Messages in this thread Patch in this message | | | From | Erick Archer <> | Subject | [PATCH] perf/x86/rapl: Prefer struct_size over open coded arithmetic | Date | Sun, 17 Mar 2024 17:44:42 +0100 |
| |
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 <erick.archer@gmx.com> --- 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
| |