From 20e490adea279d49d57b800475938f5b67926d98 Mon Sep 17 00:00:00 2001 From: Puranjay Mohan Date: Thu, 31 Aug 2023 13:12:26 +0000 Subject: [PATCH] bpf: make bpf_prog_pack allocator portable MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 and riscv use 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. On architectures that don't override bpf_jit_alloc/free_exec() this is basically a NOP. Signed-off-by: Puranjay Mohan Acked-by: Song Liu Acked-by: Björn Töpel Tested-by: Björn Töpel Acked-by: Daniel Borkmann Link: https://lore.kernel.org/r/20230831131229.497941-2-puranjay12@gmail.com Signed-off-by: Palmer Dabbelt --- 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 0f8f036d8bd1..4e3ce0542e31 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -870,7 +870,7 @@ 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; @@ -894,7 +894,7 @@ 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); @@ -932,7 +932,7 @@ 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; } @@ -956,7 +956,7 @@ 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: