linux-stable.git/fs/proc/array.c, branch linux-2.6.25.y

capabilities: remain source compatible with 32-bit raw legacy capability support.

2008-06-09T18:27:06+00:00

upstream commit: ca05a99a54db1db5bca72eccb5866d2a86f8517f

Source code out there hard-codes a notion of what the
_LINUX_CAPABILITY_VERSION #define means in terms of the semantics of the
raw capability system calls capget() and capset().  Its unfortunate, but
true.

Since the confusing header file has been in a released kernel, there is
software that is erroneously using 64-bit capabilities with the semantics
of 32-bit compatibilities.  These recently compiled programs may suffer
corruption of their memory when sys_getcap() overwrites more memory than
they are coded to expect, and the raising of added capabilities when using
sys_capset().

As such, this patch does a number of things to clean up the situation
for all. It

  1. forces the _LINUX_CAPABILITY_VERSION define to always retain its
     legacy value.

  2. adopts a new #define strategy for the kernel's internal
     implementation of the preferred magic.

  3. deprecates v2 capability magic in favor of a new (v3) magic
     number. The functionality of v3 is entirely equivalent to v2,
     the only difference being that the v2 magic causes the kernel
     to log a "deprecated" warning so the admin can find applications
     that may be using v2 inappropriately.

[User space code continues to be encouraged to use the libcap API which
protects the application from details like this.  libcap-2.10 is the first
to support v3 capabilities.]

Fixes issue reported in https://bugzilla.redhat.com/show_bug.cgi?id=447518.
Thanks to Bojan Smojver for the report.

[akpm@linux-foundation.org: s/depreciate/deprecate/g]
[akpm@linux-foundation.org: be robust about put_user size]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andrew G. Morgan 
Cc: Serge E. Hallyn 
Cc: Bojan Smojver 
Cc: stable@kernel.org
Signed-off-by: Andrew Morton 
Signed-off-by: Chris Wright

proc: seqfile convert proc_pid_status to properly handle pid namespaces

2008-02-08T17:22:24+00:00

Currently we possibly lookup the pid in the wrong pid namespace.  So
seq_file convert proc_pid_status which ensures the proper pid namespaces is
passed in.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: another build fix]
[akpm@linux-foundation.org: s390 build fix]
[akpm@linux-foundation.org: fix task_name() output]
[akpm@linux-foundation.org: fix nommu build]
Signed-off-by: Eric W. Biederman 
Cc: Andrew Morgan 
Cc: Serge Hallyn 
Cc: Cedric Le Goater 
Cc: Pavel Emelyanov 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Paul Menage 
Cc: Paul Jackson 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

seqfile convert proc_pid_statm

2008-02-08T17:22:24+00:00

This conversion is just for code cleanliness, uniformity, and general safety.

Signed-off-by: Eric W. Biederman 
Cc: Oleg Nesterov 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: rewrite do_task_stat to correctly handle pid namespaces.

2008-02-08T17:22:23+00:00

Currently (as pointed out by Oleg) do_task_stat has a race when calling
task_pid_nr_ns with the task exiting.  In addition do_task_stat is not
currently displaying information in the context of the pid namespace that
mounted the /proc filesystem.  So "cut -d' ' -f 1 /proc//stat" may not
equal .

This patch fixes the problem by converting to a single_open seq_file show
method.  Getting the pid namespace from the filesystem superblock instead of
current, and simply using the the struct pid from the inode instead of
attempting to get that same pid from the task.

Signed-off-by: Eric W. Biederman 
Cc: Oleg Nesterov 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Add 64-bit capability support to the kernel

2008-02-05T17:44:20+00:00

The patch supports legacy (32-bit) capability userspace, and where possible
translates 32-bit capabilities to/from userspace and the VFS to 64-bit
kernel space capabilities.  If a capability set cannot be compressed into
32-bits for consumption by user space, the system call fails, with -ERANGE.

FWIW libcap-2.00 supports this change (and earlier capability formats)

 http://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/

[akpm@linux-foundation.org: coding-syle fixes]
[akpm@linux-foundation.org: use get_task_comm()]
[ezk@cs.sunysb.edu: build fix]
[akpm@linux-foundation.org: do not initialise statics to 0 or NULL]
[akpm@linux-foundation.org: unused var]
[serue@us.ibm.com: export __cap_ symbols]
Signed-off-by: Andrew G. Morgan 
Cc: Stephen Smalley 
Acked-by: Serge Hallyn 
Cc: Chris Wright 
Cc: James Morris 
Cc: Casey Schaufler 
Signed-off-by: Erez Zadok 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc

2008-02-01T00:45:47+00:00

* 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc: (22 commits)
  Remove commented-out code copied from NFS
  NFS: Switch from intr mount option to TASK_KILLABLE
  Add wait_for_completion_killable
  Add wait_event_killable
  Add schedule_timeout_killable
  Use mutex_lock_killable in vfs_readdir
  Add mutex_lock_killable
  Use lock_page_killable
  Add lock_page_killable
  Add fatal_signal_pending
  Add TASK_WAKEKILL
  exit: Use task_is_*
  signal: Use task_is_*
  sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL
  ptrace: Use task_is_*
  power: Use task_is_*
  wait: Use TASK_NORMAL
  proc/base.c: Use task_is_*
  proc/array.c: Use TASK_REPORT
  perfmon: Use task_is_*
  ...

Fixed up conflicts in NFS/sunrpc manually..

fix the "remove task_ppid_nr_ns" commit

2008-01-14T21:23:00+00:00

Commit 84427eaef1fb91704c7112bdb598c810003b99f3 (remove task_ppid_nr_ns)
moved the task_tgid_nr_ns(task->real_parent) outside of lock_task_sighand().
This is wrong, ->real_parent could be freed/reused.

Both ->parent/real_parent point to nothing after __exit_signal() because
we remove the child from ->children list, and thus the child can't be
reparented when its parent exits.

rcu_read_lock() protects ->parent/real_parent, but _only_ if we know it was
valid before we take rcu lock.

Revert this part of the patch.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Linus Torvalds

remove task_ppid_nr_ns

2008-01-13T17:56:43+00:00

task_ppid_nr_ns is called in three places.  One of these should never
have called it.  In the other two, using it broke the existing
semantics.  This was presumably accidental.  If the function had not
been there, it would have been much more obvious to the eye that those
patches were changing the behavior.  We don't need this function.

In task_state, the pid of the ptracer is not the ppid of the ptracer.

In do_task_stat, ppid is the tgid of the real_parent, not its pid.
I also moved the call outside of lock_task_sighand, since it doesn't
need it.

In sys_getppid, ppid is the tgid of the real_parent, not its pid.

Signed-off-by: Roland McGrath 
Signed-off-by: Linus Torvalds

proc/array.c: Use TASK_REPORT

2007-12-06T22:20:28+00:00

Signed-off-by: Matthew Wilcox

sched: fix prev_stime calculation

2007-11-26T20:21:49+00:00

Srivatsa Vaddagiri noticed occasionally incorrect CPU usage
values in top and tracked it down to stime going below 0 in
task_stime(). Negative values are possible there due to the
sampled nature of stime/utime.

Fix suggested by Balbir Singh.

Signed-off-by: Ingo Molnar 
Tested-by: Srivatsa Vaddagiri 
Reviewed-by: Balbir Singh