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>
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
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+
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
eab09532d4: "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 (a87938b2e2: "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 c715b72c1b: "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>
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>
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>
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>
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>
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>
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>
There is a permission discrepancy when consulting msq ipc object
metadata between /proc/sysvipc/msg (0444) and the MSG_STAT shmctl
command. The later does permission checks for the object vs S_IRUGO.
As such there can be cases where EACCESS is returned via syscall but the
info is displayed anyways in the procfs files.
While this might have security implications via info leaking (albeit no
writing to the msq metadata), this behavior goes way back and showing
all the objects regardless of the permissions was most likely an
overlook - so we are stuck with it. Furthermore, modifying either the
syscall or the procfs file can cause userspace programs to break (ie
ipcs). Some applications require getting the procfs info (without root
privileges) and can be rather slow in comparison with a syscall -- up to
500x in some reported cases for shm.
This patch introduces a new MSG_STAT_ANY command such that the msq ipc
object permissions are ignored, and only audited instead. In addition,
I've left the lsm security hook checks in place, as if some policy can
block the call, then the user has no other choice than just parsing the
procfs file.
Link: http://lkml.kernel.org/r/20180215162458.10059-4-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Robert Kettler <robert.kettler@outlook.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a permission discrepancy when consulting shm ipc object
metadata between /proc/sysvipc/sem (0444) and the SEM_STAT semctl
command. The later does permission checks for the object vs S_IRUGO.
As such there can be cases where EACCESS is returned via syscall but the
info is displayed anyways in the procfs files.
While this might have security implications via info leaking (albeit no
writing to the sma metadata), this behavior goes way back and showing
all the objects regardless of the permissions was most likely an
overlook - so we are stuck with it. Furthermore, modifying either the
syscall or the procfs file can cause userspace programs to break (ie
ipcs). Some applications require getting the procfs info (without root
privileges) and can be rather slow in comparison with a syscall -- up to
500x in some reported cases for shm.
This patch introduces a new SEM_STAT_ANY command such that the sem ipc
object permissions are ignored, and only audited instead. In addition,
I've left the lsm security hook checks in place, as if some policy can
block the call, then the user has no other choice than just parsing the
procfs file.
Link: http://lkml.kernel.org/r/20180215162458.10059-3-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Robert Kettler <robert.kettler@outlook.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "sysvipc: introduce STAT_ANY commands", v2.
The following patches adds the discussed (see [1]) new command for shm
as well as for sems and msq as they are subject to the same
discrepancies for ipc object permission checks between the syscall and
via procfs. These new commands are justified in that (1) we are stuck
with this semantics as changing syscall and procfs can break userland;
and (2) some users can benefit from performance (for large amounts of
shm segments, for example) from not having to parse the procfs
interface.
Once merged, I will submit the necesary manpage updates. But I'm thinking
something like:
: diff --git a/man2/shmctl.2 b/man2/shmctl.2
: index 7bb503999941..bb00bbe21a57 100644
: --- a/man2/shmctl.2
: +++ b/man2/shmctl.2
: @@ -41,6 +41,7 @@
: .\" 2005-04-25, mtk -- noted aberrant Linux behavior w.r.t. new
: .\" attaches to a segment that has already been marked for deletion.
: .\" 2005-08-02, mtk: Added IPC_INFO, SHM_INFO, SHM_STAT descriptions.
: +.\" 2018-02-13, dbueso: Added SHM_STAT_ANY description.
: .\"
: .TH SHMCTL 2 2017-09-15 "Linux" "Linux Programmer's Manual"
: .SH NAME
: @@ -242,6 +243,18 @@ However, the
: argument is not a segment identifier, but instead an index into
: the kernel's internal array that maintains information about
: all shared memory segments on the system.
: +.TP
: +.BR SHM_STAT_ANY " (Linux-specific)"
: +Return a
: +.I shmid_ds
: +structure as for
: +.BR SHM_STAT .
: +However, the
: +.I shm_perm.mode
: +is not checked for read access for
: +.IR shmid ,
: +resembing the behaviour of
: +/proc/sysvipc/shm.
: .PP
: The caller can prevent or allow swapping of a shared
: memory segment with the following \fIcmd\fP values:
: @@ -287,7 +300,7 @@ operation returns the index of the highest used entry in the
: kernel's internal array recording information about all
: shared memory segments.
: (This information can be used with repeated
: -.B SHM_STAT
: +.B SHM_STAT/SHM_STAT_ANY
: operations to obtain information about all shared memory segments
: on the system.)
: A successful
: @@ -328,7 +341,7 @@ isn't accessible.
: \fIshmid\fP is not a valid identifier, or \fIcmd\fP
: is not a valid command.
: Or: for a
: -.B SHM_STAT
: +.B SHM_STAT/SHM_STAT_ANY
: operation, the index value specified in
: .I shmid
: referred to an array slot that is currently unused.
This patch (of 3):
There is a permission discrepancy when consulting shm ipc object metadata
between /proc/sysvipc/shm (0444) and the SHM_STAT shmctl command. The
later does permission checks for the object vs S_IRUGO. As such there can
be cases where EACCESS is returned via syscall but the info is displayed
anyways in the procfs files.
While this might have security implications via info leaking (albeit no
writing to the shm metadata), this behavior goes way back and showing all
the objects regardless of the permissions was most likely an overlook - so
we are stuck with it. Furthermore, modifying either the syscall or the
procfs file can cause userspace programs to break (ie ipcs). Some
applications require getting the procfs info (without root privileges) and
can be rather slow in comparison with a syscall -- up to 500x in some
reported cases.
This patch introduces a new SHM_STAT_ANY command such that the shm ipc
object permissions are ignored, and only audited instead. In addition,
I've left the lsm security hook checks in place, as if some policy can
block the call, then the user has no other choice than just parsing the
procfs file.
[1] https://lkml.org/lkml/2017/12/19/220
Link: http://lkml.kernel.org/r/20180215162458.10059-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Robert Kettler <robert.kettler@outlook.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
