Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 27 7月, 2008 1 次提交
  3. 26 7月, 2008 1 次提交
  5. 14 7月, 2008 1 次提交
    • S
      Security: split proc ptrace checking into read vs. attach · 006ebb40
      由 Stephen Smalley 提交于 
      Enable security modules to distinguish reading of process state via
proc from full ptrace access by renaming ptrace_may_attach to
ptrace_may_access and adding a mode argument indicating whether only
read access or full attach access is requested.  This allows security
modules to permit access to reading process state without granting
full ptrace access.  The base DAC/capability checking remains unchanged.

Read access to /proc/pid/mem continues to apply a full ptrace attach
check since check_mem_permission() already requires the current task
to already be ptracing the target.  The other ptrace checks within
proc for elements like environ, maps, and fds are changed to pass the
read mode instead of attach.

In the SELinux case, we model such reading of process state as a
reading of a proc file labeled with the target process' label.  This
enables SELinux policy to permit such reading of process state without
permitting control or manipulation of the target process, as there are
a number of cases where programs probe for such information via proc
but do not need to be able to control the target (e.g. procps,
lsof, PolicyKit, ConsoleKit).  At present we have to choose between
allowing full ptrace in policy (more permissive than required/desired)
or breaking functionality (or in some cases just silencing the denials
via dontaudit rules but this can hide genuine attacks).

This version of the patch incorporates comments from Casey Schaufler
(change/replace existing ptrace_may_attach interface, pass access
mode), and Chris Wright (provide greater consistency in the checking).

Note that like their predecessors __ptrace_may_attach and
ptrace_may_attach, the __ptrace_may_access and ptrace_may_access
interfaces use different return value conventions from each other (0
or -errno vs. 1 or 0).  I retained this difference to avoid any
changes to the caller logic but made the difference clearer by
changing the latter interface to return a bool rather than an int and
by adding a comment about it to ptrace.h for any future callers.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NJames Morris <jmorris@namei.org>
      006ebb40
  7. 07 6月, 2008 1 次提交
  9. 17 5月, 2008 1 次提交
  11. 02 5月, 2008 1 次提交
  13. 29 4月, 2008 2 次提交
    • R
      procfs: mem permission cleanup · 638fa202
      由 Roland McGrath 提交于 
      This cleans up the permission checks done for /proc/PID/mem i/o calls.  It
puts all the logic in a new function, check_mem_permission().

The old code repeated the (!MAY_PTRACE(task) || !ptrace_may_attach(task))
magical expression multiple times.  The new function does all that work in one
place, with clear comments.

The old code called security_ptrace() twice on successful checks, once in
MAY_PTRACE() and once in __ptrace_may_attach().  Now it's only called once,
and only if all other checks have succeeded.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      638fa202
    • M
      procfs task exe symlink · 925d1c40
      由 Matt Helsley 提交于 
      The kernel implements readlink of /proc/pid/exe by getting the file from
the first executable VMA.  Then the path to the file is reconstructed and
reported as the result.

Because of the VMA walk the code is slightly different on nommu systems.
This patch avoids separate /proc/pid/exe code on nommu systems.  Instead of
walking the VMAs to find the first executable file-backed VMA we store a
reference to the exec'd file in the mm_struct.

That reference would prevent the filesystem holding the executable file
from being unmounted even after unmapping the VMAs.  So we track the number
of VM_EXECUTABLE VMAs and drop the new reference when the last one is
unmapped.  This avoids pinning the mounted filesystem.

[akpm@linux-foundation.org: improve comments]
[yamamoto@valinux.co.jp: fix dup_mmap]
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Cc:"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: NYAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      925d1c40
  15. 23 4月, 2008 3 次提交
    • R
      [patch 6/7] vfs: mountinfo: add /proc/<pid>/mountinfo · 2d4d4864
      由 Ram Pai 提交于 
      [mszeredi@suse.cz] rewrite and split big patch into managable chunks

/proc/mounts in its current form lacks important information:

 - propagation state
 - root of mount for bind mounts
 - the st_dev value used within the filesystem
 - identifier for each mount and it's parent

It also suffers from the following problems:

 - not easily extendable
 - ambiguity of mountpoints within a chrooted environment
 - doesn't distinguish between filesystem dependent and independent options
 - doesn't distinguish between per mount and per super block options

This patch introduces /proc/<pid>/mountinfo which attempts to address
all these deficiencies.

Code shared between /proc/<pid>/mounts and /proc/<pid>/mountinfo is
extracted into separate functions.

Thanks to Al Viro for the help in getting the design right.
Signed-off-by: NRam Pai <linuxram@us.ibm.com>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      2d4d4864
    • M
      [patch 5/7] vfs: mountinfo: allow using process root · a1a2c409
      由 Miklos Szeredi 提交于 
      Allow /proc/<pid>/mountinfo to use the root of <pid> to calculate
mountpoints.

 - move definition of 'struct proc_mounts' to <linux/mnt_namespace.h>
 - add the process's namespace and root to this structure
 - pass a pointer to 'struct proc_mounts' into seq_operations

In addition the following cleanups are made:

 - use a common open function for /proc/<pid>/{mounts,mountstat}
 - surround namespace.c part of these proc files with #ifdef CONFIG_PROC_FS
 - make the seq_operations structures const
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      a1a2c409
    • A
      [PATCH] proc_readfd_common() race fix · 9b4f526c
      由 Al Viro 提交于 
      Since we drop the rcu_read_lock inside the loop, we can't assume
that files->fdt will remain unchanged (and not freed) between
iterations.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      9b4f526c
  17. 21 3月, 2008 1 次提交
    • A
      [NET]: Fix permissions of /proc/net · 4f42c288
      由 Andre Noll 提交于 
      commit e9720acd ([NET]: Make /proc/net a symlink on /proc/self/net (v3))
broke ganglia and probably other applications that read /proc/net/dev.

This is due to the change of permissions of /proc/net that was
introduced in that commit.

Before: dr-xr-xr-x 5 root root 0 Mar 19 11:30 /proc/net
After: dr-xr--r-- 5 root root 0 Mar 19 11:29 /proc/self/net

This patch restores the permissions to the old value which makes
ganglia happy again.

Pavel Emelyanov says:

	This also broke the postfix, as it was reported in bug #10286
	and described in detail by Benjamin.
Signed-off-by: NAndre Noll <maan@systemlinux.org>
Acked-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4f42c288
  19. 18 3月, 2008 1 次提交
  21. 12 3月, 2008 1 次提交
  23. 08 3月, 2008 1 次提交
    • P
      [NET]: Make /proc/net a symlink on /proc/self/net (v3) · e9720acd
      由 Pavel Emelyanov 提交于 
      Current /proc/net is done with so called "shadows", but current
implementation is broken and has little chances to get fixed.

The problem is that dentries subtree of /proc/net directory has
fancy revalidation rules to make processes living in different
net namespaces see different entries in /proc/net subtree, but
currently, tasks see in the /proc/net subdir the contents of any
other namespace, depending on who opened the file first.

The proposed fix is to turn /proc/net into a symlink, which points
to /proc/self/net, which in turn shows what previously was in
/proc/net - the network-related info, from the net namespace the
appropriate task lives in.

# ls -l /proc/net
lrwxrwxrwx  1 root root 8 Mar  5 15:17 /proc/net -> self/net

In other words - this behaves like /proc/mounts, but unlike
"mounts", "net" is not a file, but a directory.

Changes from v2:
* Fixed discrepancy of /proc/net nlink count and selinux labeling
  screwup pointed out by Stephen.

  To get the correct nlink count the ->getattr callback for /proc/net
  is overridden to read one from the net->proc_net entry.

  To make selinux still work the net->proc_net entry is initialized
  properly, i.e. with the "net" name and the proc_net parent.

Selinux fixes are
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>

Changes from v1:
* Fixed a task_struct leak in get_proc_task_net, pointed out by Paul.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      e9720acd
  25. 25 2月, 2008 3 次提交
  27. 24 2月, 2008 1 次提交
  29. 15 2月, 2008 5 次提交
  31. 09 2月, 2008 8 次提交
  33. 06 2月, 2008 4 次提交
    • A
      Fix /proc dcache deadlock in do_exit · 7766755a
      由 Andrea Arcangeli 提交于 
      This patch fixes a sles9 system hang in start_this_handle from a customer
with some heavy workload where all tasks are waiting on kjournald to commit
the transaction, but kjournald waits on t_updates to go down to zero (it
never does).

This was reported as a lowmem shortage deadlock but when checking the debug
data I noticed the VM wasn't under pressure at all (well it was really
under vm pressure, because lots of tasks hanged in the VM prune_dcache
methods trying to flush dirty inodes, but no task was hanging in GFP_NOFS
mode, the holder of the journal handle should have if this was a vm issue
in the first place).

No task was apparently holding the leftover handle in the committing
transaction, so I deduced t_updates was stuck to 1 because a journal_stop
was never run by some path (this turned out to be correct).  With a debug
patch adding proper reverse links and stack trace logging in ext3 deployed
in production, I found journal_stop is never run because
mark_inode_dirty_sync is called inside release_task called by do_exit.
(that was quite fun because I would have never thought about this
subtleness, I thought a regular path in ext3 had a bug and it forgot to
call journal_stop)

do_exit->release_task->mark_inode_dirty_sync->schedule() (will never
come back to run journal_stop)

The reason is that shrink_dcache_parent is racy by design (feature not
a bug) and it can do blocking I/O in some case, but the point is that
calling shrink_dcache_parent at the last stage of do_exit isn't safe
for self-reaping tasks.

I guess the memory pressure of the unbalanced highmem system allowed
to trigger this more easily.

Now mainline doesn't have this line in iput (like sles9 has):

    	     if (inode->i_state & I_DIRTY_DELAYED)
	     			mark_inode_dirty_sync(inode);

so it will probably not crash with ext3, but for example ext2 implements an
I/O-blocking ext2_put_inode that will lead to similar screwups with
ext2_free_blocks never coming back and it's definitely wrong to call
blocking-IO paths inside do_exit.  So this should fix a subtle bug in
mainline too (not verified in practice though).  The equivalent fix for
ext3 is also not verified yet to fix the problem in sles9 but I don't have
doubt it will (it usually takes days to crash, so it'll take weeks to be
sure).

An alternate fix would be to offload that work to a kernel thread, but I
don't think a reschedule for this is worth it, the vm should be able to
collect those entries for the synchronous release_task.
Signed-off-by: NAndrea Arcangeli <andrea@suse.de>
Cc: Jan Kara <jack@ucw.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7766755a
    • M
      maps4: make page monitoring /proc file optional · 1e883281
      由 Matt Mackall 提交于 
      Make /proc/ page monitoring configurable

This puts the following files under an embedded config option:

/proc/pid/clear_refs
/proc/pid/smaps
/proc/pid/pagemap
/proc/kpagecount
/proc/kpageflags

[akpm@linux-foundation.org: Kconfig fix]
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1e883281
    • M
      maps4: add /proc/pid/pagemap interface · 85863e47
      由 Matt Mackall 提交于 
      This interface provides a mapping for each page in an address space to its
physical page frame number, allowing precise determination of what pages are
mapped and what pages are shared between processes.

New in this version:

- headers gone again (as recommended by Dave Hansen and Alan Cox)
- 64-bit entries (as per discussion with Andi Kleen)
- swap pte information exported (from Dave Hansen)
- page walker callback for holes (from Dave Hansen)
- direct put_user I/O (as suggested by Rusty Russell)

This patch folds in cleanups and swap PTE support from Dave Hansen
<haveblue@us.ibm.com>.
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      85863e47
    • M
      maps4: move clear_refs code to task_mmu.c · f248dcb3
      由 Matt Mackall 提交于 
      This puts all the clear_refs code where it belongs and probably lets things
compile on MMU-less systems as well.
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f248dcb3
  35. 02 2月, 2008 1 次提交
  37. 26 1月, 2008 1 次提交
  39. 03 1月, 2008 1 次提交
  41. 07 12月, 2007 1 次提交