selftests/bpf: Remove TLD_READ_ONCE() in the user space header

TLD_READ_ONCE() is redundant as the only reference passed to it is
defined as _Atomic. The load is guaranteed to be atomic in C11 standard
(6.2.6.1). Drop the macro.

Signed-off-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Sun Jian <sun.jian.kdev@gmail.com>
Link: https://lore.kernel.org/r/20260331213555.1993883-5-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/task_local_data.h b/tools/testing/selftests/bpf/prog_tests/task_local_data.h
index e242c455ddae21c967d94fa567312756d7ab5941..91f3486439bf2f11e1f29947454e07b072305460 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/task_local_data.h
+++ b/tools/testing/selftests/bpf/prog_tests/task_local_data.h
@@ -67,8 +67,6 @@
 
 #define TLD_ROUND_UP_POWER_OF_TWO(x) (1UL << (sizeof(x) * 8 - __builtin_clzl(x - 1)))
 
-#define TLD_READ_ONCE(x) (*(volatile typeof(x) *)&(x))
-
 #ifndef TLD_DYN_DATA_SIZE
 #define TLD_DYN_DATA_SIZE 64
 #endif
@@ -184,7 +182,7 @@ static int __tld_init_data_p(int map_fd)
         */
        map_val.data = (void *)(TLD_PAGE_MASK & (intptr_t)data);
        data->start = (~TLD_PAGE_MASK & (intptr_t)data) + sizeof(struct tld_data_u);
-       map_val.meta = TLD_READ_ONCE(tld_meta_p);
+       map_val.meta = tld_meta_p;
 
        err = bpf_map_update_elem(map_fd, &tid_fd, &map_val, 0);
        if (err) {
@@ -207,7 +205,7 @@ static tld_key_t __tld_create_key(const char *name, size_t size, bool dyn_data)
        int err, i, sz, off = 0;
        __u16 cnt;
 
-       if (!TLD_READ_ONCE(tld_meta_p)) {
+       if (!tld_meta_p) {
                err = __tld_init_meta_p();
                if (err)
                        return (tld_key_t){(__s16)err};
@@ -338,7 +336,7 @@ static inline int tld_key_err_or_zero(tld_key_t key)
 __attribute__((unused))
 static void *tld_get_data(int map_fd, tld_key_t key)
 {
-       if (!TLD_READ_ONCE(tld_meta_p))
+       if (!tld_meta_p)
                return NULL;
 
        /* tld_data_p is allocated on the first invocation of tld_get_data() */

diff --git a/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c b/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c
index 9556ad3d986fa9e412952dae03e2b002d5b4ffda..e219ff506b5669b4d551157827296edb515aff52 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c
@@ -26,7 +26,7 @@ TLD_DEFINE_KEY(value0_key, "value0", sizeof(int));
  */
 static void reset_tld(void)
 {
-       if (TLD_READ_ONCE(tld_meta_p)) {
+       if (tld_meta_p) {
                /* Remove TLDs created by tld_create_key() */
                tld_meta_p->cnt = 1;
                tld_meta_p->size = TLD_DYN_DATA_SIZE;