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 foo {
int stuff;
struct boo entry[];
};
size = sizeof(struct foo) + count * sizeof(struct boo);
instance = kzalloc(size, GFP_KERNEL)
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)
Notice that, in this case, variable reqsz is not necessary,
hence it is removed.
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
index 8209a42dea72..07b3ba949da5 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
@@ -711,7 +711,6 @@ brcmf_fw_alloc_request(u32 chip, u32 chiprev,
size_t mp_path_len;
u32 i, j;
char end = '\0';
- size_t reqsz;
for (i = 0; i < table_size; i++) {
if (mapping_table[i].chipid == chip &&
@@ -726,8 +725,7 @@ brcmf_fw_alloc_request(u32 chip, u32 chiprev,
return NULL;
}
- reqsz = sizeof(*fwreq) + n_fwnames * sizeof(struct brcmf_fw_item);
- fwreq = kzalloc(reqsz, GFP_KERNEL);
+ fwreq = kzalloc(struct_size(fwreq, items, n_fwnames), GFP_KERNEL);
if (!fwreq)
return NULL;
--
2.21.0
