Return true instead of 1 in rcu_lockdep_current_cpu_online() as this
has bool as return type.
Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This handles the 'nonblock=false' case in nfs_lock_and_join_requests.
If the group is already locked and blocking is allowed, drop the inode lock
and wait for the group lock to be cleared before trying it all again.
This should fix warnings found in peterz's tree (sched/wait branch), where
might_sleep() checks are added to wait.[ch].
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Reviewed-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Currently the top level debug file system function tracer shares its
ftrace_ops with the function graph tracer. This was thought to be fine
because the tracers are not used together, as one can only enable
function or function_graph tracer in the current_tracer file.

But that assumption proved to be incorrect. The function profiler
can use the function graph tracer when function tracing is enabled.
Since all function graph users uses the function tracing ftrace_ops
this causes a conflict and when a user enables both function profiling
as well as the function tracer it will crash ftrace and disable it.

The quick solution so far is to move them as separate ftrace_ops like
it was earlier. The problem though is to synchronize the functions that
are traced because both function and function_graph tracer are limited
by the selections made in the set_ftrace_filter and set_ftrace_notrace
files.

To handle this, a new structure is made called ftrace_ops_hash. This
structure will now hold the filter_hash and notrace_hash, and the
ftrace_ops will point to this structure. That will allow two ftrace_ops
to share the same hashes.

Since most ftrace_ops do not share the hashes, and to keep allocation
simple, the ftrace_ops structure will include both a pointer to the
ftrace_ops_hash called func_hash, as well as the structure itself,
called local_hash. When the ops are registered, the func_hash pointer
will be initialized to point to the local_hash within the ftrace_ops
structure. Some of the ftrace internal ftrace_ops will be initialized
statically. This will allow for the function and function_graph tracer
to have separate ops but still share the same hash tables that determine
what functions they trace.

Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=82912Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

The GPIOD flags are defined inside the #ifdef CONFIG_GPIOLIB
switch, making the gpiolib stubs fail if these flags are used
by a consumer. This is not correct: the stubs should compile
fine without GPIOLIB.
Reported-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Commit da3c6647(I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI
config) adds a new kernel config I2C_ACPI and make I2C core built in
when the config is selected. This is wrong because distributions
etc generally compile I2C as a module and the commit broken that.
This patch is to rename I2C_ACPI to ACPI_I2C_OPREGION. New config
only controls ACPI I2C operation region code and depends on I2C=y.
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
[wsa: removed unrelated change for Kconfig]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Instead of hard coding the value properly document
that this is an userspace interface.

No intended functional change.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Commit 9183df25 ("shm: add memfd_create() syscall") added a new
system call (memfd_create) but didn't update the asm-generic unistd
header.

This patch adds the new system call to the asm-generic version of
unistd.h so that it can be used by architectures such as arm64.

Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

A wildcard entry with the 32-bits OUI 0x600d8400 was added as part of
the BCM7xxx internal PHY driver, but that entry might match other PHYs
that are not covered by this driver, so let's just remove it.

Fixes: b560a58c ("net: phy: add Broadcom BCM7xxx internal PHY driver")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@greenl8ke.davemloft.net>

Call rcu_deference_raw() directly from within rht_for_each_entry_rcu()
as list_for_each_entry_rcu() does.

Fixes the following sparse warnings:
net/netlink/af_netlink.c:2906:25:    expected struct rhash_head const *__mptr
net/netlink/af_netlink.c:2906:25:    got struct rhash_head [noderef] <asn:4>*<noident>

Fixes: e341694e ("netlink: Convert netlink_lookup() to use RCU protected hash table")
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No need to export rht_obj(), all inner to outer object translations
occur internally. It was intended to be used with rht_for_each() which
now primarily serves as the iterator for rhashtable_remove_pprev() to
effectively flush and free the full table.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Properly annotate next pointers as access is RCU protected in
the lookup path.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_tw_recycle heavily relies on tcp timestamps to build a per-host
ordering of incoming connections and teardowns without the need to
hold state on a specific quadruple for TCP_TIMEWAIT_LEN, but only for
the last measured RTO. To do so, we keep the last seen timestamp in a
per-host indexed data structure and verify if the incoming timestamp
in a connection request is strictly greater than the saved one during
last connection teardown. Thus we can verify later on that no old data
packets will be accepted by the new connection.

During moving a socket to time-wait state we already verify if timestamps
where seen on a connection. Only if that was the case we let the
time-wait socket expire after the RTO, otherwise normal TCP_TIMEWAIT_LEN
will be used. But we don't verify this on incoming SYN packets. If a
connection teardown was less than TCP_PAWS_MSL seconds in the past we
cannot guarantee to not accept data packets from an old connection if
no timestamps are present. We should drop this SYN packet. This patch
closes this loophole.

Please note, this patch does not make tcp_tw_recycle in any way more
usable but only adds another safety check:
Sporadic drops of SYN packets because of reordering in the network or
in the socket backlog queues can happen. Users behing NAT trying to
connect to a tcp_tw_recycle enabled server can get caught in blackholes
and their connection requests may regullary get dropped because hosts
behind an address translator don't have synchronized tcp timestamp clocks.
tcp_tw_recycle cannot work if peers don't have tcp timestamps enabled.

In general, use of tcp_tw_recycle is disadvised.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make sure we use the correct address-family-specific function for
handling MTU reductions from within tcp_release_cb().

Previously AF_INET6 sockets were incorrectly always using the IPv6
code path when sometimes they were handling IPv4 traffic and thus had
an IPv4 dst.
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Diagnosed-by: NWillem de Bruijn <willemb@google.com>
Fixes: 563d34d0 ("tcp: dont drop MTU reduction indications")
Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We don't know right timestamp for repaired skb-s. Wrong RTT estimations
isn't good, because some congestion modules heavily depends on it.

This patch adds the TCPCB_REPAIRED flag, which is included in
TCPCB_RETRANS.

Thanks to Eric for the advice how to fix this issue.

This patch fixes the warning:
[  879.562947] WARNING: CPU: 0 PID: 2825 at net/ipv4/tcp_input.c:3078 tcp_ack+0x11f5/0x1380()
[  879.567253] CPU: 0 PID: 2825 Comm: socket-tcpbuf-l Not tainted 3.16.0-next-20140811 #1
[  879.567829] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  879.568177]  0000000000000000 00000000c532680c ffff880039643d00 ffffffff817aa2d2
[  879.568776]  0000000000000000 ffff880039643d38 ffffffff8109afbd ffff880039d6ba80
[  879.569386]  ffff88003a449800 000000002983d6bd 0000000000000000 000000002983d6bc
[  879.569982] Call Trace:
[  879.570264]  [<ffffffff817aa2d2>] dump_stack+0x4d/0x66
[  879.570599]  [<ffffffff8109afbd>] warn_slowpath_common+0x7d/0xa0
[  879.570935]  [<ffffffff8109b0ea>] warn_slowpath_null+0x1a/0x20
[  879.571292]  [<ffffffff816d0a05>] tcp_ack+0x11f5/0x1380
[  879.571614]  [<ffffffff816d10bd>] tcp_rcv_established+0x1ed/0x710
[  879.571958]  [<ffffffff816dc9da>] tcp_v4_do_rcv+0x10a/0x370
[  879.572315]  [<ffffffff81657459>] release_sock+0x89/0x1d0
[  879.572642]  [<ffffffff816c81a0>] do_tcp_setsockopt.isra.36+0x120/0x860
[  879.573000]  [<ffffffff8110a52e>] ? rcu_read_lock_held+0x6e/0x80
[  879.573352]  [<ffffffff816c8912>] tcp_setsockopt+0x32/0x40
[  879.573678]  [<ffffffff81654ac4>] sock_common_setsockopt+0x14/0x20
[  879.574031]  [<ffffffff816537b0>] SyS_setsockopt+0x80/0xf0
[  879.574393]  [<ffffffff817b40a9>] system_call_fastpath+0x16/0x1b
[  879.574730] ---[ end trace a17cbc38eb8c5c00 ]---

v2: moving setting of skb->when for repaired skb-s in tcp_write_xmit,
    where it's set for other skb-s.

Fixes: 431a9124 ("tcp: timestamp SYN+DATA messages")
Fixes: 740b0f18 ("tcp: switch rtt estimations to usec resolution")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrey Vagin <avagin@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add tracepoint to track hugepage invalidate. This help us
in debugging difficult to track bugs.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Platforms like IBM Power Systems supports service processor
assisted dump. It provides interface to add memory region to
be captured when system is crashed.

During initialization/running we can add kernel memory region
to be collected.

Presently we don't have a way to get the log buffer base address
and size. This patch adds support to return log buffer address
and size.
Signed-off-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NAndrew Morton <akpm@linux-foundation.org>

added struct sockaddr_storage to rdma_user_cm.h without also adding an
include for linux/socket.h to make sure it is defined.  Systemtap
needs the header files to build standalone and cannot rely on other
files to pre-include other headers, so add linux/socket.h to the list
of includes in this file.

Fixes: ee7aed45 ("RDMA/ucma: Support querying for AF_IB addresses")
Signed-off-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Currently the functionality to untag traffic on input resides
as part of the vlan module and is build only when VLAN support
is enabled in the kernel.  When VLAN is disabled, the function
vlan_untag() turns into a stub and doesn't really untag the
packets.  This seems to create an interesting interaction
between VMs supporting checksum offloading and some network drivers.

There are some drivers that do not allow the user to change
tx-vlan-offload feature of the driver.  These drivers also seem
to assume that any VLAN-tagged traffic they transmit will
have the vlan information in the vlan_tci and not in the vlan
header already in the skb.  When transmitting skbs that already
have tagged data with partial checksum set, the checksum doesn't
appear to be updated correctly by the card thus resulting in a
failure to establish TCP connections.

The following is a packet trace taken on the receiver where a
sender is a VM with a VLAN configued.  The host VM is running on
doest not have VLAN support and the outging interface on the
host is tg3:
10:12:43.503055 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q
(0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27243,
offset 0, flags [DF], proto TCP (6), length 60)
    10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect
-> 0x48d9), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val
4294837885 ecr 0,nop,wscale 7], length 0
10:12:44.505556 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q
(0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27244,
offset 0, flags [DF], proto TCP (6), length 60)
    10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect
-> 0x44ee), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val
4294838888 ecr 0,nop,wscale 7], length 0

This connection finally times out.

I've only access to the TG3 hardware in this configuration thus have
only tested this with TG3 driver.  There are a lot of other drivers
that do not permit user changes to vlan acceleration features, and
I don't know if they all suffere from a similar issue.

The patch attempt to fix this another way.  It moves the vlan header
stipping code out of the vlan module and always builds it into the
kernel network core.  This way, even if vlan is not supported on
a virtualizatoin host, the virtual machines running on top of such
host will still work with VLANs enabled.

CC: Patrick McHardy <kaber@trash.net>
CC: Nithin Nayak Sujir <nsujir@broadcom.com>
CC: Michael Chan <mchan@broadcom.com>
CC: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NVladislav Yasevich <vyasevic@redhat.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Slot quirks "disable-wp" is deprecated.
Instead, use the host quirk "disable-wp".
(Because the slot-node is removed in dt-file.)
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Tested-by: NSachin Kamat <sachin.kamat@samsung.com>
Acked-by: NSeungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Tested-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Using the new registration mechanism, define a flag that indicates the
user wishes to process RMPP messages in user space rather than have
the kernel process them.
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Registrations options are specified through flags.  Definitions of flags will
be in subsequent patches.
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

Pages allocated using the DMA API have a coherent memory mapping. Make
this mapping visible to drivers so they can decide to use it instead of
creating their own redundant one.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Acked-by: NDavid Airlie <airlied@linux.ie>
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

This is the final piece of the puzzle of verifying kernel image signature
during kexec_file_load() syscall.

This patch calls into PE file routines to verify signature of bzImage.  If
signature are valid, kexec_file_load() succeeds otherwise it fails.

Two new config options have been introduced.  First one is
CONFIG_KEXEC_VERIFY_SIG.  This option enforces that kernel has to be
validly signed otherwise kernel load will fail.  If this option is not
set, no signature verification will be done.  Only exception will be when
secureboot is enabled.  In that case signature verification should be
automatically enforced when secureboot is enabled.  But that will happen
when secureboot patches are merged.

Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG.  This option
enables signature verification support on bzImage.  If this option is not
set and previous one is set, kernel image loading will fail because kernel
does not have support to verify signature of bzImage.

I tested these patches with both "pesign" and "sbsign" signed bzImages.

I used signing_key.priv key and signing_key.x509 cert for signing as
generated during kernel build process (if module signing is enabled).

Used following method to sign bzImage.

pesign
======
- Convert DER format cert to PEM format cert
openssl x509 -in signing_key.x509 -inform DER -out signing_key.x509.PEM -outform
PEM

- Generate a .p12 file from existing cert and private key file
openssl pkcs12 -export -out kernel-key.p12 -inkey signing_key.priv -in
signing_key.x509.PEM

- Import .p12 file into pesign db
pk12util -i /tmp/kernel-key.p12 -d /etc/pki/pesign

- Sign bzImage
pesign -i /boot/vmlinuz-3.16.0-rc3+ -o /boot/vmlinuz-3.16.0-rc3+.signed.pesign
-c "Glacier signing key - Magrathea" -s

sbsign
======
sbsign --key signing_key.priv --cert signing_key.x509.PEM --output
/boot/vmlinuz-3.16.0-rc3+.signed.sbsign /boot/vmlinuz-3.16.0-rc3+

Patch details:

Well all the hard work is done in previous patches.  Now bzImage loader
has just call into that code and verify whether bzImage signature are
valid or not.

Also create two config options.  First one is CONFIG_KEXEC_VERIFY_SIG.
This option enforces that kernel has to be validly signed otherwise kernel
load will fail.  If this option is not set, no signature verification will
be done.  Only exception will be when secureboot is enabled.  In that case
signature verification should be automatically enforced when secureboot is
enabled.  But that will happen when secureboot patches are merged.

Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG.  This option
enables signature verification support on bzImage.  If this option is not
set and previous one is set, kernel image loading will fail because kernel
does not have support to verify signature of bzImage.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch does two things.  It passes EFI run time mappings to second
kernel in bootparams efi_info.  Second kernel parse this info and create
new mappings in second kernel.  That means mappings in first and second
kernel will be same.  This paves the way to enable EFI in kexec kernel.

This patch also prepares and passes EFI setup data through bootparams.
This contains bunch of information about various tables and their
addresses.

These information gathering and passing has been written along the lines
of what current kexec-tools is doing to make kexec work with UEFI.

[akpm@linux-foundation.org: s/get_efi/efi_get/g, per Matt]
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Fleming <matt@console-pimps.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is loader specific code which can load bzImage and set it up for
64bit entry.  This does not take care of 32bit entry or real mode entry.

32bit mode entry can be implemented if somebody needs it.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Load purgatory code in RAM and relocate it based on the location.
Relocation code has been inspired by module relocation code and purgatory
relocation code in kexec-tools.

Also compute the checksums of loaded kexec segments and store them in
purgatory.

Arch independent code provides this functionality so that arch dependent
bootloaders can make use of it.

Helper functions are provided to get/set symbol values in purgatory which
are used by bootloaders later to set things like stack and entry point of
second kernel etc.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Previous patch provided the interface definition and this patch prvides
implementation of new syscall.

Previously segment list was prepared in user space.  Now user space just
passes kernel fd, initrd fd and command line and kernel will create a
segment list internally.

This patch contains generic part of the code.  Actual segment preparation
and loading is done by arch and image specific loader.  Which comes in
next patch.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is the new syscall kexec_file_load() declaration/interface.  I have
reserved the syscall number only for x86_64 so far.  Other architectures
(including i386) can reserve syscall number when they enable the support
for this new syscall.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

So far kexec_segment->buf was always a user space pointer as user space
passed the array of kexec_segment structures and kernel copied it.

But with new system call, list of kexec segments will be prepared by
kernel and kexec_segment->buf will point to a kernel memory.

So while I was adding code where I made assumption that ->buf is pointing
to kernel memory, sparse started giving warning.

Make ->buf a union.  And where a user space pointer is expected, access it
using ->buf and where a kernel space pointer is expected, access it using
->kbuf.  That takes care of sparse warnings.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I have added two more functions to walk through resources.

Currently walk_system_ram_range() deals with pfn and /proc/iomem can
contain partial pages.  By dealing in pfn, callback function loses the
info that last page of a memory range is a partial page and not the full
page.  So I implemented walk_system_ram_res() which returns u64 values to
callback functions and now it properly return start and end address.

walk_system_ram_range() uses find_next_system_ram() to find the next ram
resource.  This in turn only travels through siblings of top level child
and does not travers through all the nodes of the resoruce tree.  I also
need another function where I can walk through all the resources, for
example figure out where "GART" aperture is.  Figure out where ACPI memory
is.

So I wrote another function walk_iomem_res() which walks through all
/proc/iomem resources and returns matches as asked by caller.  Caller can
specify "name" of resource, start and end and flags.

Got rid of find_next_system_ram_res() and instead implemented more generic
find_next_iomem_res() which can be used to traverse top level children
only based on an argument.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Let's use the more common "unusable".

This patch was originally written and posted by Boris. I am including it
in this patch series.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

memfd_create() is similar to mmap(MAP_ANON), but returns a file-descriptor
that you can pass to mmap().  It can support sealing and avoids any
connection to user-visible mount-points.  Thus, it's not subject to quotas
on mounted file-systems, but can be used like malloc()'ed memory, but with
a file-descriptor to it.

memfd_create() returns the raw shmem file, so calls like ftruncate() can
be used to modify the underlying inode.  Also calls like fstat() will
return proper information and mark the file as regular file.  If you want
sealing, you can specify MFD_ALLOW_SEALING.  Otherwise, sealing is not
supported (like on all other regular files).

Compared to O_TMPFILE, it does not require a tmpfs mount-point and is not
subject to a filesystem size limit.  It is still properly accounted to
memcg limits, though, and to the same overcommit or no-overcommit
accounting as all user memory.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ryan Lortie <desrt@desrt.ca>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Daniel Mack <zonque@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If two processes share a common memory region, they usually want some
guarantees to allow safe access. This often includes:
  - one side cannot overwrite data while the other reads it
  - one side cannot shrink the buffer while the other accesses it
  - one side cannot grow the buffer beyond previously set boundaries

If there is a trust-relationship between both parties, there is no need
for policy enforcement.  However, if there's no trust relationship (eg.,
for general-purpose IPC) sharing memory-regions is highly fragile and
often not possible without local copies.  Look at the following two
use-cases:

  1) A graphics client wants to share its rendering-buffer with a
     graphics-server. The memory-region is allocated by the client for
     read/write access and a second FD is passed to the server. While
     scanning out from the memory region, the server has no guarantee that
     the client doesn't shrink the buffer at any time, requiring rather
     cumbersome SIGBUS handling.
  2) A process wants to perform an RPC on another process. To avoid huge
     bandwidth consumption, zero-copy is preferred. After a message is
     assembled in-memory and a FD is passed to the remote side, both sides
     want to be sure that neither modifies this shared copy, anymore. The
     source may have put sensible data into the message without a separate
     copy and the target may want to parse the message inline, to avoid a
     local copy.

While SIGBUS handling, POSIX mandatory locking and MAP_DENYWRITE provide
ways to achieve most of this, the first one is unproportionally ugly to
use in libraries and the latter two are broken/racy or even disabled due
to denial of service attacks.

This patch introduces the concept of SEALING.  If you seal a file, a
specific set of operations is blocked on that file forever.  Unlike locks,
seals can only be set, never removed.  Hence, once you verified a specific
set of seals is set, you're guaranteed that no-one can perform the blocked
operations on this file, anymore.

An initial set of SEALS is introduced by this patch:
  - SHRINK: If SEAL_SHRINK is set, the file in question cannot be reduced
            in size. This affects ftruncate() and open(O_TRUNC).
  - GROW: If SEAL_GROW is set, the file in question cannot be increased
          in size. This affects ftruncate(), fallocate() and write().
  - WRITE: If SEAL_WRITE is set, no write operations (besides resizing)
           are possible. This affects fallocate(PUNCH_HOLE), mmap() and
           write().
  - SEAL: If SEAL_SEAL is set, no further seals can be added to a file.
          This basically prevents the F_ADD_SEAL operation on a file and
          can be set to prevent others from adding further seals that you
          don't want.

The described use-cases can easily use these seals to provide safe use
without any trust-relationship:

  1) The graphics server can verify that a passed file-descriptor has
     SEAL_SHRINK set. This allows safe scanout, while the client is
     allowed to increase buffer size for window-resizing on-the-fly.
     Concurrent writes are explicitly allowed.
  2) For general-purpose IPC, both processes can verify that SEAL_SHRINK,
     SEAL_GROW and SEAL_WRITE are set. This guarantees that neither
     process can modify the data while the other side parses it.
     Furthermore, it guarantees that even with writable FDs passed to the
     peer, it cannot increase the size to hit memory-limits of the source
     process (in case the file-storage is accounted to the source).

The new API is an extension to fcntl(), adding two new commands:
  F_GET_SEALS: Return a bitset describing the seals on the file. This
               can be called on any FD if the underlying file supports
               sealing.
  F_ADD_SEALS: Change the seals of a given file. This requires WRITE
               access to the file and F_SEAL_SEAL may not already be set.
               Furthermore, the underlying file must support sealing and
               there may not be any existing shared mapping of that file.
               Otherwise, EBADF/EPERM is returned.
               The given seals are _added_ to the existing set of seals
               on the file. You cannot remove seals again.

The fcntl() handler is currently specific to shmem and disabled on all
files. A file needs to explicitly support sealing for this interface to
work. A separate syscall is added in a follow-up, which creates files that
support sealing. There is no intention to support this on other
file-systems. Semantics are unclear for non-volatile files and we lack any
use-case right now. Therefore, the implementation is specific to shmem.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ryan Lortie <desrt@desrt.ca>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Daniel Mack <zonque@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch (of 6):

The i_mmap_writable field counts existing writable mappings of an
address_space.  To allow drivers to prevent new writable mappings, make
this counter signed and prevent new writable mappings if it is negative.
This is modelled after i_writecount and DENYWRITE.

This will be required by the shmem-sealing infrastructure to prevent any
new writable mappings after the WRITE seal has been set.  In case there
exists a writable mapping, this operation will fail with EBUSY.

Note that we rely on the fact that iff you already own a writable mapping,
you can increase the counter without using the helpers.  This is the same
that we do for i_writecount.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ryan Lortie <desrt@desrt.ca>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Daniel Mack <zonque@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add this helper for consistency with pci_zalloc_coherent
and the ability to remove unnecessary memset(,0,) uses.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: "Stephen M. Cameron" <scameron@beardog.cce.hp.com>
Cc: Adam Radford <linuxraid@lsi.com>
Cc: Chaoming Li <chaoming_li@realsil.com.cn>
Cc: Chas Williams <chas@cmf.nrl.navy.mil>
Cc: Christian Benvenuti <benve@cisco.com>
Cc: Christopher Harrer <charrer@alacritech.com>
Cc: Dario Ballabio <ballabio_dario@emc.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Don Fry <pcnet32@frontier.com>
Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Forest Bond <forest@alittletooquiet.net>
Cc: Govindarajulu Varadarajan <_govind@gmx.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Jayamohan Kallickal <jayamohan.kallickal@emulex.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Lior Dotan <liodot@gmail.com>
Cc: Manish Chopra <manish.chopra@qlogic.com>
Cc: Manohar Vanga <manohar.vanga@gmail.com>
Cc: Martyn Welch <martyn.welch@ge.com>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Michael Neuffer <mike@i-Connect.Net>
Cc: Mirko Lindner <mlindner@marvell.com>
Cc: Neel Patel <neepatel@cisco.com>
Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
Cc: Rajesh Borundia <rajesh.borundia@qlogic.com>
Cc: Roland Dreier <roland@kernel.org>
Cc: Ron Mercer <ron.mercer@qlogic.com>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Shahed Shaikh <shahed.shaikh@qlogic.com>
Cc: Sony Chacko <sony.chacko@qlogic.com>
Cc: Stanislav Yakovlev <stas.yakovlev@gmail.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Sujith Sankar <ssujith@cisco.com>
Cc: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>