[patch 18/18] arch/m68k/mm/kmap.c: introduce missing kfree

Geert Uytterhoeven
2008-10-13T20:05:44Z

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From: Julia Lawall <julia@diku.dk>

Error handling code following a kmalloc should free the allocated data.

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

// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,l;
position p1,p2;
expression *ptr != NULL;
@@

(
if ((x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...)) == NULL) S
|
x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
..
if (x == NULL) S
)
<... when != x
when != if (...) { <+...x...+> }
x->f = E
..>
(
return \(0\|<+...x...+>\|ptr\);
|
return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
arch/m68k/mm/kmap.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/m68k/mm/kmap.c
+++ b/arch/m68k/mm/kmap.c
@@ -66,8 +66,10 @@ static struct vm_struct *get_io_area(uns
for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
if (size + addr < (unsigned long)tmp->addr)
break;
- if (addr > KMAP_END-size)
+ if (addr > KMAP_END-size) {
+ kfree(area);
return NULL;
+ }
addr = tmp->size + (unsigned long)tmp->addr;
}
area->addr = (void *)addr;