From ebc1415d9b4f043cef5a1fb002ec316e32167e7a Mon Sep 17 00:00:00 2001 From: Song Liu Date: Fri, 4 Feb 2022 10:57:39 -0800 Subject: [PATCH] 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: Song Liu Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220204185742.271030-7-song@kernel.org --- arch/x86/net/bpf_jit_comp.c | 7 +++++++ include/linux/bpf.h | 2 ++ kernel/bpf/core.c | 5 +++++ 3 files changed, 14 insertions(+) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 36f6fc3e6e690..c13d148f73966 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -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; +} diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 366f88afd56b4..ea0d7fd4a410a 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -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); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index e3fe53df0a717..a5ec480f9862a 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -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);