| Message ID | 20220804025442.22524-1-aijun.sun@unisoc.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 19f68ed6dc90c93daf7e54d3350ea67fead7cbbf |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf] bpf, arm64: allocate program buffer using kvcalloc instead of kcalloc | expand |
Hello: This patch was applied to bpf/bpf.git (master) by Daniel Borkmann <daniel@iogearbox.net>: On Thu, 4 Aug 2022 10:54:42 +0800 you wrote: > It is not necessary to allocate contiguous physical memory for BPF > program buffer using kcalloc. When the BPF program is large more than > memory page size, kcalloc allocates multiple memory pages from buddy > system. If the device can not provide sufficient memory, for example > in low-end android devices[1], memory allocation for BPF program is likely > failed. > > [...] Here is the summary with links: - [bpf] bpf, arm64: allocate program buffer using kvcalloc instead of kcalloc https://git.kernel.org/bpf/bpf/c/19f68ed6dc90 You are awesome, thank you!
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 42f2e9a8616c..80918e60387b 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -1399,7 +1399,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) memset(&ctx, 0, sizeof(ctx)); ctx.prog = prog; - ctx.offset = kcalloc(prog->len + 1, sizeof(int), GFP_KERNEL); + ctx.offset = kvcalloc(prog->len + 1, sizeof(int), GFP_KERNEL); if (ctx.offset == NULL) { prog = orig_prog; goto out_off; @@ -1499,7 +1499,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) ctx.offset[i] *= AARCH64_INSN_SIZE; bpf_prog_fill_jited_linfo(prog, ctx.offset + 1); out_off: - kfree(ctx.offset); + kvfree(ctx.offset); kfree(jit_data); prog->aux->jit_data = NULL; }
It is not necessary to allocate contiguous physical memory for BPF program buffer using kcalloc. When the BPF program is large more than memory page size, kcalloc allocates multiple memory pages from buddy system. If the device can not provide sufficient memory, for example in low-end android devices[1], memory allocation for BPF program is likely failed. Test cases in lib/test_bpf.c all pass on ARM64 QEMU. [1] AndroidTestSuit: page allocation failure: order:4, mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null),cpuset=foreground,mems_allowed=0 Call trace: dump_stack+0xa4/0x114 warn_alloc+0xf8/0x14c __alloc_pages_slowpath+0xac8/0xb14 __alloc_pages_nodemask+0x194/0x3d0 kmalloc_order_trace+0x44/0x1e8 __kmalloc+0x29c/0x66c bpf_int_jit_compile+0x17c/0x568 bpf_prog_select_runtime+0x4c/0x1b0 bpf_prepare_filter+0x5fc/0x6bc bpf_prog_create_from_user+0x118/0x1c0 seccomp_set_mode_filter+0x1c4/0x7cc __do_sys_prctl+0x380/0x1424 __arm64_sys_prctl+0x20/0x2c el0_svc_common+0xc8/0x22c el0_svc_handler+0x1c/0x28 el0_svc+0x8/0x100 Signed-off-by: Aijun Sun <aijun.sun@unisoc.com> --- arch/arm64/net/bpf_jit_comp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)