Commit Graph

752009 Commits

Author SHA1 Message Date
Guillaume Nault 6b9f34239b l2tp: fix races in tunnel creation
l2tp_tunnel_create() inserts the new tunnel into the namespace's tunnel
list and sets the socket's ->sk_user_data field, before returning it to
the caller. Therefore, there are two ways the tunnel can be accessed
and freed, before the caller even had the opportunity to take a
reference. In practice, syzbot could crash the module by closing the
socket right after a new tunnel was returned to pppol2tp_create().

This patch moves tunnel registration out of l2tp_tunnel_create(), so
that the caller can safely hold a reference before publishing the
tunnel. This second step is done with the new l2tp_tunnel_register()
function, which is now responsible for associating the tunnel to its
socket and for inserting it into the namespace's list.

While moving the code to l2tp_tunnel_register(), a few modifications
have been done. First, the socket validation tests are done in a helper
function, for clarity. Also, modifying the socket is now done after
having inserted the tunnel to the namespace's tunnels list. This will
allow insertion to fail, without having to revert theses modifications
in the error path (a followup patch will check for duplicate tunnels
before insertion). Either the socket is a kernel socket which we
control, or it is a user-space socket for which we have a reference on
the file descriptor. In any case, the socket isn't going to be closed
from under us.

Reported-by: syzbot+fbeeb5c3b538e8545644@syzkaller.appspotmail.com
Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 17:41:27 -04:00
Ard Biesheuvel 1eace8344c i2c: add param sanity check to i2c_transfer()
The API docs describe i2c_transfer() as taking a pointer to an array
of i2c_msg containing at least 1 entry, but leaves it to the individual
drivers to sanity check the msgs and num parameters. Let's do this in
core code instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[wsa: changed '<= 0' to '< 1']
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-11 23:33:46 +02:00
Wolfram Sang 090cecc669 MAINTAINERS: add maintainer for Renesas I2C related drivers
Intentionally missing i2c-riic here, Chris Brandt will add himself for
that one later.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-11 23:11:20 +02:00
Wolfram Sang 95df14f793 MAINTAINERS: remove me as maintainer for I2C host drivers
The number of I2C host controller drivers keeps increasing, and although
I had some success acquiring specific driver maintainers, my bandwidth
is by far not enough to act as a fallback for the rest of the drivers.
To reflect this status-quo in MAINTAINERS, add a separate entry for I2C
host drivers, let the I2C list (= community) be the contact point, and
mark this section as "Odd fixes".

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
2018-04-11 23:10:31 +02:00
Jean Delvare f7f6d915a1 i2c: i801: Restore configuration at shutdown
On some systems, the BIOS expects certain SMBus register values to
match the hardware defaults. Restore these configuration registers at
shutdown time to avoid confusing the BIOS. This avoids hard-locking
such systems upon reboot.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org
2018-04-11 23:08:13 +02:00
Jean Delvare a086bb8317 i2c: i801: Save register SMBSLVCMD value only once
Saving the original value of register SMBSLVCMD in
i801_enable_host_notify() doesn't work, because this function is
called not only at probe time but also at resume time. Do it in
i801_probe() instead, so that the saved value is not overwritten at
resume time.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 22e94bd677 ("i2c: i801: store and restore the SLVCMD register at load and unload")
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org	# v4.10+
2018-04-11 23:07:14 +02:00
Helge Deller 6769828703 parisc: Prevent panic at system halt
When issuing a "shutdown -h now", the reboot syscall calls kernel_halt()
which shouldn't return, otherwise one gets this panic:

reboot: System halted
Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000
CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 4.16.0-32bit+ #560
Backtrace:
 [<1018a694>] show_stack+0x18/0x28
 [<106e68a8>] dump_stack+0x80/0x10c
 [<101a4df8>] panic+0xfc/0x290
 [<101a90b8>] do_exit+0x73c/0x914
 [<101c7e38>] SyS_reboot+0x190/0x1d4
 [<1017e444>] syscall_exit+0x0/0x14

Fix it by letting machine_halt() call machine_power_off() which doesn't
return.

Signed-off-by: Helge Deller <deller@gmx.de>
2018-04-11 22:28:41 +02:00
Sabrina Dubroca 83c1f36f98 tun: send netlink notification when the device is modified
I added dumping of link information about tun devices over netlink in
commit 1ec010e705 ("tun: export flags, uid, gid, queue information
over netlink"), but didn't add the missing netlink notifications when
the device's exported properties change.

This patch adds notifications when owner/group or flags are modified,
when queues are attached/detached, and when a tun fd is closed.

Reported-by: Thomas Haller <thaller@redhat.com>
Fixes: 1ec010e705 ("tun: export flags, uid, gid, queue information over netlink")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:48:05 -04:00
Sabrina Dubroca 9fffc5c6dd tun: set the flags before registering the netdevice
Otherwise, register_netdevice advertises the creation of the device with
the default flags, instead of what the user requested.

Reported-by: Thomas Haller <thaller@redhat.com>
Fixes: 1ec010e705 ("tun: export flags, uid, gid, queue information over netlink")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:48:05 -04:00
Phil Elwell 47b998653f lan78xx: Don't reset the interface on open
Commit 92571a1aae ("lan78xx: Connect phy early") moves the PHY
initialisation into lan78xx_probe, but lan78xx_open subsequently calls
lan78xx_reset. As well as forcing a second round of link negotiation,
this reset frequently prevents the phy interrupt from being generated
(even though the link is up), rendering the interface unusable.

Fix this issue by removing the lan78xx_reset call from lan78xx_open.

Fixes: 92571a1aae ("lan78xx: Connect phy early")
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:44:45 -04:00
David S. Miller 9cf74f593a Merge branch 'bnxt_en-Fixes-for-net'
Michael Chan says:

====================
bnxt_en: Fixes for net.

This bug fix series include NULL pointer fixes in ethtool -x code path
and in the error clean up path when freeing IRQs, a ring accounting bug
that missed rings used by the RDMA driver, and 3 bug fixes related to TC
Flower and VF-reps.

v2: Fixed commit message of patch 4.  Changed the pound sign to $ sign
in front of the ip command.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:42:00 -04:00
Michael Chan cb98526bf9 bnxt_en: Fix NULL pointer dereference at bnxt_free_irq().
When open fails during ethtool -L ring change, for example, the driver
may crash at bnxt_free_irq() because bp->bnapi is NULL.

If we fail to allocate all the new rings, bnxt_open_nic() will free
all the memory including bp->bnapi.  Subsequent call to bnxt_close_nic()
will try to dereference bp->bnapi in bnxt_free_irq().

Fix it by checking for !bp->bnapi in bnxt_free_irq().

Fixes: e5811b8c09 ("bnxt_en: Add IRQ remapping logic.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:42:00 -04:00
Michael Chan 11c3ec7bb9 bnxt_en: Need to include RDMA rings in bnxt_check_rings().
With recent changes to reserve both L2 and RDMA rings, we need to include
the RDMA rings in bnxt_check_rings().  Otherwise we will under-estimate
the rings we need during ethtool -L and may lead to failure.

Fixes: fbcfc8e467 ("bnxt_en: Reserve completion rings and MSIX for bnxt_re RDMA driver.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:42:00 -04:00
Sriharsha Basavapatna 9d96465b11 bnxt_en: Support max-mtu with VF-reps
While a VF is configured with a bigger mtu (> 1500), any packets that
are punted to the VF-rep (slow-path) get dropped by OVS kernel-datapath
with the following message: "dropped over-mtu packet". Fix this by
returning the max-mtu value for a VF-rep derived from its corresponding VF.
VF-rep's mtu can be changed using 'ip' command as shown in this example:

	$ ip link set bnxt0_pf0vf0 mtu 9000

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:42:00 -04:00
Sriharsha Basavapatna 479ca3bf91 bnxt_en: Ignore src port field in decap filter nodes
The driver currently uses src port field (along with other fields) in the
decap tunnel key, while looking up and adding tunnel nodes. This leads to
redundant cfa_decap_filter_alloc() requests to the FW and flow-miss in the
flow engine. Fix this by ignoring the src port field in decap tunnel nodes.

Fixes: f484f6782e ("bnxt_en: add hwrm FW cmds for cfa_encap_record and decap_filter")
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:41:59 -04:00
Andy Gospodarek e85a9be93c bnxt_en: do not allow wildcard matches for L2 flows
Before this patch the following commands would succeed as far as the
user was concerned:

$ tc qdisc add dev p1p1 ingress
$ tc filter add dev p1p1 parent ffff: protocol all \
	flower skip_sw action drop
$ tc filter add dev p1p1 parent ffff: protocol ipv4 \
	flower skip_sw src_mac 00:02:00:00:00:01/44 action drop

The current flow offload infrastructure used does not support wildcard
matching for ethernet headers, so do not allow the second or third
commands to succeed.  If a user wants to drop traffic on that interface
the protocol and MAC addresses need to be specified explicitly:

$ tc qdisc add dev p1p1 ingress
$ tc filter add dev p1p1 parent ffff: protocol arp \
	flower skip_sw action drop
$ tc filter add dev p1p1 parent ffff: protocol ipv4 \
	flower skip_sw action drop
...
$ tc filter add dev p1p1 parent ffff: protocol ipv4 \
	flower skip_sw src_mac 00:02:00:00:00:01 action drop
$ tc filter add dev p1p1 parent ffff: protocol ipv4 \
	flower skip_sw src_mac 00:02:00:00:00:02 action drop
...

There are also checks for VLAN parameters in this patch as other callers
may wildcard those parameters even if tc does not.  Using different
flow infrastructure could allow this to work in the future for L2 flows,
but for now it does not.

Fixes: 2ae7408fed ("bnxt_en: bnxt: add TC flower filter offload support")
Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:41:59 -04:00
Michael Chan 7991cb9cfb bnxt_en: Fix ethtool -x crash when device is down.
Fix ethtool .get_rxfh() crash by checking for valid indirection table
address before copying the data.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 14:41:59 -04:00
Roman Li c3d7bad88e drm/amd/display: fix brightness level after resume from suspend
Adding missing call to cache current backlight values.
Otherwise the brightness resets to default value on resume.

Signed-off-by: Roman Li <Roman.Li@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2018-04-11 13:17:25 -05:00
Charlene Liu af2ac32608 drm/amd/display: HDMI has no sound after Panel power off/on
Signed-off-by: Charlene Liu <charlene.liu@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2018-04-11 13:16:10 -05:00
Evan Quan 1b59fb036a drm/amdgpu: add MP1 and THM hw ip base reg offset
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2018-04-11 13:14:01 -05:00
Huang Rui 2d4f9020d3 drm/amdgpu: fix null pointer panic with direct fw loading on gpu reset
When system uses fw direct loading, then psp context structure won't be
initiliazed. And it is also unable to execute mode reset.

[  434.601474] amdgpu 0000:0c:00.0: GPU reset begin!
[  434.694326] amdgpu 0000:0c:00.0: GPU reset
[  434.743152] BUG: unable to handle kernel NULL pointer dereference at
0000000000000058
[  434.838474] IP: psp_gpu_reset+0xc/0x30 [amdgpu]
[  434.893532] PGD 406ed9067
[  434.893533] P4D 406ed9067
[  434.926376] PUD 400b46067
[  434.959217] PMD 0
[  435.033379] Oops: 0000 [#1] SMP
[  435.072573] Modules linked in: amdgpu(OE) chash(OE) gpu_sched(OE) ttm(OE)
drm_kms_helper(OE) drm(OE) fb_sys_fops syscopyarea sysfillrect sysimgblt
rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace fscache snd_hda_codec_realtek
snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel snd_hda_codec
snd_hda_core snd_hwdep snd_pcm edac_mce_amd snd_seq_midi snd_seq_midi_event
kvm_amd snd_rawmidi kvm irqbypass crct10dif_pclmul crc32_pclmul snd_seq
ghash_clmulni_intel snd_seq_device pcbc snd_timer eeepc_wmi aesni_intel snd
asus_wmi aes_x86_64 sparse_keymap crypto_simd glue_helper joydev soundcore
wmi_bmof cryptd video i2c_piix4 shpchp 8250_dw i2c_designware_platform mac_hid
i2c_designware_core sunrpc parport_pc ppdev lp parport autofs4 hid_generic igb
usbhid dca ptp mxm_wmi pps_core ahci hid i2c_algo_bit
[  435.931754]  libahci wmi

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2018-04-11 13:12:38 -05:00
Nico Sneck b1550359d1 drm/radeon: add PX quirk for Asus K73TK
With this the dGPU turns on correctly.

Signed-off-by: Nico Sneck <nicosneck@hotmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
2018-04-11 13:11:50 -05:00
Linus Torvalds 8837c70d53 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - almost all of the rest of MM

 - kasan updates

 - lots of procfs work

 - misc things

 - lib/ updates

 - checkpatch

 - rapidio

 - ipc/shm updates

 - the start of willy's XArray conversion

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (140 commits)
  page cache: use xa_lock
  xarray: add the xa_lock to the radix_tree_root
  fscache: use appropriate radix tree accessors
  export __set_page_dirty
  unicore32: turn flush_dcache_mmap_lock into a no-op
  arm64: turn flush_dcache_mmap_lock into a no-op
  mac80211_hwsim: use DEFINE_IDA
  radix tree: use GFP_ZONEMASK bits of gfp_t for flags
  linux/const.h: refactor _BITUL and _BITULL a bit
  linux/const.h: move UL() macro to include/linux/const.h
  linux/const.h: prefix include guard of uapi/linux/const.h with _UAPI
  xen, mm: allow deferred page initialization for xen pv domains
  elf: enforce MAP_FIXED on overlaying elf segments
  fs, elf: drop MAP_FIXED usage from elf_map
  mm: introduce MAP_FIXED_NOREPLACE
  MAINTAINERS: update bouncing aacraid@adaptec.com addresses
  fs/dcache.c: add cond_resched() in shrink_dentry_list()
  include/linux/kfifo.h: fix comment
  ipc/shm.c: shm_split(): remove unneeded test for NULL shm_file_data.vm_ops
  kernel/sysctl.c: add kdoc comments to do_proc_do{u}intvec_minmax_conv_param
  ...
2018-04-11 10:51:26 -07:00
Ard Biesheuvel 24534b3511 arm64: assembler: add macros to conditionally yield the NEON under PREEMPT
Add support macros to conditionally yield the NEON (and thus the CPU)
that may be called from the assembler code.

In some cases, yielding the NEON involves saving and restoring a non
trivial amount of context (especially in the CRC folding algorithms),
and so the macro is split into three, and the code in between is only
executed when the yield path is taken, allowing the context to be preserved.
The third macro takes an optional label argument that marks the resume
path after a yield has been performed.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-11 18:50:34 +01:00
Ard Biesheuvel 0f468e221c arm64: assembler: add utility macros to push/pop stack frames
We are going to add code to all the NEON crypto routines that will
turn them into non-leaf functions, so we need to manage the stack
frames. To make this less tedious and error prone, add some macros
that take the number of callee saved registers to preserve and the
extra size to allocate in the stack frame (for locals) and emit
the ldp/stp sequences.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-11 18:50:34 +01:00
Marc Zyngier e8b22d0f45 arm64: Move the content of bpi.S to hyp-entry.S
bpi.S was introduced as we were starting to build the Spectre v2
mitigation framework, and it was rather unclear that it would
become strictly KVM specific.

Now that the picture is a lot clearer, let's move the content
of that file to hyp-entry.S, where it actually belong.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-11 18:49:30 +01:00
Marc Zyngier 22765f30db arm64: Get rid of __smccc_workaround_1_hvc_*
The very existence of __smccc_workaround_1_hvc_* is a thinko, as
KVM will never use a HVC call to perform the branch prediction
invalidation. Even as a nested hypervisor, it would use an SMC
instruction.

Let's get rid of it.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-11 18:49:30 +01:00
Marc Zyngier 8892b71885 arm64: capabilities: Rework EL2 vector hardening entry
Since 5e7951ce19 ("arm64: capabilities: Clean up midr range helpers"),
capabilities must be represented with a single entry. If multiple
CPU types can use the same capability, then they need to be enumerated
in a list.

The EL2 hardening stuff (which affects both A57 and A72) managed to
escape the conversion in the above patch thanks to the 4.17 merge
window. Let's fix it now.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-11 18:49:30 +01:00
Shanker Donthineni 4bc352ffb3 arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening
The function SMCCC_ARCH_WORKAROUND_1 was introduced as part of SMC
V1.1 Calling Convention to mitigate CVE-2017-5715. This patch uses
the standard call SMCCC_ARCH_WORKAROUND_1 for Falkor chips instead
of Silicon provider service ID 0xC2001700.

Cc: <stable@vger.kernel.org> # 4.14+
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
[maz: reworked errata framework integration]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-11 18:49:30 +01:00
Matthew Wilcox b93b016313 page cache: use xa_lock
Remove the address_space ->tree_lock and use the xa_lock newly added to
the radix_tree_root.  Rename the address_space ->page_tree to ->i_pages,
since we don't really care that it's a tree.

[willy@infradead.org: fix nds32, fs/dax.c]
  Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Matthew Wilcox f6bb2a2c0b xarray: add the xa_lock to the radix_tree_root
This results in no change in structure size on 64-bit machines as it
fits in the padding between the gfp_t and the void *.  32-bit machines
will grow the structure from 8 to 12 bytes.  Almost all radix trees are
protected with (at least) a spinlock, so as they are converted from
radix trees to xarrays, the data structures will shrink again.

Initialising the spinlock requires a name for the benefit of lockdep, so
RADIX_TREE_INIT() now needs to know the name of the radix tree it's
initialising, and so do IDR_INIT() and IDA_INIT().

Also add the xa_lock() and xa_unlock() family of wrappers to make it
easier to use the lock.  If we could rely on -fplan9-extensions in the
compiler, we could avoid all of this syntactic sugar, but that wasn't
added until gcc 4.6.

Link: http://lkml.kernel.org/r/20180313132639.17387-8-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Matthew Wilcox e5a9554196 fscache: use appropriate radix tree accessors
Don't open-code accesses to data structure internals.

Link: http://lkml.kernel.org/r/20180313132639.17387-7-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Matthew Wilcox f82b376413 export __set_page_dirty
XFS currently contains a copy-and-paste of __set_page_dirty().  Export
it from buffer.c instead.

Link: http://lkml.kernel.org/r/20180313132639.17387-6-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Matthew Wilcox d339d705f7 unicore32: turn flush_dcache_mmap_lock into a no-op
Unicore doesn't walk the VMA tree in its flush_dcache_page()
implementation, so has no need to take the tree_lock.

Link: http://lkml.kernel.org/r/20180313132639.17387-5-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Matthew Wilcox 427c896f26 arm64: turn flush_dcache_mmap_lock into a no-op
ARM64 doesn't walk the VMA tree in its flush_dcache_page()
implementation, so has no need to take the tree_lock.

Link: http://lkml.kernel.org/r/20180313132639.17387-4-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Matthew Wilcox 60a052719a mac80211_hwsim: use DEFINE_IDA
This is preferred to opencoding an IDA_INIT.

Link: http://lkml.kernel.org/r/20180313132639.17387-2-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Matthew Wilcox fa290cda10 radix tree: use GFP_ZONEMASK bits of gfp_t for flags
Patch series "XArray", v9.  (First part thereof).

This patchset is, I believe, appropriate for merging for 4.17.  It
contains the XArray implementation, to eventually replace the radix
tree, and converts the page cache to use it.

This conversion keeps the radix tree and XArray data structures in sync
at all times.  That allows us to convert the page cache one function at
a time and should allow for easier bisection.  Other than renaming some
elements of the structures, the data structures are fundamentally
unchanged; a radix tree walk and an XArray walk will touch the same
number of cachelines.  I have changes planned to the XArray data
structure, but those will happen in future patches.

Improvements the XArray has over the radix tree:

 - The radix tree provides operations like other trees do; 'insert' and
   'delete'. But what most users really want is an automatically
   resizing array, and so it makes more sense to give users an API that
   is like an array -- 'load' and 'store'. We still have an 'insert'
   operation for users that really want that semantic.

 - The XArray considers locking as part of its API. This simplifies a
   lot of users who formerly had to manage their own locking just for
   the radix tree. It also improves code generation as we can now tell
   RCU that we're holding a lock and it doesn't need to generate as much
   fencing code. The other advantage is that tree nodes can be moved
   (not yet implemented).

 - GFP flags are now parameters to calls which may need to allocate
   memory. The radix tree forced users to decide what the allocation
   flags would be at creation time. It's much clearer to specify them at
   allocation time.

 - Memory is not preloaded; we don't tie up dozens of pages on the off
   chance that the slab allocator fails. Instead, we drop the lock,
   allocate a new node and retry the operation. We have to convert all
   the radix tree, IDA and IDR preload users before we can realise this
   benefit, but I have not yet found a user which cannot be converted.

 - The XArray provides a cmpxchg operation. The radix tree forces users
   to roll their own (and at least four have).

 - Iterators take a 'max' parameter. That simplifies many users and will
   reduce the amount of iteration done.

 - Iteration can proceed backwards. We only have one user for this, but
   since it's called as part of the pagefault readahead algorithm, that
   seemed worth mentioning.

 - RCU-protected pointers are not exposed as part of the API. There are
   some fun bugs where the page cache forgets to use rcu_dereference()
   in the current codebase.

 - Value entries gain an extra bit compared to radix tree exceptional
   entries. That gives us the extra bit we need to put huge page swap
   entries in the page cache.

 - Some iterators now take a 'filter' argument instead of having
   separate iterators for tagged/untagged iterations.

The page cache is improved by this:

 - Shorter, easier to read code

 - More efficient iterations

 - Reduction in size of struct address_space

 - Fewer walks from the top of the data structure; the XArray API
   encourages staying at the leaf node and conducting operations there.

This patch (of 8):

None of these bits may be used for slab allocations, so we can use them
as radix tree flags as long as we mask them off before passing them to
the slab allocator. Move the IDR flag from the high bits to the
GFP_ZONEMASK bits.

Link: http://lkml.kernel.org/r/20180313132639.17387-3-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Masahiro Yamada 21e7bc600e linux/const.h: refactor _BITUL and _BITULL a bit
Minor cleanups available by _UL and _ULL.

Link: http://lkml.kernel.org/r/1519301715-31798-5-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Masahiro Yamada 2dd8a62c64 linux/const.h: move UL() macro to include/linux/const.h
ARM, ARM64 and UniCore32 duplicate the definition of UL():

  #define UL(x) _AC(x, UL)

This is not actually arch-specific, so it will be useful to move it to a
common header.  Currently, we only have the uapi variant for
linux/const.h, so I am creating include/linux/const.h.

I also added _UL(), _ULL() and ULL() because _AC() is mostly used in
the form either _AC(..., UL) or _AC(..., ULL).  I expect they will be
replaced in follow-up cleanups.  The underscore-prefixed ones should
be used for exported headers.

Link: http://lkml.kernel.org/r/1519301715-31798-4-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Masahiro Yamada 2a6cc8a6c0 linux/const.h: prefix include guard of uapi/linux/const.h with _UAPI
Patch series "linux/const.h: cleanups of macros such as UL(), _BITUL(),
BIT() etc", v3.

ARM, ARM64, UniCore32 define UL() as a shorthand of _AC(..., UL).  More
architectures may introduce it in the future.

UL() is arch-agnostic, and useful. So let's move it to
include/linux/const.h

Currently, <asm/memory.h> must be included to use UL().  It pulls in more
bloats just for defining some bit macros.

I posted V2 one year ago.

The previous posts are:
https://patchwork.kernel.org/patch/9498273/
https://patchwork.kernel.org/patch/9498275/
https://patchwork.kernel.org/patch/9498269/
https://patchwork.kernel.org/patch/9498271/

At that time, what blocked this series was a comment from
David Howells:
  You need to be very careful doing this.  Some userspace stuff
  depends on the guard macro names on the kernel header files.

(https://patchwork.kernel.org/patch/9498275/)

Looking at the code closer, I noticed this is not a problem.

See the following line.
https://github.com/torvalds/linux/blob/v4.16-rc2/scripts/headers_install.sh#L40

scripts/headers_install.sh rips off _UAPI prefix from guard macro names.

I ran "make headers_install" and confirmed the result is what I expect.

So, we can prefix the include guard of include/uapi/linux/const.h,
and add a new include/linux/const.h.

This patch (of 4):

I am going to add include/linux/const.h for the kernel space.

Add _UAPI to the include guard of include/uapi/linux/const.h to
prepare for that.

Please notice the guard name of the exported one will be kept as-is.
So, this commit has no impact to the userspace even if some userspace
stuff depends on the guard macro names.

scripts/headers_install.sh processes exported headers by SED, and
rips off "_UAPI" from guard macro names.

  #ifndef _UAPI_LINUX_CONST_H
  #define _UAPI_LINUX_CONST_H

will be turned into

  #ifndef _LINUX_CONST_H
  #define _LINUX_CONST_H

Link: http://lkml.kernel.org/r/1519301715-31798-2-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Pavel Tatashin 6f84f8d158 xen, mm: allow deferred page initialization for xen pv domains
Juergen Gross noticed that commit f7f99100d8 ("mm: stop zeroing memory
during allocation in vmemmap") broke XEN PV domains when deferred struct
page initialization is enabled.

This is because the xen's PagePinned() flag is getting erased from
struct pages when they are initialized later in boot.

Juergen fixed this problem by disabling deferred pages on xen pv
domains.  It is desirable, however, to have this feature available as it
reduces boot time.  This fix re-enables the feature for pv-dmains, and
fixes the problem the following way:

The fix is to delay setting PagePinned flag until struct pages for all
allocated memory are initialized, i.e.  until after free_all_bootmem().

A new x86_init.hyper op init_after_bootmem() is called to let xen know
that boot allocator is done, and hence struct pages for all the
allocated memory are now initialized.  If deferred page initialization
is enabled, the rest of struct pages are going to be initialized later
in boot once page_alloc_init_late() is called.

xen_after_bootmem() walks page table's pages and marks them pinned.

Link: http://lkml.kernel.org/r/20180226160112.24724-2-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Tested-by: Juergen Gross <jgross@suse.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Jinbum Park <jinb.park7@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jia Zhang <zhang.jia@linux.alibaba.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Michal Hocko ad55eac74f elf: enforce MAP_FIXED on overlaying elf segments
Anshuman has reported that with "fs, elf: drop MAP_FIXED usage from
elf_map" applied, some ELF binaries in his environment fail to start
with

 [   23.423642] 9148 (sed): Uhuuh, elf segment at 0000000010030000 requested but the memory is mapped already
 [   23.423706] requested [10030000, 10040000] mapped [10030000, 10040000] 100073 anon

The reason is that the above binary has overlapping elf segments:

  LOAD           0x0000000000000000 0x0000000010000000 0x0000000010000000
                 0x0000000000013a8c 0x0000000000013a8c  R E    10000
  LOAD           0x000000000001fd40 0x000000001002fd40 0x000000001002fd40
                 0x00000000000002c0 0x00000000000005e8  RW     10000
  LOAD           0x0000000000020328 0x0000000010030328 0x0000000010030328
                 0x0000000000000384 0x00000000000094a0  RW     10000

That binary has two RW LOAD segments, the first crosses a page border
into the second

  0x1002fd40 (LOAD2-vaddr) + 0x5e8 (LOAD2-memlen) == 0x10030328 (LOAD3-vaddr)

Handle this situation by enforcing MAP_FIXED when we establish a
temporary brk VMA to handle overlapping segments.  All other mappings
will still use MAP_FIXED_NOREPLACE.

Link: http://lkml.kernel.org/r/20180213100440.GM3443@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Andrei Vagin <avagin@openvz.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Kees Cook <keescook@chromium.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Michal Hocko 4ed2863951 fs, elf: drop MAP_FIXED usage from elf_map
Both load_elf_interp and load_elf_binary rely on elf_map to map segments
on a controlled address and they use MAP_FIXED to enforce that.  This is
however dangerous thing prone to silent data corruption which can be
even exploitable.

Let's take CVE-2017-1000253 as an example.  At the time (before commit
eab09532d400: "binfmt_elf: use ELF_ET_DYN_BASE only for PIE")
ELF_ET_DYN_BASE was at TASK_SIZE / 3 * 2 which is not that far away from
the stack top on 32b (legacy) memory layout (only 1GB away).  Therefore
we could end up mapping over the existing stack with some luck.

The issue has been fixed since then (a87938b2e246: "fs/binfmt_elf.c: fix
bug in loading of PIE binaries"), ELF_ET_DYN_BASE moved moved much
further from the stack (eab09532d4 and later by c715b72c1ba4: "mm:
revert x86_64 and arm64 ELF_ET_DYN_BASE base changes") and excessive
stack consumption early during execve fully stopped by da029c11e6
("exec: Limit arg stack to at most 75% of _STK_LIM").  So we should be
safe and any attack should be impractical.  On the other hand this is
just too subtle assumption so it can break quite easily and hard to
spot.

I believe that the MAP_FIXED usage in load_elf_binary (et. al) is still
fundamentally dangerous.  Moreover it shouldn't be even needed.  We are
at the early process stage and so there shouldn't be unrelated mappings
(except for stack and loader) existing so mmap for a given address should
succeed even without MAP_FIXED.  Something is terribly wrong if this is
not the case and we should rather fail than silently corrupt the
underlying mapping.

Address this issue by changing MAP_FIXED to the newly added
MAP_FIXED_NOREPLACE.  This will mean that mmap will fail if there is an
existing mapping clashing with the requested one without clobbering it.

[mhocko@suse.com: fix build]
[akpm@linux-foundation.org: coding-style fixes]
[avagin@openvz.org: don't use the same value for MAP_FIXED_NOREPLACE and MAP_SYNC]
  Link: http://lkml.kernel.org/r/20171218184916.24445-1-avagin@openvz.org
Link: http://lkml.kernel.org/r/20171213092550.2774-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Michal Hocko a4ff8e8620 mm: introduce MAP_FIXED_NOREPLACE
Patch series "mm: introduce MAP_FIXED_NOREPLACE", v2.

This has started as a follow up discussion [3][4] resulting in the
runtime failure caused by hardening patch [5] which removes MAP_FIXED
from the elf loader because MAP_FIXED is inherently dangerous as it
might silently clobber an existing underlying mapping (e.g.  stack).
The reason for the failure is that some architectures enforce an
alignment for the given address hint without MAP_FIXED used (e.g.  for
shared or file backed mappings).

One way around this would be excluding those archs which do alignment
tricks from the hardening [6].  The patch is really trivial but it has
been objected, rightfully so, that this screams for a more generic
solution.  We basically want a non-destructive MAP_FIXED.

The first patch introduced MAP_FIXED_NOREPLACE which enforces the given
address but unlike MAP_FIXED it fails with EEXIST if the given range
conflicts with an existing one.  The flag is introduced as a completely
new one rather than a MAP_FIXED extension because of the backward
compatibility.  We really want a never-clobber semantic even on older
kernels which do not recognize the flag.  Unfortunately mmap sucks
wrt flags evaluation because we do not EINVAL on unknown flags.  On
those kernels we would simply use the traditional hint based semantic so
the caller can still get a different address (which sucks) but at least
not silently corrupt an existing mapping.  I do not see a good way
around that.  Except we won't export expose the new semantic to the
userspace at all.

It seems there are users who would like to have something like that.
Jemalloc has been mentioned by Michael Ellerman [7]

Florian Weimer has mentioned the following:
: glibc ld.so currently maps DSOs without hints.  This means that the kernel
: will map right next to each other, and the offsets between them a completely
: predictable.  We would like to change that and supply a random address in a
: window of the address space.  If there is a conflict, we do not want the
: kernel to pick a non-random address. Instead, we would try again with a
: random address.

John Hubbard has mentioned CUDA example
: a) Searches /proc/<pid>/maps for a "suitable" region of available
: VA space.  "Suitable" generally means it has to have a base address
: within a certain limited range (a particular device model might
: have odd limitations, for example), it has to be large enough, and
: alignment has to be large enough (again, various devices may have
: constraints that lead us to do this).
:
: This is of course subject to races with other threads in the process.
:
: Let's say it finds a region starting at va.
:
: b) Next it does:
:     p = mmap(va, ...)
:
: *without* setting MAP_FIXED, of course (so va is just a hint), to
: attempt to safely reserve that region. If p != va, then in most cases,
: this is a failure (almost certainly due to another thread getting a
: mapping from that region before we did), and so this layer now has to
: call munmap(), before returning a "failure: retry" to upper layers.
:
:     IMPROVEMENT: --> if instead, we could call this:
:
:             p = mmap(va, ... MAP_FIXED_NOREPLACE ...)
:
:         , then we could skip the munmap() call upon failure. This
:         is a small thing, but it is useful here. (Thanks to Piotr
:         Jaroszynski and Mark Hairgrove for helping me get that detail
:         exactly right, btw.)
:
: c) After that, CUDA suballocates from p, via:
:
:      q = mmap(sub_region_start, ... MAP_FIXED ...)
:
: Interestingly enough, "freeing" is also done via MAP_FIXED, and
: setting PROT_NONE to the subregion. Anyway, I just included (c) for
: general interest.

Atomic address range probing in the multithreaded programs in general
sounds like an interesting thing to me.

The second patch simply replaces MAP_FIXED use in elf loader by
MAP_FIXED_NOREPLACE.  I believe other places which rely on MAP_FIXED
should follow.  Actually real MAP_FIXED usages should be docummented
properly and they should be more of an exception.

[1] http://lkml.kernel.org/r/20171116101900.13621-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/20171129144219.22867-1-mhocko@kernel.org
[3] http://lkml.kernel.org/r/20171107162217.382cd754@canb.auug.org.au
[4] http://lkml.kernel.org/r/1510048229.12079.7.camel@abdul.in.ibm.com
[5] http://lkml.kernel.org/r/20171023082608.6167-1-mhocko@kernel.org
[6] http://lkml.kernel.org/r/20171113094203.aofz2e7kueitk55y@dhcp22.suse.cz
[7] http://lkml.kernel.org/r/87efp1w7vy.fsf@concordia.ellerman.id.au

This patch (of 2):

MAP_FIXED is used quite often to enforce mapping at the particular range.
The main problem of this flag is, however, that it is inherently dangerous
because it unmaps existing mappings covered by the requested range.  This
can cause silent memory corruptions.  Some of them even with serious
security implications.  While the current semantic might be really
desiderable in many cases there are others which would want to enforce the
given range but rather see a failure than a silent memory corruption on a
clashing range.  Please note that there is no guarantee that a given range
is obeyed by the mmap even when it is free - e.g.  arch specific code is
allowed to apply an alignment.

Introduce a new MAP_FIXED_NOREPLACE flag for mmap to achieve this
behavior.  It has the same semantic as MAP_FIXED wrt.  the given address
request with a single exception that it fails with EEXIST if the requested
address is already covered by an existing mapping.  We still do rely on
get_unmaped_area to handle all the arch specific MAP_FIXED treatment and
check for a conflicting vma after it returns.

The flag is introduced as a completely new one rather than a MAP_FIXED
extension because of the backward compatibility.  We really want a
never-clobber semantic even on older kernels which do not recognize the
flag.  Unfortunately mmap sucks wrt.  flags evaluation because we do not
EINVAL on unknown flags.  On those kernels we would simply use the
traditional hint based semantic so the caller can still get a different
address (which sucks) but at least not silently corrupt an existing
mapping.  I do not see a good way around that.

[mpe@ellerman.id.au: fix whitespace]
[fail on clashing range with EEXIST as per Florian Weimer]
[set MAP_FIXED before round_hint_to_min as per Khalid Aziz]
Link: http://lkml.kernel.org/r/20171213092550.2774-2-mhocko@kernel.org
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Russell King - ARM Linux <linux@armlinux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jason Evans <jasone@google.com>
Cc: David Goldblatt <davidtgoldblatt@gmail.com>
Cc: Edward Tomasz Napierała <trasz@FreeBSD.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Joe Perches 721d8b41ab MAINTAINERS: update bouncing aacraid@adaptec.com addresses
Adaptec is now part of Microsemi.

Commit 2a81ffdd9d ("MAINTAINERS: Update email address for aacraid")
updated only one of the driver maintainer addresses.

Update the other two sections as the aacraid@adaptec.com address
bounces.

Link: http://lkml.kernel.org/r/1522103936.12357.27.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dave Carroll <david.carroll@microsemi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Nikolay Borisov 32785c0539 fs/dcache.c: add cond_resched() in shrink_dentry_list()
As previously reported (https://patchwork.kernel.org/patch/8642031/)
it's possible to call shrink_dentry_list with a large number of dentries
(> 10000).  This, in turn, could trigger the softlockup detector and
possibly trigger a panic.  In addition to the unmount path being
vulnerable to this scenario, at SuSE we've observed similar situation
happening during process exit on processes that touch a lot of dentries.
Here is an excerpt from a crash dump.  The number after the colon are
the number of dentries on the list passed to shrink_dentry_list:

PID 99760: 10722
PID 107530: 215
PID 108809: 24134
PID 108877: 21331
PID 141708: 16487

So we want to kill between 15k-25k dentries without yielding.

And one possible call stack looks like:

4 [ffff8839ece41db0] _raw_spin_lock at ffffffff8152a5f8
5 [ffff8839ece41db0] evict at ffffffff811c3026
6 [ffff8839ece41dd0] __dentry_kill at ffffffff811bf258
7 [ffff8839ece41df0] shrink_dentry_list at ffffffff811bf593
8 [ffff8839ece41e18] shrink_dcache_parent at ffffffff811bf830
9 [ffff8839ece41e50] proc_flush_task at ffffffff8120dd61
10 [ffff8839ece41ec0] release_task at ffffffff81059ebd
11 [ffff8839ece41f08] do_exit at ffffffff8105b8ce
12 [ffff8839ece41f78] sys_exit at ffffffff8105bd53
13 [ffff8839ece41f80] system_call_fastpath at ffffffff81532909

While some of the callers of shrink_dentry_list do use cond_resched,
this is not sufficient to prevent softlockups.  So just move
cond_resched into shrink_dentry_list from its callers.

David said: I've found hundreds of occurrences of warnings that we emit
when need_resched stays set for a prolonged period of time with the
stack trace that is included in the change log.

Link: http://lkml.kernel.org/r/1521718946-31521-1-git-send-email-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Valentin Vidic de99626c2e include/linux/kfifo.h: fix comment
Clean up unusual formatting in the note about locking.

Link: http://lkml.kernel.org/r/20180324002630.13046-1-Valentin.Vidic@CARNet.hr
Signed-off-by: Valentin Vidic <Valentin.Vidic@CARNet.hr>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Sean Young <sean@mess.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Andrew Morton a61fc2cbdf ipc/shm.c: shm_split(): remove unneeded test for NULL shm_file_data.vm_ops
This was added by the recent "ipc/shm.c: add split function to
shm_vm_ops", but it is not necessary.

Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Waiman Long 24704f3619 kernel/sysctl.c: add kdoc comments to do_proc_do{u}intvec_minmax_conv_param
Kdoc comments are added to the do_proc_dointvec_minmax_conv_param and
do_proc_douintvec_minmax_conv_param structures thare are used internally
for range checking.

The error codes returned by proc_dointvec_minmax() and
proc_douintvec_minmax() are also documented.

Link: http://lkml.kernel.org/r/1519926220-7453-3-git-send-email-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Waiman Long 64a11f3dc2 fs/proc/proc_sysctl.c: fix typo in sysctl_check_table_array()
Patch series "ipc: Clamp *mni to the real IPCMNI limit", v3.

The sysctl parameters msgmni, shmmni and semmni have an inherent limit
of IPC_MNI (32k).  However, users may not be aware of that because they
can write a value much higher than that without getting any error or
notification.  Reading the parameters back will show the newly written
values which are not real.

Enforcing the limit by failing sysctl parameter write, however, can
break existing user applications.  To address this delemma, a new flags
field is introduced into the ctl_table.  The value CTL_FLAGS_CLAMP_RANGE
can be added to any ctl_table entries to enable a looser range clamping
without returning any error.  For example,

  .flags = CTL_FLAGS_CLAMP_RANGE,

This flags value are now used for the range checking of shmmni, msgmni
and semmni without breaking existing applications.  If any out of range
value is written to those sysctl parameters, the following warning will
be printed instead.

  Kernel parameter "shmmni" was set out of range [0, 32768], clamped to 32768.

Reading the values back will show 32768 instead of some fake values.

This patch (of 6):

Fix a typo.

Link: http://lkml.kernel.org/r/1519926220-7453-2-git-send-email-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00