From b62e408c05228f40e69bb38a48db8961cac6cd23 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 26 Aug 2009 14:29:22 -0700 Subject: flex_array: convert element_nr formals to unsigned It's problematic to allow signed element_nr's or total's to be passed as part of the flex array API. flex_array_alloc() allows total_nr_elements to be set to a negative quantity, which is obviously erroneous. flex_array_get() and flex_array_put() allows negative array indices in dereferencing an array part, which could address memory mapped before struct flex_array. The fix is to convert all existing element_nr formals to be qualified as unsigned. Existing checks to compare it to total_nr_elements or the max array size based on element_size need not be changed. Signed-off-by: David Rientjes Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/flex_array.h | 10 ++++++---- lib/flex_array.c | 24 +++++++++++++----------- 2 files changed, 19 insertions(+), 15 deletions(-) diff --git a/include/linux/flex_array.h b/include/linux/flex_array.h index 603160db7c98..45ff18491514 100644 --- a/include/linux/flex_array.h +++ b/include/linux/flex_array.h @@ -36,12 +36,14 @@ struct flex_array { .total_nr_elements = (total), \ } } } -struct flex_array *flex_array_alloc(int element_size, int total, gfp_t flags); -int flex_array_prealloc(struct flex_array *fa, int start, int end, gfp_t flags); +struct flex_array *flex_array_alloc(int element_size, unsigned int total, + gfp_t flags); +int flex_array_prealloc(struct flex_array *fa, unsigned int start, + unsigned int end, gfp_t flags); void flex_array_free(struct flex_array *fa); void flex_array_free_parts(struct flex_array *fa); -int flex_array_put(struct flex_array *fa, int element_nr, void *src, +int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src, gfp_t flags); -void *flex_array_get(struct flex_array *fa, int element_nr); +void *flex_array_get(struct flex_array *fa, unsigned int element_nr); #endif /* _FLEX_ARRAY_H */ diff --git a/lib/flex_array.c b/lib/flex_array.c index cf4e372cae90..7baed2fc3bc8 100644 --- a/lib/flex_array.c +++ b/lib/flex_array.c @@ -99,7 +99,8 @@ static inline int elements_fit_in_base(struct flex_array *fa) * capacity in the base structure. Also note that no effort is made * to efficiently pack objects across page boundaries. */ -struct flex_array *flex_array_alloc(int element_size, int total, gfp_t flags) +struct flex_array *flex_array_alloc(int element_size, unsigned int total, + gfp_t flags) { struct flex_array *ret; int max_size = nr_base_part_ptrs() * __elements_per_part(element_size); @@ -115,7 +116,8 @@ struct flex_array *flex_array_alloc(int element_size, int total, gfp_t flags) return ret; } -static int fa_element_to_part_nr(struct flex_array *fa, int element_nr) +static int fa_element_to_part_nr(struct flex_array *fa, + unsigned int element_nr) { return element_nr / __elements_per_part(fa->element_size); } @@ -143,14 +145,12 @@ void flex_array_free(struct flex_array *fa) kfree(fa); } -static int fa_index_inside_part(struct flex_array *fa, int element_nr) +static unsigned int index_inside_part(struct flex_array *fa, + unsigned int element_nr) { - return element_nr % __elements_per_part(fa->element_size); -} + unsigned int part_offset; -static int index_inside_part(struct flex_array *fa, int element_nr) -{ - int part_offset = fa_index_inside_part(fa, element_nr); + part_offset = element_nr % __elements_per_part(fa->element_size); return part_offset * fa->element_size; } @@ -185,7 +185,8 @@ __fa_get_part(struct flex_array *fa, int part_nr, gfp_t flags) * * Locking must be provided by the caller. */ -int flex_array_put(struct flex_array *fa, int element_nr, void *src, gfp_t flags) +int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src, + gfp_t flags) { int part_nr = fa_element_to_part_nr(fa, element_nr); struct flex_array_part *part; @@ -217,7 +218,8 @@ int flex_array_put(struct flex_array *fa, int element_nr, void *src, gfp_t flags * * Locking must be provided by the caller. */ -int flex_array_prealloc(struct flex_array *fa, int start, int end, gfp_t flags) +int flex_array_prealloc(struct flex_array *fa, unsigned int start, + unsigned int end, gfp_t flags) { int start_part; int end_part; @@ -248,7 +250,7 @@ int flex_array_prealloc(struct flex_array *fa, int start, int end, gfp_t flags) * * Locking must be provided by the caller. */ -void *flex_array_get(struct flex_array *fa, int element_nr) +void *flex_array_get(struct flex_array *fa, unsigned int element_nr) { int part_nr = fa_element_to_part_nr(fa, element_nr); struct flex_array_part *part; -- cgit v1.2.3-58-ga151