linux.git/fs/proc/base.c, branch v2.6.22-rc4

smaps: only define clear_refs for CONFIG_MMU

2007-05-09T03:41:14+00:00

/proc/pid/clear_refs is only defined in the CONFIG_MMU case, so make sure we
don't have any references to clear_refs_smap() in generic procfs code.

Signed-off-by: David Rientjes 
Signed-off-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

procfs: use simple_read_from_buffer()

2007-05-08T18:15:14+00:00

Cleanup using simple_read_from_buffer() in procfs.

Signed-off-by: Akinobu Mita 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove redundant check from proc_setattr()

2007-05-08T18:15:10+00:00

notify_change() already calls security_inode_setattr() before
calling iop->setattr.

Signed-off-by: Tony Jones 
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: John Johansen 
Acked-by: Stephen Smalley 
Cc: James Morris 
Cc: Chris Wright 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix race between cat /proc/*/wchan and rmmod et al

2007-05-08T18:15:08+00:00

kallsyms_lookup() can go iterating over modules list unprotected which is OK
for emergency situations (oops), but not OK for regular stuff like
/proc/*/wchan.

Introduce lookup_symbol_name()/lookup_module_symbol_name() which copy symbol
name into caller-supplied buffer or return -ERANGE.  All copying is done with
module_mutex held, so...

Signed-off-by: Alexey Dobriyan 
Cc: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Simplify kallsyms_lookup()

2007-05-08T18:15:08+00:00

Several kallsyms_lookup() pass dummy arguments but only need, say, module's
name.  Make kallsyms_lookup() accept NULLs where possible.

Also, makes picture clearer about what interfaces are needed for all symbol
resolving business.

Signed-off-by: Alexey Dobriyan 
Cc: Rusty Russell 
Acked-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

header cleaning: don't include smp_lock.h when not used

2007-05-08T18:15:07+00:00

Remove includes of  where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).

Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

/proc/*/oom_score oops re badness

2007-05-08T18:15:04+00:00

Eternal quest to make

	while true; do cat /proc/fs/xfs/stat >/dev/null 2>/dev/null; done
	while true; do find /proc -type f 2>/dev/null | xargs cat >/dev/null 2>/dev/null; done
	while true; do modprobe xfs; rmmod xfs; done

work reliably continues and now kernel oopses in the following way:

BUG: unable to handle ... at virtual address 6b6b6b6b
EIP is at badness
process: cat
	proc_oom_score
	proc_info_read
	sys_fstat64
	vfs_read
	proc_info_read
	sys_read

Failing code is prefetch hidden in list_for_each_entry() in badness().
badness() is reachable from two points. One is proc_oom_score, another
is out_of_memory() => select_bad_process() => badness().

Second path grabs tasklist_lock, while first doesn't.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

add file position info to proc

2007-05-08T18:15:03+00:00

Add support for finding out the current file position, open flags and
possibly other info in the future.

These new entries are added:

  /proc/PID/fdinfo/FD
  /proc/PID/task/TID/fdinfo/FD

For each fd the information is provided in the following format:

pos:	1234
flags:	0100002

[bunk@stusta.de: make struct proc_fdinfo_file_operations static]
Signed-off-by: Miklos Szeredi 
Cc: Alexey Dobriyan 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

procfs: reorder struct pid_dentry to save space on 64bit archs, and constify them

2007-05-08T18:15:03+00:00

Change the order of fields of struct pid_entry (file fs/proc/base.c) in order
to avoid a hole on 64bit archs.  (8 bytes saved per object)

Also change all pid_entry arrays to be const qualified, to make clear they
must not be modified.

Before (on x86_64) :

# size fs/proc/base.o
   text    data     bss     dec     hex filename
  15549    2192       0   17741    454d fs/proc/base.o

After :

# size fs/proc/base.o
   text    data     bss     dec     hex filename
  17229     176       0   17405    43fd fs/proc/base.o

Thats 336 bytes saved on kernel size on x86_64

Signed-off-by: Eric Dumazet 
Acked-by: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: maps protection

2007-05-08T18:15:02+00:00

The /proc/pid/ "maps", "smaps", and "numa_maps" files contain sensitive
information about the memory location and usage of processes.  Issues:

- maps should not be world-readable, especially if programs expect any
  kind of ASLR protection from local attackers.
- maps cannot just be 0400 because "-D_FORTIFY_SOURCE=2 -O2" makes glibc
  check the maps when %n is in a *printf call, and a setuid(getuid())
  process wouldn't be able to read its own maps file.  (For reference
  see http://lkml.org/lkml/2006/1/22/150)
- a system-wide toggle is needed to allow prior behavior in the case of
  non-root applications that depend on access to the maps contents.

This change implements a check using "ptrace_may_attach" before allowing
access to read the maps contents.  To control this protection, the new knob
/proc/sys/kernel/maps_protect has been added, with corresponding updates to
the procfs documentation.

[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: New sysctl numbers are old hat]
Signed-off-by: Kees Cook 
Cc: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds