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authorHou Tao2021-10-25 14:40:23 +0800
committerAlexei Starovoitov2021-11-01 14:10:00 -0700
commit35346ab64132d0f5919b06932d708c0d10360553 (patch)
treedfa39e7231a75a2e84dbfc6fad96ad52321042ea
parent31a645aea4f8da5bb190ce322c6e5aacaef13855 (diff)
bpf: Factor out helpers for ctx access checking
Factor out two helpers to check the read access of ctx for raw tp and BTF function. bpf_tracing_ctx_access() is used to check the read access to argument is valid, and bpf_tracing_btf_ctx_access() checks whether the btf type of argument is valid besides the checking of argument read. bpf_tracing_btf_ctx_access() will be used by the following patch. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20211025064025.2567443-3-houtao1@huawei.com
-rw-r--r--include/linux/bpf.h23
-rw-r--r--kernel/trace/bpf_trace.c16
-rw-r--r--net/ipv4/bpf_tcp_ca.c9
3 files changed, 26 insertions, 22 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index aabd3540aaaf..67f71e7def56 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1650,6 +1650,29 @@ bool bpf_prog_test_check_kfunc_call(u32 kfunc_id, struct module *owner);
bool btf_ctx_access(int off, int size, enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info);
+
+static inline bool bpf_tracing_ctx_access(int off, int size,
+ enum bpf_access_type type)
+{
+ if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
+ return false;
+ if (type != BPF_READ)
+ return false;
+ if (off % size != 0)
+ return false;
+ return true;
+}
+
+static inline bool bpf_tracing_btf_ctx_access(int off, int size,
+ enum bpf_access_type type,
+ const struct bpf_prog *prog,
+ struct bpf_insn_access_aux *info)
+{
+ if (!bpf_tracing_ctx_access(off, size, type))
+ return false;
+ return btf_ctx_access(off, size, type, prog, info);
+}
+
int btf_struct_access(struct bpf_verifier_log *log, const struct btf *btf,
const struct btf_type *t, int off, int size,
enum bpf_access_type atype,
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index cbcd0d6fca7c..7396488793ff 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1646,13 +1646,7 @@ static bool raw_tp_prog_is_valid_access(int off, int size,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
- if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
- return false;
- if (type != BPF_READ)
- return false;
- if (off % size != 0)
- return false;
- return true;
+ return bpf_tracing_ctx_access(off, size, type);
}
static bool tracing_prog_is_valid_access(int off, int size,
@@ -1660,13 +1654,7 @@ static bool tracing_prog_is_valid_access(int off, int size,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
- if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
- return false;
- if (type != BPF_READ)
- return false;
- if (off % size != 0)
- return false;
- return btf_ctx_access(off, size, type, prog, info);
+ return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
}
int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c
index 57709ac09fb2..2cf02b4d77fb 100644
--- a/net/ipv4/bpf_tcp_ca.c
+++ b/net/ipv4/bpf_tcp_ca.c
@@ -81,14 +81,7 @@ static bool bpf_tcp_ca_is_valid_access(int off, int size,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
- if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
- return false;
- if (type != BPF_READ)
- return false;
- if (off % size != 0)
- return false;
-
- if (!btf_ctx_access(off, size, type, prog, info))
+ if (!bpf_tracing_btf_ctx_access(off, size, type, prog, info))
return false;
if (info->reg_type == PTR_TO_BTF_ID && info->btf_id == sock_id)