Commit Graph

4791 Commits

Author SHA1 Message Date
Josef Bacik
dd0bb688ea bpf: add a bpf_override_function helper
Error injection is sloppy and very ad-hoc.  BPF could fill this niche
perfectly with it's kprobe functionality.  We could make sure errors are
only triggered in specific call chains that we care about with very
specific situations.  Accomplish this with the bpf_override_funciton
helper.  This will modify the probe'd callers return value to the
specified value and set the PC to an override function that simply
returns, bypassing the originally probed function.  This gives us a nice
clean way to implement systematic error injection for all of our code
paths.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-11 12:18:05 +09:00
Richard Guy Briggs
42d5e37654 audit: filter PATH records keyed on filesystem magic
Tracefs or debugfs were causing hundreds to thousands of PATH records to
be associated with the init_module and finit_module SYSCALL records on a
few modules when the following rule was in place for startup:
	-a always,exit -F arch=x86_64 -S init_module -F key=mod-load

Provide a method to ignore these large number of PATH records from
overwhelming the logs if they are not of interest.  Introduce a new
filter list "AUDIT_FILTER_FS", with a new field type AUDIT_FSTYPE,
which keys off the filesystem 4-octet hexadecimal magic identifier to
filter specific filesystem PATH records.

An example rule would look like:
	-a never,filesystem -F fstype=0x74726163 -F key=ignore_tracefs
	-a never,filesystem -F fstype=0x64626720 -F key=ignore_debugfs

Arguably the better way to address this issue is to disable tracefs and
debugfs on boot from production systems.

See: https://github.com/linux-audit/audit-kernel/issues/16
See: https://github.com/linux-audit/audit-userspace/issues/8
Test case: https://github.com/linux-audit/audit-testsuite/issues/42

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: fixed the whitespace damage in kernel/auditsc.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-10 16:08:56 -05:00
Mark Greer
4d63adfe12 NFC: Add NFC_CMD_DEACTIVATE_TARGET support
Once an NFC target (i.e., a tag) is found, it remains active until
there is a failure reading or writing it (often caused by the target
moving out of range).  While the target is active, the NFC adapter
and antenna must remain powered.  This wastes power when the target
remains in range but the client application no longer cares whether
it is there or not.

To mitigate this, add a new netlink command that allows userspace
to deactivate an active target.  When issued, this command will cause
the NFC subsystem to act as though the target was moved out of range.
Once the command has been executed, the client application can power
off the NFC adapter to reduce power consumption.

Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2017-11-10 00:03:39 +01:00
Christian Borntraeger
da9a1446d2 KVM: s390: provide a capability for AIS state migration
The AIS capability was introduced in 4.12, while the interface to
migrate the state was added in 4.13. Unfortunately it is not possible
for userspace to detect the migration capability without creating a flic
kvm device. As in QEMU the cpu model detection runs on the "none"
machine this will result in cpu model issues regarding the "ais"
capability.

To get the "ais" capability properly let's add a new KVM capability that
tells userspace that AIS states can be migrated.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Halil Pasic <pasic@linux.vnet.ibm.com>
2017-11-09 16:48:51 +01:00
Jason Gerecke
9e429d5649 HID: wacom: generic: Send BTN_STYLUS3 when both barrel switches are set
The Wacom Pro Pen 3D includes a third barrel switch which is intended to
be particularly useful in applications where one frequency uses pan, zoom,
and rotate to navigate around a scene or model. The pen is compatible with
the MobileStudio Pro, 2nd-gen Intuos Pro, and Cintiq Pro. When the third
button is pressed, these devices set both the HID_DG_BARRELSWITCH and
HID_DG_BARRELSWITCH2 usages since their HID descriptors do not include a
usage specific to the button.

Rather than send both BTN_STYLUS and BTN_STYLUS2 when the third button is
pressed, userspace (libinput) has requested that we detect this condition
and report a newly-defined BTN_STYLUS3 event instead. We could define a
quirk specific to devices compatible with the Pro Pen 3D, but the liklihood
of seeing both barrel switch bits set with other pens/devices is low enough
to not worry about (pens mechanically prevent accidental activation of
multiple switches).

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-11-09 13:32:43 +01:00
Matthew Garrett
096b854648 EVM: Include security.apparmor in EVM measurements
Apparmor will be gaining support for security.apparmor labels, and it
would be helpful to include these in EVM validation now so appropriate
signatures can be generated even before full support is merged.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: John Johansen <John.johansen@canonical.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Yi Yang
b2d0f5d5dc openvswitch: enable NSH support
v16->17
 - Fixed disputed check code: keep them in nsh_push and nsh_pop
   but also add them in __ovs_nla_copy_actions

v15->v16
 - Add csum recalculation for nsh_push, nsh_pop and set_nsh
   pointed out by Pravin
 - Move nsh key into the union with ipv4 and ipv6 and add
   check for nsh key in match_validate pointed out by Pravin
 - Add nsh check in validate_set and __ovs_nla_copy_actions

v14->v15
 - Check size in nsh_hdr_from_nlattr
 - Fixed four small issues pointed out By Jiri and Eric

v13->v14
 - Rename skb_push_nsh to nsh_push per Dave's comment
 - Rename skb_pop_nsh to nsh_pop per Dave's comment

v12->v13
 - Fix NSH header length check in set_nsh

v11->v12
 - Fix missing changes old comments pointed out
 - Fix new comments for v11

v10->v11
 - Fix the left three disputable comments for v9
   but not fixed in v10.

v9->v10
 - Change struct ovs_key_nsh to
       struct ovs_nsh_key_base base;
       __be32 context[NSH_MD1_CONTEXT_SIZE];
 - Fix new comments for v9

v8->v9
 - Fix build error reported by daily intel build
   because nsh module isn't selected by openvswitch

v7->v8
 - Rework nested value and mask for OVS_KEY_ATTR_NSH
 - Change pop_nsh to adapt to nsh kernel module
 - Fix many issues per comments from Jiri Benc

v6->v7
 - Remove NSH GSO patches in v6 because Jiri Benc
   reworked it as another patch series and they have
   been merged.
 - Change it to adapt to nsh kernel module added by NSH
   GSO patch series

v5->v6
 - Fix the rest comments for v4.
 - Add NSH GSO support for VxLAN-gpe + NSH and
   Eth + NSH.

v4->v5
 - Fix many comments by Jiri Benc and Eric Garver
   for v4.

v3->v4
 - Add new NSH match field ttl
 - Update NSH header to the latest format
   which will be final format and won't change
   per its author's confirmation.
 - Fix comments for v3.

v2->v3
 - Change OVS_KEY_ATTR_NSH to nested key to handle
   length-fixed attributes and length-variable
   attriubte more flexibly.
 - Remove struct ovs_action_push_nsh completely
 - Add code to handle nested attribute for SET_MASKED
 - Change PUSH_NSH to use the nested OVS_KEY_ATTR_NSH
   to transfer NSH header data.
 - Fix comments and coding style issues by Jiri and Eric

v1->v2
 - Change encap_nsh and decap_nsh to push_nsh and pop_nsh
 - Dynamically allocate struct ovs_action_push_nsh for
   length-variable metadata.

OVS master and 2.8 branch has merged NSH userspace
patch series, this patch is to enable NSH support
in kernel data path in order that OVS can support
NSH in compat mode by porting this.

Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Eric Garver <e@erig.me>
Acked-by: Pravin Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-08 16:12:33 +09:00
Nogah Frankel
602f3baf22 net_sch: red: Add offload ability to RED qdisc
Add the ability to offload RED qdisc by using ndo_setup_tc.
There are four commands for RED offloading:
* TC_RED_SET: handles set and change.
* TC_RED_DESTROY: handle qdisc destroy.
* TC_RED_STATS: update the qdiscs counters (given as reference)
* TC_RED_XSTAT: returns red xstats.

Whether RED is being offloaded is being determined every time dump action
is being called because parent change of this qdisc could change its
offload state but doesn't require any RED function to be called.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-08 12:23:37 +09:00
Tom Herbert
fddb231ebe ila: Add a hook type for LWT routes
In LWT tunnels both an input and output route method is defined.
If both of these are executed in the same path then double translation
happens and the effect is not correct.

This patch adds a new attribute that indicates the hook type. Two
values are defined for route output and route output. ILA
translation is only done for the one that is set. The default is
to enable ILA on route output.

Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-08 11:20:49 +09:00
Tom Herbert
70d5aef48a ila: allow configuration of identifier type
Allow identifier to be explicitly configured for a mapping.
This can either be one of the identifier types specified in the
ILA draft or a value of ILA_ATYPE_USE_FORMAT which means the
identifier type is inferred from the identifier type field.
If a value other than ILA_ATYPE_USE_FORMAT is set for a
mapping then it is assumed that the identifier type field is
not present in an identifier.

Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-08 11:20:48 +09:00
Tom Herbert
84287bb328 ila: add checksum neutral map auto
Add checksum neutral auto that performs checksum neutral mapping
without using the C-bit. This is enabled by configuration of
a mapping.

The checksum neutral function has been split into
ila_csum_do_neutral_fmt and ila_csum_do_neutral_nofmt. The former
handles the C-bit and includes it in the adjustment value. The latter
just sets the adjustment value on the locator diff only.

Added configuration for checksum neutral map aut in ila_lwt
and ila_xlat.

Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-08 11:20:48 +09:00
Felipe Balbi
6f27f4f97e usb: core: add Status Type definitions
USB 3.1 added a PTM_STATUS type. Let's add a define for it and
following patches will let usb_get_status() accept the new argument.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 15:47:19 +01:00
Ingo Molnar
8c5db92a70 Merge branch 'linus' into locking/core, to resolve conflicts
Conflicts:
	include/linux/compiler-clang.h
	include/linux/compiler-gcc.h
	include/linux/compiler-intel.h
	include/uapi/linux/stddef.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-07 10:32:44 +01:00
Roman Gushchin
ebc614f687 bpf, cgroup: implement eBPF-based device controller for cgroup v2
Cgroup v2 lacks the device controller, provided by cgroup v1.
This patch adds a new eBPF program type, which in combination
of previously added ability to attach multiple eBPF programs
to a cgroup, will provide a similar functionality, but with some
additional flexibility.

This patch introduces a BPF_PROG_TYPE_CGROUP_DEVICE program type.
A program takes major and minor device numbers, device type
(block/character) and access type (mknod/read/write) as parameters
and returns an integer which defines if the operation should be
allowed or terminated with -EPERM.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05 23:26:51 +09:00
David S. Miller
488e5b30d3 Merge tag 'mlx5-updates-2017-11-04' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux
Saeed Mahameed says:

====================
mlx5-updates-2017-11-04

This series includes:

From Huy: dscp to priority mapping for Ethernet packet.

===================================================
First six patches enable differentiated services code point (dscp) to
priority mapping for Ethernet packet. Once this feature is
enabled, the packet is routed to the corresponding priority based on its
dscp. User can combine this feature with priority flow control (pfc)
feature to have priority flow control based on the dscp.

Firmware interface:
Mellanox firmware provides two control knobs for this feature:
  QPTS register allow changing the trust state between dscp and
  pcp mode. The default is pcp mode. Once in dscp mode, firmware will
  route the packet based on its dscp value if the dscp field exists.

  QPDPM register allow mapping a specific dscp (0 to 63) to a
  specific priority (0 to 7). By default, all the dscps are mapped to
  priority zero.

Software interface:
This feature is controlled via application priority TLV. IEEE
specification P802.1Qcd/D2.1 defines priority selector id 5 for
application priority TLV. This APP TLV selector defines DSCP to priority
map. This APP TLV can be sent by the switch or can be set locally using
software such as lldptool. In mlx5 drivers, we add the support for net
dcb's getapp and setapp call back. Mlx5 driver only handles the selector
id 5 application entry (dscp application priority application entry).
If user sends multiple dscp to priority APP TLV entries on the same
dscp, the last sent one will take effect. All the previous sent will be
deleted.

The firmware trust state (in QPTS register) is changed based on the
number of dscp to priority application entries. When the first dscp to
priority application entry is added by the user, the trust state is
changed to dscp. When the last dscp to priority application entry is
deleted by the user, the trust state is changed to pcp.

When the port is in DSCP trust state, the transmit queue is selected
based on the dscp of the skb.

When the port is in DSCP trust state and vport inline mode is not NONE,
firmware requires mlx5 driver to copy the IP header to the
wqe ethernet segment inline header if the skb has it.
This is done by changing the transmit queue sq's min inline mode to L3.
Note that the min inline mode of sqs that belong to other features
such as xdpsq, icosq are not modified.
===================================================

Plus to the dscp series, some small misc changes are include as well:

From Inbar, Ethtool msglvl support and some debug prints in DCBNL logic
From Or Gerlitz, Enlarge the NIC TC offload table size
From Rabie, Initialize destination_flow struct to 0
From Feras, Add inner TTC table to IPoIB flow steering
From Tal, Enable CQE based moderation on TX CQ
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05 23:25:02 +09:00
Jakub Kicinski
bd601b6ada bpf: report offload info to user space
Extend struct bpf_prog_info to contain information about program
being bound to a device.  Since the netdev may get destroyed while
program still exists we need a flag to indicate the program is
loaded for a device, even if the device is gone.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05 22:26:18 +09:00
Jakub Kicinski
ab3f0063c4 bpf: offload: add infrastructure for loading programs for a specific netdev
The fact that we don't know which device the program is going
to be used on is quite limiting in current eBPF infrastructure.
We have to reverse or limit the changes which kernel makes to
the loaded bytecode if we want it to be offloaded to a networking
device.  We also have to invent new APIs for debugging and
troubleshooting support.

Make it possible to load programs for a specific netdev.  This
helps us to bring the debug information closer to the core
eBPF infrastructure (e.g. we will be able to reuse the verifer
log in device JIT).  It allows device JITs to perform translation
on the original bytecode.

__bpf_prog_get() when called to get a reference for an attachment
point will now refuse to give it if program has a device assigned.
Following patches will add a version of that function which passes
the expected netdev in. @type argument in __bpf_prog_get() is
renamed to attach_type to make it clearer that it's only set on
attachment.

All calls to ndo_bpf are protected by rtnl, only verifier callbacks
are not.  We need a wait queue to make sure netdev doesn't get
destroyed while verifier is still running and calling its driver.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05 22:26:18 +09:00
Jiri Benc
79e1ad148c rtnetlink: use netnsid to query interface
Currently, when an application gets netnsid from the kernel (for example as
the result of RTM_GETLINK call on one end of the veth pair), it's not much
useful. There's no reliable way to get to the netns fd from the netnsid, nor
does any kernel API accept netnsid.

Extend the RTM_GETLINK call to also accept netnsid. It will operate on the
netns with the given netnsid in such case. Of course, the calling process
needs to have enough capabilities in the target name space; for now, require
CAP_NET_ADMIN. This can be relaxed in the future.

To signal to the calling process that the kernel understood the new
IFLA_IF_NETNSID attribute in the query, it will include it in the response.
This is needed to detect older kernels, as they will just ignore
IFLA_IF_NETNSID and query in the current name space.

This patch implemetns IFLA_IF_NETNSID only for get and dump. For set
operations, this can be extended later.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05 21:49:17 +09:00
Jiri Benc
9354d45203 openvswitch: reliable interface indentification in port dumps
This patch allows reliable identification of netdevice interfaces connected
to openvswitch bridges. In particular, user space queries the netdev
interfaces belonging to the ports for statistics, up/down state, etc.
Datapath dump needs to provide enough information for the user space to be
able to do that.

Currently, only interface names are returned. This is not sufficient, as
openvswitch allows its ports to be in different name spaces and the
interface name is valid only in its name space. What is needed and generally
used in other netlink APIs, is the pair ifindex+netnsid.

The solution is addition of the ifindex+netnsid pair (or only ifindex if in
the same name space) to vport get/dump operation.

On request side, ideally the ifindex+netnsid pair could be used to
get/set/del the corresponding vport. This is not implemented by this patch
and can be added later if needed.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05 21:49:17 +09:00
Huy Nguyen
ee20598194 net/dcb: Add dscp to priority selector type
IEEE specification P802.1Qcd/D2.1 defines priority selector 5.
This APP TLV selector defines DSCP to priority map.
This patch defines such DSCP selector.

Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2017-11-04 21:23:32 -07:00
David S. Miller
2a171788ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Files removed in 'net-next' had their license header updated
in 'net'.  We take the remove from 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04 09:26:51 +09:00
Mario Limonciello
f2645fa317 platform/x86: dell-smbios-wmi: introduce userspace interface
It's important for the driver to provide a R/W ioctl to ensure that
two competing userspace processes don't race to provide or read each
others data.

This userspace character device will be used to perform SMBIOS calls
from any applications.

It provides an ioctl that will allow passing the WMI calling
interface buffer between userspace and kernel space.

This character device is intended to deprecate the dcdbas kernel module
and the interface that it provides to userspace.

To perform an SMBIOS IOCTL call using the character device userspace will
perform a read() on the the character device.  The WMI bus will provide
a u64 variable containing the necessary size of the IOCTL buffer.

The API for interacting with this interface is defined in documentation
as well as the WMI uapi header provides the format of the structures.

Not all userspace requests will be accepted.  The dell-smbios filtering
functionality will be used to prevent access to certain tokens and calls.

All whitelisted commands and tokens are now shared out to userspace so
applications don't need to define them in their own headers.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-11-03 16:34:00 -07:00
Mario Limonciello
44b6b76611 platform/x86: wmi: create userspace interface for drivers
For WMI operations that are only Set or Query readable and writable sysfs
attributes created by WMI vendor drivers or the bus driver makes sense.

For other WMI operations that are run on Method, there needs to be a
way to guarantee to userspace that the results from the method call
belong to the data request to the method call.  Sysfs attributes don't
work well in this scenario because two userspace processes may be
competing at reading/writing an attribute and step on each other's
data.

When a WMI vendor driver declares a callback method in the wmi_driver
the WMI bus driver will create a character device that maps to that
function.  This callback method will be responsible for filtering
invalid requests and performing the actual call.

That character device will correspond to this path:
/dev/wmi/$driver

Performing read() on this character device will provide the size
of the buffer that the character device needs to perform calls.
This buffer size can be set by vendor drivers through a new symbol
or when MOF parsing is available by the MOF.

Performing ioctl() on this character device will be interpretd
by the WMI bus driver. It will perform sanity tests for size of
data, test them for a valid instance, copy the data from userspace
and pass iton to the vendor driver to further process and run.

This creates an implicit policy that each driver will only be allowed
a single character device.  If a module matches multiple GUID's,
the wmi_devices will need to be all handled by the same wmi_driver.

The WMI vendor drivers will be responsible for managing inappropriate
access to this character device and proper locking on data used by
it.

When a WMI vendor driver is unloaded the WMI bus driver will clean
up the character device and any memory allocated for the call.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-11-03 16:34:00 -07:00
Dave Martin
2d2123bc7c arm64/sve: Add prctl controls for userspace vector length management
This patch adds two arm64-specific prctls, to permit userspace to
control its vector length:

 * PR_SVE_SET_VL: set the thread's SVE vector length and vector
   length inheritance mode.

 * PR_SVE_GET_VL: get the same information.

Although these prctls resemble instruction set features in the SVE
architecture, they provide additional control: the vector length
inheritance mode is Linux-specific and nothing to do with the
architecture, and the architecture does not permit EL0 to set its
own vector length directly.  Both can be used in portable tools
without requiring the use of SVE instructions.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
[will: Fixed up prctl constants to avoid clash with PDEATHSIG]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03 15:24:19 +00:00
Dave Martin
43d4da2c45 arm64/sve: ptrace and ELF coredump support
This patch defines and implements a new regset NT_ARM_SVE, which
describes a thread's SVE register state.  This allows a debugger to
manipulate the SVE state, as well as being included in ELF
coredumps for post-mortem debugging.

Because the regset size and layout are dependent on the thread's
current vector length, it is not possible to define a C struct to
describe the regset contents as is done for existing regsets.
Instead, and for the same reasons, NT_ARM_SVE is based on the
freeform variable-layout approach used for the SVE signal frame.

Additionally, to reduce debug overhead when debugging threads that
might or might not have live SVE register state, NT_ARM_SVE may be
presented in one of two different formats: the old struct
user_fpsimd_state format is embedded for describing the state of a
thread with no live SVE state, whereas a new variable-layout
structure is embedded for describing live SVE state.  This avoids a
debugger needing to poll NT_PRFPREG in addition to NT_ARM_SVE, and
allows existing userspace code to handle the non-SVE case without
too much modification.

For this to work, NT_ARM_SVE is defined with a fixed-format header
of type struct user_sve_header, which the recipient can use to
figure out the content, size and layout of the reset of the regset.
Accessor macros are defined to allow the vector-length-dependent
parts of the regset to be manipulated.

Signed-off-by: Alan Hayward <alan.hayward@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
Cc: Okamoto Takayuki <tokamoto@jp.fujitsu.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03 15:24:18 +00:00