bpf: Rename __kptr_ref -> __kptr and __kptr -> __kptr_untrusted.

__kptr meant to store PTR_UNTRUSTED kernel pointers inside bpf maps.
The concept felt useful, but didn't get much traction,
since bpf_rdonly_cast() was added soon after and bpf programs received
a simpler way to access PTR_UNTRUSTED kernel pointers
without going through restrictive __kptr usage.

Rename __kptr_ref -> __kptr and __kptr -> __kptr_untrusted to indicate
its intended usage.
The main goal of __kptr_untrusted was to read/write such pointers
directly while bpf_kptr_xchg was a mechanism to access refcnted
kernel pointers. The next patch will allow RCU protected __kptr access
with direct read. At that point __kptr_untrusted will be deprecated.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-2-alexei.starovoitov@gmail.com

10 files changed, 23 insertions, 23 deletions

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 5ec1871acb2f..7d12d3e620cc 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -174,8 +174,8 @@ enum libbpf_tristate {
 
 #define __kconfig __attribute__((section(".kconfig")))
 #define __ksym __attribute__((section(".ksyms")))
+#define __kptr_untrusted __attribute__((btf_type_tag("kptr_untrusted")))
 #define __kptr __attribute__((btf_type_tag("kptr")))
-#define __kptr_ref __attribute__((btf_type_tag("kptr_ref")))
 
 #ifndef ___bpf_concat
 #define ___bpf_concat(a, b) a ## b
diff --git a/tools/testing/selftests/bpf/progs/cb_refs.c b/tools/testing/selftests/bpf/progs/cb_refs.c
index 7653df1bc787..ce96b33e38d6 100644
--- a/tools/testing/selftests/bpf/progs/cb_refs.c
+++ b/tools/testing/selftests/bpf/progs/cb_refs.c
@@ -4,7 +4,7 @@
 #include <bpf/bpf_helpers.h>
 
 struct map_value {
-	struct prog_test_ref_kfunc __kptr_ref *ptr;
+	struct prog_test_ref_kfunc __kptr *ptr;
 };
 
 struct {
diff --git a/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h b/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h
index 2f8de933b957..d0b7cd0d09d7 100644
--- a/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h
+++ b/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h
@@ -10,7 +10,7 @@
 #include <bpf/bpf_tracing.h>
 
 struct __cgrps_kfunc_map_value {
-	struct cgroup __kptr_ref * cgrp;
+	struct cgroup __kptr * cgrp;
 };
 
 struct hash_map {
diff --git a/tools/testing/selftests/bpf/progs/cpumask_common.h b/tools/testing/selftests/bpf/progs/cpumask_common.h
index ad34f3b602be..65e5496ca1b2 100644
--- a/tools/testing/selftests/bpf/progs/cpumask_common.h
+++ b/tools/testing/selftests/bpf/progs/cpumask_common.h
@@ -10,7 +10,7 @@
 int err;
 
 struct __cpumask_map_value {
-	struct bpf_cpumask __kptr_ref * cpumask;
+	struct bpf_cpumask __kptr * cpumask;
 };
 
 struct array_map {
diff --git a/tools/testing/selftests/bpf/progs/jit_probe_mem.c b/tools/testing/selftests/bpf/progs/jit_probe_mem.c
index 2d2e61470794..13f00ca2ed0a 100644
--- a/tools/testing/selftests/bpf/progs/jit_probe_mem.c
+++ b/tools/testing/selftests/bpf/progs/jit_probe_mem.c
@@ -4,7 +4,7 @@
 #include <bpf/bpf_tracing.h>
 #include <bpf/bpf_helpers.h>
 
-static struct prog_test_ref_kfunc __kptr_ref *v;
+static struct prog_test_ref_kfunc __kptr *v;
 long total_sum = -1;
 
 extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp) __ksym;
diff --git a/tools/testing/selftests/bpf/progs/lru_bug.c b/tools/testing/selftests/bpf/progs/lru_bug.c
index 687081a724b3..ad73029cb1e3 100644
--- a/tools/testing/selftests/bpf/progs/lru_bug.c
+++ b/tools/testing/selftests/bpf/progs/lru_bug.c
@@ -4,7 +4,7 @@
 #include <bpf/bpf_helpers.h>
 
 struct map_value {
-	struct task_struct __kptr *ptr;
+	struct task_struct __kptr_untrusted *ptr;
 };
 
 struct {
diff --git a/tools/testing/selftests/bpf/progs/map_kptr.c b/tools/testing/selftests/bpf/progs/map_kptr.c
index a24d17bc17eb..3fe7cde4cbfd 100644
--- a/tools/testing/selftests/bpf/progs/map_kptr.c
+++ b/tools/testing/selftests/bpf/progs/map_kptr.c
@@ -4,8 +4,8 @@
 #include <bpf/bpf_helpers.h>
 
 struct map_value {
-	struct prog_test_ref_kfunc __kptr *unref_ptr;
-	struct prog_test_ref_kfunc __kptr_ref *ref_ptr;
+	struct prog_test_ref_kfunc __kptr_untrusted *unref_ptr;
+	struct prog_test_ref_kfunc __kptr *ref_ptr;
 };
 
 struct array_map {
diff --git a/tools/testing/selftests/bpf/progs/map_kptr_fail.c b/tools/testing/selftests/bpf/progs/map_kptr_fail.c
index 760e41e1a632..e19e2a5f38cf 100644
--- a/tools/testing/selftests/bpf/progs/map_kptr_fail.c
+++ b/tools/testing/selftests/bpf/progs/map_kptr_fail.c
@@ -7,9 +7,9 @@
 
 struct map_value {
 	char buf[8];
-	struct prog_test_ref_kfunc __kptr *unref_ptr;
-	struct prog_test_ref_kfunc __kptr_ref *ref_ptr;
-	struct prog_test_member __kptr_ref *ref_memb_ptr;
+	struct prog_test_ref_kfunc __kptr_untrusted *unref_ptr;
+	struct prog_test_ref_kfunc __kptr *ref_ptr;
+	struct prog_test_member __kptr *ref_memb_ptr;
 };
 
 struct array_map {
diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_common.h b/tools/testing/selftests/bpf/progs/task_kfunc_common.h
index c0ffd171743e..4c2a4b0e3a25 100644
--- a/tools/testing/selftests/bpf/progs/task_kfunc_common.h
+++ b/tools/testing/selftests/bpf/progs/task_kfunc_common.h
@@ -10,7 +10,7 @@
 #include <bpf/bpf_tracing.h>
 
 struct __tasks_kfunc_map_value {
-	struct task_struct __kptr_ref * task;
+	struct task_struct __kptr * task;
 };
 
 struct hash_map {
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 8b9949bb833d..49a70d9beb0b 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -699,13 +699,13 @@ static int create_cgroup_storage(bool percpu)
  *   struct bpf_timer t;
  * };
  * struct btf_ptr {
+ *   struct prog_test_ref_kfunc __kptr_untrusted *ptr;
  *   struct prog_test_ref_kfunc __kptr *ptr;
- *   struct prog_test_ref_kfunc __kptr_ref *ptr;
- *   struct prog_test_member __kptr_ref *ptr;
+ *   struct prog_test_member __kptr *ptr;
  * }
  */
 static const char btf_str_sec[] = "\0bpf_spin_lock\0val\0cnt\0l\0bpf_timer\0timer\0t"
-				  "\0btf_ptr\0prog_test_ref_kfunc\0ptr\0kptr\0kptr_ref"
+				  "\0btf_ptr\0prog_test_ref_kfunc\0ptr\0kptr\0kptr_untrusted"
 				  "\0prog_test_member";
 static __u32 btf_raw_types[] = {
 	/* int */
@@ -724,20 +724,20 @@ static __u32 btf_raw_types[] = {
 	BTF_MEMBER_ENC(41, 4, 0), /* struct bpf_timer t; */
 	/* struct prog_test_ref_kfunc */		/* [6] */
 	BTF_STRUCT_ENC(51, 0, 0),
-	BTF_STRUCT_ENC(89, 0, 0),			/* [7] */
+	BTF_STRUCT_ENC(95, 0, 0),			/* [7] */
+	/* type tag "kptr_untrusted" */
+	BTF_TYPE_TAG_ENC(80, 6),			/* [8] */
 	/* type tag "kptr" */
-	BTF_TYPE_TAG_ENC(75, 6),			/* [8] */
-	/* type tag "kptr_ref" */
-	BTF_TYPE_TAG_ENC(80, 6),			/* [9] */
-	BTF_TYPE_TAG_ENC(80, 7),			/* [10] */
+	BTF_TYPE_TAG_ENC(75, 6),			/* [9] */
+	BTF_TYPE_TAG_ENC(75, 7),			/* [10] */
 	BTF_PTR_ENC(8),					/* [11] */
 	BTF_PTR_ENC(9),					/* [12] */
 	BTF_PTR_ENC(10),				/* [13] */
 	/* struct btf_ptr */				/* [14] */
 	BTF_STRUCT_ENC(43, 3, 24),
-	BTF_MEMBER_ENC(71, 11, 0), /* struct prog_test_ref_kfunc __kptr *ptr; */
-	BTF_MEMBER_ENC(71, 12, 64), /* struct prog_test_ref_kfunc __kptr_ref *ptr; */
-	BTF_MEMBER_ENC(71, 13, 128), /* struct prog_test_member __kptr_ref *ptr; */
+	BTF_MEMBER_ENC(71, 11, 0), /* struct prog_test_ref_kfunc __kptr_untrusted *ptr; */
+	BTF_MEMBER_ENC(71, 12, 64), /* struct prog_test_ref_kfunc __kptr *ptr; */
+	BTF_MEMBER_ENC(71, 13, 128), /* struct prog_test_member __kptr *ptr; */
 };
 
 static char bpf_vlog[UINT_MAX >> 8];