The following commit has been merged into the perf/core branch of tip:
Commit-ID: dfbc411e0a5ea72fdd563b2c7d627e9d993d865c
Gitweb: https://git.kernel.org/tip/dfbc411e0a5ea72fdd563b2c7d627e9d993d865c
Author: Erick Archer <erick.archer@xxxxxxx>
AuthorDate: Sun, 17 Mar 2024 17:44:42 +01:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Thu, 21 Mar 2024 20:58:43 +01:00
perf/x86/rapl: Prefer struct_size() over open coded arithmetic
This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows:
https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
https://github.com/KSPP/linux/issues/160
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.
Signed-off-by: Erick Archer <erick.archer@xxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240317164442.6729-1-erick.archer@xxxxxxx
---
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 fb2b196..8ef08b5 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;
|