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authorDavid Rientjes <rientjes@google.com>2009-08-26 14:29:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-08-26 20:06:52 -0700
commita30b595d2ca6d39e784a1bed5f2b35f3d7a03af7 (patch)
tree101d1cdf6088a36a09ad5470a062331a74ab657d /lib/flex_array.c
parent054b2b13ccba4876a1ce98a7ede7dab7d6893d01 (diff)
downloadvexpress-lsk-a30b595d2ca6d39e784a1bed5f2b35f3d7a03af7.tar.gz
flex_array: fix get function for elements in base starting at non-zero
If all array elements fit into the base structure and data is copied using flex_array_put() starting at a non-zero index, flex_array_get() will fail to return the data. This fixes the bug by only checking for NULL parts when all elements do not fit in the base structure when flex_array_get() is used. Otherwise, fa_element_to_part_nr() will always be 0 since there are no parts structures needed and such element may never have been put. Thus, it will remain NULL due to the kzalloc() of the base. Additionally, flex_array_put() now only checks for a NULL part when all elements do not fit in the base structure. This is otherwise unnecessary since the base structure is guaranteed to exist (or we would have already hit a NULL pointer). Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/flex_array.c')
-rw-r--r--lib/flex_array.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/lib/flex_array.c b/lib/flex_array.c
index 08f1636d296..e73c691aec3 100644
--- a/lib/flex_array.c
+++ b/lib/flex_array.c
@@ -198,10 +198,11 @@ int flex_array_put(struct flex_array *fa, int element_nr, void *src, gfp_t flags
return -ENOSPC;
if (elements_fit_in_base(fa))
part = (struct flex_array_part *)&fa->parts[0];
- else
+ else {
part = __fa_get_part(fa, part_nr, flags);
- if (!part)
- return -ENOMEM;
+ if (!part)
+ return -ENOMEM;
+ }
dst = &part->elements[index_inside_part(fa, element_nr)];
memcpy(dst, src, fa->element_size);
return 0;
@@ -257,11 +258,12 @@ void *flex_array_get(struct flex_array *fa, int element_nr)
if (element_nr >= fa->total_nr_elements)
return NULL;
- if (!fa->parts[part_nr])
- return NULL;
if (elements_fit_in_base(fa))
part = (struct flex_array_part *)&fa->parts[0];
- else
+ else {
part = fa->parts[part_nr];
+ if (!part)
+ return NULL;
+ }
return &part->elements[index_inside_part(fa, element_nr)];
}