From dfbc411e0a5ea72fdd563b2c7d627e9d993d865c Mon Sep 17 00:00:00 2001 From: Erick Archer Date: Sun, 17 Mar 2024 17:44:42 +0100 Subject: [PATCH] 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 Signed-off-by: Ingo Molnar Reviewed-by: Gustavo A. R. Silva Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20240317164442.6729-1-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 fb2b1961e5a33..8ef08b5d55a75 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; -- 2.30.2