This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1][2].
As the "rapl_pmus" variable is a pointer to "struct rapl_pmus" and
this structure ends in a flexible array:
struct rapl_pmus {
[...]
struct rapl_pmu *pmus[] __counted_by(maxdie);
};
the preferred way in the kernel is to use the struct_size() helper to
do the arithmetic instead of the calculation "size + count * size" in
the kzalloc() function.
This way, the code is more readable and safer.
Link:
https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
[1]
Link: https://github.com/KSPP/linux/issues/160 [2]
Signed-off-by: Erick Archer <[email protected]>
---
arch/x86/events/rapl.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c
index fb2b1961e5a3..8ef08b5d55a7 100644
--- a/arch/x86/events/rapl.c
+++ b/arch/x86/events/rapl.c
@@ -675,10 +675,8 @@ static const struct attribute_group *rapl_attr_update[] = {
static int __init init_rapl_pmus(void)
{
int maxdie = topology_max_packages() * topology_max_dies_per_package();
- size_t size;
- size = sizeof(*rapl_pmus) + maxdie * sizeof(struct rapl_pmu *);
- rapl_pmus = kzalloc(size, GFP_KERNEL);
+ rapl_pmus = kzalloc(struct_size(rapl_pmus, pmus, maxdie), GFP_KERNEL);
if (!rapl_pmus)
return -ENOMEM;
--
2.25.1
