Commit Graph

522 Commits

Author SHA1 Message Date
Oleg Nesterov
c7a3a88c93 uprobes: Fix mmap_region()'s mm->mm_rb corruption if uprobe_mmap() fails
This patch fixes:

  https://bugzilla.redhat.com/show_bug.cgi?id=843640

If mmap_region()->uprobe_mmap() fails, unmap_and_free_vma path
does unmap_region() but does not remove the soon-to-be-freed vma
from rb tree. Actually there are more problems but this is how
William noticed this bug.

Perhaps we could do do_munmap() + return in this case, but in
fact it is simply wrong to abort if uprobe_mmap() fails. Until
at least we move the !UPROBE_COPY_INSN code from
install_breakpoint() to uprobe_register().

For example, uprobe_mmap()->install_breakpoint() can fail if the
probed insn is not supported (remember, uprobe_register()
succeeds if nobody mmaps inode/offset), mmap() should not fail
in this case.

dup_mmap()->uprobe_mmap() is wrong too by the same reason,
fork() can race with uprobe_register() and fail for no reason if
it wins the race and does install_breakpoint() first.

And, if nothing else, both mmap_region() and dup_mmap() return
success if uprobe_mmap() fails. Change them to ignore the error
code from uprobe_mmap().

Reported-and-tested-by: William Cohen <wcohen@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> # v3.5
Cc: Anton Arapov <anton@redhat.com>
Cc: William Cohen <wcohen@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120819171042.GB26957@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-08-21 11:48:12 +02:00
Andrew Morton
c255a45805 memcg: rename config variables
Sanity:

CONFIG_CGROUP_MEM_RES_CTLR -> CONFIG_MEMCG
CONFIG_CGROUP_MEM_RES_CTLR_SWAP -> CONFIG_MEMCG_SWAP
CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED -> CONFIG_MEMCG_SWAP_ENABLED
CONFIG_CGROUP_MEM_RES_CTLR_KMEM -> CONFIG_MEMCG_KMEM

[mhocko@suse.cz: fix missed bits]
Cc: Glauber Costa <glommer@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:43 -07:00
Huang Shijie
44de9d0cad mm: account the total_vm in the vm_stat_account()
vm_stat_account() accounts the shared_vm, stack_vm and reserved_vm now.
But we can also account for total_vm in the vm_stat_account() which makes
the code tidy.

Even for mprotect_fixup(), we can get the right result in the end.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:39 -07:00
Akinobu Mita
f19b9f74b7 fork: fix error handling in dup_task()
The function dup_task() may fail at the following function calls in the
following order.

0) alloc_task_struct_node()
1) alloc_thread_info_node()
2) arch_dup_task_struct()

Error by 0) is not a matter, it can just return.  But error by 1) requires
releasing task_struct allocated by 0) before it returns.  Likewise, error
by 2) requires releasing task_struct and thread_info allocated by 0) and
1).

The existing error handling calls free_task_struct() and
free_thread_info() which do not only release task_struct and thread_info,
but also call architecture specific arch_release_task_struct() and
arch_release_thread_info().

The problem is that task_struct and thread_info are not fully initialized
yet at this point, but arch_release_task_struct() and
arch_release_thread_info() are called with them.

For example, x86 defines its own arch_release_task_struct() that releases
a task_xstate.  If alloc_thread_info_node() fails in dup_task(),
arch_release_task_struct() is called with task_struct which is just
allocated and filled with garbage in this error handling.

This actually happened with tools/testing/fault-injection/failcmd.sh

	# env FAILCMD_TYPE=fail_page_alloc \
		./tools/testing/fault-injection/failcmd.sh --times=100 \
		--min-order=0 --ignore-gfp-wait=0 \
		-- make -C tools/testing/selftests/ run_tests

In order to fix this issue, make free_{task_struct,thread_info}() not to
call arch_release_{task_struct,thread_info}() and call
arch_release_{task_struct,thread_info}() implicitly where needed.

Default arch_release_task_struct() and arch_release_thread_info() are
defined as empty by default.  So this change only affects the
architectures which implement their own arch_release_task_struct() or
arch_release_thread_info() as listed below.

arch_release_task_struct(): x86, sh
arch_release_thread_info(): mn10300, tile

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Salman Qazi <sqazi@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:20 -07:00
Andrew Morton
87bec58a52 revert "sched: Fix fork() error path to not crash"
To make way for "fork: fix error handling in dup_task()", which fixes the
errors more completely.

Cc: Salman Qazi <sqazi@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:20 -07:00
Huang Shijie
b2412b7fa7 fork: use vma_pages() to simplify the code
The current code can be replaced by vma_pages().  So use it to simplify
the code.

[akpm@linux-foundation.org: initialise `len' at its definition site]
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:20 -07:00
Linus Torvalds
a66d2c8f7e Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull the big VFS changes from Al Viro:
 "This one is *big* and changes quite a few things around VFS.  What's in there:

   - the first of two really major architecture changes - death to open
     intents.

     The former is finally there; it was very long in making, but with
     Miklos getting through really hard and messy final push in
     fs/namei.c, we finally have it.  Unlike his variant, this one
     doesn't introduce struct opendata; what we have instead is
     ->atomic_open() taking preallocated struct file * and passing
     everything via its fields.

     Instead of returning struct file *, it returns -E...  on error, 0
     on success and 1 in "deal with it yourself" case (e.g.  symlink
     found on server, etc.).

     See comments before fs/namei.c:atomic_open().  That made a lot of
     goodies finally possible and quite a few are in that pile:
     ->lookup(), ->d_revalidate() and ->create() do not get struct
     nameidata * anymore; ->lookup() and ->d_revalidate() get lookup
     flags instead, ->create() gets "do we want it exclusive" flag.

     With the introduction of new helper (kern_path_locked()) we are rid
     of all struct nameidata instances outside of fs/namei.c; it's still
     visible in namei.h, but not for long.  Come the next cycle,
     declaration will move either to fs/internal.h or to fs/namei.c
     itself.  [me, miklos, hch]

   - The second major change: behaviour of final fput().  Now we have
     __fput() done without any locks held by caller *and* not from deep
     in call stack.

     That obviously lifts a lot of constraints on the locking in there.
     Moreover, it's legal now to call fput() from atomic contexts (which
     has immediately simplified life for aio.c).  We also don't need
     anti-recursion logics in __scm_destroy() anymore.

     There is a price, though - the damn thing has become partially
     asynchronous.  For fput() from normal process we are guaranteed
     that pending __fput() will be done before the caller returns to
     userland, exits or gets stopped for ptrace.

     For kernel threads and atomic contexts it's done via
     schedule_work(), so theoretically we might need a way to make sure
     it's finished; so far only one such place had been found, but there
     might be more.

     There's flush_delayed_fput() (do all pending __fput()) and there's
     __fput_sync() (fput() analog doing __fput() immediately).  I hope
     we won't need them often; see warnings in fs/file_table.c for
     details.  [me, based on task_work series from Oleg merged last
     cycle]

   - sync series from Jan

   - large part of "death to sync_supers()" work from Artem; the only
     bits missing here are exofs and ext4 ones.  As far as I understand,
     those are going via the exofs and ext4 trees resp.; once they are
     in, we can put ->write_super() to the rest, along with the thread
     calling it.

   - preparatory bits from unionmount series (from dhowells).

   - assorted cleanups and fixes all over the place, as usual.

  This is not the last pile for this cycle; there's at least jlayton's
  ESTALE work and fsfreeze series (the latter - in dire need of fixes,
  so I'm not sure it'll make the cut this cycle).  I'll probably throw
  symlink/hardlink restrictions stuff from Kees into the next pile, too.
  Plus there's a lot of misc patches I hadn't thrown into that one -
  it's large enough as it is..."

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (127 commits)
  ext4: switch EXT4_IOC_RESIZE_FS to mnt_want_write_file()
  btrfs: switch btrfs_ioctl_balance() to mnt_want_write_file()
  switch dentry_open() to struct path, make it grab references itself
  spufs: shift dget/mntget towards dentry_open()
  zoran: don't bother with struct file * in zoran_map
  ecryptfs: don't reinvent the wheels, please - use struct completion
  don't expose I_NEW inodes via dentry->d_inode
  tidy up namei.c a bit
  unobfuscate follow_up() a bit
  ext3: pass custom EOF to generic_file_llseek_size()
  ext4: use core vfs llseek code for dir seeks
  vfs: allow custom EOF in generic_file_llseek code
  vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder sync passes
  vfs: Remove unnecessary flushing of block devices
  vfs: Make sys_sync writeout also block device inodes
  vfs: Create function for iterating over block devices
  vfs: Reorder operations during sys_sync
  quota: Move quota syncing to ->sync_fs method
  quota: Split dquot_quota_sync() to writeback and cache flushing part
  vfs: Move noop_backing_dev_info check from sync into writeback
  ...
2012-07-23 12:27:27 -07:00
Al Viro
158e1645e0 trim task_work: get rid of hlist
layout based on Oleg's suggestion; single-linked list,
task->task_works points to the last element, forward pointer
from said last element points to head.  I'd still prefer
much more regular scheme with two pointers in task_work,
but...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:57:55 +04:00
Salman Qazi
164c33c6ad sched: Fix fork() error path to not crash
In dup_task_struct(), if arch_dup_task_struct() fails, the clean up
code fails to clean up correctly.  That's because the clean up
code depends on unininitalized ti->task pointer.  We fix this
by making sure that the task and thread_info know about each other
before we attempt to take the error path.

Signed-off-by: Salman Qazi <sqazi@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120626011815.11323.5533.stgit@dungbeetle.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-05 20:57:32 +02:00
Linus Torvalds
48d212a2ee Revert "mm: correctly synchronize rss-counters at exit/exec"
This reverts commit 40af1bbdca.

It's horribly and utterly broken for at least the following reasons:

 - calling sync_mm_rss() from mmput() is fundamentally wrong, because
   there's absolutely no reason to believe that the task that does the
   mmput() always does it on its own VM.  Example: fork, ptrace, /proc -
   you name it.

 - calling it *after* having done mmdrop() on it is doubly insane, since
   the mm struct may well be gone now.

 - testing mm against NULL before you call it is insane too, since a
NULL mm there would have caused oopses long before.

.. and those are just the three bugs I found before I decided to give up
looking for me and revert it asap.  I should have caught it before I
even took it, but I trusted Andrew too much.

Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07 17:54:07 -07:00
Konstantin Khlebnikov
40af1bbdca mm: correctly synchronize rss-counters at exit/exec
mm->rss_stat counters have per-task delta: task->rss_stat.  Before
changing task->mm pointer the kernel must flush this delta with
sync_mm_rss().

do_exit() already calls sync_mm_rss() to flush the rss-counters before
committing the rss statistics into task->signal->maxrss, taskstats,
audit and other stuff.  Unfortunately the kernel does this before
calling mm_release(), which can call put_user() for processing
task->clear_child_tid.  So at this point we can trigger page-faults and
task->rss_stat becomes non-zero again.  As a result mm->rss_stat becomes
inconsistent and check_mm() will print something like this:

| BUG: Bad rss-counter state mm:ffff88020813c380 idx:1 val:-1
| BUG: Bad rss-counter state mm:ffff88020813c380 idx:2 val:1

This patch moves sync_mm_rss() into mm_release(), and moves mm_release()
out of do_exit() and calls it earlier.  After mm_release() there should
be no pagefaults.

[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>		[3.4.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07 14:43:55 -07:00
Linus Torvalds
fb21affa49 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull second pile of signal handling patches from Al Viro:
 "This one is just task_work_add() series + remaining prereqs for it.

  There probably will be another pull request from that tree this
  cycle - at least for helpers, to get them out of the way for per-arch
  fixes remaining in the tree."

Fix trivial conflict in kernel/irq/manage.c: the merge of Andrew's pile
had brought in commit 97fd75b7b8 ("kernel/irq/manage.c: use the
pr_foo() infrastructure to prefix printks") which changed one of the
pr_err() calls that this merge moves around.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  keys: kill task_struct->replacement_session_keyring
  keys: kill the dummy key_replace_session_keyring()
  keys: change keyctl_session_to_parent() to use task_work_add()
  genirq: reimplement exit_irq_thread() hook via task_work_add()
  task_work_add: generic process-context callbacks
  avr32: missed _TIF_NOTIFY_RESUME on one of do_notify_resume callers
  parisc: need to check NOTIFY_RESUME when exiting from syscall
  move key_repace_session_keyring() into tracehook_notify_resume()
  TIF_NOTIFY_RESUME is defined on all targets now
2012-05-31 18:47:30 -07:00
Linus Torvalds
08615d7d85 Merge branch 'akpm' (Andrew's patch-bomb)
Merge misc patches from Andrew Morton:

 - the "misc" tree - stuff from all over the map

 - checkpatch updates

 - fatfs

 - kmod changes

 - procfs

 - cpumask

 - UML

 - kexec

 - mqueue

 - rapidio

 - pidns

 - some checkpoint-restore feature work.  Reluctantly.  Most of it
   delayed a release.  I'm still rather worried that we don't have a
   clear roadmap to completion for this work.

* emailed from Andrew Morton <akpm@linux-foundation.org>: (78 patches)
  kconfig: update compression algorithm info
  c/r: prctl: add ability to set new mm_struct::exe_file
  c/r: prctl: extend PR_SET_MM to set up more mm_struct entries
  c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat
  syscalls, x86: add __NR_kcmp syscall
  fs, proc: introduce /proc/<pid>/task/<tid>/children entry
  sysctl: make kernel.ns_last_pid control dependent on CHECKPOINT_RESTORE
  aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()
  eventfd: change int to __u64 in eventfd_signal()
  fs/nls: add Apple NLS
  pidns: make killed children autoreap
  pidns: use task_active_pid_ns in do_notify_parent
  rapidio/tsi721: add DMA engine support
  rapidio: add DMA engine support for RIO data transfers
  ipc/mqueue: add rbtree node caching support
  tools/selftests: add mq_perf_tests
  ipc/mqueue: strengthen checks on mqueue creation
  ipc/mqueue: correct mq_attr_ok test
  ipc/mqueue: improve performance of send/recv
  selftests: add mq_open_tests
  ...
2012-05-31 18:10:18 -07:00
Konstantin Khlebnikov
f7505d64f2 fork: call complete_vfork_done() after clearing child_tid and flushing rss-counters
Child should wake up the parent from vfork() only after finishing all
operations with shared mm.  There is no sense in using
CLONE_CHILD_CLEARTID together with CLONE_VFORK, but it looks more accurate
now.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31 17:49:29 -07:00
Linus Torvalds
0d167518e0 Merge branch 'for-3.5/core' of git://git.kernel.dk/linux-block
Merge block/IO core bits from Jens Axboe:
 "This is a bit bigger on the core side than usual, but that is purely
  because we decided to hold off on parts of Tejun's submission on 3.4
  to give it a bit more time to simmer.  As a consequence, it's seen a
  long cycle in for-next.

  It contains:

   - Bug fix from Dan, wrong locking type.
   - Relax splice gifting restriction from Eric.
   - A ton of updates from Tejun, primarily for blkcg.  This improves
     the code a lot, making the API nicer and cleaner, and also includes
     fixes for how we handle and tie policies and re-activate on
     switches.  The changes also include generic bug fixes.
   - A simple fix from Vivek, along with a fix for doing proper delayed
     allocation of the blkcg stats."

Fix up annoying conflict just due to different merge resolution in
Documentation/feature-removal-schedule.txt

* 'for-3.5/core' of git://git.kernel.dk/linux-block: (92 commits)
  blkcg: tg_stats_alloc_lock is an irq lock
  vmsplice: relax alignement requirements for SPLICE_F_GIFT
  blkcg: use radix tree to index blkgs from blkcg
  blkcg: fix blkcg->css ref leak in __blkg_lookup_create()
  block: fix elvpriv allocation failure handling
  block: collapse blk_alloc_request() into get_request()
  blkcg: collapse blkcg_policy_ops into blkcg_policy
  blkcg: embed struct blkg_policy_data in policy specific data
  blkcg: mass rename of blkcg API
  blkcg: style cleanups for blk-cgroup.h
  blkcg: remove blkio_group->path[]
  blkcg: blkg_rwstat_read() was missing inline
  blkcg: shoot down blkgs if all policies are deactivated
  blkcg: drop stuff unused after per-queue policy activation update
  blkcg: implement per-queue policy activation
  blkcg: add request_queue->root_blkg
  blkcg: make request_queue bypassing on allocation
  blkcg: make sure blkg_lookup() returns %NULL if @q is bypassing
  blkcg: make blkg_conf_prep() take @pol and return with queue lock held
  blkcg: remove static policy ID enums
  ...
2012-05-30 08:52:42 -07:00
Siddhesh Poyarekar
7edc8b0ac1 mm/fork: fix overflow in vma length when copying mmap on clone
The vma length in dup_mmap is calculated and stored in a unsigned int,
which is insufficient and hence overflows for very large maps (beyond
16TB). The following program demonstrates this:

#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>

#define GIG 1024 * 1024 * 1024L
#define EXTENT 16393

int main(void)
{
        int i, r;
        void *m;
        char buf[1024];

        for (i = 0; i < EXTENT; i++) {
                m = mmap(NULL, (size_t) 1 * 1024 * 1024 * 1024L,
                         PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);

                if (m == (void *)-1)
                        printf("MMAP Failed: %d\n", m);
                else
                        printf("%d : MMAP returned %p\n", i, m);

                r = fork();

                if (r == 0) {
                        printf("%d: successed\n", i);
                        return 0;
                } else if (r < 0)
                        printf("FORK Failed: %d\n", r);
                else if (r > 0)
                        wait(NULL);
        }
        return 0;
}

Increase the storage size of the result to unsigned long, which is
sufficient for storing the difference between addresses.

Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:19 -07:00
Rik van Riel
e709ffd616 mm: remove swap token code
The swap token code no longer fits in with the current VM model.  It
does not play well with cgroups or the better NUMA placement code in
development, since we have only one swap token globally.

It also has the potential to mess with scalability of the system, by
increasing the number of non-reclaimable pages on the active and
inactive anon LRU lists.

Last but not least, the swap token code has been broken for a year
without complaints, as reported by Konstantin Khlebnikov.  This suggests
we no longer have much use for it.

The days of sub-1G memory systems with heavy use of swap are over.  If
we ever need thrashing reducing code in the future, we will have to
implement something that does scale.

Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Bob Picco <bpicco@meloft.net>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:19 -07:00
Linus Torvalds
654443e20d Merge branch 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull user-space probe instrumentation from Ingo Molnar:
 "The uprobes code originates from SystemTap and has been used for years
  in Fedora and RHEL kernels.  This version is much rewritten, reviews
  from PeterZ, Oleg and myself shaped the end result.

  This tree includes uprobes support in 'perf probe' - but SystemTap
  (and other tools) can take advantage of user probe points as well.

  Sample usage of uprobes via perf, for example to profile malloc()
  calls without modifying user-space binaries.

  First boot a new kernel with CONFIG_UPROBE_EVENT=y enabled.

  If you don't know which function you want to probe you can pick one
  from 'perf top' or can get a list all functions that can be probed
  within libc (binaries can be specified as well):

	$ perf probe -F -x /lib/libc.so.6

  To probe libc's malloc():

	$ perf probe -x /lib64/libc.so.6 malloc
	Added new event:
	probe_libc:malloc    (on 0x7eac0)

  You can now use it in all perf tools, such as:

	perf record -e probe_libc:malloc -aR sleep 1

  Make use of it to create a call graph (as the flat profile is going to
  look very boring):

	$ perf record -e probe_libc:malloc -gR make
	[ perf record: Woken up 173 times to write data ]
	[ perf record: Captured and wrote 44.190 MB perf.data (~1930712

	$ perf report | less

	  32.03%            git  libc-2.15.so   [.] malloc
	                    |
	                    --- malloc

	  29.49%            cc1  libc-2.15.so   [.] malloc
	                    |
	                    --- malloc
	                       |
	                       |--0.95%-- 0x208eb1000000000
	                       |
	                       |--0.63%-- htab_traverse_noresize

	  11.04%             as  libc-2.15.so   [.] malloc
	                     |
	                     --- malloc
	                        |

	   7.15%             ld  libc-2.15.so   [.] malloc
	                     |
	                     --- malloc
	                        |

	   5.07%             sh  libc-2.15.so   [.] malloc
	                     |
	                     --- malloc
	                        |
	   4.99%  python-config  libc-2.15.so   [.] malloc
	          |
	          --- malloc
	             |
	   4.54%           make  libc-2.15.so   [.] malloc
	                   |
	                   --- malloc
	                      |
	                      |--7.34%-- glob
	                      |          |
	                      |          |--93.18%-- 0x41588f
	                      |          |
	                      |           --6.82%-- glob
	                      |                     0x41588f

	   ...

  Or:

	$ perf report -g flat | less

	# Overhead        Command  Shared Object      Symbol
	# ........  .............  .............  ..........
	#
	  32.03%            git  libc-2.15.so   [.] malloc
	          27.19%
	              malloc

	  29.49%            cc1  libc-2.15.so   [.] malloc
	          24.77%
	              malloc

	  11.04%             as  libc-2.15.so   [.] malloc
	          11.02%
	              malloc

	   7.15%             ld  libc-2.15.so   [.] malloc
	           6.57%
	              malloc

	 ...

  The core uprobes design is fairly straightforward: uprobes probe
  points register themselves at (inode:offset) addresses of
  libraries/binaries, after which all existing (or new) vmas that map
  that address will have a software breakpoint injected at that address.
  vmas are COW-ed to preserve original content.  The probe points are
  kept in an rbtree.

  If user-space executes the probed inode:offset instruction address
  then an event is generated which can be recovered from the regular
  perf event channels and mmap-ed ring-buffer.

  Multiple probes at the same address are supported, they create a
  dynamic callback list of event consumers.

  The basic model is further complicated by the XOL speedup: the
  original instruction that is probed is copied (in an architecture
  specific fashion) and executed out of line when the probe triggers.
  The XOL area is a single vma per process, with a fixed number of
  entries (which limits probe execution parallelism).

  The API: uprobes are installed/removed via
  /sys/kernel/debug/tracing/uprobe_events, the API is integrated to
  align with the kprobes interface as much as possible, but is separate
  to it.

  Injecting a probe point is privileged operation, which can be relaxed
  by setting perf_paranoid to -1.

  You can use multiple probes as well and mix them with kprobes and
  regular PMU events or tracepoints, when instrumenting a task."

Fix up trivial conflicts in mm/memory.c due to previous cleanup of
unmap_single_vma().

* 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  perf probe: Detect probe target when m/x options are absent
  perf probe: Provide perf interface for uprobes
  tracing: Fix kconfig warning due to a typo
  tracing: Provide trace events interface for uprobes
  tracing: Extract out common code for kprobes/uprobes trace events
  tracing: Modify is_delete, is_return from int to bool
  uprobes/core: Decrement uprobe count before the pages are unmapped
  uprobes/core: Make background page replacement logic account for rss_stat counters
  uprobes/core: Optimize probe hits with the help of a counter
  uprobes/core: Allocate XOL slots for uprobes use
  uprobes/core: Handle breakpoint and singlestep exceptions
  uprobes/core: Rename bkpt to swbp
  uprobes/core: Make order of function parameters consistent across functions
  uprobes/core: Make macro names consistent
  uprobes: Update copyright notices
  uprobes/core: Move insn to arch specific structure
  uprobes/core: Remove uprobe_opcode_sz
  uprobes/core: Make instruction tables volatile
  uprobes: Move to kernel/events/
  uprobes/core: Clean up, refactor and improve the code
  ...
2012-05-24 11:39:34 -07:00
Oleg Nesterov
e73f8959af task_work_add: generic process-context callbacks
Provide a simple mechanism that allows running code in the (nonatomic)
context of the arbitrary task.

The caller does task_work_add(task, task_work) and this task executes
task_work->func() either from do_notify_resume() or from do_exit().  The
callback can rely on PF_EXITING to detect the latter case.

"struct task_work" can be embedded in another struct, still it has "void
*data" to handle the most common/simple case.

This allows us to kill the ->replacement_session_keyring hack, and
potentially this can have more users.

Performance-wise, this adds 2 "unlikely(!hlist_empty())" checks into
tracehook_notify_resume() and do_exit().  But at the same time we can
remove the "replacement_session_keyring != NULL" checks from
arch/*/signal.c and exit_creds().

Note: task_work_add/task_work_run abuses ->pi_lock.  This is only because
this lock is already used by lookup_pi_state() to synchronize with
do_exit() setting PF_EXITING.  Fortunately the scope of this lock in
task_work.c is really tiny, and the code is unlikely anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Smith <dsmith@redhat.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-23 22:09:21 -04:00
Linus Torvalds
ec0d7f18ab Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull fpu state cleanups from Ingo Molnar:
 "This tree streamlines further aspects of FPU handling by eliminating
  the prepare_to_copy() complication and moving that logic to
  arch_dup_task_struct().

  It also fixes the FPU dumps in threaded core dumps, removes and old
  (and now invalid) assumption plus micro-optimizes the exit path by
  avoiding an FPU save for dead tasks."

Fixed up trivial add-add conflict in arch/sh/kernel/process.c that came
in because we now do the FPU handling in arch_dup_task_struct() rather
than the legacy (and now gone) prepare_to_copy().

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, fpu: drop the fpu state during thread exit
  x86, xsave: remove thread_has_fpu() bug check in __sanitize_i387_state()
  coredump: ensure the fpu state is flushed for proper multi-threaded core dump
  fork: move the real prepare_to_copy() users to arch_dup_task_struct()
2012-05-23 10:59:07 -07:00
Linus Torvalds
cb60e3e65c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "New notable features:
   - The seccomp work from Will Drewry
   - PR_{GET,SET}_NO_NEW_PRIVS from Andy Lutomirski
   - Longer security labels for Smack from Casey Schaufler
   - Additional ptrace restriction modes for Yama by Kees Cook"

Fix up trivial context conflicts in arch/x86/Kconfig and include/linux/filter.h

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (65 commits)
  apparmor: fix long path failure due to disconnected path
  apparmor: fix profile lookup for unconfined
  ima: fix filename hint to reflect script interpreter name
  KEYS: Don't check for NULL key pointer in key_validate()
  Smack: allow for significantly longer Smack labels v4
  gfp flags for security_inode_alloc()?
  Smack: recursive tramsmute
  Yama: replace capable() with ns_capable()
  TOMOYO: Accept manager programs which do not start with / .
  KEYS: Add invalidation support
  KEYS: Do LRU discard in full keyrings
  KEYS: Permit in-place link replacement in keyring list
  KEYS: Perform RCU synchronisation on keys prior to key destruction
  KEYS: Announce key type (un)registration
  KEYS: Reorganise keys Makefile
  KEYS: Move the key config into security/keys/Kconfig
  KEYS: Use the compat keyctl() syscall wrapper on Sparc64 for Sparc32 compat
  Yama: remove an unused variable
  samples/seccomp: fix dependencies on arch macros
  Yama: add additional ptrace scopes
  ...
2012-05-21 20:27:36 -07:00
Linus Torvalds
bf67f3a5c4 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp hotplug cleanups from Thomas Gleixner:
 "This series is merily a cleanup of code copied around in arch/* and
  not changing any of the real cpu hotplug horrors yet.  I wish I'd had
  something more substantial for 3.5, but I underestimated the lurking
  horror..."

Fix up trivial conflicts in arch/{arm,sparc,x86}/Kconfig and
arch/sparc/include/asm/thread_info_32.h

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
  um: Remove leftover declaration of alloc_task_struct_node()
  task_allocator: Use config switches instead of magic defines
  sparc: Use common threadinfo allocator
  score: Use common threadinfo allocator
  sh-use-common-threadinfo-allocator
  mn10300: Use common threadinfo allocator
  powerpc: Use common threadinfo allocator
  mips: Use common threadinfo allocator
  hexagon: Use common threadinfo allocator
  m32r: Use common threadinfo allocator
  frv: Use common threadinfo allocator
  cris: Use common threadinfo allocator
  x86: Use common threadinfo allocator
  c6x: Use common threadinfo allocator
  fork: Provide kmemcache based thread_info allocator
  tile: Use common threadinfo allocator
  fork: Provide weak arch_release_[task_struct|thread_info] functions
  fork: Move thread info gfp flags to header
  fork: Remove the weak insanity
  sh: Remove cpu_idle_wait()
  ...
2012-05-21 19:43:57 -07:00
Suresh Siddha
55ccf3fe3f fork: move the real prepare_to_copy() users to arch_dup_task_struct()
Historical prepare_to_copy() is mostly a no-op, duplicated for majority of
the architectures and the rest following the x86 model of flushing the extended
register state like fpu there.

Remove it and use the arch_dup_task_struct() instead.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-16 15:16:26 -07:00
Mike Galbraith
5e2bf01422 namespaces, pid_ns: fix leakage on fork() failure
Fork() failure post namespace creation for a child cloned with
CLONE_NEWPID leaks pid_namespace/mnt_cache due to proc being mounted
during creation, but not unmounted during cleanup.  Call
pid_ns_release_proc() during cleanup.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Louis Rilling <louis.rilling@kerlabs.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-10 15:06:44 -07:00
Thomas Gleixner
f5e1028736 task_allocator: Use config switches instead of magic defines
Replace __HAVE_ARCH_TASK_ALLOCATOR and __HAVE_ARCH_THREAD_ALLOCATOR
with proper config switches.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20120505150142.371309416@linutronix.de
2012-05-08 14:08:46 +02:00