From 720e6a435194fb5237833a4a7ec6aa60a78964a8 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 31 Aug 2022 08:26:46 -0700 Subject: bpf: Allow struct argument in trampoline based programs Allow struct argument in trampoline based programs where the struct size should be <= 16 bytes. In such cases, the argument will be put into up to 2 registers for bpf, x86_64 and arm64 architectures. To support arch-specific trampoline manipulation, add arg_flags for additional struct information about arguments in btf_func_model. Such information will be used in arch specific function arch_prepare_bpf_trampoline() to prepare argument access properly in trampoline. Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20220831152646.2078089-1-yhs@fb.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 9c1674973e03..4d32f125f4af 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -727,10 +727,14 @@ enum bpf_cgroup_storage_type { */ #define MAX_BPF_FUNC_REG_ARGS 5 +/* The argument is a structure. */ +#define BTF_FMODEL_STRUCT_ARG BIT(0) + struct btf_func_model { u8 ret_size; u8 nr_args; u8 arg_size[MAX_BPF_FUNC_ARGS]; + u8 arg_flags[MAX_BPF_FUNC_ARGS]; }; /* Restore arguments before returning from trampoline to let original function -- cgit v1.2.3-59-g8ed1b