tree e1fe64719a08c8676338d40736a26839a4b4e626
parent 9bb1b7e879091f09fc677dca10c5e132b68a9da3
author Julia Lawall <julia@diku.dk> 1228257292 -0300
committer Mauro Carvalho Chehab <mchehab@redhat.com> 1230637106 -0200

V4L/DVB (9796): drivers/media/video/cx88/cx88-alsa.c: Adjust error-handling code

In the function cx88_audio_initdev, the value card has been created using
snd_card_new.  The other error handling code in this function frees the
value using snd_card_free.  I have thus changed the first error case to do
the same.  On the other hand, it may be that card is not sufficiently
initialized at this point to use snd_card_free, in which case something
else should be done to free the memory in the error case.

In the function snd_cx88_create the call kfree(chip) in one error case
looks suspicious, both because it is not done in the other error code, and
because chip points into the middle of the memory allocated by
snd_card_new, ie it is not itself associated with a separate kmalloc.
Therefore I have removed it.

The semantic match that finds the first problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
statement S,S1;
position p1,p2,p3;
expression E,E1;
type T,T1;
expression *ptr != NULL;
@@

(
 if ((x@p1 = snd_card_new(...)) == NULL) S
|
 x@p1 = snd_card_new(...);
)
 ... when != snd_card_free(...,(T)x,...)
     when != if (...) { <+... snd_card_free(...,(T)x,...) ...+> }
     when != true x == NULL || ...
     when != x = E
     when != E = (T)x
     when any
(
 if (x == NULL || ...) S1
|
 if@p2 (...) {
  ... when != snd_card_free(...,(T1)x,...)
      when != if (...) { <+... snd_card_free(...,(T1)x,...) ...+> }
      when != x = E1
      when != E1 = (T1)x
(
  return \(0\|<+...x...+>\|ptr\);
|
  return@p3 ...;
)
}
)

@ script:python @
p1 << r.p1;
p3 << r.p3;
@@

print "* file: %s snd_card_new: %s return: %s" % (p1[0].file,p1[0].line,p3[0].line)

// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>