When CONFIG_POSIX_TIMERS is disabled, it is preferable to remove related
structures from struct task_struct and struct signal_struct as they
won't contain anything useful and shouldn't be relied upon by mistake.
Code still referencing those structures is also disabled here.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
We have seen proc_pid_readdir() invocations holding cpu for more than 50
ms. Add a cond_resched() to be gentle with other tasks.
[akpm@linux-foundation.org: coding style fix]
Link: http://lkml.kernel.org/r/1484238380.15816.42.camel@edumazet-glaptop3.roam.corp.google.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of making the files owned by the GLOBAL_ROOT_USER. Make
non-dumpable files whose mm has always lived in a user namespace owned
by the user namespace root. This allows the container root to have
things work as expected in a container.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Processes can only alter their own security attributes via
/proc/pid/attr nodes. This is presently enforced by each individual
security module and is also imposed by the Linux credentials
implementation, which only allows a task to alter its own credentials.
Move the check enforcing this restriction from the individual
security modules to proc_pid_attr_write() before calling the security hook,
and drop the unnecessary task argument to the security hook since it can
only ever be the current task.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull partial readlink cleanups from Miklos Szeredi.
This is the uncontroversial part of the readlink cleanup patch-set that
simplifies the default readlink handling.
Miklos and Al are still discussing the rest of the series.
* git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
vfs: make generic_readlink() static
vfs: remove ".readlink = generic_readlink" assignments
vfs: default to generic_readlink()
vfs: replace calling i_op->readlink with vfs_readlink()
proc/self: use generic_readlink
ecryptfs: use vfs_get_link()
bad_inode: add missing i_op initializers
Pull audit updates from Paul Moore:
"After the small number of patches for v4.9, we've got a much bigger
pile for v4.10.
The bulk of these patches involve a rework of the audit backlog queue
to enable us to move the netlink multicasting out of the task/thread
that generates the audit record and into the kernel thread that emits
the record (just like we do for the audit unicast to auditd).
While we were playing with the backlog queue(s) we fixed a number of
other little problems with the code, and from all the testing so far
things look to be in much better shape now. Doing this also allowed us
to re-enable disabling IRQs for some netns operations ("netns: avoid
disabling irq for netns id").
The remaining patches fix some small problems that are well documented
in the commit descriptions, as well as adding session ID filtering
support"
* 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit:
audit: use proper refcount locking on audit_sock
netns: avoid disabling irq for netns id
audit: don't ever sleep on a command record/message
audit: handle a clean auditd shutdown with grace
audit: wake up kauditd_thread after auditd registers
audit: rework audit_log_start()
audit: rework the audit queue handling
audit: rename the queues and kauditd related functions
audit: queue netlink multicast sends just like we do for unicast sends
audit: fixup audit_init()
audit: move kaudit thread start from auditd registration to kaudit init (#2)
audit: add support for session ID user filter
audit: fix formatting of AUDIT_CONFIG_CHANGE events
audit: skip sessionid sentinel value when auto-incrementing
audit: tame initialization warning len_abuf in audit_log_execve_info
audit: less stack usage for /proc/*/loginuid
Pull security subsystem updates from James Morris:
"Generally pretty quiet for this release. Highlights:
Yama:
- allow ptrace access for original parent after re-parenting
TPM:
- add documentation
- many bugfixes & cleanups
- define a generic open() method for ascii & bios measurements
Integrity:
- Harden against malformed xattrs
SELinux:
- bugfixes & cleanups
Smack:
- Remove unnecessary smack_known_invalid label
- Do not apply star label in smack_setprocattr hook
- parse mnt opts after privileges check (fixes unpriv DoS vuln)"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (56 commits)
Yama: allow access for the current ptrace parent
tpm: adjust return value of tpm_read_log
tpm: vtpm_proxy: conditionally call tpm_chip_unregister
tpm: Fix handling of missing event log
tpm: Check the bios_dir entry for NULL before accessing it
tpm: return -ENODEV if np is not set
tpm: cleanup of printk error messages
tpm: replace of_find_node_by_name() with dev of_node property
tpm: redefine read_log() to handle ACPI/OF at runtime
tpm: fix the missing .owner in tpm_bios_measurements_ops
tpm: have event log use the tpm_chip
tpm: drop tpm1_chip_register(/unregister)
tpm: replace dynamically allocated bios_dir with a static array
tpm: replace symbolic permission with octal for securityfs files
char: tpm: fix kerneldoc tpm2_unseal_trusted name typo
tpm_tis: Allow tpm_tis to be bound using DT
tpm, tpm_vtpm_proxy: add kdoc comments for VTPM_PROXY_IOC_NEW_DEV
tpm: Only call pm_runtime_get_sync if device has a parent
tpm: define a generic open() method for ascii & bios measurements
Documentation: tpm: add the Physical TPM device tree binding documentation
...
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Merge tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross:
"Xen features and fixes for 4.10
These are some fixes, a move of some arm related headers to share them
between arm and arm64 and a series introducing a helper to make code
more readable.
The most notable change is David stepping down as maintainer of the
Xen hypervisor interface. This results in me sending you the pull
requests for Xen related code from now on"
* tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (29 commits)
xen/balloon: Only mark a page as managed when it is released
xenbus: fix deadlock on writes to /proc/xen/xenbus
xen/scsifront: don't request a slot on the ring until request is ready
xen/x86: Increase xen_e820_map to E820_X_MAX possible entries
x86: Make E820_X_MAX unconditionally larger than E820MAX
xen/pci: Bubble up error and fix description.
xen: xenbus: set error code on failure
xen: set error code on failures
arm/xen: Use alloc_percpu rather than __alloc_percpu
arm/arm64: xen: Move shared architecture headers to include/xen/arm
xen/events: use xen_vcpu_id mapping for EVTCHNOP_status
xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing
xen-scsifront: Add a missing call to kfree
MAINTAINERS: update XEN HYPERVISOR INTERFACE
xenfs: Use proc_create_mount_point() to create /proc/xen
xen-platform: use builtin_pci_driver
xen-netback: fix error handling output
xen: make use of xenbus_read_unsigned() in xenbus
xen: make use of xenbus_read_unsigned() in xen-pciback
xen: make use of xenbus_read_unsigned() in xen-fbfront
...
Runtime nlink calculation works but meh. I don't know how to do it at
compile time, but I know how to do it at init time.
Shift "2+" part into init time as a bonus.
Link: http://lkml.kernel.org/r/20161122195549.GB29812@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Comparison for "<" works equally well as comparison for "<=" but one
SUB/LEA is saved (no, it is not optimised away, at least here).
Link: http://lkml.kernel.org/r/20161122195143.GA29812@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
format_decode and vsnprintf occasionally show up in perf top, so I went
looking for places that might not need the full printf power. With the
help of kprobes, I gathered some statistics on which format strings we
mostly pass to vsnprintf. On a trivial desktop workload, I hit "%x" 25%
of the time, so something apparently reads /proc/pid/status (which does
5*16 printf("%x") calls) a lot.
With this patch, reading /proc/pid/status is 30% faster according to
this microbenchmark:
char buf[4096];
int i, fd;
for (i = 0; i < 10000; ++i) {
fd = open("/proc/self/status", O_RDONLY);
read(fd, buf, sizeof(buf));
close(fd);
}
Link: http://lkml.kernel.org/r/1474410485-1305-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andrei Vagin <avagin@openvz.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some comments were obsoleted since commit 05c0ae21c0 ("try a saner
locking for pde_opener...").
Some new comments added.
Some confusing comments replaced with equally confusing ones.
Link: http://lkml.kernel.org/r/20161029160231.GD1246@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kzalloc is too much, half of the fields will be reinitialized anyway.
If proc file doesn't have ->release hook (some still do not), clearing
is unnecessary because it will be freed immediately.
Link: http://lkml.kernel.org/r/20161029155747.GC1246@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
list_del_init() is too much, structure will be freed in three lines
anyway.
Link: http://lkml.kernel.org/r/20161029155313.GA1246@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linux doesn't support 4GB+ filenames in /proc, so unsigned long is too
much.
MOV r64, r/m64 is larger than MOV r32, r/m32.
Link: http://lkml.kernel.org/r/20161029161123.GG1246@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
"unsigned int" is better on x86_64 because it most of the time it
autoexpands to 64-bit value while "int" requires MOVSX instruction.
Link: http://lkml.kernel.org/r/20161029160810.GF1246@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Similar to being able to examine if a process has been correctly
confined with seccomp, the state of no_new_privs is equally interesting,
so this adds it to /proc/$pid/status.
Link: http://lkml.kernel.org/r/20161103214041.GA58566@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jann Horn <jann@thejh.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Rodrigo Freire <rfreire@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Robert Ho <robert.hu@intel.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Richard W.M. Jones" <rjones@redhat.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The other pagetable walks in task_mmu.c have a cond_resched() after
walking their ptes: add a cond_resched() in gather_pte_stats() too, for
reading /proc/<id>/numa_maps. Only pagemap_pmd_range() has a
cond_resched() in its (unusually expensive) pmd_trans_huge case: more
should probably be added, but leave them unchanged for now.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1612052157400.13021@eggly.anvils
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If .readlink == NULL implies generic_readlink().
Generated by:
to_del="\.readlink.*=.*generic_readlink"
for i in `git grep -l $to_del`; do sed -i "/$to_del"/d $i; done
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The /proc/self and /proc/self-thread symlinks have separate but identical
functionality for reading and following. This cleanup utilizes
generic_readlink to remove the duplication.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Mounting proc in user namespace containers fails if the xenbus
filesystem is mounted on /proc/xen because this directory fails
the "permanently empty" test. proc_create_mount_point() exists
specifically to create such mountpoints in proc but is currently
proc-internal. Export this interface to modules, then use it in
xenbus when creating /proc/xen.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Pass the file mode of the proc inode to be created to
proc_pid_make_inode. In proc_pid_make_inode, initialize inode->i_mode
before calling security_task_to_inode. This allows selinux to set
isec->sclass right away without introducing "half-initialized" inode
security structs.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
%u requires 10 characters at most not 20.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Reading auxv of any kernel thread results in NULL pointer dereferencing
in auxv_read() where mm can be NULL. Fix that by checking for NULL mm
and bailing out early. This is also the original behavior changed by
recent commit c531716785 ("proc: switch auxv to use of __mem_open()").
# cat /proc/2/auxv
Unable to handle kernel NULL pointer dereference at virtual address 000000a8
Internal error: Oops: 17 [#1] PREEMPT SMP ARM
CPU: 3 PID: 113 Comm: cat Not tainted 4.9.0-rc1-ARCH+ #1
Hardware name: BCM2709
task: ea3b0b00 task.stack: e99b2000
PC is at auxv_read+0x24/0x4c
LR is at do_readv_writev+0x2fc/0x37c
Process cat (pid: 113, stack limit = 0xe99b2210)
Call chain:
auxv_read
do_readv_writev
vfs_readv
default_file_splice_read
splice_direct_to_actor
do_splice_direct
do_sendfile
SyS_sendfile64
ret_fast_syscall
Fixes: c531716785 ("proc: switch auxv to use of __mem_open()")
Link: http://lkml.kernel.org/r/1476966200-14457-1-git-send-email-chianglungyu@gmail.com
Signed-off-by: Leon Yu <chianglungyu@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Janis Danisevskis <jdanis@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that Lorenzo cleaned things up and made the FOLL_FORCE users
explicit, it becomes obvious how some of them don't really need
FOLL_FORCE at all.
So remove FOLL_FORCE from the proc code that reads the command line and
arguments from user space.
The mem_rw() function actually does want FOLL_FORCE, because gdd (and
possibly many other debuggers) use it as a much more convenient version
of PTRACE_PEEKDATA, but we should consider making the FOLL_FORCE part
conditional on actually being a ptracer. This does not actually do
that, just moves adds a comment to that effect and moves the gup_flags
settings next to each other.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vmap stack fixes from Ingo Molnar:
"This is fallout from CONFIG_HAVE_ARCH_VMAP_STACK=y on x86: stack
accesses that used to be just somewhat questionable are now totally
buggy.
These changes try to do it without breaking the ABI: the fields are
left there, they are just reporting zero, or reporting narrower
information (the maps file change)"
* 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
mm: Change vm_is_stack_for_task() to vm_is_stack_for_current()
fs/proc: Stop trying to report thread stacks
fs/proc: Stop reporting eip and esp in /proc/PID/stat
mm/numa: Remove duplicated include from mprotect.c
This reverts more of:
b76437579d ("procfs: mark thread stack correctly in proc/<pid>/maps")
... which was partially reverted by:
65376df582 ("proc: revert /proc/<pid>/maps [stack:TID] annotation")
Originally, /proc/PID/task/TID/maps was the same as /proc/TID/maps.
In current kernels, /proc/PID/maps (or /proc/TID/maps even for
threads) shows "[stack]" for VMAs in the mm's stack address range.
In contrast, /proc/PID/task/TID/maps uses KSTK_ESP to guess the
target thread's stack's VMA. This is racy, probably returns garbage
and, on arches with CONFIG_TASK_INFO_IN_THREAD=y, is also crash-prone:
KSTK_ESP is not safe to use on tasks that aren't known to be running
ordinary process-context kernel code.
This patch removes the difference and just shows "[stack]" for VMAs
in the mm's stack range. This is IMO much more sensible -- the
actual "stack" address really is treated specially by the VM code,
and the current thread stack isn't even well-defined for programs
that frequently switch stacks on their own.
Reported-by: Jann Horn <jann@thejh.net>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux API <linux-api@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tycho Andersen <tycho.andersen@canonical.com>
Link: http://lkml.kernel.org/r/3e678474ec14e0a0ec34c611016753eea2e1b8ba.1475257877.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reporting these fields on a non-current task is dangerous. If the
task is in any state other than normal kernel code, they may contain
garbage or even kernel addresses on some architectures. (x86_64
used to do this. I bet lots of architectures still do.) With
CONFIG_THREAD_INFO_IN_TASK=y, it can OOPS, too.
As far as I know, there are no use programs that make any material
use of these fields, so just get rid of them.
Reported-by: Jann Horn <jann@thejh.net>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux API <linux-api@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Tycho Andersen <tycho.andersen@canonical.com>
Link: http://lkml.kernel.org/r/a5fed4c3f4e33ed25d4bb03567e329bc5a712bcc.1475257877.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This removes the 'write' argument from access_remote_vm() and replaces
it with 'gup_flags' as use of this function previously silently implied
FOLL_FORCE, whereas after this patch callers explicitly pass this flag.
We make this explicit as use of FOLL_FORCE can result in surprising
behaviour (and hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull more vfs updates from Al Viro:
">rename2() work from Miklos + current_time() from Deepa"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Replace current_fs_time() with current_time()
fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
fs: Replace CURRENT_TIME with current_time() for inode timestamps
fs: proc: Delete inode time initializations in proc_alloc_inode()
vfs: Add current_time() api
vfs: add note about i_op->rename changes to porting
fs: rename "rename2" i_op to "rename"
vfs: remove unused i_op->rename
fs: make remaining filesystems use .rename2
libfs: support RENAME_NOREPLACE in simple_rename()
fs: support RENAME_NOREPLACE for local filesystems
ncpfs: fix unused variable warning
Pull misc vfs updates from Al Viro:
"Assorted misc bits and pieces.
There are several single-topic branches left after this (rename2
series from Miklos, current_time series from Deepa Dinamani, xattr
series from Andreas, uaccess stuff from from me) and I'd prefer to
send those separately"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
proc: switch auxv to use of __mem_open()
hpfs: support FIEMAP
cifs: get rid of unused arguments of CIFSSMBWrite()
posix_acl: uapi header split
posix_acl: xattr representation cleanups
fs/aio.c: eliminate redundant loads in put_aio_ring_file
fs/internal.h: add const to ns_dentry_operations declaration
compat: remove compat_printk()
fs/buffer.c: make __getblk_slow() static
proc: unsigned file descriptors
fs/file: more unsigned file descriptors
fs: compat: remove redundant check of nr_segs
cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
cifs: don't use memcpy() to copy struct iov_iter
get rid of separate multipage fault-in primitives
fs: Avoid premature clearing of capabilities
fs: Give dentry to inode_change_ok() instead of inode
fuse: Propagate dentry down to inode_change_ok()
ceph: Propagate dentry down to inode_change_ok()
xfs: Propagate dentry down to inode_change_ok()
...
Current supplementary groups code can massively overallocate memory and
is implemented in a way so that access to individual gid is done via 2D
array.
If number of gids is <= 32, memory allocation is more or less tolerable
(140/148 bytes). But if it is not, code allocates full page (!)
regardless and, what's even more fun, doesn't reuse small 32-entry
array.
2D array means dependent shifts, loads and LEAs without possibility to
optimize them (gid is never known at compile time).
All of the above is unnecessary. Switch to the usual
trailing-zero-len-array scheme. Memory is allocated with
kmalloc/vmalloc() and only as much as needed. Accesses become simpler
(LEA 8(gi,idx,4) or even without displacement).
Maximum number of gids is 65536 which translates to 256KB+8 bytes. I
think kernel can handle such allocation.
On my usual desktop system with whole 9 (nine) aux groups, struct
group_info shrinks from 148 bytes to 44 bytes, yay!
Nice side effects:
- "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing,
- fix little mess in net/ipv4/ping.c
should have been using GROUP_AT macro but this point becomes moot,
- aux group allocation is persistent and should be accounted as such.
Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recently, Redhat reported that nvml test suite failed on QEMU/KVM,
more detailed info please refer to:
https://bugzilla.redhat.com/show_bug.cgi?id=1365721
Actually, this bug is not only for NVDIMM/DAX but also for any other
file systems. This simple test case abstracted from nvml can easily
reproduce this bug in common environment:
-------------------------- testcase.c -----------------------------
int
is_pmem_proc(const void *addr, size_t len)
{
const char *caddr = addr;
FILE *fp;
if ((fp = fopen("/proc/self/smaps", "r")) == NULL) {
printf("!/proc/self/smaps");
return 0;
}
int retval = 0; /* assume false until proven otherwise */
char line[PROCMAXLEN]; /* for fgets() */
char *lo = NULL; /* beginning of current range in smaps file */
char *hi = NULL; /* end of current range in smaps file */
int needmm = 0; /* looking for mm flag for current range */
while (fgets(line, PROCMAXLEN, fp) != NULL) {
static const char vmflags[] = "VmFlags:";
static const char mm[] = " wr";
/* check for range line */
if (sscanf(line, "%p-%p", &lo, &hi) == 2) {
if (needmm) {
/* last range matched, but no mm flag found */
printf("never found mm flag.\n");
break;
} else if (caddr < lo) {
/* never found the range for caddr */
printf("#######no match for addr %p.\n", caddr);
break;
} else if (caddr < hi) {
/* start address is in this range */
size_t rangelen = (size_t)(hi - caddr);
/* remember that matching has started */
needmm = 1;
/* calculate remaining range to search for */
if (len > rangelen) {
len -= rangelen;
caddr += rangelen;
printf("matched %zu bytes in range "
"%p-%p, %zu left over.\n",
rangelen, lo, hi, len);
} else {
len = 0;
printf("matched all bytes in range "
"%p-%p.\n", lo, hi);
}
}
} else if (needmm && strncmp(line, vmflags,
sizeof(vmflags) - 1) == 0) {
if (strstr(&line[sizeof(vmflags) - 1], mm) != NULL) {
printf("mm flag found.\n");
if (len == 0) {
/* entire range matched */
retval = 1;
break;
}
needmm = 0; /* saw what was needed */
} else {
/* mm flag not set for some or all of range */
printf("range has no mm flag.\n");
break;
}
}
}
fclose(fp);
printf("returning %d.\n", retval);
return retval;
}
void *Addr;
size_t Size;
/*
* worker -- the work each thread performs
*/
static void *
worker(void *arg)
{
int *ret = (int *)arg;
*ret = is_pmem_proc(Addr, Size);
return NULL;
}
int main(int argc, char *argv[])
{
if (argc < 2 || argc > 3) {
printf("usage: %s file [env].\n", argv[0]);
return -1;
}
int fd = open(argv[1], O_RDWR);
struct stat stbuf;
fstat(fd, &stbuf);
Size = stbuf.st_size;
Addr = mmap(0, stbuf.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
close(fd);
pthread_t threads[NTHREAD];
int ret[NTHREAD];
/* kick off NTHREAD threads */
for (int i = 0; i < NTHREAD; i++)
pthread_create(&threads[i], NULL, worker, &ret[i]);
/* wait for all the threads to complete */
for (int i = 0; i < NTHREAD; i++)
pthread_join(threads[i], NULL);
/* verify that all the threads return the same value */
for (int i = 1; i < NTHREAD; i++) {
if (ret[0] != ret[i]) {
printf("Error i %d ret[0] = %d ret[i] = %d.\n", i,
ret[0], ret[i]);
}
}
printf("%d", ret[0]);
return 0;
}
It failed as some threads can not find the memory region in
"/proc/self/smaps" which is allocated in the main process
It is caused by proc fs which uses 'file->version' to indicate the VMA that
is the last one has already been handled by read() system call. When the
next read() issues, it uses the 'version' to find the VMA, then the next
VMA is what we want to handle, the related code is as follows:
if (last_addr) {
vma = find_vma(mm, last_addr);
if (vma && (vma = m_next_vma(priv, vma)))
return vma;
}
However, VMA will be lost if the last VMA is gone, e.g:
The process VMA list is A->B->C->D
CPU 0 CPU 1
read() system call
handle VMA B
version = B
return to userspace
unmap VMA B
issue read() again to continue to get
the region info
find_vma(version) will get VMA C
m_next_vma(C) will get VMA D
handle D
!!! VMA C is lost !!!
In order to fix this bug, we make 'file->version' indicate the end address
of the current VMA. m_start will then look up a vma which with vma_start
< last_vm_end and moves on to the next vma if we found the same or an
overlapping vma. This will guarantee that we will not miss an exclusive
vma but we can still miss one if the previous vma was shrunk. This is
acceptable because guaranteeing "never miss a vma" is simply not feasible.
User has to cope with some inconsistencies if the file is not read in one
go.
[mhocko@suse.com: changelog fixes]
Link: http://lkml.kernel.org/r/1475296958-27652-1-git-send-email-robert.hu@intel.com
Acked-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Robert Hu <robert.hu@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In changing from checking ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)
to capable(CAP_SYS_NICE), I missed that ptrace_my_access succeeds when p
== current, but the CAP_SYS_NICE doesn't.
Thus while the previous commit was intended to loosen the needed
privileges to modify a processes timerslack, it needlessly restricted a
task modifying its own timerslack via the proc/<tid>/timerslack_ns
(which is permitted also via the PR_SET_TIMERSLACK method).
This patch corrects this by checking if p == current before checking the
CAP_SYS_NICE value.
This patch applies on top of my two previous patches currently in -mm
Link: http://lkml.kernel.org/r/1471906870-28624-1-git-send-email-john.stultz@linaro.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Elliott Hughes <enh@google.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>
As requested, this patch checks the existing LSM hooks
task_getscheduler/task_setscheduler when reading or modifying the task's
timerslack value.
Previous versions added new get/settimerslack LSM hooks, but since they
checked the same PROCESS__SET/GETSCHED values as existing hooks, it was
suggested we just use the existing ones.
Link: http://lkml.kernel.org/r/1469132667-17377-2-git-send-email-john.stultz@linaro.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Elliott Hughes <enh@google.com>
Cc: James Morris <jmorris@namei.org>
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>
When an interface to allow a task to change another tasks timerslack was
first proposed, it was suggested that something greater then
CAP_SYS_NICE would be needed, as a task could be delayed further then
what normally could be done with nice adjustments.
So CAP_SYS_PTRACE was adopted instead for what became the
/proc/<tid>/timerslack_ns interface. However, for Android (where this
feature originates), giving the system_server CAP_SYS_PTRACE would allow
it to observe and modify all tasks memory. This is considered too high
a privilege level for only needing to change the timerslack.
After some discussion, it was realized that a CAP_SYS_NICE process can
set a task as SCHED_FIFO, so they could fork some spinning processes and
set them all SCHED_FIFO 99, in effect delaying all other tasks for an
infinite amount of time.
So as a CAP_SYS_NICE task can already cause trouble for other tasks,
using it as a required capability for accessing and modifying
/proc/<tid>/timerslack_ns seems sufficient.
Thus, this patch loosens the capability requirements to CAP_SYS_NICE and
removes CAP_SYS_PTRACE, simplifying some of the code flow as well.
This is technically an ABI change, but as the feature just landed in
4.6, I suspect no one is yet using it.
Link: http://lkml.kernel.org/r/1469132667-17377-1-git-send-email-john.stultz@linaro.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Nick Kralevich <nnk@google.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Elliott Hughes <enh@google.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>
Use a specific routine to emit most lines so that the code is easier to
read and maintain.
akpm:
text data bss dec hex filename
2976 8 0 2984 ba8 fs/proc/meminfo.o before
2669 8 0 2677 a75 fs/proc/meminfo.o after
Link: http://lkml.kernel.org/r/8fce7fdef2ba081a4ef531594e97da8a9feebb58.1470810406.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow some seq_puts removals by taking a string instead of a single
char.
[akpm@linux-foundation.org: update vmstat_show(), per Joe]
Link: http://lkml.kernel.org/r/667e1cf3d436de91a5698170a1e98d882905e956.1470704995.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Trying to walk all of virtual memory requires architecture specific
knowledge. On x86_64, addresses must be sign extended from bit 48,
whereas on arm64 the top VA_BITS of address space have their own set of
page tables.
clear_refs_write() calls walk_page_range() on the range 0 to ~0UL, it
provides a test_walk() callback that only expects to be walking over
VMAs. Currently walk_pmd_range() will skip memory regions that don't
have a VMA, reporting them as a hole.
As this call only expects to walk user address space, make it walk 0 to
'highest_vm_end'.
Link: http://lkml.kernel.org/r/1472655792-22439-1-git-send-email-james.morse@arm.com
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: 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>
Pull namespace updates from Eric Biederman:
"This set of changes is a number of smaller things that have been
overlooked in other development cycles focused on more fundamental
change. The devpts changes are small things that were a distraction
until we managed to kill off DEVPTS_MULTPLE_INSTANCES. There is an
trivial regression fix to autofs for the unprivileged mount changes
that went in last cycle. A pair of ioctls has been added by Andrey
Vagin making it is possible to discover the relationships between
namespaces when referring to them through file descriptors.
The big user visible change is starting to add simple resource limits
to catch programs that misbehave. With namespaces in general and user
namespaces in particular allowing users to use more kinds of
resources, it has become important to have something to limit errant
programs. Because the purpose of these limits is to catch errant
programs the code needs to be inexpensive to use as it always on, and
the default limits need to be high enough that well behaved programs
on well behaved systems don't encounter them.
To this end, after some review I have implemented per user per user
namespace limits, and use them to limit the number of namespaces. The
limits being per user mean that one user can not exhause the limits of
another user. The limits being per user namespace allow contexts where
the limit is 0 and security conscious folks can remove from their
threat anlysis the code used to manage namespaces (as they have
historically done as it root only). At the same time the limits being
per user namespace allow other parts of the system to use namespaces.
Namespaces are increasingly being used in application sand boxing
scenarios so an all or nothing disable for the entire system for the
security conscious folks makes increasing use of these sandboxes
impossible.
There is also added a limit on the maximum number of mounts present in
a single mount namespace. It is nontrivial to guess what a reasonable
system wide limit on the number of mount structure in the kernel would
be, especially as it various based on how a system is using
containers. A limit on the number of mounts in a mount namespace
however is much easier to understand and set. In most cases in
practice only about 1000 mounts are used. Given that some autofs
scenarious have the potential to be 30,000 to 50,000 mounts I have set
the default limit for the number of mounts at 100,000 which is well
above every known set of users but low enough that the mount hash
tables don't degrade unreaonsably.
These limits are a start. I expect this estabilishes a pattern that
other limits for resources that namespaces use will follow. There has
been interest in making inotify event limits per user per user
namespace as well as interest expressed in making details about what
is going on in the kernel more visible"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (28 commits)
autofs: Fix automounts by using current_real_cred()->uid
mnt: Add a per mount namespace limit on the number of mounts
netns: move {inc,dec}_net_namespaces into #ifdef
nsfs: Simplify __ns_get_path
tools/testing: add a test to check nsfs ioctl-s
nsfs: add ioctl to get a parent namespace
nsfs: add ioctl to get an owning user namespace for ns file descriptor
kernel: add a helper to get an owning user namespace for a namespace
devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts
devpts: Remove sync_filesystems
devpts: Make devpts_kill_sb safe if fsi is NULL
devpts: Simplify devpts_mount by using mount_nodev
devpts: Move the creation of /dev/pts/ptmx into fill_super
devpts: Move parse_mount_options into fill_super
userns: When the per user per user namespace limit is reached return ENOSPC
userns; Document per user per user namespace limits.
mntns: Add a limit on the number of mount namespaces.
netns: Add a limit on the number of net namespaces
cgroupns: Add a limit on the number of cgroup namespaces
ipcns: Add a limit on the number of ipc namespaces
...
Pull networking updates from David Miller:
1) BBR TCP congestion control, from Neal Cardwell, Yuchung Cheng and
co. at Google. https://lwn.net/Articles/701165/
2) Do TCP Small Queues for retransmits, from Eric Dumazet.
3) Support collect_md mode for all IPV4 and IPV6 tunnels, from Alexei
Starovoitov.
4) Allow cls_flower to classify packets in ip tunnels, from Amir Vadai.
5) Support DSA tagging in older mv88e6xxx switches, from Andrew Lunn.
6) Support GMAC protocol in iwlwifi mwm, from Ayala Beker.
7) Support ndo_poll_controller in mlx5, from Calvin Owens.
8) Move VRF processing to an output hook and allow l3mdev to be
loopback, from David Ahern.
9) Support SOCK_DESTROY for UDP sockets. Also from David Ahern.
10) Congestion control in RXRPC, from David Howells.
11) Support geneve RX offload in ixgbe, from Emil Tantilov.
12) When hitting pressure for new incoming TCP data SKBs, perform a
partial rathern than a full purge of the OFO queue (which could be
huge). From Eric Dumazet.
13) Convert XFRM state and policy lookups to RCU, from Florian Westphal.
14) Support RX network flow classification to igb, from Gangfeng Huang.
15) Hardware offloading of eBPF in nfp driver, from Jakub Kicinski.
16) New skbmod packet action, from Jamal Hadi Salim.
17) Remove some inefficiencies in snmp proc output, from Jia He.
18) Add FIB notifications to properly propagate route changes to
hardware which is doing forwarding offloading. From Jiri Pirko.
19) New dsa driver for qca8xxx chips, from John Crispin.
20) Implement RFC7559 ipv6 router solicitation backoff, from Maciej
Żenczykowski.
21) Add L3 mode to ipvlan, from Mahesh Bandewar.
22) Support 802.1ad in mlx4, from Moshe Shemesh.
23) Support hardware LRO in mediatek driver, from Nelson Chang.
24) Add TC offloading to mlx5, from Or Gerlitz.
25) Convert various drivers to ethtool ksettings interfaces, from
Philippe Reynes.
26) TX max rate limiting for cxgb4, from Rahul Lakkireddy.
27) NAPI support for ath10k, from Rajkumar Manoharan.
28) Support XDP in mlx5, from Rana Shahout and Saeed Mahameed.
29) UDP replicast support in TIPC, from Richard Alpe.
30) Per-queue statistics for qed driver, from Sudarsana Reddy Kalluru.
31) Support BQL in thunderx driver, from Sunil Goutham.
32) TSO support in alx driver, from Tobias Regnery.
33) Add stream parser engine and use it in kcm.
34) Support async DHCP replies in ipconfig module, from Uwe
Kleine-König.
35) DSA port fast aging for mv88e6xxx driver, from Vivien Didelot.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1715 commits)
mlxsw: switchx2: Fix misuse of hard_header_len
mlxsw: spectrum: Fix misuse of hard_header_len
net/faraday: Stop NCSI device on shutdown
net/ncsi: Introduce ncsi_stop_dev()
net/ncsi: Rework the channel monitoring
net/ncsi: Allow to extend NCSI request properties
net/ncsi: Rework request index allocation
net/ncsi: Don't probe on the reserved channel ID (0x1f)
net/ncsi: Introduce NCSI_RESERVED_CHANNEL
net/ncsi: Avoid unused-value build warning from ia64-linux-gcc
net: Add netdev all_adj_list refcnt propagation to fix panic
net: phy: Add Edge-rate driver for Microsemi PHYs.
vmxnet3: Wake queue from reset work
i40e: avoid NULL pointer dereference and recursive errors on early PCI error
qed: Add RoCE ll2 & GSI support
qed: Add support for memory registeration verbs
qed: Add support for QP verbs
qed: PD,PKEY and CQ verb support
qed: Add support for RoCE hw init
qede: Add qedr framework
...
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.
CURRENT_TIME is also not y2038 safe.
This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.
Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
proc uses new_inode_pseudo() to allocate a new inode.
This in turn calls the proc_inode_alloc() callback.
But, at this point, inode is still not initialized
with the super_block pointer which only happens just
before alloc_inode() returns after the call to
inode_init_always().
Also, the inode times are initialized again after the
call to new_inode_pseudo() in proc_inode_alloc().
The assignemet in proc_alloc_inode() is redundant and
also doesn't work after the current_time() api is
changed to take struct inode* instead of
struct *super_block.
This bug was reported after current_time() was used to
assign times in proc_alloc_inode().
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com> [0-day test robot]
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
We hit hardened usercopy feature check for kernel text access by reading
kcore file:
usercopy: kernel memory exposure attempt detected from ffffffff8179a01f (<kernel text>) (4065 bytes)
kernel BUG at mm/usercopy.c:75!
Bypassing this check for kcore by adding bounce buffer for ktext data.
Reported-by: Steve Best <sbest@redhat.com>
Fixes: f5509cc18d ("mm: Hardened usercopy")
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Next patch adds bounce buffer for ktext area, so it's
convenient to have single bounce buffer for both
vmalloc/module and ktext cases.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Conflicts:
drivers/net/ethernet/mediatek/mtk_eth_soc.c
drivers/net/ethernet/qlogic/qed/qed_dcbx.c
drivers/net/phy/Kconfig
All conflicts were cases of overlapping commits.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull libnvdimm fixes from Dan Williams:
"nvdimm fixes for v4.8, two of them are tagged for -stable:
- Fix devm_memremap_pages() to use track_pfn_insert(). Otherwise,
DAX pmd mappings end up with an uncached pgprot, and unusable
performance for the device-dax interface. The device-dax interface
appeared in 4.7 so this is tagged for -stable.
- Fix a couple VM_BUG_ON() checks in the show_smaps() path to
understand DAX pmd entries. This fix is tagged for -stable.
- Fix a mis-merge of the nfit machine-check handler to flip the
polarity of an if() to match the final version of the patch that
Vishal sent for 4.8-rc1. Without this the nfit machine check
handler never detects / inserts new 'badblocks' entries which
applications use to identify lost portions of files.
- For test purposes, fix the nvdimm_clear_poison() path to operate on
legacy / simulated nvdimm memory ranges. Without this fix a test
can set badblocks, but never clear them on these ranges.
- Fix the range checking done by dax_dev_pmd_fault(). This is not
tagged for -stable since this problem is mitigated by specifying
aligned resources at device-dax setup time.
These patches have appeared in a next release over the past week. The
recent rebase you can see in the timestamps was to drop an invalid fix
as identified by the updated device-dax unit tests [1]. The -mm
touches have an ack from Andrew"
[1]: "[ndctl PATCH 0/3] device-dax test for recent kernel bugs"
https://lists.01.org/pipermail/linux-nvdimm/2016-September/006855.html
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
libnvdimm: allow legacy (e820) pmem region to clear bad blocks
nfit, mce: Fix SPA matching logic in MCE handler
mm: fix cache mode of dax pmd mappings
mm: fix show_smap() for zone_device-pmd ranges
dax: fix mapping size check
Attempting to dump /proc/<pid>/smaps for a process with pmd dax mappings
currently results in the following VM_BUG_ONs:
kernel BUG at mm/huge_memory.c:1105!
task: ffff88045f16b140 task.stack: ffff88045be14000
RIP: 0010:[<ffffffff81268f9b>] [<ffffffff81268f9b>] follow_trans_huge_pmd+0x2cb/0x340
[..]
Call Trace:
[<ffffffff81306030>] smaps_pte_range+0xa0/0x4b0
[<ffffffff814c2755>] ? vsnprintf+0x255/0x4c0
[<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0
[<ffffffff8123c8a2>] walk_page_vma+0x62/0x80
[<ffffffff81307656>] show_smap+0xa6/0x2b0
kernel BUG at fs/proc/task_mmu.c:585!
RIP: 0010:[<ffffffff81306469>] [<ffffffff81306469>] smaps_pte_range+0x499/0x4b0
Call Trace:
[<ffffffff814c2795>] ? vsnprintf+0x255/0x4c0
[<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0
[<ffffffff8123c8a2>] walk_page_vma+0x62/0x80
[<ffffffff81307696>] show_smap+0xa6/0x2b0
These locations are sanity checking page flags that must be set for an
anonymous transparent huge page, but are not set for the zone_device
pages associated with dax mappings.
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Pull audit fixes from Paul Moore:
"Two small patches to fix some bugs with the audit-by-executable
functionality we introduced back in v4.3 (both patches are marked
for the stable folks)"
* 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit:
audit: fix exe_file access in audit_exe_compare
mm: introduce get_task_exe_file
For more convenient access if one has a pointer to the task.
As a minor nit take advantage of the fact that only task lock + rcu are
needed to safely grab ->exe_file. This saves mm refcount dance.
Use the helper in proc_exe_link.
Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Cc: <stable@vger.kernel.org> # 4.3.x
Signed-off-by: Paul Moore <paul@paul-moore.com>
When printing call return addresses found on a stack, /proc/<pid>/stack
can sometimes give a confusing result. If the call instruction was the
last instruction in the function (which can happen when calling a
noreturn function), '%pS' will incorrectly display the name of the
function which happens to be next in the object code, rather than the
name of the actual calling function.
Use '%pB' instead, which was created for this exact purpose.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/47ad2821e5ebdbed1fbf83fb85424ae4fbdf8b6e.1471535549.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Minor overlapping changes for both merge conflicts.
Resolution work done by Stephen Rothwell was used
as a reference.
Signed-off-by: David S. Miller <davem@davemloft.net>
If net namespace is attached to a user namespace let's make container's
root owner of sysctls affecting said network namespace instead of global
root.
This also allows us to clean up net_ctl_permissions() because we do not
need to fudge permissions anymore for the container's owner since it now
owns the objects in question.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are certain parameters that belong to net namespace and that are
exported in /proc. They should be controllable by the container's owner,
but are currently owned by global root and thus not available.
Let's change proc code to inherit ownership of parent entry, and when
create per-ns "net" proc entry set it up as owned by container's owner.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
meminfo_proc_show() and si_mem_available() are using the wrong helpers
for calculating the size of the LRUs. The user-visible impact is that
there appears to be an abnormally high number of unevictable pages.
Link: http://lkml.kernel.org/r/20160805105805.GR2799@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Passing nsproxy into sysctl_table_root.lookup was a premature
optimization in attempt to avoid depending on current. The
directory /proc/self/sys has not appeared and if and when
it does this code will need to be reviewed closely and reworked
anyway. So remove the premature optimization.
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull more vfs updates from Al Viro:
"Assorted cleanups and fixes.
In the "trivial API change" department - ->d_compare() losing 'parent'
argument"
* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
cachefiles: Fix race between inactivating and culling a cache object
9p: use clone_fid()
9p: fix braino introduced in "9p: new helper - v9fs_parent_fid()"
vfs: make dentry_needs_remove_privs() internal
vfs: remove file_needs_remove_privs()
vfs: fix deadlock in file_remove_privs() on overlayfs
get rid of 'parent' argument of ->d_compare()
cifs, msdos, vfat, hfs+: don't bother with parent in ->d_compare()
affs ->d_compare(): don't bother with ->d_inode
fold _d_rehash() and __d_rehash() together
fold dentry_rcuwalk_invalidate() into its only remaining caller
Pull qstr constification updates from Al Viro:
"Fairly self-contained bunch - surprising lot of places passes struct
qstr * as an argument when const struct qstr * would suffice; it
complicates analysis for no good reason.
I'd prefer to feed that separately from the assorted fixes (those are
in #for-linus and with somewhat trickier topology)"
* 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
qstr: constify instances in adfs
qstr: constify instances in lustre
qstr: constify instances in f2fs
qstr: constify instances in ext2
qstr: constify instances in vfat
qstr: constify instances in procfs
qstr: constify instances in fuse
qstr constify instances in fs/dcache.c
qstr: constify instances in nfs
qstr: constify instances in ocfs2
qstr: constify instances in autofs4
qstr: constify instances in hfs
qstr: constify instances in hfsplus
qstr: constify instances in logfs
qstr: constify dentry_init_security
With gcc < 4.2 (e.g. 4.1.2):
CC fs/proc/task_mmu.o
cc1: error: unrecognized command line option "-Wno-override-init"
To fix this, only enable the compiler option when it is actually
supported by the compiler.
Fixes: ca52953f5f ("fs/proc/task_mmu.c: suppress compilation warnings with W=1")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Suppress a bunch of warnings of the form:
fs/proc/task_mmu.c: In function 'show_smap_vma_flags':
fs/proc/task_mmu.c:635:22: warning: initialized field overwritten [-Wt override-init]
[ilog2(VM_READ)] = "rd",
^~~~
fs/proc/task_mmu.c:635:22: note: (near initialization for 'mnemonics[0]')
They happen because of the way we intentionally build the table, so
silence the warning when building with 'make W=1'.
Link: http://lkml.kernel.org/r/8727.1470022083@turing-police.cc.vt.edu
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
/proc/stat shows (among lots of other things) the current boottime (i.e.
number of seconds since boot). While a 32-bit number is sufficient for
this particular case, we want to get rid of the 'struct timespec'
suffers from a 32-bit overflow in 2038.
This changes the code to use a struct timespec64, which is known to be
safe in all cases.
Link: http://lkml.kernel.org/r/20160617201247.2292101-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was needed before to ensure that ->signal != 0 and do_each_thread()
is safe, see commit b95c35e76b ("oom: fix the unsafe usage of
badness() in proc_oom_score()") for details.
Today tsk->signal can't go away and for_each_thread(tsk) is always safe.
Link: http://lkml.kernel.org/r/20160608211921.GA15508@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull userns vfs updates from Eric Biederman:
"This tree contains some very long awaited work on generalizing the
user namespace support for mounting filesystems to include filesystems
with a backing store. The real world target is fuse but the goal is
to update the vfs to allow any filesystem to be supported. This
patchset is based on a lot of code review and testing to approach that
goal.
While looking at what is needed to support the fuse filesystem it
became clear that there were things like xattrs for security modules
that needed special treatment. That the resolution of those concerns
would not be fuse specific. That sorting out these general issues
made most sense at the generic level, where the right people could be
drawn into the conversation, and the issues could be solved for
everyone.
At a high level what this patchset does a couple of simple things:
- Add a user namespace owner (s_user_ns) to struct super_block.
- Teach the vfs to handle filesystem uids and gids not mapping into
to kuids and kgids and being reported as INVALID_UID and
INVALID_GID in vfs data structures.
By assigning a user namespace owner filesystems that are mounted with
only user namespace privilege can be detected. This allows security
modules and the like to know which mounts may not be trusted. This
also allows the set of uids and gids that are communicated to the
filesystem to be capped at the set of kuids and kgids that are in the
owning user namespace of the filesystem.
One of the crazier corner casees this handles is the case of inodes
whose i_uid or i_gid are not mapped into the vfs. Most of the code
simply doesn't care but it is easy to confuse the inode writeback path
so no operation that could cause an inode write-back is permitted for
such inodes (aka only reads are allowed).
This set of changes starts out by cleaning up the code paths involved
in user namespace permirted mounts. Then when things are clean enough
adds code that cleanly sets s_user_ns. Then additional restrictions
are added that are possible now that the filesystem superblock
contains owner information.
These changes should not affect anyone in practice, but there are some
parts of these restrictions that are changes in behavior.
- Andy's restriction on suid executables that does not honor the
suid bit when the path is from another mount namespace (think
/proc/[pid]/fd/) or when the filesystem was mounted by a less
privileged user.
- The replacement of the user namespace implicit setting of MNT_NODEV
with implicitly setting SB_I_NODEV on the filesystem superblock
instead.
Using SB_I_NODEV is a stronger form that happens to make this state
user invisible. The user visibility can be managed but it caused
problems when it was introduced from applications reasonably
expecting mount flags to be what they were set to.
There is a little bit of work remaining before it is safe to support
mounting filesystems with backing store in user namespaces, beyond
what is in this set of changes.
- Verifying the mounter has permission to read/write the block device
during mount.
- Teaching the integrity modules IMA and EVM to handle filesystems
mounted with only user namespace root and to reduce trust in their
security xattrs accordingly.
- Capturing the mounters credentials and using that for permission
checks in d_automount and the like. (Given that overlayfs already
does this, and we need the work in d_automount it make sense to
generalize this case).
Furthermore there are a few changes that are on the wishlist:
- Get all filesystems supporting posix acls using the generic posix
acls so that posix_acl_fix_xattr_from_user and
posix_acl_fix_xattr_to_user may be removed. [Maintainability]
- Reducing the permission checks in places such as remount to allow
the superblock owner to perform them.
- Allowing the superblock owner to chown files with unmapped uids and
gids to something that is mapped so the files may be treated
normally.
I am not considering even obvious relaxations of permission checks
until it is clear there are no more corner cases that need to be
locked down and handled generically.
Many thanks to Seth Forshee who kept this code alive, and putting up
with me rewriting substantial portions of what he did to handle more
corner cases, and for his diligent testing and reviewing of my
changes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (30 commits)
fs: Call d_automount with the filesystems creds
fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns
evm: Translate user/group ids relative to s_user_ns when computing HMAC
dquot: For now explicitly don't support filesystems outside of init_user_ns
quota: Handle quota data stored in s_user_ns in quota_setxquota
quota: Ensure qids map to the filesystem
vfs: Don't create inodes with a uid or gid unknown to the vfs
vfs: Don't modify inodes with a uid or gid unknown to the vfs
cred: Reject inodes with invalid ids in set_create_file_as()
fs: Check for invalid i_uid in may_follow_link()
vfs: Verify acls are valid within superblock's s_user_ns.
userns: Handle -1 in k[ug]id_has_mapping when !CONFIG_USER_NS
fs: Refuse uid/gid changes which don't map into s_user_ns
selinux: Add support for unprivileged mounts from user namespaces
Smack: Handle labels consistently in untrusted mounts
Smack: Add support for unprivileged mounts from user namespaces
fs: Treat foreign mounts as nosuid
fs: Limit file caps to the user namespace of the super block
userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag
userns: Remove implicit MNT_NODEV fragility.
...
Merge more updates from Andrew Morton:
"The rest of MM"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (101 commits)
mm, compaction: simplify contended compaction handling
mm, compaction: introduce direct compaction priority
mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations
mm, page_alloc: make THP-specific decisions more generic
mm, page_alloc: restructure direct compaction handling in slowpath
mm, page_alloc: don't retry initial attempt in slowpath
mm, page_alloc: set alloc_flags only once in slowpath
lib/stackdepot.c: use __GFP_NOWARN for stack allocations
mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB
mm, kasan: account for object redzone in SLUB's nearest_obj()
mm: fix use-after-free if memory allocation failed in vma_adjust()
zsmalloc: Delete an unnecessary check before the function call "iput"
mm/memblock.c: fix index adjustment error in __next_mem_range_rev()
mem-hotplug: alloc new page from a nearest neighbor node when mem-offline
mm: optimize copy_page_to/from_iter_iovec
mm: add cond_resched() to generic_swapfile_activate()
Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements"
mm, compaction: don't isolate PageWriteback pages in MIGRATE_SYNC_LIGHT mode
mm: hwpoison: remove incorrect comments
make __section_nr() more efficient
...
Currently, NR_KERNEL_STACK tracks the number of kernel stacks in a zone.
This only makes sense if each kernel stack exists entirely in one zone,
and allowing vmapped stacks could break this assumption.
Since frv has THREAD_SIZE < PAGE_SIZE, we need to track kernel stack
allocations in a unit that divides both THREAD_SIZE and PAGE_SIZE on all
architectures. Keep it simple and use KiB.
Link: http://lkml.kernel.org/r/083c71e642c5fa5f1b6898902e1b2db7b48940d4.1468523549.git.luto@kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are now a number of accounting oddities such as mapped file pages
being accounted for on the node while the total number of file pages are
accounted on the zone. This can be coped with to some extent but it's
confusing so this patch moves the relevant file-based accounted. Due to
throttling logic in the page allocator for reliable OOM detection, it is
still necessary to track dirty and writeback pages on a per-zone basis.
[mgorman@techsingularity.net: fix NR_ZONE_WRITE_PENDING accounting]
Link: http://lkml.kernel.org/r/1468404004-5085-5-git-send-email-mgorman@techsingularity.net
Link: http://lkml.kernel.org/r/1467970510-21195-20-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NR_FILE_PAGES is the number of file pages.
NR_FILE_MAPPED is the number of mapped file pages.
NR_ANON_PAGES is the number of mapped anon pages.
This is unhelpful naming as it's easy to confuse NR_FILE_MAPPED and
NR_ANON_PAGES for mapped pages. This patch renames NR_ANON_PAGES so we
have
NR_FILE_PAGES is the number of file pages.
NR_FILE_MAPPED is the number of mapped file pages.
NR_ANON_MAPPED is the number of mapped anon pages.
Link: http://lkml.kernel.org/r/1467970510-21195-19-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reclaim makes decisions based on the number of pages that are mapped but
it's mixing node and zone information. Account NR_FILE_MAPPED and
NR_ANON_PAGES pages on the node.
Link: http://lkml.kernel.org/r/1467970510-21195-18-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
oom_score_adj is shared for the thread groups (via struct signal) but this
is not sufficient to cover processes sharing mm (CLONE_VM without
CLONE_SIGHAND) and so we can easily end up in a situation when some
processes update their oom_score_adj and confuse the oom killer. In the
worst case some of those processes might hide from the oom killer
altogether via OOM_SCORE_ADJ_MIN while others are eligible. OOM killer
would then pick up those eligible but won't be allowed to kill others
sharing the same mm so the mm wouldn't release the mm and so the memory.
It would be ideal to have the oom_score_adj per mm_struct because that is
the natural entity OOM killer considers. But this will not work because
some programs are doing
vfork()
set_oom_adj()
exec()
We can achieve the same though. oom_score_adj write handler can set the
oom_score_adj for all processes sharing the same mm if the task is not in
the middle of vfork. As a result all the processes will share the same
oom_score_adj. The current implementation is rather pessimistic and
checks all the existing processes by default if there is more than 1
holder of the mm but we do not have any reliable way to check for external
users yet.
Link: http://lkml.kernel.org/r/1466426628-15074-5-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we have two proc interfaces to set oom_score_adj. The legacy
/proc/<pid>/oom_adj and /proc/<pid>/oom_score_adj which both have their
specific handlers. Big part of the logic is duplicated so extract the
common code into __set_oom_adj helper. Legacy knob still expects some
details slightly different so make sure those are handled same way - e.g.
the legacy mode ignores oom_score_adj_min and it warns about the usage.
This patch shouldn't introduce any functional changes.
Link: http://lkml.kernel.org/r/1466426628-15074-4-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg has pointed out that can simplify both oom_adj_{read,write} and
oom_score_adj_{read,write} even further and drop the sighand lock. The
main purpose of the lock was to protect p->signal from going away but this
will not happen since ea6d290ca3 ("signals: make task_struct->signal
immutable/refcountable").
The other role of the lock was to synchronize different writers,
especially those with CAP_SYS_RESOURCE. Introduce a mutex for this
purpose. Later patches will need this lock anyway.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/1466426628-15074-3-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Series "Handle oom bypass more gracefully", V5
The following 10 patches should put some order to very rare cases of mm
shared between processes and make the paths which bypass the oom killer
oom reapable and therefore much more reliable finally. Even though mm
shared outside of thread group is rare (either vforked tasks for a short
period, use_mm by kernel threads or exotic thread model of
clone(CLONE_VM) without CLONE_SIGHAND) it is better to cover them. Not
only it makes the current oom killer logic quite hard to follow and
reason about it can lead to weird corner cases. E.g. it is possible to
select an oom victim which shares the mm with unkillable process or
bypass the oom killer even when other processes sharing the mm are still
alive and other weird cases.
Patch 1 drops bogus task_lock and mm check from oom_{score_}adj_write.
This can be considered a bug fix with a low impact as nobody has noticed
for years.
Patch 2 drops sighand lock because it is not needed anymore as pointed
by Oleg.
Patch 3 is a clean up of oom_score_adj handling and a preparatory work
for later patches.
Patch 4 enforces oom_adj_score to be consistent between processes
sharing the mm to behave consistently with the regular thread groups.
This can be considered a user visible behavior change because one thread
group updating oom_score_adj will affect others which share the same mm
via clone(CLONE_VM). I argue that this should be acceptable because we
already have the same behavior for threads in the same thread group and
sharing the mm without signal struct is just a different model of
threading. This is probably the most controversial part of the series,
I would like to find some consensus here. There were some suggestions
to hook some counter/oom_score_adj into the mm_struct but I feel that
this is not necessary right now and we can rely on proc handler +
oom_kill_process to DTRT. I can be convinced otherwise but I strongly
think that whatever we do the userspace has to have a way to see the
current oom priority as consistently as possible.
Patch 5 makes sure that no vforked task is selected if it is sharing the
mm with oom unkillable task.
Patch 6 ensures that all user tasks sharing the mm are killed which in
turn makes sure that all oom victims are oom reapable.
Patch 7 guarantees that task_will_free_mem will always imply reapable
bypass of the oom killer.
Patch 8 is new in this version and it addresses an issue pointed out by
0-day OOM report where an oom victim was reaped several times.
Patch 9 puts an upper bound on how many times oom_reaper tries to reap a
task and hides it from the oom killer to move on when no progress can be
made. This will give an upper bound to how long an oom_reapable task
can block the oom killer from selecting another victim if the oom_reaper
is not able to reap the victim.
Patch 10 tries to plug the (hopefully) last hole when we can still lock
up when the oom victim is shared with oom unkillable tasks (kthreads and
global init). We just try to be best effort in that case and rather
fallback to kill something else than risk a lockup.
This patch (of 10):
Both oom_adj_write and oom_score_adj_write are using task_lock, check for
task->mm and fail if it is NULL. This is not needed because the
oom_score_adj is per signal struct so we do not need mm at all. The code
has been introduced by 3d5992d2ac ("oom: add per-mm oom disable count")
but we do not do per-mm oom disable since c9f01245b6 ("oom: remove
oom_disable_count").
The task->mm check is even not correct because the current thread might
have exited but the thread group might be still alive - e.g. thread group
leader would lead that echo $VAL > /proc/pid/oom_score_adj would always
fail with EINVAL while /proc/pid/task/$other_tid/oom_score_adj would
succeed. This is unexpected at best.
Remove the lock along with the check to fix the unexpected behavior and
also because there is not real need for the lock in the first place.
Link: http://lkml.kernel.org/r/1466426628-15074-2-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This changes the vfs dentry hashing to mix in the parent pointer at the
_beginning_ of the hash, rather than at the end.
That actually improves both the hash and the code generation, because we
can move more of the computation to the "static" part of the dcache
setup, and do less at lookup runtime.
It turns out that a lot of other hash users also really wanted to mix in
a base pointer as a 'salt' for the hash, and so the slightly extended
interface ends up working well for other cases too.
Users that want a string hash that is purely about the string pass in a
'salt' pointer of NULL.
* merge branch 'salted-string-hash':
fs/dcache.c: Save one 32-bit multiply in dcache lookup
vfs: make the string hashes salt the hash
Let's add ShmemHugePages and ShmemPmdMapped fields into meminfo and
smaps. It indicates how many times we allocate and map shmem THP.
NR_ANON_TRANSPARENT_HUGEPAGES is renamed to NR_ANON_THPS.
Link: http://lkml.kernel.org/r/1466021202-61880-27-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a function may_open_dev that tests MNT_NODEV and a new
superblock flab SB_I_NODEV. Use this new function in all of the
places where MNT_NODEV was previously tested.
Add the new SB_I_NODEV s_iflag to proc, sysfs, and mqueuefs as those
filesystems should never support device nodes, and a simple superblock
flags makes that very hard to get wrong. With SB_I_NODEV set if any
device nodes somehow manage to show up on on a filesystem those
device nodes will be unopenable.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Move the call of get_pid_ns, the call of proc_parse_options, and
the setting of s_iflags into proc_fill_super so that mount_ns
can be used.
Convert proc_mount to call mount_ns and remove the now unnecessary
code.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Reviewed-by: Djalal Harouni <tixxdz@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Replace the call of fs_fully_visible in do_new_mount from before the
new superblock is allocated with a call of mount_too_revealing after
the superblock is allocated. This winds up being a much better location
for maintainability of the code.
The first change this enables is the replacement of FS_USERNS_VISIBLE
with SB_I_USERNS_VISIBLE. Moving the flag from struct filesystem_type
to sb_iflags on the superblock.
Unfortunately mount_too_revealing fundamentally needs to touch
mnt_flags adding several MNT_LOCKED_XXX flags at the appropriate
times. If the mnt_flags did not need to be touched the code
could be easily moved into the filesystem specific mount code.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time. It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.
A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.
Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge filesystem stacking fixes from Jann Horn.
* emailed patches from Jann Horn <jannh@google.com>:
sched: panic on corrupted stack end
ecryptfs: forbid opening files without mmap handler
proc: prevent stacking filesystems on top
This prevents stacking filesystems (ecryptfs and overlayfs) from using
procfs as lower filesystem. There is too much magic going on inside
procfs, and there is no good reason to stack stuff on top of procfs.
(For example, procfs does access checks in VFS open handlers, and
ecryptfs by design calls open handlers from a kernel thread that doesn't
drop privileges or so.)
Signed-off-by: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CLEAR_REFS_MM_HIWATER_RSS and CLEAR_REFS_SOFT_DIRTY are relying on
mmap_sem for write. If the waiting task gets killed by the oom killer
and it would operate on the current's mm it would block oom_reaper from
asynchronous address space reclaim and reduce the chances of timely OOM
resolving. Wait for the lock in the killable mode and return with EINTR
if the task got killed while waiting. This will also expedite the
return to the userspace and do_exit even if the mm is remote.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Petr Cermak <petrcermak@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Nicolas Pitre