On Sat, Jan 20, 2024 at 02:54:00PM +0100, Erick Archer wrote: > As noted in the "Deprecated Interfaces, Language Features, Attributes, > and Conventions" documentation [1], size calculations (especially > multiplication) should not be performed in memory allocator (or similar) > function arguments due to the risk of them overflowing. This could lead > to values wrapping around and a smaller allocation being made than the > caller was expecting. Using those allocations could lead to linear > overflows of heap memory and other misbehaviors. > > So, use the purpose specific kcalloc() function instead of the argument > count * size in the kzalloc() function. > > Also, it is preferred to use sizeof(*pointer) instead of sizeof(type) > due to the type of the variable can change and one needs not change the > former (unlike the latter). > > Link: > https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments > [1] > Link: https://github.com/KSPP/linux/issues/162 > Signed-off-by: Erick Archer <[email protected]> > --- > arch/riscv/kernel/cpufeature.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > index 89920f84d0a3..549a76e34c4e 100644 > --- a/arch/riscv/kernel/cpufeature.c > +++ b/arch/riscv/kernel/cpufeature.c > @@ -901,8 +901,7 @@ static int check_unaligned_access_all_cpus(void) > { > unsigned int cpu; > unsigned int cpu_count = num_possible_cpus(); > - struct page **bufs = kzalloc(cpu_count * sizeof(struct page *), > - GFP_KERNEL); > + struct page **bufs = kcalloc(cpu_count, sizeof(*bufs), GFP_KERNEL); > > if (!bufs) { > pr_warn("Allocation failure, not measuring misaligned > performance\n"); > -- > 2.25.1 >
Reviewed-by: Andrew Jones <[email protected]>
