bpf: Zero index arg error string for dynptr and iter

Andrii spotted that process_dynptr_func's rejection of incorrect
argument register type will print an error string where argument numbers
are not zero-indexed, unlike elsewhere in the verifier.  Fix this by
subtracting 1 from regno. The same scenario exists for iterator
messages. Fix selftest error strings that match on the exact argument
number while we're at it to ensure clean bisection.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241203002235.3776418-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

5 files changed, 23 insertions, 23 deletions

diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c
index 8f36c9de7591..dfd817d0348c 100644
--- a/tools/testing/selftests/bpf/progs/dynptr_fail.c
+++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c
@@ -149,7 +149,7 @@ int ringbuf_release_uninit_dynptr(void *ctx)
 
 /* A dynptr can't be used after it has been invalidated */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #3")
+__failure __msg("Expected an initialized dynptr as arg #2")
 int use_after_invalid(void *ctx)
 {
 	struct bpf_dynptr ptr;
@@ -428,7 +428,7 @@ int invalid_helper2(void *ctx)
 
 /* A bpf_dynptr is invalidated if it's been written into */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #1")
+__failure __msg("Expected an initialized dynptr as arg #0")
 int invalid_write1(void *ctx)
 {
 	struct bpf_dynptr ptr;
@@ -1407,7 +1407,7 @@ int invalid_slice_rdwr_rdonly(struct __sk_buff *skb)
 
 /* bpf_dynptr_adjust can only be called on initialized dynptrs */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #1")
+__failure __msg("Expected an initialized dynptr as arg #0")
 int dynptr_adjust_invalid(void *ctx)
 {
 	struct bpf_dynptr ptr = {};
@@ -1420,7 +1420,7 @@ int dynptr_adjust_invalid(void *ctx)
 
 /* bpf_dynptr_is_null can only be called on initialized dynptrs */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #1")
+__failure __msg("Expected an initialized dynptr as arg #0")
 int dynptr_is_null_invalid(void *ctx)
 {
 	struct bpf_dynptr ptr = {};
@@ -1433,7 +1433,7 @@ int dynptr_is_null_invalid(void *ctx)
 
 /* bpf_dynptr_is_rdonly can only be called on initialized dynptrs */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #1")
+__failure __msg("Expected an initialized dynptr as arg #0")
 int dynptr_is_rdonly_invalid(void *ctx)
 {
 	struct bpf_dynptr ptr = {};
@@ -1446,7 +1446,7 @@ int dynptr_is_rdonly_invalid(void *ctx)
 
 /* bpf_dynptr_size can only be called on initialized dynptrs */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #1")
+__failure __msg("Expected an initialized dynptr as arg #0")
 int dynptr_size_invalid(void *ctx)
 {
 	struct bpf_dynptr ptr = {};
@@ -1459,7 +1459,7 @@ int dynptr_size_invalid(void *ctx)
 
 /* Only initialized dynptrs can be cloned */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #1")
+__failure __msg("Expected an initialized dynptr as arg #0")
 int clone_invalid1(void *ctx)
 {
 	struct bpf_dynptr ptr1 = {};
@@ -1493,7 +1493,7 @@ int clone_invalid2(struct xdp_md *xdp)
 
 /* Invalidating a dynptr should invalidate its clones */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #3")
+__failure __msg("Expected an initialized dynptr as arg #2")
 int clone_invalidate1(void *ctx)
 {
 	struct bpf_dynptr clone;
@@ -1514,7 +1514,7 @@ int clone_invalidate1(void *ctx)
 
 /* Invalidating a dynptr should invalidate its parent */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #3")
+__failure __msg("Expected an initialized dynptr as arg #2")
 int clone_invalidate2(void *ctx)
 {
 	struct bpf_dynptr ptr;
@@ -1535,7 +1535,7 @@ int clone_invalidate2(void *ctx)
 
 /* Invalidating a dynptr should invalidate its siblings */
 SEC("?raw_tp")
-__failure __msg("Expected an initialized dynptr as arg #3")
+__failure __msg("Expected an initialized dynptr as arg #2")
 int clone_invalidate3(void *ctx)
 {
 	struct bpf_dynptr ptr;
@@ -1723,7 +1723,7 @@ __noinline long global_call_bpf_dynptr(const struct bpf_dynptr *dynptr)
 }
 
 SEC("?raw_tp")
-__failure __msg("arg#1 expected pointer to stack or const struct bpf_dynptr")
+__failure __msg("arg#0 expected pointer to stack or const struct bpf_dynptr")
 int test_dynptr_reg_type(void *ctx)
 {
 	struct task_struct *current = NULL;
diff --git a/tools/testing/selftests/bpf/progs/iters_state_safety.c b/tools/testing/selftests/bpf/progs/iters_state_safety.c
index d47e59aba6de..f41257eadbb2 100644
--- a/tools/testing/selftests/bpf/progs/iters_state_safety.c
+++ b/tools/testing/selftests/bpf/progs/iters_state_safety.c
@@ -73,7 +73,7 @@ int create_and_forget_to_destroy_fail(void *ctx)
 }
 
 SEC("?raw_tp")
-__failure __msg("expected an initialized iter_num as arg #1")
+__failure __msg("expected an initialized iter_num as arg #0")
 int destroy_without_creating_fail(void *ctx)
 {
 	/* init with zeros to stop verifier complaining about uninit stack */
@@ -91,7 +91,7 @@ int destroy_without_creating_fail(void *ctx)
 }
 
 SEC("?raw_tp")
-__failure __msg("expected an initialized iter_num as arg #1")
+__failure __msg("expected an initialized iter_num as arg #0")
 int compromise_iter_w_direct_write_fail(void *ctx)
 {
 	struct bpf_iter_num iter;
@@ -143,7 +143,7 @@ int compromise_iter_w_direct_write_and_skip_destroy_fail(void *ctx)
 }
 
 SEC("?raw_tp")
-__failure __msg("expected an initialized iter_num as arg #1")
+__failure __msg("expected an initialized iter_num as arg #0")
 int compromise_iter_w_helper_write_fail(void *ctx)
 {
 	struct bpf_iter_num iter;
@@ -230,7 +230,7 @@ int valid_stack_reuse(void *ctx)
 }
 
 SEC("?raw_tp")
-__failure __msg("expected uninitialized iter_num as arg #1")
+__failure __msg("expected uninitialized iter_num as arg #0")
 int double_create_fail(void *ctx)
 {
 	struct bpf_iter_num iter;
@@ -258,7 +258,7 @@ int double_create_fail(void *ctx)
 }
 
 SEC("?raw_tp")
-__failure __msg("expected an initialized iter_num as arg #1")
+__failure __msg("expected an initialized iter_num as arg #0")
 int double_destroy_fail(void *ctx)
 {
 	struct bpf_iter_num iter;
@@ -284,7 +284,7 @@ int double_destroy_fail(void *ctx)
 }
 
 SEC("?raw_tp")
-__failure __msg("expected an initialized iter_num as arg #1")
+__failure __msg("expected an initialized iter_num as arg #0")
 int next_without_new_fail(void *ctx)
 {
 	struct bpf_iter_num iter;
@@ -305,7 +305,7 @@ int next_without_new_fail(void *ctx)
 }
 
 SEC("?raw_tp")
-__failure __msg("expected an initialized iter_num as arg #1")
+__failure __msg("expected an initialized iter_num as arg #0")
 int next_after_destroy_fail(void *ctx)
 {
 	struct bpf_iter_num iter;
diff --git a/tools/testing/selftests/bpf/progs/iters_testmod_seq.c b/tools/testing/selftests/bpf/progs/iters_testmod_seq.c
index 4a176e6aede8..6543d5b6e0a9 100644
--- a/tools/testing/selftests/bpf/progs/iters_testmod_seq.c
+++ b/tools/testing/selftests/bpf/progs/iters_testmod_seq.c
@@ -79,7 +79,7 @@ int testmod_seq_truncated(const void *ctx)
 
 SEC("?raw_tp")
 __failure
-__msg("expected an initialized iter_testmod_seq as arg #2")
+__msg("expected an initialized iter_testmod_seq as arg #1")
 int testmod_seq_getter_before_bad(const void *ctx)
 {
 	struct bpf_iter_testmod_seq it;
@@ -89,7 +89,7 @@ int testmod_seq_getter_before_bad(const void *ctx)
 
 SEC("?raw_tp")
 __failure
-__msg("expected an initialized iter_testmod_seq as arg #2")
+__msg("expected an initialized iter_testmod_seq as arg #1")
 int testmod_seq_getter_after_bad(const void *ctx)
 {
 	struct bpf_iter_testmod_seq it;
diff --git a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
index e68667aec6a6..cd4d752bd089 100644
--- a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
+++ b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
@@ -45,7 +45,7 @@ int BPF_PROG(not_valid_dynptr, int cmd, union bpf_attr *attr, unsigned int size)
 }
 
 SEC("?lsm.s/bpf")
-__failure __msg("arg#1 expected pointer to stack or const struct bpf_dynptr")
+__failure __msg("arg#0 expected pointer to stack or const struct bpf_dynptr")
 int BPF_PROG(not_ptr_to_stack, int cmd, union bpf_attr *attr, unsigned int size)
 {
 	unsigned long val = 0;
diff --git a/tools/testing/selftests/bpf/progs/verifier_bits_iter.c b/tools/testing/selftests/bpf/progs/verifier_bits_iter.c
index a7a6ae6c162f..8bcddadfc4da 100644
--- a/tools/testing/selftests/bpf/progs/verifier_bits_iter.c
+++ b/tools/testing/selftests/bpf/progs/verifier_bits_iter.c
@@ -32,7 +32,7 @@ int BPF_PROG(no_destroy, struct bpf_iter_meta *meta, struct cgroup *cgrp)
 
 SEC("iter/cgroup")
 __description("uninitialized iter in ->next()")
-__failure __msg("expected an initialized iter_bits as arg #1")
+__failure __msg("expected an initialized iter_bits as arg #0")
 int BPF_PROG(next_uninit, struct bpf_iter_meta *meta, struct cgroup *cgrp)
 {
 	struct bpf_iter_bits it = {};
@@ -43,7 +43,7 @@ int BPF_PROG(next_uninit, struct bpf_iter_meta *meta, struct cgroup *cgrp)
 
 SEC("iter/cgroup")
 __description("uninitialized iter in ->destroy()")
-__failure __msg("expected an initialized iter_bits as arg #1")
+__failure __msg("expected an initialized iter_bits as arg #0")
 int BPF_PROG(destroy_uninit, struct bpf_iter_meta *meta, struct cgroup *cgrp)
 {
 	struct bpf_iter_bits it = {};