The PR_DUMPABLE flag causes the pid related paths of the proc file
system to be owned by ROOT.
The implementation of pthread_set/getname_np however needs access to
/proc/<pid>/task/<tid>/comm. If PR_DUMPABLE is false this
implementation is locked out.
This patch installs a special permission function for the file "comm"
that grants read and write access to all threads of the same group
regardless of the ownership of the inode. For all other threads the
function falls back to the generic inode permission check.
[akpm@linux-foundation.org: fix spello in comment]
Signed-off-by: Janis Danisevskis <jdanis@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Minfei Huang <mnfhuang@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Calvin Owens <calvinowens@fb.com>
Cc: Jann Horn <jann@thejh.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's not possible to read the process umask without also modifying it,
which is what umask(2) does. A library cannot read umask safely,
especially if the main program might be multithreaded.
Add a new status line ("Umask") in /proc/<PID>/status. It contains the
file mode creation mask (umask) in octal. It is only shown for tasks
which have task->fs.
This patch is adapted from one originally written by Pierre Carrier.
The use case is that we have endless trouble with people setting weird
umask() values (usually on the grounds of "security"), and then
everything breaking. I'm on the hook to fix these. We'd like to add
debugging to our program so we can dump out the umask in debug reports.
Previous versions of the patch used a syscall so you could only read
your own umask. That's all I need. However there was quite a lot of
push-back from those, so this new version exports it in /proc.
See:
https://lkml.org/lkml/2016/4/13/704 [umask2]
https://lkml.org/lkml/2016/4/13/487 [getumask]
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Acked-by: Konstantin Khlebnikov <koct9i@gmail.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pierre Carrier <pierre@spotify.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge updates from Andrew Morton:
- fsnotify fix
- poll() timeout fix
- a few scripts/ tweaks
- debugobjects updates
- the (small) ocfs2 queue
- Minor fixes to kernel/padata.c
- Maybe half of the MM queue
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (117 commits)
mm, page_alloc: restore the original nodemask if the fast path allocation failed
mm, page_alloc: uninline the bad page part of check_new_page()
mm, page_alloc: don't duplicate code in free_pcp_prepare
mm, page_alloc: defer debugging checks of pages allocated from the PCP
mm, page_alloc: defer debugging checks of freed pages until a PCP drain
cpuset: use static key better and convert to new API
mm, page_alloc: inline pageblock lookup in page free fast paths
mm, page_alloc: remove unnecessary variable from free_pcppages_bulk
mm, page_alloc: pull out side effects from free_pages_check
mm, page_alloc: un-inline the bad part of free_pages_check
mm, page_alloc: check multiple page fields with a single branch
mm, page_alloc: remove field from alloc_context
mm, page_alloc: avoid looking up the first zone in a zonelist twice
mm, page_alloc: shortcut watermark checks for order-0 pages
mm, page_alloc: reduce cost of fair zone allocation policy retry
mm, page_alloc: shorten the page allocator fast path
mm, page_alloc: check once if a zone has isolated pageblocks
mm, page_alloc: move __GFP_HARDWALL modifications out of the fastpath
mm, page_alloc: simplify last cpupid reset
mm, page_alloc: remove unnecessary initialisation from __alloc_pages_nodemask()
...
Many developers already know that field for reference count of the
struct page is _count and atomic type. They would try to handle it
directly and this could break the purpose of page reference count
tracepoint. To prevent direct _count modification, this patch rename it
to _refcount and add warning message on the code. After that, developer
who need to handle reference count will find that field should not be
accessed directly.
[akpm@linux-foundation.org: fix comments, per Vlastimil]
[akpm@linux-foundation.org: Documentation/vm/transhuge.txt too]
[sfr@canb.auug.org.au: sync ethernet driver changes]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Sunil Goutham <sgoutham@cavium.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Manish Chopra <manish.chopra@qlogic.com>
Cc: Yuval Mintz <yuval.mintz@qlogic.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for 4.7. Here's the summary of
the changes:
- ATH79: Support for DTB passuing using the UHI boot protocol
- ATH79: Remove support for builtin DTB.
- ATH79: Add zboot debug serial support.
- ATH79: Add initial support for Dragino MS14 (Dragine 2), Onion Omega
and DPT-Module.
- ATH79: Update devicetree clock support for AR9132 and AR9331.
- ATH79: Cleanup the DT code.
- ATH79: Support newer SOCs in ath79_ddr_ctrl_init.
- ATH79: Fix regression in PCI window initialization.
- BCM47xx: Move SPROM driver to drivers/firmware/
- BCM63xx: Enable partition parser in defconfig.
- BMIPS: BMIPS5000 has I cache filing from D cache
- BMIPS: BMIPS: Add cpu-feature-overrides.h
- BMIPS: Add Whirlwind support
- BMIPS: Adjust mips-hpt-frequency for BCM7435
- BMIPS: Remove maxcpus from BCM97435SVMB DTS
- BMIPS: Add missing 7038 L1 register cells to BCM7435
- BMIPS: Various tweaks to initialization code.
- BMIPS: Enable partition parser in defconfig.
- BMIPS: Cache tweaks.
- BMIPS: Add UART, I2C and SATA devices to DT.
- BMIPS: Add BCM6358 and BCM63268support
- BMIPS: Add device tree example for BCM6358.
- BMIPS: Improve Improve BCM6328 and BCM6368 device trees
- Lantiq: Add support for device tree file from boot loader
- Lantiq: Allow build with no built-in DT.
- Loongson 3: Reserve 32MB for RS780E integrated GPU.
- Loongson 3: Fix build error after ld-version.sh modification
- Loongson 3: Move chipset ACPI code from drivers to arch.
- Loongson 3: Speedup irq processing.
- Loongson 3: Add basic Loongson 3A support.
- Loongson 3: Set cache flush handlers to nop.
- Loongson 3: Invalidate special TLBs when needed.
- Loongson 3: Fast TLB refill handler.
- MT7620: Fallback strategy for invalid syscfg0.
- Netlogic: Fix CP0_EBASE redefinition warnings
- Octeon: Initialization fixes
- Octeon: Add DTS files for the D-Link DSR-1000N and EdgeRouter Lite
- Octeon: Enable add Octeon-drivers in cavium_octeon_defconfig
- Octeon: Correctly handle endian-swapped initramfs images.
- Octeon: Support CN73xx, CN75xx and CN78xx.
- Octeon: Remove dead code from cvmx-sysinfo.
- Octeon: Extend number of supported CPUs past 32.
- Octeon: Remove some code limiting NR_IRQS to 255.
- Octeon: Simplify octeon_irq_ciu_gpio_set_type.
- Octeon: Mark some functions __init in smp.c
- Octeon: Octeon: Add Octeon III CN7xxx interface detection
- PIC32: Add serial driver and bindings for it.
- PIC32: Add PIC32 deadman timer driver and bindings.
- PIC32: Add PIC32 clock timer driver and bindings.
- Pistachio: Determine SoC revision during boot
- Sibyte: Fix Kconfig dependencies of SIBYTE_BUS_WATCHER.
- Sibyte: Strip redundant comments from bcm1480_regs.h.
- Panic immediately if panic_on_oops is set.
- module: fix incorrect IS_ERR_VALUE macro usage.
- module: Make consistent use of pr_*
- Remove no longer needed work_on_cpu() call.
- Remove CONFIG_IPV6_PRIVACY from defconfigs.
- Fix registers of non-crashing CPUs in dumps.
- Handle MIPSisms in new vmcore_elf32_check_arch.
- Select CONFIG_HANDLE_DOMAIN_IRQ and make it work.
- Allow RIXI to be used on non-R2 or R6 cores.
- Reserve nosave data for hibernation
- Fix siginfo.h to use strict POSIX types.
- Don't unwind user mode with EVA.
- Fix watchpoint restoration
- Ptrace watchpoints for R6.
- Sync icache when it fills from dcache
- I6400 I-cache fills from dcache.
- Various MSA fixes.
- Cleanup MIPS_CPU_* definitions.
- Signal: Move generic copy_siginfo to signal.h
- Signal: Fix uapi include in exported asm/siginfo.h
- Timer fixes for sake of KVM.
- XPA TLB refill fixes.
- Treat perf counter feature
- Update John Crispin's email address
- Add PIC32 watchdog and bindings.
- Handle R10000 LL/SC bug in set_pte()
- cpufreq: Various fixes for Longson1.
- R6: Fix R2 emulation.
- mathemu: Cosmetic fix to ADDIUPC emulation, plenty of other small fixes
- ELF: ABI and FP fixes.
- Allow for relocatable kernel and use that to support KASLR.
- Fix CPC_BASE_ADDR mask
- Plenty fo smp-cps, CM, R6 and M6250 fixes.
- Make reset_control_ops const.
- Fix kernel command line handling of leading whitespace.
- Cleanups to cache handling.
- Add brcm, bcm6345-l1-intc device tree bindings.
- Use generic clkdev.h header
- Remove CLK_IS_ROOT usage.
- Misc small cleanups.
- CM: Fix compilation error when !MIPS_CM
- oprofile: Fix a preemption issue
- Detect DSP ASE v3 support:1"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (275 commits)
MIPS: pic32mzda: fix getting timer clock rate.
MIPS: ath79: fix regression in PCI window initialization
MIPS: ath79: make ath79_ddr_ctrl_init() compatible for newer SoCs
MIPS: Fix VZ probe gas errors with binutils <2.24
MIPS: perf: Fix I6400 event numbers
MIPS: DEC: Export `ioasic_ssr_lock' to modules
MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC
MIPS: CM: Fix compilation error when !MIPS_CM
MIPS: Fix genvdso error on rebuild
USB: ohci-jz4740: Remove obsolete driver
MIPS: JZ4740: Probe OHCI platform device via DT
MIPS: JZ4740: Qi LB60: Remove support for AVT2 variant
MIPS: pistachio: Determine SoC revision during boot
MIPS: BMIPS: Adjust mips-hpt-frequency for BCM7435
mips: mt7620: fallback to SDRAM when syscfg0 does not have a valid value for the memory type
MIPS: Prevent "restoration" of MSA context in non-MSA kernels
MIPS: cevt-r4k: Dynamically calculate min_delta_ns
MIPS: malta-time: Take seconds into account
MIPS: malta-time: Start GIC count before syncing to RTC
MIPS: Force CPUs to lose FP context during mode switches
...
Pull parallel filesystem directory handling update from Al Viro.
This is the main parallel directory work by Al that makes the vfs layer
able to do lookup and readdir in parallel within a single directory.
That's a big change, since this used to be all protected by the
directory inode mutex.
The inode mutex is replaced by an rwsem, and serialization of lookups of
a single name is done by a "in-progress" dentry marker.
The series begins with xattr cleanups, and then ends with switching
filesystems over to actually doing the readdir in parallel (switching to
the "iterate_shared()" that only takes the read lock).
A more detailed explanation of the process from Al Viro:
"The xattr work starts with some acl fixes, then switches ->getxattr to
passing inode and dentry separately. This is the point where the
things start to get tricky - that got merged into the very beginning
of the -rc3-based #work.lookups, to allow untangling the
security_d_instantiate() mess. The xattr work itself proceeds to
switch a lot of filesystems to generic_...xattr(); no complications
there.
After that initial xattr work, the series then does the following:
- untangle security_d_instantiate()
- convert a bunch of open-coded lookup_one_len_unlocked() to calls of
that thing; one such place (in overlayfs) actually yields a trivial
conflict with overlayfs fixes later in the cycle - overlayfs ended
up switching to a variant of lookup_one_len_unlocked() sans the
permission checks. I would've dropped that commit (it gets
overridden on merge from #ovl-fixes in #for-next; proper resolution
is to use the variant in mainline fs/overlayfs/super.c), but I
didn't want to rebase the damn thing - it was fairly late in the
cycle...
- some filesystems had managed to depend on lookup/lookup exclusion
for *fs-internal* data structures in a way that would break if we
relaxed the VFS exclusion. Fixing hadn't been hard, fortunately.
- core of that series - parallel lookup machinery, replacing
->i_mutex with rwsem, making lookup_slow() take it only shared. At
that point lookups happen in parallel; lookups on the same name
wait for the in-progress one to be done with that dentry.
Surprisingly little code, at that - almost all of it is in
fs/dcache.c, with fs/namei.c changes limited to lookup_slow() -
making it use the new primitive and actually switching to locking
shared.
- parallel readdir stuff - first of all, we provide the exclusion on
per-struct file basis, same as we do for read() vs lseek() for
regular files. That takes care of most of the needed exclusion in
readdir/readdir; however, these guys are trickier than lookups, so
I went for switching them one-by-one. To do that, a new method
'->iterate_shared()' is added and filesystems are switched to it
as they are either confirmed to be OK with shared lock on directory
or fixed to be OK with that. I hope to kill the original method
come next cycle (almost all in-tree filesystems are switched
already), but it's still not quite finished.
- several filesystems get switched to parallel readdir. The
interesting part here is dealing with dcache preseeding by readdir;
that needs minor adjustment to be safe with directory locked only
shared.
Most of the filesystems doing that got switched to in those
commits. Important exception: NFS. Turns out that NFS folks, with
their, er, insistence on VFS getting the fuck out of the way of the
Smart Filesystem Code That Knows How And What To Lock(tm) have
grown the locking of their own. They had their own homegrown
rwsem, with lookup/readdir/atomic_open being *writers* (sillyunlink
is the reader there). Of course, with VFS getting the fuck out of
the way, as requested, the actual smarts of the smart filesystem
code etc. had become exposed...
- do_last/lookup_open/atomic_open cleanups. As the result, open()
without O_CREAT locks the directory only shared. Including the
->atomic_open() case. Backmerge from #for-linus in the middle of
that - atomic_open() fix got brought in.
- then comes NFS switch to saner (VFS-based ;-) locking, killing the
homegrown "lookup and readdir are writers" kinda-sorta rwsem. All
exclusion for sillyunlink/lookup is done by the parallel lookups
mechanism. Exclusion between sillyunlink and rmdir is a real rwsem
now - rmdir being the writer.
Result: NFS lookups/readdirs/O_CREAT-less opens happen in parallel
now.
- the rest of the series consists of switching a lot of filesystems
to parallel readdir; in a lot of cases ->llseek() gets simplified
as well. One backmerge in there (again, #for-linus - rockridge
fix)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (74 commits)
ext4: switch to ->iterate_shared()
hfs: switch to ->iterate_shared()
hfsplus: switch to ->iterate_shared()
hostfs: switch to ->iterate_shared()
hpfs: switch to ->iterate_shared()
hpfs: handle allocation failures in hpfs_add_pos()
gfs2: switch to ->iterate_shared()
f2fs: switch to ->iterate_shared()
afs: switch to ->iterate_shared()
befs: switch to ->iterate_shared()
befs: constify stuff a bit
isofs: switch to ->iterate_shared()
get_acorn_filename(): deobfuscate a bit
btrfs: switch to ->iterate_shared()
logfs: no need to lock directory in lseek
switch ecryptfs to ->iterate_shared
9p: switch to ->iterate_shared()
fat: switch to ->iterate_shared()
romfs, squashfs: switch to ->iterate_shared()
more trivial ->iterate_shared conversions
...
Backmerge to resolve a conflict in ovl_lookup_real();
"ovl_lookup_real(): use lookup_one_len_unlocked()" instead,
but it was too late in the cycle to rebase.
This reverts the 4.6-rc1 commit 7e2bc81da3 ("proc/base: make prompt
shell start from new line after executing "cat /proc/$pid/wchan")
because it breaks /proc/$PID/whcan formatting in ps and top.
Revert also because the patch is inconsistent - it adds a newline at the
end of only the '0' wchan, and does not add a newline when
/proc/$PID/wchan contains a symbol name.
eg.
$ ps -eo pid,stat,wchan,comm
PID STAT WCHAN COMMAND
...
1189 S - dbus-launch
1190 Ssl 0
dbus-daemon
1198 Sl 0
lightdm
1299 Ss ep_pol systemd
1301 S - (sd-pam)
1304 Ss wait sh
Signed-off-by: Robin Humble <plaguedbypenguins@gmail.com>
Cc: Minfei Huang <mnfhuang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If /proc/<PID>/environ gets read before the envp[] array is fully set up
in create_{aout,elf,elf_fdpic,flat}_tables(), we might end up trying to
read more bytes than are actually written, as env_start will already be
set but env_end will still be zero, making the range calculation
underflow, allowing to read beyond the end of what has been written.
Fix this as it is done for /proc/<PID>/cmdline by testing env_end for
zero. It is, apparently, intentionally set last in create_*_tables().
This bug was found by the PaX size_overflow plugin that detected the
arithmetic underflow of 'this_len = env_end - (env_start + src)' when
env_end is still zero.
The expected consequence is that userland trying to access
/proc/<PID>/environ of a not yet fully set up process may get
inconsistent data as we're in the middle of copying in the environment
variables.
Fixes: https://forums.grsecurity.net/viewtopic.php?f=3&t=4363
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=116461
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Pax Team <pageexec@freemail.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In gather_pte_stats() a THP pmd is cast into a pte, which is wrong
because the layouts may differ depending on the architecture. On s390
this will lead to inaccurate numa_maps accounting in /proc because of
misguided pte_present() and pte_dirty() checks on the fake pte.
On other architectures pte_present() and pte_dirty() may work by chance,
but there may be an issue with direct-access (dax) mappings w/o
underlying struct pages when HAVE_PTE_SPECIAL is set and THP is
available. In vm_normal_page() the fake pte will be checked with
pte_special() and because there is no "special" bit in a pmd, this will
always return false and the VM_PFNMAP | VM_MIXEDMAP checking will be
skipped. On dax mappings w/o struct pages, an invalid struct page
pointer would then be returned that can crash the kernel.
This patch fixes the numa_maps THP handling by introducing new "_pmd"
variants of the can_gather_numa_stats() and vm_normal_page() functions.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> [4.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull cgroup namespace support from Tejun Heo:
"These are changes to implement namespace support for cgroup which has
been pending for quite some time now. It is very straight-forward and
only affects what part of cgroup hierarchies are visible.
After unsharing, mounting a cgroup fs will be scoped to the cgroups
the task belonged to at the time of unsharing and the cgroup paths
exposed to userland would be adjusted accordingly"
* 'for-4.6-ns' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix and restructure error handling in copy_cgroup_ns()
cgroup: fix alloc_cgroup_ns() error handling in copy_cgroup_ns()
Add FS_USERNS_FLAG to cgroup fs
cgroup: Add documentation for cgroup namespaces
cgroup: mount cgroupns-root when inside non-init cgroupns
kernfs: define kernfs_node_dentry
cgroup: cgroup namespace setns support
cgroup: introduce cgroup namespaces
sched: new clone flag CLONE_NEWCGROUP for cgroup namespace
kernfs: Add API to generate relative kernfs path
Pull x86 protection key support from Ingo Molnar:
"This tree adds support for a new memory protection hardware feature
that is available in upcoming Intel CPUs: 'protection keys' (pkeys).
There's a background article at LWN.net:
https://lwn.net/Articles/643797/
The gist is that protection keys allow the encoding of
user-controllable permission masks in the pte. So instead of having a
fixed protection mask in the pte (which needs a system call to change
and works on a per page basis), the user can map a (handful of)
protection mask variants and can change the masks runtime relatively
cheaply, without having to change every single page in the affected
virtual memory range.
This allows the dynamic switching of the protection bits of large
amounts of virtual memory, via user-space instructions. It also
allows more precise control of MMU permission bits: for example the
executable bit is separate from the read bit (see more about that
below).
This tree adds the MM infrastructure and low level x86 glue needed for
that, plus it adds a high level API to make use of protection keys -
if a user-space application calls:
mmap(..., PROT_EXEC);
or
mprotect(ptr, sz, PROT_EXEC);
(note PROT_EXEC-only, without PROT_READ/WRITE), the kernel will notice
this special case, and will set a special protection key on this
memory range. It also sets the appropriate bits in the Protection
Keys User Rights (PKRU) register so that the memory becomes unreadable
and unwritable.
So using protection keys the kernel is able to implement 'true'
PROT_EXEC on x86 CPUs: without protection keys PROT_EXEC implies
PROT_READ as well. Unreadable executable mappings have security
advantages: they cannot be read via information leaks to figure out
ASLR details, nor can they be scanned for ROP gadgets - and they
cannot be used by exploits for data purposes either.
We know about no user-space code that relies on pure PROT_EXEC
mappings today, but binary loaders could start making use of this new
feature to map binaries and libraries in a more secure fashion.
There is other pending pkeys work that offers more high level system
call APIs to manage protection keys - but those are not part of this
pull request.
Right now there's a Kconfig that controls this feature
(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) that is default enabled
(like most x86 CPU feature enablement code that has no runtime
overhead), but it's not user-configurable at the moment. If there's
any serious problem with this then we can make it configurable and/or
flip the default"
* 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
x86/mm/pkeys: Fix mismerge of protection keys CPUID bits
mm/pkeys: Fix siginfo ABI breakage caused by new u64 field
x86/mm/pkeys: Fix access_error() denial of writes to write-only VMA
mm/core, x86/mm/pkeys: Add execute-only protection keys support
x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits() for VMA flags
x86/mm/pkeys: Allow kernel to modify user pkey rights register
x86/fpu: Allow setting of XSAVE state
x86/mm: Factor out LDT init from context init
mm/core, x86/mm/pkeys: Add arch_validate_pkey()
mm/core, arch, powerpc: Pass a protection key in to calc_vm_flag_bits()
x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU
x86/mm/pkeys: Add Kconfig prompt to existing config option
x86/mm/pkeys: Dump pkey from VMA in /proc/pid/smaps
x86/mm/pkeys: Dump PKRU with other kernel registers
mm/core, x86/mm/pkeys: Differentiate instruction fetches
x86/mm/pkeys: Optimize fault handling in access_error()
mm/core: Do not enforce PKEY permissions on remote mm access
um, pkeys: Add UML arch_*_access_permitted() methods
mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys
x86/mm/gup: Simplify get_user_pages() PTE bit handling
...
On i686 PAE enabled machine the contiguous physical area could be large
and it can cause trimming down variables in below calculation in
read_vmcore() and mmap_vmcore():
tsz = min_t(size_t, m->offset + m->size - *fpos, buflen);
That is, the types being used is like below on i686:
m->offset: unsigned long long int
m->size: unsigned long long int
*fpos: loff_t (long long int)
buflen: size_t (unsigned int)
So casting (m->offset + m->size - *fpos) by size_t means truncating a
given value by 4GB.
Suppose (m->offset + m->size - *fpos) being truncated to 0, buflen >0
then we will get tsz = 0. It is of course not an expected result.
Similarly we could also get other truncated values less than buflen.
Then the real size passed down is not correct any more.
If (m->offset + m->size - *fpos) is above 4GB, read_vmcore or
mmap_vmcore use the min_t result with truncated values being compared to
buflen. Then, fpos proceeds with the wrong value so that we reach below
bugs:
1) read_vmcore will refuse to continue so makedumpfile fails.
2) mmap_vmcore will trigger BUG_ON() in remap_pfn_range().
Use unsigned long long in min_t instead so that the variables in are not
truncated.
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jianyu Zhan <nasa4836@gmail.com>
Cc: Minfei Huang <mhuang@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is not elegant that prompt shell does not start from new line after
executing "cat /proc/$pid/wchan". Make prompt shell start from new
line.
Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch provides a proc/PID/timerslack_ns interface which exposes a
task's timerslack value in nanoseconds and allows it to be changed.
This allows power/performance management software to set timer slack for
other threads according to its policy for the thread (such as when the
thread is designated foreground vs. background activity)
If the value written is non-zero, slack is set to that value. Otherwise
sets it to the default for the thread.
This interface checks that the calling task has permissions to to use
PTRACE_MODE_ATTACH_FSCREDS on the target task, so that we can ensure
arbitrary apps do not change the timer slack for other apps.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory
statistics protocol, corresponding to 'Available' in /proc/meminfo.
It indicates to the hypervisor how big the balloon can be inflated
without pushing the guest system to swap. This metric would be very
useful in VM orchestration software to improve memory management of
different VMs under overcommit.
This patch (of 2):
Factor out calculation of the available memory counter into a separate
exportable function, in order to be able to use it in other parts of the
kernel.
In particular, it appears a relevant metric to report to the hypervisor
via virtio-balloon statistics interface (in a followup patch).
Signed-off-by: Igor Redko <redkoi@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently /proc/kpageflags returns just KPF_COMPOUND_TAIL for slab tail
pages, which is inconvenient when grasping how slab pages are
distributed (userspace always needs to check which kind of tail pages by
itself). This patch sets KPF_SLAB for such pages.
With this patch:
$ grep Slab /proc/meminfo ; tools/vm/page-types -b slab
Slab: 64880 kB
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000080 16220 63 _______S__________________________________ slab
total 16220 63
16220 pages equals to 64880 kB, so returned result is consistent with the
global counter.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently /proc/kpageflags returns nothing for "tail" buddy pages, which
is inconvenient when grasping how free pages are distributed. This
patch sets KPF_BUDDY for such pages.
With this patch:
$ grep MemFree /proc/meminfo ; tools/vm/page-types -b buddy
MemFree: 3134992 kB
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000400 779272 3044 __________B_______________________________ buddy
0x0000000000000c00 4385 17 __________BM______________________________ buddy,mmap
total 783657 3061
783657 pages is 3134628 kB (roughly consistent with the global counter,)
so it's OK.
[akpm@linux-foundation.org: update comment, per Naoya]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Janis Danisevskis
Richard W.M. Jones
Linus Torvalds
Joonsoo Kim
Al Viro
Daniel Wagner
Robin Humble
Mathias Krause
Gerald Schaefer
Kirill A. Shutemov
Dave Young
Minfei Huang
Eric Engestrom
John Stultz
Igor Redko
Naoya Horiguchi
Dave Hansen