linux-toradex.git/fs/proc/kcore.c, branch v3.0.79

/proc/kcore: fix seeking

2011-01-13T16:03:17+00:00

Commit 34aacb2920 ("procfs: Use generic_file_llseek in /proc/kcore") broke
seeking on /proc/kcore.  This changes it back to use default_llseek in
order to restore the original behavior.

The problem with generic_file_llseek is that it only allows seeks up to
inode->i_sb->s_maxbytes, which is 2GB-1 on procfs, where the memory file
offset values in the /proc/kcore PT_LOAD segments may exceed or start
beyond that offset value.

A similar revert was made for /proc/vmcore.

Signed-off-by: Dave Anderson 
Acked-by: Frederic Weisbecker 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kcore: add _text to KCORE_TEXT

2010-05-27T16:12:47+00:00

Extend KCORE_TEXT to cover the pages between _text and _stext, to allow
examining some important page table pages.

`readelf -a` output on x86_64 before and after patch:
	  Type           Offset             VirtAddr           PhysAddr
before    LOAD           0x00007fff8100c000 0xffffffff81009000 0x0000000000000000
after     LOAD           0x00007fff81003000 0xffffffff81000000 0x0000000000000000

The newly covered pages are:

	0xffffffff81000000  etc.
	0xffffffff81001000 
	0xffffffff81002000 
	0xffffffff81003000 
	0xffffffff81004000 
	0xffffffff81005000 
	0xffffffff81006000 
	0xffffffff81007000 
	0xffffffff81008000 

Before patch, /proc/kcore shows outdated contents for the above page
table pages, for example:

	(gdb) p level3_ident_pgt
	$1 = {} 0xffffffff81002000 
	(gdb) p/x *((pud_t *)&level3_ident_pgt)@512
	$2 = {{pud = 0x1006063}, {pud = 0x0} }

while the real content is:

	root@hp /home/wfg# hexdump -s 0x1002000 -n 4096 /dev/mem
	1002000 6063 0100 0000 0000 8067 0000 0000 0000
	1002010 0000 0000 0000 0000 0000 0000 0000 0000
	*
	1003000

That is, on a x86_64 box with 2GB memory, we can see first-1GB / full-2GB
identity mapping before/after patch:

	(gdb) p/x *((pud_t *)&level3_ident_pgt)@512
before  $1 = {{pud = 0x1006063}, {pud = 0x0} }
after   $1 = {{pud = 0x1006063}, {pud = 0x8067}, {pud = 0x0} }

Obviously the content before patch is wrong.

Signed-off-by: Wu Fengguang 
Cc: Andi Kleen 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'bkl/procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing

2010-05-20T00:23:28+00:00

* 'bkl/procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
  sunrpc: Include missing smp_lock.h
  procfs: Kill the bkl in ioctl
  procfs: Push down the bkl from ioctl
  procfs: Use generic_file_llseek in /proc/vmcore
  procfs: Use generic_file_llseek in /proc/kmsg
  procfs: Use generic_file_llseek in /proc/kcore
  procfs: Kill BKL in llseek on proc base

procfs: Use generic_file_llseek in /proc/kcore

2010-04-09T14:32:02+00:00

/proc/kcore has no llseek and then falls down to use default_llseek.
This is racy against read_kcore() that directly manipulates fpos
but it doesn't hold the bkl there so using it in llseek doesn't
protect anything.

Let's use generic_file_llseek() instead.

Signed-off-by: Frederic Weisbecker 
Acked-by: Arnd Bergmann 
Cc: Thomas Gleixner 
Cc: Andrew Morton 
Cc: Ingo Molnar 
Cc: John Kacur 
Cc: KAMEZAWA Hiroyuki 
Cc: Al Viro

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

kcore: fix test for end of list

2010-03-24T23:31:22+00:00

"m" is never NULL here.  We need a different test for the end of list
condition.

Signed-off-by: Dan Carpenter 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: WANG Cong 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: includecheck fix: proc, kcore.c

2009-10-08T14:36:38+00:00

fix the following 'make includecheck' warning:

  fs/proc/kcore.c: linux/mm.h is included more than once.

Signed-off-by: Jaswinder Singh Rajput 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

/proc/kcore: update stat.st_size after memory hotplug

2009-09-23T14:39:42+00:00

After memory hotplug (or other events in future), kcore size can be
modified.

To update inode->i_size, we have to know inode/dentry but we can't get it
from inside /proc directly.  But considerinyg memory hotplug, kcore image
is updated only when it's opened.  Then, updating inode->i_size at open()
is enough.

Signed-off-by: KAMEZAWA Hiroyuki 
Acked-by: WANG Cong 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

/proc/kcore: fix stat.st_size

2009-09-23T14:39:42+00:00

Presently the size of /proc/kcore which can be read by 'ls -l' is 0.  But
it's not the correct value.

On x86-64, ls -l shows
 ... root root 140737486266368 2009-09-17 10:29 /proc/kcore
Then, 7FFFFFFE02000. This comes from vmalloc area's size.
(*) This shows "core" size, not  memory size.

This patch shows the size by updating "size" field in struct
proc_dir_entry.  Later, lookup routine will create inode and fill
inode->i_size based on this value.  Then, this has a problem.

 - Once inode is cached, inode->i_size will never be updated.

Then, this patch is not memory-hotplug-aware.

To update inode->i_size, we have to know dentry or inode.
But there is no way to lookup them by inside kernel. Hmmm....
Next patch will try it.

Signed-off-by: KAMEZAWA Hiroyuki 
Acked-by: WANG Cong 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kcore: more fixes for init

2009-09-23T14:39:42+00:00

proc_kcore_init() doesn't check NULL case.  fix it and remove unnecessary
comments.

Signed-off-by: KAMEZAWA Hiroyuki 
Acked-by: WANG Cong 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds