From: Song Liu <song@kernel.org>
Date: Fri, 4 Feb 2022 10:57:39 -0800
Subject: bpf: Introduce bpf_arch_text_copy
Patch-mainline: v5.18-rc1
Git-commit: ebc1415d9b4f043cef5a1fb002ec316e32167e7a
References: jsc#PED-1377
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 <song@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220204185742.271030-7-song@kernel.org
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
arch/x86/net/bpf_jit_comp.c | 7 +++++++
include/linux/bpf.h | 2 ++
kernel/bpf/core.c | 5 +++++
3 files changed, 14 insertions(+)
--- 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;
+}
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2373,6 +2373,8 @@ 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);
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2440,6 +2440,11 @@ int __weak bpf_arch_text_poke(void *ip,
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);