Pull namespace updates from Eric Biederman:
"Life has been busy and I have not gotten half as much done this round
as I would have liked. I delayed it so that a minor conflict
resolution with the mips tree could spend a little time in linux-next
before I sent this pull request.
This includes two long delayed user namespace changes from Kirill
Tkhai. It also includes a very useful change from Serge Hallyn that
allows the security capability attribute to be used inside of user
namespaces. The practical effect of this is people can now untar
tarballs and install rpms in user namespaces. It had been suggested to
generalize this and encode some of the namespace information
information in the xattr name. Upon close inspection that makes the
things that should be hard easy and the things that should be easy
more expensive.
Then there is my bugfix/cleanup for signal injection that removes the
magic encoding of the siginfo union member from the kernel internal
si_code. The mips folks reported the case where I had used FPE_FIXME
me is impossible so I have remove FPE_FIXME from mips, while at the
same time including a return statement in that case to keep gcc from
complaining about unitialized variables.
I almost finished the work to get make copy_siginfo_to_user a trivial
copy to user. The code is available at:
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git neuter-copy_siginfo_to_user-v3
But I did not have time/energy to get the code posted and reviewed
before the merge window opened.
I was able to see that the security excuse for just copying fields
that we know are initialized doesn't work in practice there are buggy
initializations that don't initialize the proper fields in siginfo. So
we still sometimes copy unitialized data to userspace"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
Introduce v3 namespaced file capabilities
mips/signal: In force_fcr31_sig return in the impossible case
signal: Remove kernel interal si_code magic
fcntl: Don't use ambiguous SIG_POLL si_codes
prctl: Allow local CAP_SYS_ADMIN changing exe_file
security: Use user_namespace::level to avoid redundant iterations in cap_capable()
userns,pidns: Verify the userns for new pid namespaces
signal/testing: Don't look for __SI_FAULT in userspace
signal/mips: Document a conflict with SI_USER with SIGFPE
signal/sparc: Document a conflict with SI_USER with SIGFPE
signal/ia64: Document a conflict with SI_USER with SIGFPE
signal/alpha: Document a conflict with SI_USER for SIGTRAP
Merge more updates from Andrew Morton:
- most of the rest of MM
- a small number of misc things
- lib/ updates
- checkpatch
- autofs updates
- ipc/ updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (126 commits)
ipc: optimize semget/shmget/msgget for lots of keys
ipc/sem: play nicer with large nsops allocations
ipc/sem: drop sem_checkid helper
ipc: convert kern_ipc_perm.refcount from atomic_t to refcount_t
ipc: convert sem_undo_list.refcnt from atomic_t to refcount_t
ipc: convert ipc_namespace.count from atomic_t to refcount_t
kcov: support compat processes
sh: defconfig: cleanup from old Kconfig options
mn10300: defconfig: cleanup from old Kconfig options
m32r: defconfig: cleanup from old Kconfig options
drivers/pps: use surrounding "if PPS" to remove numerous dependency checks
drivers/pps: aesthetic tweaks to PPS-related content
cpumask: make cpumask_next() out-of-line
kmod: move #ifdef CONFIG_MODULES wrapper to Makefile
kmod: split off umh headers into its own file
MAINTAINERS: clarify kmod is just a kernel module loader
kmod: split out umh code into its own file
test_kmod: flip INT checks to be consistent
test_kmod: remove paranoid UINT_MAX check on uint range processing
vfat: deduplicate hex2bin()
...
Alpha already had an optimised fill-memory-with-16-bit-quantity
assembler routine called memsetw(). It has a slightly different calling
convention from memset16() in that it takes a byte count, not a count of
words. That's the same convention used by ARM's __memset routines, so
rename Alpha's routine to match and add a memset16() wrapper around it.
Then convert Alpha's scr_memsetw() to call memset16() instead of
memsetw().
Link: http://lkml.kernel.org/r/20170720184539.31609-6-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'pci-v4.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
- add enhanced Downstream Port Containment support, which prints more
details about Root Port Programmed I/O errors (Dongdong Liu)
- add Layerscape ls1088a and ls2088a support (Hou Zhiqiang)
- add MediaTek MT2712 and MT7622 support (Ryder Lee)
- add MediaTek MT2712 and MT7622 MSI support (Honghui Zhang)
- add Qualcom IPQ8074 support (Varadarajan Narayanan)
- add R-Car r8a7743/5 device tree support (Biju Das)
- add Rockchip per-lane PHY support for better power management (Shawn
Lin)
- fix IRQ mapping for hot-added devices by replacing the
pci_fixup_irqs() boot-time design with a host bridge hook called at
probe-time (Lorenzo Pieralisi, Matthew Minter)
- fix race when enabling two devices that results in upstream bridge
not being enabled correctly (Srinath Mannam)
- fix pciehp power fault infinite loop (Keith Busch)
- fix SHPC bridge MSI hotplug events by enabling bus mastering
(Aleksandr Bezzubikov)
- fix a VFIO issue by correcting PCIe capability sizes (Alex
Williamson)
- fix an INTD issue on Xilinx and possibly other drivers by unifying
INTx IRQ domain support (Paul Burton)
- avoid IOMMU stalls by marking AMD Stoney GPU ATS as broken (Joerg
Roedel)
- allow APM X-Gene device assignment to guests by adding an ACS quirk
(Feng Kan)
- fix driver crashes by disabling Extended Tags on Broadcom HT2100
(Extended Tags support is required for PCIe Receivers but not
Requesters, and we now enable them by default when Requesters support
them) (Sinan Kaya)
- fix MSIs for devices that use phantom RIDs for DMA by assuming MSIs
use the real Requester ID (not a phantom RID) (Robin Murphy)
- prevent assignment of Intel VMD children to guests (which may be
supported eventually, but isn't yet) by not associating an IOMMU with
them (Jon Derrick)
- fix Intel VMD suspend/resume by releasing IRQs on suspend (Scott
Bauer)
- fix a Function-Level Reset issue with Intel 750 NVMe by waiting
longer (up to 60sec instead of 1sec) for device to become ready
(Sinan Kaya)
- fix a Function-Level Reset issue on iProc Stingray by working around
hardware defects in the CRS implementation (Oza Pawandeep)
- fix an issue with Intel NVMe P3700 after an iProc reset by adding a
delay during shutdown (Oza Pawandeep)
- fix a Microsoft Hyper-V lockdep issue by polling instead of blocking
in compose_msi_msg() (Stephen Hemminger)
- fix a wireless LAN driver timeout by clearing DesignWare MSI
interrupt status after it is handled, not before (Faiz Abbas)
- fix DesignWare ATU enable checking (Jisheng Zhang)
- reduce Layerscape dependencies on the bootloader by doing more
initialization in the driver (Hou Zhiqiang)
- improve Intel VMD performance allowing allocation of more IRQ vectors
than present CPUs (Keith Busch)
- improve endpoint framework support for initial DMA mask, different
BAR sizes, configurable page sizes, MSI, test driver, etc (Kishon
Vijay Abraham I, Stan Drozd)
- rework CRS support to add periodic messages while we poll during
enumeration and after Function-Level Reset and prepare for possible
other uses of CRS (Sinan Kaya)
- clean up Root Port AER handling by removing unnecessary code and
moving error handler methods to struct pcie_port_service_driver
(Christoph Hellwig)
- clean up error handling paths in various drivers (Bjorn Andersson,
Fabio Estevam, Gustavo A. R. Silva, Harunobu Kurokawa, Jeffy Chen,
Lorenzo Pieralisi, Sergei Shtylyov)
- clean up SR-IOV resource handling by disabling VF decoding before
updating the corresponding resource structs (Gavin Shan)
- clean up DesignWare-based drivers by unifying quirks to update Class
Code and Interrupt Pin and related handling of write-protected
registers (Hou Zhiqiang)
- clean up by adding empty generic pcibios_align_resource() and
pcibios_fixup_bus() and removing empty arch-specific implementations
(Palmer Dabbelt)
- request exclusive reset control for several drivers to allow cleanup
elsewhere (Philipp Zabel)
- constify various structures (Arvind Yadav, Bhumika Goyal)
- convert from full_name() to %pOF (Rob Herring)
- remove unused variables from iProc, HiSi, Altera, Keystone (Shawn
Lin)
* tag 'pci-v4.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (170 commits)
PCI: xgene: Clean up whitespace
PCI: xgene: Define XGENE_PCI_EXP_CAP and use generic PCI_EXP_RTCTL offset
PCI: xgene: Fix platform_get_irq() error handling
PCI: xilinx-nwl: Fix platform_get_irq() error handling
PCI: rockchip: Fix platform_get_irq() error handling
PCI: altera: Fix platform_get_irq() error handling
PCI: spear13xx: Fix platform_get_irq() error handling
PCI: artpec6: Fix platform_get_irq() error handling
PCI: armada8k: Fix platform_get_irq() error handling
PCI: dra7xx: Fix platform_get_irq() error handling
PCI: exynos: Fix platform_get_irq() error handling
PCI: iproc: Clean up whitespace
PCI: iproc: Rename PCI_EXP_CAP to IPROC_PCI_EXP_CAP
PCI: iproc: Add 500ms delay during device shutdown
PCI: Fix typos and whitespace errors
PCI: Remove unused "res" variable from pci_resource_io()
PCI: Correct kernel-doc of pci_vpd_srdt_size(), pci_vpd_srdt_tag()
PCI/AER: Reformat AER register definitions
iommu/vt-d: Prevent VMD child devices from being remapping targets
x86/PCI: Use is_vmd() rather than relying on the domain number
...
Merge updates from Andrew Morton:
- various misc bits
- DAX updates
- OCFS2
- most of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (119 commits)
mm,fork: introduce MADV_WIPEONFORK
x86,mpx: make mpx depend on x86-64 to free up VMA flag
mm: add /proc/pid/smaps_rollup
mm: hugetlb: clear target sub-page last when clearing huge page
mm: oom: let oom_reap_task and exit_mmap run concurrently
swap: choose swap device according to numa node
mm: replace TIF_MEMDIE checks by tsk_is_oom_victim
mm, oom: do not rely on TIF_MEMDIE for memory reserves access
z3fold: use per-cpu unbuddied lists
mm, swap: don't use VMA based swap readahead if HDD is used as swap
mm, swap: add sysfs interface for VMA based swap readahead
mm, swap: VMA based swap readahead
mm, swap: fix swap readahead marking
mm, swap: add swap readahead hit statistics
mm/vmalloc.c: don't reinvent the wheel but use existing llist API
mm/vmstat.c: fix wrong comment
selftests/memfd: add memfd_create hugetlbfs selftest
mm/shmem: add hugetlbfs support to memfd_create()
mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups
mm/vmalloc.c: halve the number of comparisons performed in pcpu_get_vm_areas()
...
Introduce MADV_WIPEONFORK semantics, which result in a VMA being empty
in the child process after fork. This differs from MADV_DONTFORK in one
important way.
If a child process accesses memory that was MADV_WIPEONFORK, it will get
zeroes. The address ranges are still valid, they are just empty.
If a child process accesses memory that was MADV_DONTFORK, it will get a
segmentation fault, since those address ranges are no longer valid in
the child after fork.
Since MADV_DONTFORK also seems to be used to allow very large programs
to fork in systems with strict memory overcommit restrictions, changing
the semantics of MADV_DONTFORK might break existing programs.
MADV_WIPEONFORK only works on private, anonymous VMAs.
The use case is libraries that store or cache information, and want to
know that they need to regenerate it in the child process after fork.
Examples of this would be:
- systemd/pulseaudio API checks (fail after fork) (replacing a getpid
check, which is too slow without a PID cache)
- PKCS#11 API reinitialization check (mandated by specification)
- glibc's upcoming PRNG (reseed after fork)
- OpenSSL PRNG (reseed after fork)
The security benefits of a forking server having a re-inialized PRNG in
every child process are pretty obvious. However, due to libraries
having all kinds of internal state, and programs getting compiled with
many different versions of each library, it is unreasonable to expect
calling programs to re-initialize everything manually after fork.
A further complication is the proliferation of clone flags, programs
bypassing glibc's functions to call clone directly, and programs calling
unshare, causing the glibc pthread_atfork hook to not get called.
It would be better to have the kernel take care of this automatically.
The patch also adds MADV_KEEPONFORK, to undo the effects of a prior
MADV_WIPEONFORK.
This is similar to the OpenBSD minherit syscall with MAP_INHERIT_ZERO:
https://man.openbsd.org/minherit.2
[akpm@linux-foundation.org: numerically order arch/parisc/include/uapi/asm/mman.h #defines]
Link: http://lkml.kernel.org/r/20170811212829.29186-3-riel@redhat.com
Signed-off-by: Rik van Riel <riel@redhat.com>
Reported-by: Florian Weimer <fweimer@redhat.com>
Reported-by: Colm MacCártaigh <colm@allcosts.net>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Cc: <linux-api@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A non-default huge page size can be encoded in the flags argument of the
mmap system call. The definitions for these encodings are in arch
specific header files. However, all architectures use the same values.
Consolidate all the definitions in the primary user header file
(uapi/linux/mman.h). Include definitions for all known huge page sizes.
Use the generic encoding definitions in hugetlb_encode.h as the basis
for these definitions.
Link: http://lkml.kernel.org/r/1501527386-10736-3-git-send-email-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
1) Support ipv6 checksum offload in sunvnet driver, from Shannon
Nelson.
2) Move to RB-tree instead of custom AVL code in inetpeer, from Eric
Dumazet.
3) Allow generic XDP to work on virtual devices, from John Fastabend.
4) Add bpf device maps and XDP_REDIRECT, which can be used to build
arbitrary switching frameworks using XDP. From John Fastabend.
5) Remove UFO offloads from the tree, gave us little other than bugs.
6) Remove the IPSEC flow cache, from Florian Westphal.
7) Support ipv6 route offload in mlxsw driver.
8) Support VF representors in bnxt_en, from Sathya Perla.
9) Add support for forward error correction modes to ethtool, from
Vidya Sagar Ravipati.
10) Add time filter for packet scheduler action dumping, from Jamal Hadi
Salim.
11) Extend the zerocopy sendmsg() used by virtio and tap to regular
sockets via MSG_ZEROCOPY. From Willem de Bruijn.
12) Significantly rework value tracking in the BPF verifier, from Edward
Cree.
13) Add new jump instructions to eBPF, from Daniel Borkmann.
14) Rework rtnetlink plumbing so that operations can be run without
taking the RTNL semaphore. From Florian Westphal.
15) Support XDP in tap driver, from Jason Wang.
16) Add 32-bit eBPF JIT for ARM, from Shubham Bansal.
17) Add Huawei hinic ethernet driver.
18) Allow to report MD5 keys in TCP inet_diag dumps, from Ivan
Delalande.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1780 commits)
i40e: point wb_desc at the nvm_wb_desc during i40e_read_nvm_aq
i40e: avoid NVM acquire deadlock during NVM update
drivers: net: xgene: Remove return statement from void function
drivers: net: xgene: Configure tx/rx delay for ACPI
drivers: net: xgene: Read tx/rx delay for ACPI
rocker: fix kcalloc parameter order
rds: Fix non-atomic operation on shared flag variable
net: sched: don't use GFP_KERNEL under spin lock
vhost_net: correctly check tx avail during rx busy polling
net: mdio-mux: add mdio_mux parameter to mdio_mux_init()
rxrpc: Make service connection lookup always check for retry
net: stmmac: Delete dead code for MDIO registration
gianfar: Fix Tx flow control deactivation
cxgb4: Ignore MPS_TX_INT_CAUSE[Bubble] for T6
cxgb4: Fix pause frame count in t4_get_port_stats
cxgb4: fix memory leak
tun: rename generic_xdp to skb_xdp
tun: reserve extra headroom only when XDP is set
net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping
net: dsa: bcm_sf2: Advertise number of egress queues
...
Pull alpha updates from Matt Turner:
"This contains some small clean up patches I've neglected, and some
build improvements from Ben Hutchings"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha:
alpha: math-emu: Fix modular build
alpha: Restore symbol versions for symbols exported from assembly
alpha: defconfig: Cleanup from old Kconfig options
alpha: use kobj_to_dev()
alpha: squash lines for immediate return
alpha: kernel: Use vma_pages()
alpha: silence a buffer overflow warning
alpha: marvel: make use of raw_spinlock variants
alpha: cleanup: remove __NR_sys_epoll_*, leave __NR_epoll_*
alpha: use generic fb.h
Commit 00fc0e0dda ("alpha: move exports to actual definitions") also
removed the exports of the math emulator hooks, which are defined in C
code. In case anyone cares about the option of CONFIG_MATHEMU=m, add
exports next to those definitions. Also add a MODULE_LICENSE.
Fixes: 00fc0e0dda ("alpha: move exports to actual definitions")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Add <asm/asm-prototypes.h> so that genksyms knows the types of
these symbols and can generate CRCs for them.
Fixes: 00fc0e0dda ("alpha: move exports to actual definitions")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Remove old, dead Kconfig options (in order appearing in this commit):
- IP_NF_QUEUE: commit 3dd6664fac ("netfilter: remove unused "config
IP_NF_QUEUE"");
- AUTOFS_FS: commit 561c5cf923 ("staging: Remove autofs3");
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Remove unneeded variables and assignments.
While we are here, fix the coding style of SMC37c669_read_config():
- replace whitespaces at the start of lines with tabs
- remove unneeded whitespaces around parentheses
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Replace explicit computation of vma page count by a call to
vma_pages()
Signed-off-by: Shyam Saini <mayhs11saini@gmail.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
We check that "member" is in bounds for the first line, but we also use
it on the next line without checking which is a mistake.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
The alpha/marvel code currently implements an irq_chip for handling
interrupts; due to how irq_chip handling is done, it's necessary for the
irq_chip methods to be invoked from hardirq context, even on a a
real-time kernel. Because the spinlock_t type becomes a "sleeping"
spinlock w/ RT kernels, it is not suitable to be used with irq_chips.
A quick audit of the operations under the lock reveal that they do only
minimal, bounded work, and are therefore safe to do under a raw spinlock.
Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
__NR_sys_epoll_create and friends are alpha-specific
while __NR_epoll_create is a generic name for other
arches.
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: linux-alpha@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Matt Turner <mattst88@gmail.com>
The arch uses a verbatim copy of the asm-generic version and does not
add any own implemntations to the header, so use asm-generic/fb.h
instead of duplicating code.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Pull locking updates from Ingo Molnar:
- Add 'cross-release' support to lockdep, which allows APIs like
completions, where it's not the 'owner' who releases the lock, to be
tracked. It's all activated automatically under
CONFIG_PROVE_LOCKING=y.
- Clean up (restructure) the x86 atomics op implementation to be more
readable, in preparation of KASAN annotations. (Dmitry Vyukov)
- Fix static keys (Paolo Bonzini)
- Add killable versions of down_read() et al (Kirill Tkhai)
- Rework and fix jump_label locking (Marc Zyngier, Paolo Bonzini)
- Rework (and fix) tlb_flush_pending() barriers (Peter Zijlstra)
- Remove smp_mb__before_spinlock() and convert its usages, introduce
smp_mb__after_spinlock() (Peter Zijlstra)
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits)
locking/lockdep/selftests: Fix mixed read-write ABBA tests
sched/completion: Avoid unnecessary stack allocation for COMPLETION_INITIALIZER_ONSTACK()
acpi/nfit: Fix COMPLETION_INITIALIZER_ONSTACK() abuse
locking/pvqspinlock: Relax cmpxchg's to improve performance on some architectures
smp: Avoid using two cache lines for struct call_single_data
locking/lockdep: Untangle xhlock history save/restore from task independence
locking/refcounts, x86/asm: Disable CONFIG_ARCH_HAS_REFCOUNT for the time being
futex: Remove duplicated code and fix undefined behaviour
Documentation/locking/atomic: Finish the document...
locking/lockdep: Fix workqueue crossrelease annotation
workqueue/lockdep: 'Fix' flush_work() annotation
locking/lockdep/selftests: Add mixed read-write ABBA tests
mm, locking/barriers: Clarify tlb_flush_pending() barriers
locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE and CONFIG_LOCKDEP_COMPLETIONS truly non-interactive
locking/lockdep: Explicitly initialize wq_barrier::done::map
locking/lockdep: Rename CONFIG_LOCKDEP_COMPLETE to CONFIG_LOCKDEP_COMPLETIONS
locking/lockdep: Reword title of LOCKDEP_CROSSRELEASE config
locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE part of CONFIG_PROVE_LOCKING
locking/refcounts, x86/asm: Implement fast refcount overflow protection
locking/lockdep: Fix the rollback and overwrite detection logic in crossrelease
...
Pull RCU updates from Ingo Molnad:
"The main RCU related changes in this cycle were:
- Removal of spin_unlock_wait()
- SRCU updates
- RCU torture-test updates
- RCU Documentation updates
- Extend the sys_membarrier() ABI with the MEMBARRIER_CMD_PRIVATE_EXPEDITED variant
- Miscellaneous RCU fixes
- CPU-hotplug fixes"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
arch: Remove spin_unlock_wait() arch-specific definitions
locking: Remove spin_unlock_wait() generic definitions
drivers/ata: Replace spin_unlock_wait() with lock/unlock pair
ipc: Replace spin_unlock_wait() with lock/unlock pair
exit: Replace spin_unlock_wait() with lock/unlock pair
completion: Replace spin_unlock_wait() with lock/unlock pair
doc: Set down RCU's scheduling-clock-interrupt needs
doc: No longer allowed to use rcu_dereference on non-pointers
doc: Add RCU files to docbook-generation files
doc: Update memory-barriers.txt for read-to-write dependencies
doc: Update RCU documentation
membarrier: Provide expedited private command
rcu: Remove exports from rcu_idle_exit() and rcu_idle_enter()
rcu: Add warning to rcu_idle_enter() for irqs enabled
rcu: Make rcu_idle_enter() rely on callers disabling irqs
rcu: Add assertions verifying blocked-tasks list
rcu/tracing: Set disable_rcu_irq_enter on rcu_eqs_exit()
rcu: Add TPS() protection for _rcu_barrier_trace strings
rcu: Use idle versions of swait to make idle-hack clear
swait: Add idle variants which don't contribute to load average
...
This fixes compiler errors in perf such as:
tests/attr.c: In function 'store_event':
tests/attr.c:66:27: error: format '%llu' expects argument of type 'long long unsigned int', but argument 6 has type '__u64 {aka long unsigned int}' [-Werror=format=]
snprintf(path, PATH_MAX, "%s/event-%d-%llu-%d", dir,
^
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tested-by: Michael Cree <mcree@orcon.net.nz>
Cc: stable@vger.kernel.org
Signed-off-by: Matt Turner <mattst88@gmail.com>
Commit 3cc2dac5be ("drivers/video/fbdev/atyfb: Replace MTRR UC hole
with strong UC") introduces calls to ioremap_wc and ioremap_uc. This
causes build failures with alpha:allmodconfig. Map the missing functions
to ioremap_nocache.
Fixes: 3cc2dac5be ("drivers/video/fbdev/atyfb:
Replace MTRR UC hole with strong UC")
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Since commit 71810db27c (modversions: treat symbol CRCs
as 32 bit quantities) R_ALPHA_REFLONG relocations can be required
to load modules. This implements it.
Tested-by: Bob Tracy <rct@gherkin.frus.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Patch 8525023121 introduced a typo.
That said, the identity AND insns added by that patch are more
clearly written as MOV. At the same time, re-schedule the ev6
version so that the first dispatch can execute in parallel.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Matt Turner <mattst88@gmail.com>
There are direct branches between {str*cpy,str*cat} and stx*cpy.
Ensure the branches are within range by merging these objects.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Matt Turner <mattst88@gmail.com>
There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.
Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.
This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046f8 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.
And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.
Note that s390 removed access_ok check in d12a29703 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390]
Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org>
Reviewed-by: Will Deacon <will.deacon@arm.com> [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker <dalias@libc.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn <jonas@southpole.se>
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Stafford Horne <shorne@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson <rth@twiddle.net>
Cc: Chris Zankel <chris@zankel.net>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
There is no agreed-upon definition of spin_unlock_wait()'s semantics,
and it appears that all callers could do just as well with a lock/unlock
pair. This commit therefore removes the underlying arch-specific
arch_spin_unlock_wait() for all architectures providing them.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
The send call ignores unknown flags. Legacy applications may already
unwittingly pass MSG_ZEROCOPY. Continue to ignore this flag unless a
socket opts in to zerocopy.
Introduce socket option SO_ZEROCOPY to enable MSG_ZEROCOPY processing.
Processes can also query this socket option to detect kernel support
for the feature. Older kernels will return ENOPROTOOPT.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The pci_fixup_irqs() function allocates IRQs for all PCI devices present in
a system; those PCI devices possibly belong to different PCI bus trees (and
possibly rooted at different host bridges) and may well be enabled (ie
probed and bound to a driver) by the time pci_fixup_irqs() is called when
probing a given host bridge driver.
Furthermore, current kernel code relying on pci_fixup_irqs() to assign
legacy PCI IRQs to devices does not work at all for hotplugged devices in
that the code carrying out the IRQ fixup is called at host bridge driver
probe time, which just cannot take into account devices hotplugged after
the system has booted.
The introduction of map/swizzle function hooks in struct pci_host_bridge
allows us to define per-bridge map/swizzle functions that can be used at
device probe time in PCI core code to allocate IRQs for a given device
(through pci_assign_irq()).
Convert PCI host bridge initialization code to the
pci_scan_root_bus_bridge() API (that allows to pass a struct
pci_host_bridge with initialized map/swizzle pointers) and remove the
pci_fixup_irqs() call from arch code.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
struct siginfo is a union and the kernel since 2.4 has been hiding a union
tag in the high 16bits of si_code using the values:
__SI_KILL
__SI_TIMER
__SI_POLL
__SI_FAULT
__SI_CHLD
__SI_RT
__SI_MESGQ
__SI_SYS
While this looks plausible on the surface, in practice this situation has
not worked well.
- Injected positive signals are not copied to user space properly
unless they have these magic high bits set.
- Injected positive signals are not reported properly by signalfd
unless they have these magic high bits set.
- These kernel internal values leaked to userspace via ptrace_peek_siginfo
- It was possible to inject these kernel internal values and cause the
the kernel to misbehave.
- Kernel developers got confused and expected these kernel internal values
in userspace in kernel self tests.
- Kernel developers got confused and set si_code to __SI_FAULT which
is SI_USER in userspace which causes userspace to think an ordinary user
sent the signal and that it was not kernel generated.
- The values make it impossible to reorganize the code to transform
siginfo_copy_to_user into a plain copy_to_user. As si_code must
be massaged before being passed to userspace.
So remove these kernel internal si codes and make the kernel code simpler
and more maintainable.
To replace these kernel internal magic si_codes introduce the helper
function siginfo_layout, that takes a signal number and an si_code and
computes which union member of siginfo is being used. Have
siginfo_layout return an enumeration so that gcc will have enough
information to warn if a switch statement does not handle all of union
members.
A couple of architectures have a messed up ABI that defines signal
specific duplications of SI_USER which causes more special cases in
siginfo_layout than I would like. The good news is only problem
architectures pay the cost.
Update all of the code that used the previous magic __SI_ values to
use the new SIL_ values and to call siginfo_layout to get those
values. Escept where not all of the cases are handled remove the
defaults in the switch statements so that if a new case is missed in
the future the lack will show up at compile time.
Modify the code that copies siginfo si_code to userspace to just copy
the value and not cast si_code to a short first. The high bits are no
longer used to hold a magic union member.
Fixup the siginfo header files to stop including the __SI_ values in
their constants and for the headers that were missing it to properly
update the number of si_codes for each signal type.
The fixes to copy_siginfo_from_user32 implementations has the
interesting property that several of them perviously should never have
worked as the __SI_ values they depended up where kernel internal.
With that dependency gone those implementations should work much
better.
The idea of not passing the __SI_ values out to userspace and then
not reinserting them has been tested with criu and criu worked without
changes.
Ref: 2.4.0-test1
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Setting si_code to __SI_FAULT results in a userspace seeing
an si_code of 0. This is the same si_code as SI_USER. Posix
and common sense requires that SI_USER not be a signal specific
si_code. As such this use of 0 for the si_code is a pretty
horribly broken ABI.
Given that alpha is on it's last legs I don't know that it is worth
fixing this, but it is worth documenting what is going on so that
no one decides to copy this bad decision.
This was introduced during the 2.5 development cycle so this
mess has had a long time for people to be able to depend upon it.
v2: Added FPE_FIXME for alpha as Helge Deller <deller@gmx.de> pointed out
with his alternate patch one of the cases is SIGFPE not SIGTRAP.
Cc: Helge Deller <deller@gmx.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: linux-alpha@vger.kernel.org
Acked-by: Richard Henderson <rth@twiddle.net>
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Ref: 0a635c7a84cf ("Fill in siginfo_t.")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This ioctl does nothing to justify an _IOC_READ or _IOC_WRITE flag
because it doesn't copy anything from/to userspace to access the
argument.
Fixes: 54ebbfb160 ("tty: add TIOCGPTPEER ioctl")
Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Acked-by: Aleksa Sarai <asarai@suse.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull user access str* updates from Al Viro:
"uaccess str...() dead code removal"
* 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
s390 keyboard.c: don't open-code strndup_user()
mips: get rid of unused __strnlen_user()
get rid of unused __strncpy_from_user() instances
kill strlen_user()
Pull alpha user access updates from Al Viro:
"Several alpha osf_sys.c uaccess cleanups - getdomainname() had insane
byte-by-byte copying of string to userland (instead of strnlen +
copy_to_user) plus yet another compat variant of timeval/itimerval
with associated copyin/copyout primitives"
* 'misc.alpha' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
osf_sigstack(): switch to put_user()
osf_sys.c: switch handling of timeval32/itimerval32 to copy_{to,from}_user()
osf_getdomainname(): use copy_to_user()
Pull misc compat stuff updates from Al Viro:
"This part is basically untangling various compat stuff. Compat
syscalls moved to their native counterparts, getting rid of quite a
bit of double-copying and/or set_fs() uses. A lot of field-by-field
copyin/copyout killed off.
- kernel/compat.c is much closer to containing just the
copyin/copyout of compat structs. Not all compat syscalls are gone
from it yet, but it's getting there.
- ipc/compat_mq.c killed off completely.
- block/compat_ioctl.c cleaned up; floppy compat ioctls moved to
drivers/block/floppy.c where they belong. Yes, there are several
drivers that implement some of the same ioctls. Some are m68k and
one is 32bit-only pmac. drivers/block/floppy.c is the only one in
that bunch that can be built on biarch"
* 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
mqueue: move compat syscalls to native ones
usbdevfs: get rid of field-by-field copyin
compat_hdio_ioctl: get rid of set_fs()
take floppy compat ioctls to sodding floppy.c
ipmi: get rid of field-by-field __get_user()
ipmi: get COMPAT_IPMICTL_RECEIVE_MSG in sync with the native one
rt_sigtimedwait(): move compat to native
select: switch compat_{get,put}_fd_set() to compat_{get,put}_bitmap()
put_compat_rusage(): switch to copy_to_user()
sigpending(): move compat to native
getrlimit()/setrlimit(): move compat to native
times(2): move compat to native
compat_{get,put}_bitmap(): use unsafe_{get,put}_user()
fb_get_fscreeninfo(): don't bother with do_fb_ioctl()
do_sigaltstack(): lift copying to/from userland into callers
take compat_sys_old_getrlimit() to native syscall
trim __ARCH_WANT_SYS_OLD_GETRLIMIT
Pull wait syscall updates from Al Viro:
"Consolidating sys_wait* and compat counterparts.
Gets rid of set_fs()/double-copy mess, simplifies the whole thing
(lifting the copyouts to the syscalls means less headache in the part
that does actual work - fewer failure exits, to start with), gets rid
of the overhead of field-by-field __put_user()"
* 'work.sys_wait' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
osf_wait4: switch to kernel_wait4()
waitid(): switch copyout of siginfo to unsafe_put_user()
wait_task_zombie: consolidate info logics
kill wait_noreap_copyout()
lift getrusage() from wait_noreap_copyout()
waitid(2): leave copyout of siginfo to syscall itself
kernel_wait4()/kernel_waitid(): delay copying status to userland
wait4(2)/waitid(2): separate copying rusage to userland
move compat wait4 and waitid next to native variants
Pull networking updates from David Miller:
"Reasonably busy this cycle, but perhaps not as busy as in the 4.12
merge window:
1) Several optimizations for UDP processing under high load from
Paolo Abeni.
2) Support pacing internally in TCP when using the sch_fq packet
scheduler for this is not practical. From Eric Dumazet.
3) Support mutliple filter chains per qdisc, from Jiri Pirko.
4) Move to 1ms TCP timestamp clock, from Eric Dumazet.
5) Add batch dequeueing to vhost_net, from Jason Wang.
6) Flesh out more completely SCTP checksum offload support, from
Davide Caratti.
7) More plumbing of extended netlink ACKs, from David Ahern, Pablo
Neira Ayuso, and Matthias Schiffer.
8) Add devlink support to nfp driver, from Simon Horman.
9) Add RTM_F_FIB_MATCH flag to RTM_GETROUTE queries, from Roopa
Prabhu.
10) Add stack depth tracking to BPF verifier and use this information
in the various eBPF JITs. From Alexei Starovoitov.
11) Support XDP on qed device VFs, from Yuval Mintz.
12) Introduce BPF PROG ID for better introspection of installed BPF
programs. From Martin KaFai Lau.
13) Add bpf_set_hash helper for TC bpf programs, from Daniel Borkmann.
14) For loads, allow narrower accesses in bpf verifier checking, from
Yonghong Song.
15) Support MIPS in the BPF selftests and samples infrastructure, the
MIPS eBPF JIT will be merged in via the MIPS GIT tree. From David
Daney.
16) Support kernel based TLS, from Dave Watson and others.
17) Remove completely DST garbage collection, from Wei Wang.
18) Allow installing TCP MD5 rules using prefixes, from Ivan
Delalande.
19) Add XDP support to Intel i40e driver, from Björn Töpel
20) Add support for TC flower offload in nfp driver, from Simon
Horman, Pieter Jansen van Vuuren, Benjamin LaHaise, Jakub
Kicinski, and Bert van Leeuwen.
21) IPSEC offloading support in mlx5, from Ilan Tayari.
22) Add HW PTP support to macb driver, from Rafal Ozieblo.
23) Networking refcount_t conversions, From Elena Reshetova.
24) Add sock_ops support to BPF, from Lawrence Brako. This is useful
for tuning the TCP sockopt settings of a group of applications,
currently via CGROUPs"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1899 commits)
net: phy: dp83867: add workaround for incorrect RX_CTRL pin strap
dt-bindings: phy: dp83867: provide a workaround for incorrect RX_CTRL pin strap
cxgb4: Support for get_ts_info ethtool method
cxgb4: Add PTP Hardware Clock (PHC) support
cxgb4: time stamping interface for PTP
nfp: default to chained metadata prepend format
nfp: remove legacy MAC address lookup
nfp: improve order of interfaces in breakout mode
net: macb: remove extraneous return when MACB_EXT_DESC is defined
bpf: add missing break in for the TCP_BPF_SNDCWND_CLAMP case
bpf: fix return in load_bpf_file
mpls: fix rtm policy in mpls_getroute
net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t
net, ax25: convert ax25_route.refcount from atomic_t to refcount_t
net, ax25: convert ax25_uid_assoc.refcount from atomic_t to refcount_t
net, sctp: convert sctp_ep_common.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_transport.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_chunk.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_datamsg.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_auth_bytes.refcnt from atomic_t to refcount_t
...
This adds the new getsockopt(2) option SO_PEERGROUPS on SOL_SOCKET to
retrieve the auxiliary groups of the remote peer. It is designed to
naturally extend SO_PEERCRED. That is, the underlying data is from the
same credentials. Regarding its syntax, it is based on SO_PEERSEC. That
is, if the provided buffer is too small, ERANGE is returned and @optlen
is updated. Otherwise, the information is copied, @optlen is set to the
actual size, and 0 is returned.
While SO_PEERCRED (and thus `struct ucred') already returns the primary
group, it lacks the auxiliary group vector. However, nearly all access
controls (including kernel side VFS and SYSVIPC, but also user-space
polkit, DBus, ...) consider the entire set of groups, rather than just
the primary group. But this is currently not possible with pure
SO_PEERCRED. Instead, user-space has to work around this and query the
system database for the auxiliary groups of a UID retrieved via
SO_PEERCRED.
Unfortunately, there is no race-free way to query the auxiliary groups
of the PID/UID retrieved via SO_PEERCRED. Hence, the current user-space
solution is to use getgrouplist(3p), which itself falls back to NSS and
whatever is configured in nsswitch.conf(3). This effectively checks
which groups we *would* assign to the user if it logged in *now*. On
normal systems it is as easy as reading /etc/group, but with NSS it can
resort to quering network databases (eg., LDAP), using IPC or network
communication.
Long story short: Whenever we want to use auxiliary groups for access
checks on IPC, we need further IPC to talk to the user/group databases,
rather than just relying on SO_PEERCRED and the incoming socket. This
is unfortunate, and might even result in dead-locks if the database
query uses the same IPC as the original request.
So far, those recursions / dead-locks have been avoided by using
primitive IPC for all crucial NSS modules. However, we want to avoid
re-inventing the wheel for each NSS module that might be involved in
user/group queries. Hence, we would preferably make DBus (and other IPC
that supports access-management based on groups) work without resorting
to the user/group database. This new SO_PEERGROUPS ioctl would allow us
to make dbus-daemon work without ever calling into NSS.
Cc: Michal Sekletar <msekleta@redhat.com>
Cc: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When opening the slave end of a PTY, it is not possible for userspace to
safely ensure that /dev/pts/$num is actually a slave (in cases where the
mount namespace in which devpts was mounted is controlled by an
untrusted process). In addition, there are several unresolvable
race conditions if userspace were to attempt to detect attacks through
stat(2) and other similar methods [in addition it is not clear how
userspace could detect attacks involving FUSE].
Resolve this by providing an interface for userpace to safely open the
"peer" end of a PTY file descriptor by using the dentry cached by
devpts. Since it is not possible to have an open master PTY without
having its slave exposed in /dev/pts this interface is safe. This
interface currently does not provide a way to get the master pty (since
it is not clear whether such an interface is safe or even useful).
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Valentin Rothberg <vrothberg@suse.com>
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
