Commit ebc1415d authored by Song Liu's avatar Song Liu Committed by Alexei Starovoitov
Browse files

bpf: Introduce bpf_arch_text_copy 



This will be used to copy JITed text to RO protected module memory. On
x86, bpf_arch_text_copy is implemented with text_poke_copy.

bpf_arch_text_copy returns pointer to dst on success, and ERR_PTR(errno)
on errors.

Signed-off-by: default avatarSong Liu <song@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220204185742.271030-7-song@kernel.org
parent 0e06b403

arch/x86/net/bpf_jit_comp.c

+7 −0
Original line number Diff line number Diff line
@@ -2412,3 +2412,10 @@ bool bpf_jit_supports_kfunc_call(void) 
{

	return true;

}



void *bpf_arch_text_copy(void *dst, void *src, size_t len)

{

	if (text_poke_copy(dst, src, len) == NULL)

		return ERR_PTR(-EINVAL);

	return dst;

}

include/linux/bpf.h

+2 −0
Original line number Diff line number Diff line
@@ -2362,6 +2362,8 @@ enum bpf_text_poke_type { 
int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,

		       void *addr1, void *addr2);



void *bpf_arch_text_copy(void *dst, void *src, size_t len);



struct btf_id_set;

bool btf_id_set_contains(const struct btf_id_set *set, u32 id);

kernel/bpf/core.c

+5 −0
Original line number Diff line number Diff line
@@ -2440,6 +2440,11 @@ int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, 
	return -ENOTSUPP;

}



void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)

{

	return ERR_PTR(-ENOTSUPP);

}



DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);

EXPORT_SYMBOL(bpf_stats_enabled_key);