On Mon, Jun 5, 2023 at 12:40 AM Puranjay Mohan <puranjay12@xxxxxxxxx> wrote:
>
> The bpf_prog_pack allocator currently uses module_alloc() and
> module_memfree() to allocate and free memory. This is not portable
> because different architectures use different methods for allocating
> memory for BPF programs. Like ARM64 uses vmalloc()/vfree().
>
> Use bpf_jit_alloc_exec() and bpf_jit_free_exec() for memory management
> in bpf_prog_pack allocator. Other architectures can override these with
> their implementation and will be able to use bpf_prog_pack directly.
>
> Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
Acked-by: Song Liu <song@xxxxxxxxxx>
> ---
> kernel/bpf/core.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 7421487422d4..2bc9092bf9be 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -860,7 +860,7 @@ static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_ins
> GFP_KERNEL);
> if (!pack)
> return NULL;
> - pack->ptr = module_alloc(BPF_PROG_PACK_SIZE);
> + pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE);
> if (!pack->ptr) {
> kfree(pack);
> return NULL;
> @@ -884,7 +884,7 @@ void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
> mutex_lock(&pack_mutex);
> if (size > BPF_PROG_PACK_SIZE) {
> size = round_up(size, PAGE_SIZE);
> - ptr = module_alloc(size);
> + ptr = bpf_jit_alloc_exec(size);
> if (ptr) {
> bpf_fill_ill_insns(ptr, size);
> set_vm_flush_reset_perms(ptr);
> @@ -922,7 +922,7 @@ void bpf_prog_pack_free(struct bpf_binary_header *hdr)
>
> mutex_lock(&pack_mutex);
> if (hdr->size > BPF_PROG_PACK_SIZE) {
> - module_memfree(hdr);
> + bpf_jit_free_exec(hdr);
> goto out;
> }
>
> @@ -946,7 +946,7 @@ void bpf_prog_pack_free(struct bpf_binary_header *hdr)
> if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
> BPF_PROG_CHUNK_COUNT, 0) == 0) {
> list_del(&pack->list);
> - module_memfree(pack->ptr);
> + bpf_jit_free_exec(pack->ptr);
> kfree(pack);
> }
> out:
> --
> 2.39.2
>
