPIDRPRW is only accessible in PL1, so it can only be used in the kernel.
This replaces 2 loads with a mrc instruction for each percpu variable
access. With hackbench, the performance improvement is 1.4% on Cortex-A9
(highbank). Taking an average of 30 runs of "hackbench -l 1000" yields:
Before: 6.2191
After: 6.1348
Will Deacon reported similar delta on v6 with 11MPCore.
The asm "memory clobber" are needed here to ensure the percpu offset
gets reloaded. Testing by Will found that this would not happen in
__schedule() which is a bit of a special case as preemption is disabled
but the execution can move cores.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If a kernel is configured with a DT containing more /cpu nodes than
nr_cpu_ids, the number of cpus must be capped in the DT parsing
code. Current code carries out the check, but fails to cap the
value and the check is executed after the cpu logical index is used,
which can lead to memory corruption due to index overflow.
This patch refactors the check against nr_cpu_ids and move it before
any computed index is used in the parsing code.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
As soon as the device tree is unflattened the cpu logical to physical
mapping is carried out in setup_arch to build a proper array of MPIDR and
corresponding logical indexes.
The mapping could have been carried out using the flattened DT blob and
related primitives, but since the mapping is not needed by early boot
code it can safely be executed when the device tree has been uncompressed to
its tree data structure.
This patch adds the arm_dt_init_cpu maps() function call in setup_arch().
If the kernel is not compiled with DT support the function is empty and
no logical mapping takes place through it; the mapping carried out in
smp_setup_processor_id() is left unchanged.
If DT is supported the mapping created in smp_setup_processor_id() is overriden.
The DT mapping also sets the possible cpus mask, hence platform
code need not set it again in the respective smp_init_cpus() functions.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
When booting through a device tree, the kernel cpu logical id map can be
initialized using device tree data passed by FW or through an embedded blob.
This patch adds a function that parses device tree "cpu" nodes and
retrieves the corresponding CPUs hardware identifiers (MPIDR).
It sets the possible cpus and the cpu logical map values according to
the number of CPUs defined in the device tree and respective properties.
The device tree HW identifiers are considered valid if all CPU nodes contain
a "reg" property, there are no duplicate "reg" entries and the DT defines a
CPU node whose "reg" property matches the MPIDR[23:0] of the boot CPU.
The primary CPU is assigned cpu logical number 0 to keep the current convention
valid.
Current bindings documentation is included in the patch:
Documentation/devicetree/bindings/arm/cpus.txt
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
This patch applies some basic changes to the smp_setup_processor_id()
ARM implementation to make the code that builds cpu_logical_map more
uniform across the kernel.
The function now prints the full extent of the boot CPU MPIDR[23:0] and
initializes the cpu_logical_map for CPUs up to nr_cpu_ids.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
This patch updates the topology initialization code to use the newly
defined accessors to retrieve the MPIDR affinity levels.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Kernel subsystems other than the topology layer need the MPIDR
mask definitions to access the MPIDR without relying on hardcoded
masks. This patch moves the MPIDR register masks definition to
a header file and defines a macro to simplify access to MPIDR bit fields
representing affinity levels.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Currently, reading /proc/cpuinfo provides userspace with CPU ID of
the CPU carrying out the read from the file. This is fine as long as all
CPUs in the system are the same. With the advent of big.LITTLE and
heterogenous ARM systems this approach provides user space with incorrect
bits of information since CPU ids in the system might differ from the one
provided by the CPU reading the file.
This patch updates the cpuinfo show function so that a read from
/proc/cpuinfo prints HW information for all online CPUs at once, mirroring
x86 behaviour.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
The advent of big.LITTLE ARM platforms requires the kernel to be able
to identify the MIDRs of all online CPUs upon request. MIDRs are stashed
at boot time so that kernel subsystems can detect the MIDR of online CPUs
by simply retrieving per-CPU data updated by all booted CPUs.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
On tracehook-friendly platforms, a system call number of -1 falls
through without running much code or taking much action.
ARM is different. This adds a short-circuit check in the trace path to
avoid any additional work, as suggested by Russell King, to make sure
that ARM behaves the same way as other platforms.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Drewry <wad@chromium.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There is very little difference in the TIF_SECCOMP and TIF_SYSCALL_WORK
path in entry-common.S, so merge TIF_SECCOMP into TIF_SYSCALL_WORK and
move seccomp into the syscall_trace_enter() handler.
Expanded some of the tracehook logic into the callers to make this code
more readable. Since tracehook needs to do register changing, this portion
is best left in its own function instead of copy/pasting into the callers.
Additionally, the return value for secure_computing() is now checked
and a -1 value will result in the system call being skipped.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Drewry <wad@chromium.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add function arch_send_wakeup_ipi_mask(), so that platform code can
use it as an easy way to wake up cores that are in WFI.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
WARN_ONCE is a bit OTT for some of the simple failure cases encountered
in hw_breakpoint, so use either pr_warning or pr_warn_once instead.
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The coprocessor register CRn for accesses to the debug register can be a
different one than C0. Take this into account for the ARM_DBG_READ and
the ARM_DBG_WRITE macro.
The inline assembler calls which used a coprocessor register CRn other
than C0 are replaced by the ARM_DBG_READ or ARM_DBG_WRITE macro.
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Rather than attempt to enable monitor mode explicitly when scheduling in
a breakpoint event (which could raise an undefined exception trap when
accessing DBGDSCRext), instead check that DBGDSCRint.MDBGen is set
during event validation and report an error to the caller if not.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Booting on a v6 core without the CPUID feature registers (e.g. 1136)
leads to a noisy dmesg complaining about their absence.
This patch changes the pr_warning into a pr_warn_once to keep the log
quieter.
Signed-off-by: Will Deacon <will.deacon@arm.com>
v6 cores do not provide a way to clear the debug registers without first
enabling monitor mode, meaning that we could take spurious debug
exceptions. Instead, rely on the registers being in a sane state when we
boot as they are defined to be disabled out of reset anyway.
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The debug register reset sequence for v7 and v7.1 is congruent with
tap-dancing through a minefield.
Rather than wait until we've blown ourselves to pieces, this patch
instead checks the debug_err_mask after each potentially faulting
operation. We also move the enabling of monitor_mode to the end of the
sequence in order to prevent spurious debug events generated by UNKNOWN
register values.
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Detecting whether halting debug is enabled is no longer possible via
the DBGDSCR in v7.1, returning an UNKNOWN value for the HDBGen bit via
CP14 when the OS lock is clear.
This patch removes the halting mode check and ensures that accesses to
the internal and external views of the DBGDSCR are serialised with an
instruction barrier.
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The OS save and restore register are optional in debug architecture v7,
so check the status register before attempting to clear the OS lock.
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Commit 7be2958 (ARM: PMU: Add runtime PM Support) updated the ARM PMU code to
use runtime PM which was prototyped and validated on the OMAP devices. In this
commit, there is no call pm_runtime_enable() and for OMAP devices
pm_runtime_enable() is currently being called from the OMAP PMU code when the
PMU device is created. However, there are two problems with this:
1. For any other ARM device wishing to use runtime PM for PMU they will need
to call pm_runtime_enable() for runtime PM to work.
2. When booting with device-tree and using device-tree to create the PMU
device, pm_runtime_enable() needs to be called from within the ARM PERF
driver as we are no longer calling any device specific code to create the
device. Hence, PMU does not work on OMAP devices that use the runtime PM
callbacks when using device-tree to create the PMU device.
Therefore, call pm_runtime_enable() directly from the ARM PMU driver when
registering the device. For platforms that do not use runtime PM,
pm_runtime_enable() does nothing and for platforms that do use runtime PM but
may not require it specifically for PMU, this will just add a little overhead
when initialising and uninitialising the PMU device.
Tested with PERF on OMAP2420, OMAP3430 and OMAP4460.
Acked-by: Kevin Hilman <khilman@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Perf has three ways to name a PMU: either by passing an explicit char *,
reading arm_pmu->name or accessing arm_pmu->pmu.name.
Just use arm_pmu->name consistently in the ARM backend.
Signed-off-by: Will Deacon <will.deacon@arm.com>
When attempting to reset the PMU state for either a NULL PMU or a PMU
implementation without a reset function, return NOTIFY_DONE from the CPU
notifier as we don't care about the hotplug event.
Signed-off-by: Will Deacon <will.deacon@arm.com>
The current practice of registering the cpu hotplug notifier at PMU
registration time won't be safe with multiple PMUs, as we'll repeatedly
attempt to register the notifier. This has the unfortunate effect of
silently corrupting the notifier list, leading to boot stalling.
Instead, register the notifier at init time. Its sanity checks will
prevent anything bad from happening if the notifier is called before we
have any PMUs registered.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Multi-cluster ARMv7 systems may have CPU PMUs with different number of
counters.
This patch updates armv7_pmnc_counter_valid so that it takes a pmu
argument and checks the counter validity against that. We also remove a
number of redundant counter checks whether the current PMU is not easily
retrievable.
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The arm_pmu functions have wildly varied parameters which can often be
derived from struct perf_event.
This patch changes the arm_pmu function prototypes so that struct
perf_event pointers are passed in preference to fields that can be
derived from the event.
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Supporting multiple, heterogeneous CPU PMUs requires us to allocate the
arm_pmu structures dynamically as the devices are probed.
This patch removes the static structure definitions for each CPU PMU
type and instead passes pointers to the PMU-specific init functions.
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Add minimal guest support to perf, so it can distinguish whether
the PMU interrupt was in the host or the guest, as well as collecting
some very basic information (guest PC, user vs kernel mode).
This is not feature complete though, as it doesn't support backtracing
in the guest.
Based on the x86 implementation, tested with KVM/ARM.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Pull arm fixes from Russell King:
"Not much here again.
The two most notable things here are the sched_clock() fix, which was
causing problems with the scheduling of threaded IRQs after a suspend
event, and the vfp fix, which afaik has only been seen on some older
OMAP boards. Nevertheless, both are fairly important fixes."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: 7569/1: mm: uninitialized warning corrections
ARM: 7567/1: io: avoid GCC's offsettable addressing modes for halfword accesses
ARM: 7566/1: vfp: fix save and restore when running on pre-VFPv3 and CONFIG_VFPv3 set
ARM: 7565/1: sched: stop sched_clock() during suspend
Add the ARM machine identifier to sortextable and select the
config option so that we can sort the exception table at compile
time. sortextable relies on a section named __ex_table existing
in the vmlinux, but ARM's linker script places the exception
table in the data section. Give the exception table its own
section so that sortextable can find it.
This allows us to skip the sorting step during boot.
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
It has been brought to my knowledge that the .setup()/.stop()
function pair in the SMP TWD is going to be called from atomic
contexts for CPUs coming and going, and then the
clk_prepare()/clk_unprepare() calls cannot be called
on subsequent .setup()/.stop() iterations. This is however
just the tip of an iceberg as the function pair is not
designed to be reentrant at all.
This change makes the SMP_TWD clock .setup()/.stop() pair reentrant
by splitting the .setup() function in three parts:
- One COMMON part that is executed the first time the first CPU
in the TWD cluster is initialized. This will fetch the TWD
clk for the cluster and prepare+enable it. If no clk is
available it will calibrate the rate instead.
- One part that is executed the FIRST TIME a certain CPU is
brought on-line. This initializes and sets up the clock event
for a certain CPU.
- One part that is executed on every subsequent .setup() call.
This will re-initialize the clock event. This is augmented
to call the clk_enable()/clk_disable() pair properly.
Cc: Shawn Guo <shawn.guo@linaro.org>
Reported-by: Peter Chen <peter.chen@freescale.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
A minor code refactoring saving a few lines by merging prepare()
and enable() calls.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The scheduler imposes a requirement to sched_clock()
which is to stop the clock during suspend, if we don't
do that any RT thread will be rescheduled in the future
which might cause any sort of problems.
This became an issue on OMAP when we converted omap-i2c.c
to use threaded IRQs, it turned out that depending on how
much time we spent on suspend, the I2C IRQ thread would
end up being rescheduled so far in the future that I2C
transfers would timeout and, because omap_hsmmc depends
on an I2C-connected device to detect if an MMC card is
inserted in the slot, our rootfs would just vanish.
arch/arm/kernel/sched_clock.c already had an optional
implementation (sched_clock_needs_suspend()) which would
handle scheduler's requirement properly, what this patch
does is simply to make that implementation non-optional.
Note that this has the side-effect that printk timings
won't reflect the actual time spent on suspend so other
methods to measure that will have to be used.
This has been tested with beagleboard XM (OMAP3630) and
pandaboard rev A3 (OMAP4430). Suspend to RAM is now working
after this patch.
Thanks to Kevin Hilman for helping out with debugging.
Acked-by: Kevin Hilman <khilman@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull ARM fixes from Russell King:
"A random collection of various fixes, mainly from Arnd and a few other
people. Not thing really stands out here."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: drop experimental status for hotplug and Thumb2
ARM: 7560/1: SMP_TWD: use DIV_ROUND_CLOSEST() for periodic mode
ARM: 7559/1: smp: switch away from the idmap before updating init_mm.mm_count
ARM: 7556/1: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD
ARM: 7555/1: kexec: fix segment memory addresses check
ARM: warnings in arch/arm/include/asm/uaccess.h
ARM: binfmt_flat: unused variable 'persistent'
ARM: be really quiet when building with 'make -s'
ARM: pass -marm to gcc by default for both C and assembler
ARM: Xen: fix initial build problems
ARM: export default read_current_timer
ARM: Fix another build warning in arch/arm/mm/alignment.c
ARM: export set_irq_flags
ARM: kprobes: make more tests conditional
The periodic mode is currently calculated by a simple division
but we should pay more attention to our integer arithmetics.
Also delete a comment that does not make any sense.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When booting a secondary CPU, the primary CPU hands two sets of page
tables via the secondary_data struct:
(1) swapper_pg_dir: a normal, cacheable, shared (if SMP) mapping
of the kernel image (i.e. the tables used by init_mm).
(2) idmap_pgd: an uncached mapping of the .idmap.text ELF
section.
The idmap is generally used when enabling and disabling the MMU, which
includes early CPU boot. In this case, the secondary CPU switches to
swapper as soon as it enters C code:
struct mm_struct *mm = &init_mm;
unsigned int cpu = smp_processor_id();
/*
* All kernel threads share the same mm context; grab a
* reference and switch to it.
*/
atomic_inc(&mm->mm_count);
current->active_mm = mm;
cpumask_set_cpu(cpu, mm_cpumask(mm));
cpu_switch_mm(mm->pgd, mm);
This causes a problem on ARMv7, where the identity mapping is treated as
strongly-ordered leading to architecturally UNPREDICTABLE behaviour of
exclusive accesses, such as those used by atomic_inc.
This patch re-orders the secondary_start_kernel function so that we
switch to swapper before performing any exclusive accesses.
Cc: <stable@vger.kernel.org>
Cc: David McKay <david.mckay@st.com>
Reported-by: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
1. On ARM platform, "nohlt" can be used to prevent core from idle
process, returning immediately.
2. There are two interfaces, exported for other modules, named
"disable_hlt" and "enable_hlt" are used to enable/disable the
cpuidle mechanism by increasing/decreasing "hlt_counter".
Disable_hlt and enable_hlt are paired operation,
when you first call disable_hlt and then enable_hlt, the
semantics are right.
3. There is no obvious constraint to prevent user(driver/module)
code to prevent the case that enable_hlt is ahead of disable_hlt,
which is a fatal operation on kernel state change from user,
and there is no any WARNING or notification if the case happens
in current kernel code.
This patch aims to report BUG when the case happens, just like
what the kernel do when enable_irq is ahead of disable_irq.
Link: https://patchwork.kernel.org/patch/1527881/
Signed-off-by: fwu <fwu@marvell.com>
Signed-off-by: YiLu Mao <ylmao@marvell.com>
Signed-off-by: Ning Jiang <ning.jiang@marvell.com>
Acked-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The PERF_EVENT_IOC_PERIOD ioctl command can be used to change the
sample period of a running perf_event. Consequently, when calculating
the next event period, the new period will only be considered after the
previous one has overflowed.
This patch changes the calculation of the remaining event ticks so that
they are offset if the period has changed.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Andreas Sandberg <andreas.sandberg@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit c564df4db8 (ARM: 7540/1: kexec:
Check segment memory addresses) added a safety check with accidentally
reversed condition, and broke kexec functionality on ARM. Fix this.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
