Messages in this thread Patch in this message | | | Date | Thu, 6 Jun 2019 13:18:53 -0500 | From | "Gustavo A. R. Silva" <> | Subject | [PATCH v2] kernel: module: Use struct_size() helper |
| |
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example:
struct module_sect_attrs { ... struct module_sect_attr attrs[0]; };
Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes.
So, replace the following form:
sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0]
with:
struct_size(sect_attrs, attrs, nloaded)
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- Changes in v2: - Update changelog text by adding a better description for the motivation and usage of the struct_size() helper.
kernel/module.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c index 80c7c09584cf..3f3bb090fbf4 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1492,8 +1492,7 @@ static void add_sect_attrs(struct module *mod, const struct load_info *info) for (i = 0; i < info->hdr->e_shnum; i++) if (!sect_empty(&info->sechdrs[i])) nloaded++; - size[0] = ALIGN(sizeof(*sect_attrs) - + nloaded * sizeof(sect_attrs->attrs[0]), + size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), sizeof(sect_attrs->grp.attrs[0])); size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]); sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); -- 2.21.0
| |