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  1. 16 Jul, 2010 12 commits
    • Jiri Slaby's avatar
      unistd: add __NR_prlimit64 syscall numbers · f33ebbe9
      Jiri Slaby authored 
      Add __NR_prlimit64 syscall numbers to asm-generic. Add them also to
asm-x86, both 32 and 64-bit.
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
      f33ebbe9
    • Jiri Slaby's avatar
      rlimits: implement prlimit64 syscall · c022a0ac
      Jiri Slaby authored 
      This patch adds the code to support the sys_prlimit64 syscall which
modifies-and-returns the rlim values of a selected process atomically.
The first parameter, pid, being 0 means current process.

Unlike the current implementation, it is a generic interface,
architecture indepentent so that we needn't handle compat stuff
anymore. In the future, after glibc start to use this we can deprecate
sys_setrlimit and sys_getrlimit in favor to clean up the code finally.

It also adds a possibility of changing limits of other processes. We
check the user's permissions to do that and if it succeeds, the new
limits are propagated online. This is good for large scale
applications such as SAP or databases where administrators need to
change limits time by time (e.g. on crashes increase core size). And
it is unacceptable to restart the service.

For safety, all rlim users now either use accessors or doesn't need
them due to
- locking
- the fact a process was just forked and nobody else knows about it
  yet (and nobody can't thus read/write limits)
hence it is safe to modify limits now.

The limitation is that we currently stay at ulong internal
representation. So the rlim64_is_infinity check is used where value is
compared against ULONG_MAX on 32-bit which is the maximum value there.

And since internally the limits are held in struct rlimit, converters
which are used before and after do_prlimit call in sys_prlimit64 are
introduced.
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      c022a0ac
    • Jiri Slaby's avatar
      rlimits: switch more rlimit syscalls to do_prlimit · b9518345
      Jiri Slaby authored 
      After we added more generic do_prlimit, switch sys_getrlimit to that.
Also switch compat handling, so we can get rid of ugly __user casts
and avoid setting process' address limit to kernel data and back.
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      b9518345
    • Jiri Slaby's avatar
      rlimits: redo do_setrlimit to more generic do_prlimit · 5b41535a
      Jiri Slaby authored 
      It now allows also reading of limits. I.e. all read and writes will
later use this function.

It takes two parameters, new and old limits which can be both NULL.
If new is non-NULL, the value in it is set to rlimits.
If old is non-NULL, current rlimits are stored there.
If both are non-NULL, old are stored prior to setting the new ones,
atomically.
(Similar to sigaction.)
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      5b41535a
    • Jiri Slaby's avatar
      rlimits: add rlimit64 structure · 6a1d5e2c
      Jiri Slaby authored 
      Add a platform independent structure for resource limits to use with
a new prlimit64 syscall. This structure is the same which uses glibc
for 64-bit limits.

Also add corresponding infinity which is a 64-bit full of bit-ones.
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      6a1d5e2c
    • Jiri Slaby's avatar
      rlimits: do security check under task_lock · 86f162f4
      Jiri Slaby authored 
      Do security_task_setrlimit under task_lock. Other tasks may change
limits under our hands while we are checking limits inside the
function. From now on, they can't.

Note that all the security work is done under a spinlock here now.
Security hooks count with that, they are called from interrupt context
(like security_task_kill) and with spinlocks already held (e.g.
capable->security_capable).
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Acked-by: default avatarJames Morris <jmorris@namei.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      86f162f4
    • Jiri Slaby's avatar
      rlimits: allow setrlimit to non-current tasks · 1c1e618d
      Jiri Slaby authored 
      Add locking to allow setrlimit accept task parameter other than
current.

Namely, lock tasklist_lock for read and check whether the task
structure has sighand non-null. Do all the signal processing under
that lock still held.

There are some points:
1) security_task_setrlimit is now called with that lock held. This is
   not new, many security_* functions are called with this lock held
   already so it doesn't harm (all this security_* stuff does almost
   the same).
2) task->sighand->siglock (in update_rlimit_cpu) is nested in
   tasklist_lock. This dependence is already existing.
3) tsk->alloc_lock is nested in tasklist_lock. This is OK too, already
   existing dependence.
Signed-off-by: default avatarJiri Slaby <jirislaby@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
      1c1e618d
    • Jiri Slaby's avatar
      rlimits: split sys_setrlimit · 7855c35d
      Jiri Slaby authored 
      Create do_setrlimit from sys_setrlimit and declare do_setrlimit
in the resource header. This is the first phase to have generic
do_prlimit which allows to be called from read, write and compat
rlimits code.

The new do_setrlimit also accepts a task pointer to change the limits
of. Currently, it cannot be other than current, but this will change
with locking later.

Also pass tsk->group_leader to security_task_setrlimit to check
whether current is allowed to change rlimits of the process and not
its arbitrary thread because it makes more sense given that rlimit are
per process and not per-thread.
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      7855c35d
    • Oleg Nesterov's avatar
      rlimits: selinux, do rlimits changes under task_lock · eb2d55a3
      Oleg Nesterov authored 
      When doing an exec, selinux updates rlimits in its code of current
process depending on current max. Make sure max or cur doesn't change
in the meantime by grabbing task_lock which do_prlimit needs for
changing limits too.

While at it, use rlimit helper for accessing CPU rlimit a line below.
To have a volatile access too.
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Cc: Oleg Nesterov <oleg@redhat.com>
      eb2d55a3
    • Oleg Nesterov's avatar
      rlimits: make sure ->rlim_max never grows in sys_setrlimit · 2fb9d268
      Oleg Nesterov authored 
      Mostly preparation for Jiri's changes, but probably makes sense anyway.

sys_setrlimit() checks new_rlim.rlim_max <= old_rlim->rlim_max, but when
it takes task_lock() old_rlim->rlim_max can be already lowered. Move this
check under task_lock().

Currently this is not important, we can only race with our sub-thread,
this means the application is stupid. But when we change the code to allow
the update of !current task's limits, it becomes important to make sure
->rlim_max can be lowered "reliably" even if we race with the application
doing sys_setrlimit().
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      2fb9d268
    • Jiri Slaby's avatar
      rlimits: add task_struct to update_rlimit_cpu · 5ab46b34
      Jiri Slaby authored 
      Add task_struct as a parameter to update_rlimit_cpu to be able to set
rlimit_cpu of different task than current.
Signed-off-by: default avatarJiri Slaby <jirislaby@gmail.com>
Acked-by: default avatarJames Morris <jmorris@namei.org>
      5ab46b34
    • Jiri Slaby's avatar
      rlimits: security, add task_struct to setrlimit · 8fd00b4d
      Jiri Slaby authored 
      Add task_struct to task_setrlimit of security_operations to be able to set
rlimit of task other than current.
Signed-off-by: default avatarJiri Slaby <jirislaby@gmail.com>
Acked-by: default avatarEric Paris <eparis@redhat.com>
Acked-by: default avatarJames Morris <jmorris@namei.org>
      8fd00b4d
  3. 15 Jul, 2010 3 commits
  5. 14 Jul, 2010 4 commits
  7. 12 Jul, 2010 8 commits
  9. 11 Jul, 2010 10 commits
  11. 10 Jul, 2010 3 commits
    • Russell King's avatar
      ARM: lockdep: fix unannotated irqs-on · ac78884e
      Russell King authored 
      CPU: Testing write buffer coherency: ok
------------[ cut here ]------------
WARNING: at kernel/lockdep.c:3145 check_flags+0xcc/0x1dc()
Modules linked in:
[<c0035120>] (unwind_backtrace+0x0/0xf8) from [<c0355374>] (dump_stack+0x20/0x24)
[<c0355374>] (dump_stack+0x20/0x24) from [<c0060c04>] (warn_slowpath_common+0x58/0x70)
[<c0060c04>] (warn_slowpath_common+0x58/0x70) from [<c0060c3c>] (warn_slowpath_null+0x20/0x24)
[<c0060c3c>] (warn_slowpath_null+0x20/0x24) from [<c008f224>] (check_flags+0xcc/0x1dc)
[<c008f224>] (check_flags+0xcc/0x1dc) from [<c00945dc>] (lock_acquire+0x50/0x140)
[<c00945dc>] (lock_acquire+0x50/0x140) from [<c0358434>] (_raw_spin_lock+0x50/0x88)
[<c0358434>] (_raw_spin_lock+0x50/0x88) from [<c00fd114>] (set_task_comm+0x2c/0x60)
[<c00fd114>] (set_task_comm+0x2c/0x60) from [<c007e184>] (kthreadd+0x30/0x108)
[<c007e184>] (kthreadd+0x30/0x108) from [<c0030104>] (kernel_thread_exit+0x0/0x8)
---[ end trace 1b75b31a2719ed1c ]---
possible reason: unannotated irqs-on.
irq event stamp: 3
hardirqs last  enabled at (2): [<c0059bb0>] finish_task_switch+0x48/0xb0
hardirqs last disabled at (3): [<c002f0b0>] ret_slow_syscall+0xc/0x1c
softirqs last  enabled at (0): [<c005f3e0>] copy_process+0x394/0xe5c
softirqs last disabled at (0): [<(null)>] (null)

Fix this by ensuring that the lockdep interrupt state is manipulated in
the appropriate places.  We essentially treat userspace as an entirely
separate environment which isn't relevant to lockdep (lockdep doesn't
monitor userspace.)  We don't tell lockdep that IRQs will be enabled
in that environment.

Instead, when creating kernel threads (which is a rare event compared
to entering/leaving userspace) we have to update the lockdep state.  Do
this by starting threads with IRQs disabled, and in the kthread helper,
tell lockdep that IRQs are enabled, and enable them.

This provides lockdep with a consistent view of the current IRQ state
in kernel space.

This also revert portions of 0d928b0b
which didn't fix the problem.
Tested-by: default avatarMing Lei <tom.leiming@gmail.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      ac78884e
    • Guenter Roeck's avatar
      i2c/mips: Fix error return codes from Sibyte i2c bus driver · 102b59c6
      Guenter Roeck authored 
      Sibyte i2c bus driver returns non-descriptive error values.
Update to return error values as defined in Documentation/i2c/fault-codes.
Signed-off-by: default avatarGuenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
      102b59c6
    • Jean Delvare's avatar
      i2c: Fix probability check · 827900c5
      Jean Delvare authored 
      The new unified probing function differs from the original code, and
the preliminary test whether probing is possible must be updated
accordingly.
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
      827900c5
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