[PATCHv4 bpf-next 03/13] bpf: Reuse canonical string formatter for ctx errs

[Joe Stringer]

The array "reg_type_str" provides canonical formatting of register
types, however a couple of places would previously check whether a
register represented the context and write the name "context" directly.
An upcoming commit will add another pointer type to these statements, so
to provide more accurate error messages in the verifier, update these
error messages to use "reg_type_str" instead.

Signed-off-by: Joe Stringer <j...@wand.net.nz>
---
v4: New patch.
---
 kernel/bpf/verifier.c                       |  7 +++----
 tools/testing/selftests/bpf/test_verifier.c | 10 +++++-----
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index abf567200574..8b4e70eeced2 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1763,8 +1763,7 @@ static int check_xadd(struct bpf_verifier_env *env, int 
insn_idx, struct bpf_ins
        if (is_ctx_reg(env, insn->dst_reg) ||
            is_pkt_reg(env, insn->dst_reg)) {
                verbose(env, "BPF_XADD stores into R%d %s is not allowed\n",
-                       insn->dst_reg, is_ctx_reg(env, insn->dst_reg) ?
-                       "context" : "packet");
+                       insn->dst_reg, reg_type_str[insn->dst_reg]);
                return -EACCES;
        }
 
@@ -4871,8 +4870,8 @@ static int do_check(struct bpf_verifier_env *env)
                                return err;
 
                        if (is_ctx_reg(env, insn->dst_reg)) {
-                               verbose(env, "BPF_ST stores into R%d context is 
not allowed\n",
-                                       insn->dst_reg);
+                               verbose(env, "BPF_ST stores into R%d %s is not 
allowed\n",
+                                       insn->dst_reg, 
reg_type_str[insn->dst_reg]);
                                return -EACCES;
                        }
 
diff --git a/tools/testing/selftests/bpf/test_verifier.c 
b/tools/testing/selftests/bpf/test_verifier.c
index a90be44f61e0..6e0b3f148cdb 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -3276,7 +3276,7 @@ static struct bpf_test tests[] = {
                        BPF_ST_MEM(BPF_DW, BPF_REG_1, offsetof(struct 
__sk_buff, mark), 0),
                        BPF_EXIT_INSN(),
                },
-               .errstr = "BPF_ST stores into R1 context is not allowed",
+               .errstr = "BPF_ST stores into R1 inv is not allowed",
                .result = REJECT,
                .prog_type = BPF_PROG_TYPE_SCHED_CLS,
        },
@@ -3288,7 +3288,7 @@ static struct bpf_test tests[] = {
                                     BPF_REG_0, offsetof(struct __sk_buff, 
mark), 0),
                        BPF_EXIT_INSN(),
                },
-               .errstr = "BPF_XADD stores into R1 context is not allowed",
+               .errstr = "BPF_XADD stores into R1 inv is not allowed",
                .result = REJECT,
                .prog_type = BPF_PROG_TYPE_SCHED_CLS,
        },
@@ -5266,7 +5266,7 @@ static struct bpf_test tests[] = {
                .errstr_unpriv = "R2 leaks addr into mem",
                .result_unpriv = REJECT,
                .result = REJECT,
-               .errstr = "BPF_XADD stores into R1 context is not allowed",
+               .errstr = "BPF_XADD stores into R1 inv is not allowed",
        },
        {
                "leak pointer into ctx 2",
@@ -5281,7 +5281,7 @@ static struct bpf_test tests[] = {
                .errstr_unpriv = "R10 leaks addr into mem",
                .result_unpriv = REJECT,
                .result = REJECT,
-               .errstr = "BPF_XADD stores into R1 context is not allowed",
+               .errstr = "BPF_XADD stores into R1 inv is not allowed",
        },
        {
                "leak pointer into ctx 3",
@@ -12230,7 +12230,7 @@ static struct bpf_test tests[] = {
                        BPF_EXIT_INSN(),
                },
                .result = REJECT,
-               .errstr = "BPF_XADD stores into R2 packet",
+               .errstr = "BPF_XADD stores into R2 ctx",
                .prog_type = BPF_PROG_TYPE_XDP,
        },
        {
-- 
2.17.1