As in commit f21afc25f9 ("smp.h: Use local_irq_{save,restore}() in
!SMP version of on_each_cpu()"), we don't want to enable irqs if they
are not already enabled.
I don't know of any bugs currently caused by this unconditional
local_irq_enable(), but I want to use this function in MIPS/OCTEON early
boot (when we have early_boot_irqs_disabled). This also makes this
function have similar semantics to on_each_cpu() which is good in
itself.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All of the other non-trivial !SMP versions of functions in smp.h are
out-of-line in up.c. Move on_each_cpu() there as well.
This allows us to get rid of the #include <linux/irqflags.h>. The
drawback is that this makes both the x86_64 and i386 defconfig !SMP
kernels about 200 bytes larger each.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The SMP version of this function doesn't unconditionally enable irqs, so
neither should this !SMP version. There are no know problems caused by
this, but we make the change for consistency's sake.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As in commit f21afc25f9 ("smp.h: Use local_irq_{save,restore}() in
!SMP version of on_each_cpu()"), we don't want to enable irqs if they
are not already enabled. There are currently no known problematical
callers of these functions, but since it is a known failure pattern, we
preemptively fix them.
Since they are not trivial functions, make them non-inline by moving
them to up.c. This also makes it so we don't have to fix #include
dependancies for preempt_{disable,enable}.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When running with GENERIC_LOCKBREAK=y, the locking implementations emit
calls to arch_{read,write,spin}_relax when spinning on a contended lock
in order to allow architectures to favour the CPU owning the lock if
possible.
In reality, everybody apart from PowerPC and S390 just does cpu_relax()
here, so make that the default behaviour and allow it to be overridden
if required.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I found the following pattern that leads in to interesting findings:
grep -r "ret.*|=.*__put_user" *
grep -r "ret.*|=.*__get_user" *
grep -r "ret.*|=.*__copy" *
The __put_user() calls in compat_ioctl.c, ptrace compat, signal compat,
since those appear in compat code, we could probably expect the kernel
addresses not to be reachable in the lower 32-bit range, so I think they
might not be exploitable.
For the "__get_user" cases, I don't think those are exploitable: the worse
that can happen is that the kernel will copy kernel memory into in-kernel
buffers, and will fail immediately afterward.
The alpha csum_partial_copy_from_user() seems to be missing the
access_ok() check entirely. The fix is inspired from x86. This could
lead to information leak on alpha. I also noticed that many architectures
map csum_partial_copy_from_user() to csum_partial_copy_generic(), but I
wonder if the latter is performing the access checks on every
architectures.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
do_fork() denies CLONE_THREAD | CLONE_PARENT if NEWUSER | NEWPID.
Then later copy_process() denies CLONE_SIGHAND if the new process will
be in a different pid namespace (task_active_pid_ns() doesn't match
current->nsproxy->pid_ns).
This looks confusing and inconsistent. CLONE_NEWPID is very similar to
the case when ->pid_ns was already unshared, we want the same
restrictions so copy_process() should also nack CLONE_PARENT.
And it would be better to deny CLONE_NEWUSER && CLONE_SIGHAND as well
just for consistency.
Kill the "CLONE_NEWUSER | CLONE_NEWPID" check in do_fork() and change
copy_process() to do the same check along with ->pid_ns check we already
have.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Colin Walters <walters@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 8382fcac1b ("pidns: Outlaw thread creation after
unshare(CLONE_NEWPID)") nacks CLONE_NEWPID if the forking process
unshared pid_ns. This is correct but unnecessary, copy_pid_ns() does
the same check.
Remove the CLONE_NEWPID check to cleanup the code and prepare for the
next change.
Test-case:
static int child(void *arg)
{
return 0;
}
static char stack[16 * 1024];
int main(void)
{
pid_t pid;
assert(unshare(CLONE_NEWUSER | CLONE_NEWPID) == 0);
pid = clone(child, stack + sizeof(stack) / 2,
CLONE_NEWPID | SIGCHLD, NULL);
assert(pid < 0 && errno == EINVAL);
return 0;
}
clone(CLONE_NEWPID) correctly fails with or without this change.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Colin Walters <walters@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 8382fcac1b ("pidns: Outlaw thread creation after
unshare(CLONE_NEWPID)") nacks CLONE_VM if the forking process unshared
pid_ns, this obviously breaks vfork:
int main(void)
{
assert(unshare(CLONE_NEWUSER | CLONE_NEWPID) == 0);
assert(vfork() >= 0);
_exit(0);
return 0;
}
fails without this patch.
Change this check to use CLONE_SIGHAND instead. This also forbids
CLONE_THREAD automatically, and this is what the comment implies.
We could probably even drop CLONE_SIGHAND and use CLONE_THREAD, but it
would be safer to not do this. The current check denies CLONE_SIGHAND
implicitely and there is no reason to change this.
Eric said "CLONE_SIGHAND is fine. CLONE_THREAD would be even better.
Having shared signal handling between two different pid namespaces is
the case that we are fundamentally guarding against."
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Colin Walters <walters@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs pile 3 (of many) from Al Viro:
"Waiman's conversion of d_path() and bits related to it,
kern_path_mountpoint(), several cleanups and fixes (exportfs
one is -stable fodder, IMO).
There definitely will be more... ;-/"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
split read_seqretry_or_unlock(), convert d_walk() to resulting primitives
dcache: Translating dentry into pathname without taking rename_lock
autofs4 - fix device ioctl mount lookup
introduce kern_path_mountpoint()
rename user_path_umountat() to user_path_mountpoint_at()
take unlazy_walk() into umount_lookup_last()
Kill indirect include of file.h from eventfd.h, use fdget() in cgroup.c
prune_super(): sb->s_op is never NULL
exportfs: don't assume that ->iterate() won't feed us too long entries
afs: get rid of redundant ->d_name.len checks
Pull tracing updates from Steven Rostedt:
"Not much changes for the 3.12 merge window. The major tracing changes
are still in flux, and will have to wait for 3.13.
The changes for 3.12 are mostly clean ups and minor fixes.
H Peter Anvin added a check to x86_32 static function tracing that
helps a small segment of the kernel community.
Oleg Nesterov had a few changes from 3.11, but were mostly clean ups
and not worth pushing in the -rc time frame.
Li Zefan had small clean up with annotating a raw_init with __init.
I fixed a slight race in updating function callbacks, but the race is
so small and the bug that happens when it occurs is so minor it's not
even worth pushing to stable.
The only real enhancement is from Alexander Z Lam that made the
tracing_cpumask work for trace buffer instances, instead of them all
sharing a global cpumask"
* tag 'trace-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/rcu: Do not trace debug_lockdep_rcu_enabled()
x86-32, ftrace: Fix static ftrace when early microcode is enabled
ftrace: Fix a slight race in modifying what function callback gets traced
tracing: Make tracing_cpumask available for all instances
tracing: Kill the !CONFIG_MODULES code in trace_events.c
tracing: Don't pass file_operations array to event_create_dir()
tracing: Kill trace_create_file_ops() and friends
tracing/syscalls: Annotate raw_init function with __init
Pull xfs updates from Ben Myers:
"For 3.12-rc1 there are a number of bugfixes in addition to work to
ease usage of shared code between libxfs and the kernel, the rest of
the work to enable project and group quotas to be used simultaneously,
performance optimisations in the log and the CIL, directory entry file
type support, fixes for log space reservations, some spelling/grammar
cleanups, and the addition of user namespace support.
- introduce readahead to log recovery
- add directory entry file type support
- fix a number of spelling errors in comments
- introduce new Q_XGETQSTATV quotactl for project quotas
- add USER_NS support
- log space reservation rework
- CIL optimisations
- kernel/userspace libxfs rework"
* tag 'xfs-for-linus-v3.12-rc1' of git://oss.sgi.com/xfs/xfs: (112 commits)
xfs: XFS_MOUNT_QUOTA_ALL needed by userspace
xfs: dtype changed xfs_dir2_sfe_put_ino to xfs_dir3_sfe_put_ino
Fix wrong flag ASSERT in xfs_attr_shortform_getvalue
xfs: finish removing IOP_* macros.
xfs: inode log reservations are too small
xfs: check correct status variable for xfs_inobt_get_rec() call
xfs: inode buffers may not be valid during recovery readahead
xfs: check LSN ordering for v5 superblocks during recovery
xfs: btree block LSN escaping to disk uninitialised
XFS: Assertion failed: first <= last && last < BBTOB(bp->b_length), file: fs/xfs/xfs_trans_buf.c, line: 568
xfs: fix bad dquot buffer size in log recovery readahead
xfs: don't account buffer cancellation during log recovery readahead
xfs: check for underflow in xfs_iformat_fork()
xfs: xfs_dir3_sfe_put_ino can be static
xfs: introduce object readahead to log recovery
xfs: Simplify xfs_ail_min() with list_first_entry_or_null()
xfs: Register hotcpu notifier after initialization
xfs: add xfs sb v4 support for dirent filetype field
xfs: Add write support for dirent filetype field
xfs: Add read-only support for dirent filetype field
...
kernel/cgroup.c is the only place in the tree that relies on eventfd.h
pulling file.h; move that include there. Switch from eventfd_fget()/fput()
to fdget()/fdput(), while we are at it - eventfd_ctx_fileget() will fail
on non-eventfd descriptors just fine, no need to do that check twice...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull namespace changes from Eric Biederman:
"This is an assorted mishmash of small cleanups, enhancements and bug
fixes.
The major theme is user namespace mount restrictions. nsown_capable
is killed as it encourages not thinking about details that need to be
considered. A very hard to hit pid namespace exiting bug was finally
tracked and fixed. A couple of cleanups to the basic namespace
infrastructure.
Finally there is an enhancement that makes per user namespace
capabilities usable as capabilities, and an enhancement that allows
the per userns root to nice other processes in the user namespace"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
userns: Kill nsown_capable it makes the wrong thing easy
capabilities: allow nice if we are privileged
pidns: Don't have unshare(CLONE_NEWPID) imply CLONE_THREAD
userns: Allow PR_CAPBSET_DROP in a user namespace.
namespaces: Simplify copy_namespaces so it is clear what is going on.
pidns: Fix hang in zap_pid_ns_processes by sending a potentially extra wakeup
sysfs: Restrict mounting sysfs
userns: Better restrictions on when proc and sysfs can be mounted
vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces
kernel/nsproxy.c: Improving a snippet of code.
proc: Restrict mounting the proc filesystem
vfs: Lock in place mounts from more privileged users
Pull crypto update from Herbert Xu:
"Here is the crypto update for 3.12:
- Added MODULE_SOFTDEP to allow pre-loading of modules.
- Reinstated crct10dif driver using the module softdep feature.
- Allow via rng driver to be auto-loaded.
- Split large input data when necessary in nx.
- Handle zero length messages correctly for GCM/XCBC in nx.
- Handle SHA-2 chunks bigger than block size properly in nx.
- Handle unaligned lengths in omap-aes.
- Added SHA384/SHA512 to omap-sham.
- Added OMAP5/AM43XX SHAM support.
- Added OMAP4 TRNG support.
- Misc fixes"
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (66 commits)
Reinstate "crypto: crct10dif - Wrap crc_t10dif function all to use crypto transform framework"
hwrng: via - Add MODULE_DEVICE_TABLE
crypto: fcrypt - Fix bitoperation for compilation with clang
crypto: nx - fix SHA-2 for chunks bigger than block size
crypto: nx - fix GCM for zero length messages
crypto: nx - fix XCBC for zero length messages
crypto: nx - fix limits to sg lists for AES-CCM
crypto: nx - fix limits to sg lists for AES-XCBC
crypto: nx - fix limits to sg lists for AES-GCM
crypto: nx - fix limits to sg lists for AES-CTR
crypto: nx - fix limits to sg lists for AES-CBC
crypto: nx - fix limits to sg lists for AES-ECB
crypto: nx - add offset to nx_build_sg_lists()
padata - Register hotcpu notifier after initialization
padata - share code between CPU_ONLINE and CPU_DOWN_FAILED, same to CPU_DOWN_PREPARE and CPU_UP_CANCELED
hwrng: omap - reorder OMAP TRNG driver code
crypto: omap-sham - correct dma burst size
crypto: omap-sham - Enable Polling mode if DMA fails
crypto: tegra-aes - bitwise vs logical and
crypto: sahara - checking the wrong variable
...
Pull trivial tree from Jiri Kosina:
"The usual trivial updates all over the tree -- mostly typo fixes and
documentation updates"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (52 commits)
doc: Documentation/cputopology.txt fix typo
treewide: Convert retrun typos to return
Fix comment typo for init_cma_reserved_pageblock
Documentation/trace: Correcting and extending tracepoint documentation
mm/hotplug: fix a typo in Documentation/memory-hotplug.txt
power: Documentation: Update s2ram link
doc: fix a typo in Documentation/00-INDEX
Documentation/printk-formats.txt: No casts needed for u64/s64
doc: Fix typo "is is" in Documentations
treewide: Fix printks with 0x%#
zram: doc fixes
Documentation/kmemcheck: update kmemcheck documentation
doc: documentation/hwspinlock.txt fix typo
PM / Hibernate: add section for resume options
doc: filesystems : Fix typo in Documentations/filesystems
scsi/megaraid fixed several typos in comments
ppc: init_32: Fix error typo "CONFIG_START_KERNEL"
treewide: Add __GFP_NOWARN to k.alloc calls with v.alloc fallbacks
page_isolation: Fix a comment typo in test_pages_isolated()
doc: fix a typo about irq affinity
...
Oleg Nesterov
David Daney
Uwe Kleine-König
Will Deacon
Chen Gang
Andi Kleen
Mathieu Desnoyers
Naoya Horiguchi
Xishi Qiu
Linus Torvalds
Al Viro
Herbert Xu