Implement KVM_{GET,SET}_ONE_REG ioctl based access to the guest CP0
Count and Compare registers. These registers are special in that writing
to them has side effects (adjusting the time until the next timer
interrupt) and reading of Count depends on the time. Therefore add a
couple of callbacks so that different implementations (trap & emulate or
VZ) can implement them differently depending on what the hardware
provides.
The trap & emulate versions mostly duplicate what happens when a T&E
guest reads or writes these registers, so it inherits the same
limitations which can be fixed in later patches.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When MIPS KVM needs to write a TLB entry for the guest it reads the
CP0_Random register, uses it to generate the CP_Index, and writes the
TLB entry using the TLBWI instruction (tlb_write_indexed()).
However there's an instruction for that, TLBWR (tlb_write_random()) so
use that instead.
This happens to also fix an issue with Ingenic XBurst cores where the
same TLB entry is replaced each time preventing forward progress on
stores due to alternating between TLB load misses for the instruction
fetch and TLB store misses.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
MIPS KVM uses mips32_SyncICache to synchronise the icache with the
dcache after dynamically modifying guest instructions or writing guest
exception vector. However this uses rdhwr to get the SYNCI step, which
causes a reserved instruction exception on Ingenic XBurst cores.
It would seem to make more sense to use local_flush_icache_range()
instead which does the same thing but is more portable.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Each MIPS KVM guest has its own copy of the KVM exception vector. This
contains the TLB refill exception handler at offset 0x000, the general
exception handler at offset 0x180, and interrupt exception handlers at
offset 0x200 in case Cause_IV=1. A common handler is copied to offset
0x2000 and offset 0x3000 is used for temporarily storing k1 during entry
from guest.
However the amount of memory allocated for this purpose is calculated as
0x200 rounded up to the next page boundary, which is insufficient if 4KB
pages are in use. This can lead to the common handler at offset 0x2000
being overwritten and infinitely recursive exceptions on the next exit
from the guest.
Increase the minimum size from 0x200 to 0x4000 to cover the full use of
the page.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1. Several minor fixes and cleanups for KVM:
2. Fix flag check for gdb support
3. Remove unnecessary vcpu start
4. Remove code duplication for sigp interrupts
5. Better DAT handling for the TPROT instruction
6. Correct addressing exception for standby memory
ASUS A8JN with AD1986A codec seems following the normal EAPD in the
normal order (0 = off, 1 = on) unlike other machines with AD1986A.
Apply the workaround used for Toshiba laptop that showed the same
problem.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=75041
Cc: <stable@vger.kernel.org> [3.11+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Sometimes it's useful to let the user, while doing performance research,
know what in the IEEE754 exceptions has caused many times of FP emulation
when running a specific application. This patch adds 5 more files to
/sys/kernel/debug/mips/fpuemustats/, whose filenames begin with "ieee754".
These stats are in addition to the existing cp1ops, cp1xops, errors, loads
and stores, which may not be useful in understanding the reasons of ieee754
exceptions.
[ralf@linux-mips.org: Fixed reject due to other changes to the kernel
FP assist software.]
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven.Hill@imgtec.com
Cc: james.hogan@imgtec.com
Patchwork: http://patchwork.linux-mips.org/patch/7044/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Checks for CONFIG_SND_DEBUG_ROM were added in v2.5.5 but a Kconfig
symbol SND_DEBUG_ROM was never added. These checks have always
evaluated to false. Remove them and the printk()s they hide.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Checks for CONFIG_BCM_CS4297A_CSWARM were added in v2.6.11. The related
Kconfig symbol was never added so these checks always evaluated to true.
Remove them.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Commit 294d1351ff
"pinctrl: sirf: switch to using allocated state container"
caused a build conflict due to a bad conflict resolution
when cherry-picking the patch. Fix it up.
Cc: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Based on original patch from Jeng-fang (Nick) Wang
When standby memory is specified for a guest Linux, but no virtual memory has
been allocated on the Qemu host backing that guest, the guest memory detection
process encounters a memory access exception which is not thrown from the KVM
handle_tprot() instruction-handler function. The access exception comes from
sie64a returning EFAULT, which then passes an addressing exception to the guest.
Unfortunately this does not the proper PSW fixup (nullifying vs.
suppressing) so the guest will get a fault for the wrong address.
Let's just intercept the tprot instruction all the time to do the right thing
and not go the page fault handler path for standby memory. tprot is only used
by Linux during startup so some exits should be ok.
Without this patch, standby memory cannot be used with KVM.
Signed-off-by: Nick Wang <jfwang@us.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch removes the start of a VCPU when delivering a RESTART interrupt.
Interrupt delivery is called from kvm_arch_vcpu_ioctl_run. So the VCPU is
already considered started - no need to call kvm_s390_vcpu_start. This function
will early exit anyway.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch fixes a minor bug when updating the guest debug settings.
We should check the given debug flags, not the already set ones.
Doesn't do any harm but too many (for now unused) flags could be set internally
without error.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
We have all the logic to inject interrupts available in
kvm_s390_inject_vcpu(), so let's use it instead of
injecting irqs manually to the list in sigp code.
SIGP stop is special because we have to check the
action_flags before injecting the interrupt. As
the action_flags are not available in kvm_s390_inject_vcpu()
we leave the code for the stop order code untouched for now.
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
The TPROT instruction can be used to check the accessability of storage
for any kind of logical addresses. So far, our handler only supported
real addresses. This patch now also enables support for addresses that
have to be translated via DAT first. And while we're at it, change the
code to use the common KVM function gfn_to_hva_prot() to check for the
validity and writability of the memory page.
Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This patch adds a function for translating logical guest addresses into
physical guest addresses without touching the memory at the given location.
Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
The i386 ABI disagrees with most other ABIs regarding alignment of
data types larger than 4 bytes: on most ABIs a padding must be added
at end of the structures, while it is not required on i386.
So for most ABI struct c4iw_create_cq_resp gets implicitly padded
to be aligned on a 8 bytes multiple, while for i386, such padding
is not added.
The tool pahole can be used to find such implicit padding:
$ pahole --anon_include \
--nested_anon_include \
--recursive \
--class_name c4iw_create_cq_resp \
drivers/infiniband/hw/cxgb4/iw_cxgb4.o
Then, structure layout can be compared between i386 and x86_64:
+++ obj-i386/drivers/infiniband/hw/cxgb4/iw_cxgb4.o.pahole.txt 2014-03-28 11:43:05.547432195 +0100
--- obj-x86_64/drivers/infiniband/hw/cxgb4/iw_cxgb4.o.pahole.txt 2014-03-28 10:55:10.990133017 +0100
@@ -14,9 +13,8 @@ struct c4iw_create_cq_resp {
__u32 size; /* 28 4 */
__u32 qid_mask; /* 32 4 */
- /* size: 36, cachelines: 1, members: 6 */
- /* last cacheline: 36 bytes */
+ /* size: 40, cachelines: 1, members: 6 */
+ /* padding: 4 */
+ /* last cacheline: 40 bytes */
};
This ABI disagreement will make an x86_64 kernel try to write past the
buffer provided by an i386 binary.
When boundary check will be implemented, the x86_64 kernel will refuse
to write past the i386 userspace provided buffer and the uverbs will
fail.
If the structure is on a page boundary and the next page is not
mapped, ib_copy_to_udata() will fail and the uverb will fail.
This patch adds an explicit padding at end of structure
c4iw_create_cq_resp, and, like 92b0ca7cb1 ("IB/mlx5: Fix stack info
leak in mlx5_ib_alloc_ucontext()"), makes function c4iw_create_cq()
not writting this padding field to userspace. This way, x86_64 kernel
will be able to write struct c4iw_create_cq_resp as expected by
unpatched and patched i386 libcxgb4.
Link: http://marc.info/?i=cover.1399309513.git.ydroneaud@opteya.com
Cc: <stable@vger.kernel.org>
Fixes: cfdda9d764 ("RDMA/cxgb4: Add driver for Chelsio T4 RNIC")
Fixes: e24a72a330 ("RDMA/cxgb4: Fix four byte info leak in c4iw_create_cq()")
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
SRP defines pr_fmt(fmt) to be "PFX fmt", and then includes a bunch of
header files before it gets around to defining PFX. This causes
problems if any of the header files do a pr_... and use pr_fmt().
Fix this by using KBUILD_MODNAME instead of the private PFX.
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Avoid leaking a kref count in ib_umad_open() if port->ib_dev == NULL
or if nonseekable_open() fails.
Avoid leaking a kref count, that sm_sem is kept down and also that the
IB_PORT_SM capability mask is not cleared in ib_umad_sm_open() if
nonseekable_open() fails.
Since container_of() never returns NULL, remove the code that tests
whether container_of() returns NULL.
Moving the kref_get() call from the start of ib_umad_*open() to the
end is safe since it is the responsibility of the caller of these
functions to ensure that the cdev pointer remains valid until at least
when these functions return.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: <stable@vger.kernel.org>
[ydroneaud@opteya.com: rework a bit to reduce the amount of code changed]
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
[ nonseekable_open() can't actually fail, but.... - Roland ]
Signed-off-by: Roland Dreier <roland@purestorage.com>
This commit adds the sysfs interface for enabling QP0 on VFs for
selected VF/port.
By default, no VFs are enabled for QP0 operation.
To enable QP0 operation on a VF/port, under
/sys/class/infiniband/mlx4_x/iov/<b:d:f>/ports/x there are two new entries:
- smi_enabled (read-only). Indicates whether smi is currently
enabled for the indicated VF/port
- enable_smi_admin (rw). Used by the admin to request that smi
capability be enabled or disabled for the indicated VF/port.
0 = disable, 1 = enable.
The requested enablement will occur at the next reset of the
VF (e.g. driver restart on the VM which owns the VF).
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This commit adds the infrastructure for enabling selected VFs to
operate SMI (QP0) MADs without restriction.
Additionally, for these enabled VFs, their QP0 proxy and tunnel QPs
are MLX QPs. As such, they operate over VL15. Therefore, they are
not affected by "credit" problems or changes in the VLArb table (which
may shut down VL0).
Non-enabled VFs may only create UD proxy QP0 qps (which are forced by
the hypervisor to send packets using the q-key it assigns and places
in the qp-context). Thus, non-enabled VFs will not pose a security
risk. The hypervisor discards any privileged MADs it receives from
these non-enabled VFs.
By default, all VFs are NOT enabled, and must explicitly be enabled
by the administrator.
The sysfs interface which operates the VF enablement infrastructure
is provided in the next commit.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Currently, VFs in SRIOV VFs are denied QP0 access. The main reason
for this decision is security, since Subnet Management Datagrams
(SMPs) are not restricted by network partitioning and may affect the
physical network topology. Moreover, even the SM may be denied access
from portions of the network by setting management keys unknown to the
SM.
However, it is desirable to grant SMI access to certain privileged
VFs, so that certain network management activities may be conducted
within virtual machines instead of the hypervisor.
This commit does the following:
1. Create QP0 tunnel QPs for all VFs.
2. Discard SMI mads sent-from/received-for non-privileged VFs in the
hypervisor MAD multiplex/demultiplex logic. SMI mads from/for
privileged VFs are allowed to pass.
3. MAD_IFC wrapper changes/fixes. For non-privileged VFs, only
host-view MAD_IFC commands are allowed, and only for SMI LID-Routed
GET mads. For privileged VFs, there are no restrictions.
This commit does not allow privileged VFs as yet. To determine if a VF
is privileged, it calls function mlx4_vf_smi_enabled(). This function
returns 0 unconditionally for now.
The next two commits allow defining and activating privileged VFs.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
mlx4_ib_modify_port is invoked in IB for resetting the Q_Key violations
counters and for modifying the IB port capability flags.
For example, when opensm is started up on the hypervisor,
mlx4_ib_modify_port is called to set the port's IsSM flag.
In multifunction mode, the SET_PORT command used in this flow should
be wrapped (so that the PF port capability flags are also tracked,
thus enabling the aggregate of all the VF/PF capability flags to be
tracked properly).
The procedure mlx4_SET_PORT() in main.c is also renamed to mlx4_ib_SET_PORT()
to differentiate it from procedure mlx4_SET_PORT() in port.c.
mlx4_ib_SET_PORT() is used exclusively by mlx4_ib_modify_port().
Finally, the CM invokes ib_modify_port() to set the IsCMSupported flag
even when running over RoCE. Therefore, when RoCE is active,
mlx4_ib_modify_port should return OK unconditionally (since the
capability flags and qkey violations counter are not relevant).
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Commit eb17711bc1 ("net/mlx4_core: Introduce nic_info new flag in
QUERY_FUNC_CAP") did:
if (func_cap->flags1 & QUERY_FUNC_CAP_FLAGS1_OFFSET) {
which should be:
if (func_cap->flags1 & QUERY_FUNC_CAP_FLAGS1_FORCE_VLAN) {
Fix that.
Fixes: eb17711bc1 ("net/mlx4_core: Introduce nic_info new flag in QUERY_FUNC_CAP")
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
In order to help benchmark the time tracepoints take, a new config
option is added called CONFIG_TRACEPOINT_BENCHMARK. When this option
is set a tracepoint is created called "benchmark:benchmark_event".
When the tracepoint is enabled, it kicks off a kernel thread that
goes into an infinite loop (calling cond_sched() to let other tasks
run), and calls the tracepoint. Each iteration will record the time
it took to write to the tracepoint and the next iteration that
data will be passed to the tracepoint itself. That is, the tracepoint
will report the time it took to do the previous tracepoint.
The string written to the tracepoint is a static string of 128 bytes
to keep the time the same. The initial string is simply a write of
"START". The second string records the cold cache time of the first
write which is not added to the rest of the calculations.
As it is a tight loop, it benchmarks as hot cache. That's fine because
we care most about hot paths that are probably in cache already.
An example of the output:
START
first=3672 [COLD CACHED]
last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712
last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337
last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064
last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411
last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389
last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull devfreq updates for v3.16 from MyungJoo Ham.
- Clean up with modern macro in the core and drivers.
- Fix incorrect error returns
- Remove dead CONFIG check.
- Fix resource leak in a driver.
* tag 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq:
PM / devfreq: remove checks for CONFIG_EXYNOS_ASV
PM / devfreq: exynos5: Use devm_devfreq_* function using device resource management
PM / devfreq: exynos4: Use devm_devfreq_* function using device resource management
PM / devfreq: Add devm_devfreq_{register,unregister}_opp_notfier function
PM / devfreq: Add resource-managed function for devfreq device
PM / devfreq: Fix devfreq_remove_device() to improve the sequence of resource free
PM / devfreq: exynos: make more PPMU code common
PM / devfreq: exynos5: introduce struct busfreq_ppmu_data
PM / devfreq: exynos4: introduce struct busfreq_ppmu_data
PM / devfreq: exynos4: use common PPMU code
PM / devfreq: exynos5: Add CONFIG_PM_OPP dependency to fix probe fail
PM / devfreq: exynos5: Use SIMPLE_DEV_PM_OPS macro
PM / devfreq: exynos4: Add CONFIG_PM_OPP dependency to fix probe fail
PM / devfreq: exynos4: Use SIMPLE_DEV_PM_OPS macro
PM / devfreq: exynos4: Fix bug of resource leak and code clean on probe()
Pull ARM fixes from Russell King:
"The usual random collection of relatively small ARM fixes"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8063/1: bL_switcher: fix individual online status reporting of removed CPUs
ARM: 8064/1: fix v7-M signal return
ARM: 8057/1: amba: Add Qualcomm vendor ID.
ARM: 8052/1: unwind: Fix handling of "Pop r4-r[4+nnn],r14" opcode
ARM: 8051/1: put_user: fix possible data corruption in put_user
ARM: 8048/1: fix v7-M setup stack location
The object and block layouts already exist in their own
subdirectories. This patch completes the set!
Note that as a layout denotes nfs4 already, I stripped
that prefix out of the file names.
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>
Acked-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
trace_printk() is used to debug fast paths within the kernel. Places
that gets called in any context (interrupt or NMI) or thousands of
times a second. Something you do not want to do with a printk().
In order to make it completely lockless as it needs a temporary buffer
to handle some of the string formatting, a page is created per cpu for
every context (four per cpu; normal, softirq, irq, NMI).
Since trace_printk() should only be used for debugging purposes,
there's no reason to waste memory on these buffers on a production
system. That means, trace_printk() should never be used unless a
developer is debugging their kernel. There's macro magic to allocate
the buffers if trace_printk() is used anywhere in the kernel.
To help enforce that trace_printk() isn't used outside of development,
when it is used, a nasty banner is displayed on bootup (or when a module
is loaded that uses trace_printk() and the kernel core does not).
Here's the banner:
**********************************************************
** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **
** **
** trace_printk() being used. Allocating extra memory. **
** **
** This means that this is a DEBUG kernel and it is **
** unsafe for produciton use. **
** **
** If you see this message and you are not debugging **
** the kernel, report this immediately to your vendor! **
** **
** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **
**********************************************************
That should hopefully keep developers from trying to sneak in a
trace_printk() or two.
Link: http://lkml.kernel.org/p/20140528131440.2283213c@gandalf.local.home
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When configure kprobe events of ftrace with "stacktrace" option enabled
in arm, there is no stacktrace was recorded after the kprobe event was
triggered. The root cause is no save_stack_trace_regs() function implemented.
Implement the save_stack_trace_regs() function in arm, then ftrace will
call this architecture-related function to record the stacktrace into
ring buffer.
After this fix, stacktrace can be recorded, for example:
# mount -t debugfs nodev /sys/kernel/debug
# echo "p:netrx net_rx_action" >> /sys/kernel/debug/tracing/kprobe_events
# echo 1 > /sys/kernel/debug/tracing/events/kprobes/netrx/enable
# echo 1 > /sys/kernel/debug/tracing/options/stacktrace
# echo 1 > /sys/kernel/debug/tracing/tracing_on
# ping 127.0.0.1 -c 1
# echo 0 > /sys/kernel/debug/tracing/tracing_on
# cat /sys/kernel/debug/tracing/trace
# tracer: nop
#
# entries-in-buffer/entries-written: 12/12 #P:1
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
<------ missing some entries ---------------->
ping-1200 [000] dNs1 667.603250: netrx: (net_rx_action+0x0/0x1f8)
ping-1200 [000] dNs1 667.604738: <stack trace>
=> net_rx_action
=> do_softirq
=> local_bh_enable
=> ip_finish_output
=> ip_output
=> ip_local_out
=> ip_send_skb
=> ip_push_pending_frames
=> raw_sendmsg
=> inet_sendmsg
=> sock_sendmsg
=> SyS_sendto
=> ret_fast_syscall
Signed-off-by: Lin Yongting <linyongting@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Support for ARM710 CPUs was removed in v3.5. Now remove the last code
depending on its Kconfig macro.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We will reach fixup handler when one thread(say cpu0) caused an undefined exception, while another thread(say cpu1) is unmmaping the page.
Fixup handler returns to the next userspace instruction which has caused the undef execption, rather than going to the same instruction.
ARM ARM says that after undefined exception, the PC will be pointing
to the next instruction. ie +4 offset in case of ARM and +2 in case of Thumb
And there is no correction offset passed to vector_stub in case of
undef exception.
File: arch/arm/kernel/entry-armv.S +1085
vector_stub und, UND_MODE
During an undefined exception, in normal scenario(ie when ldrt
instruction does not cause an abort) after resorting the context in
VFP hardware, the PC is modified as show below before jumping to
ret_from_exception which is in r9.
File: arch/arm/vfp/vfphw.S +169
@ The context stored in the VFP hardware is up to date with this thread
vfp_hw_state_valid:
tst r1, #FPEXC_EX
bne process_exception @ might as well handle the pending
@ exception before retrying branch
@ out before setting an FPEXC that
@ stops us reading stuff
VFPFMXR FPEXC, r1 @ Restore FPEXC last
sub r2, r2, #4 @ Retry current instruction - if Thumb
str r2, [sp, #S_PC] @ mode it's two 16-bit instructions,
@ else it's one 32-bit instruction, so
@ always subtract 4 from the following
@ instruction address.
But if ldrt results in an abort, we reach the fixup handler and return
to ret_from_execption without correcting the pc.
This patch modifes the fixup handler to re-execute the same instruction which caused undefined execption.
Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com>
Signed-off-by: Arun KS <getarunks@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
asm-generic offers an atomic-add based rwsem implementation, which
can avoid the need for heavier, spinlock-based synchronisation on the
fast path.
This patch makes use of the optimised implementation for ARM CPUs.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
