Add macros implementing an 'assert' statement primitive using macros,
built on top of the BPF exceptions support introduced in previous
patches.
The bpf_assert_*_value variants allow supplying a value which can the be
inspected within the exception handler to signify the assert statement
that led to the program being terminated abruptly.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
---
.../testing/selftests/bpf/bpf_experimental.h | 20 +++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h
index d27e694392a7..30774fef455c 100644
--- a/tools/testing/selftests/bpf/bpf_experimental.h
+++ b/tools/testing/selftests/bpf/bpf_experimental.h
@@ -139,4 +139,24 @@ extern void bpf_throw(u64 cookie) __ksym;
extern void bpf_set_exception_callback(int (*cb)(u64)) __ksym;
+#define __bpf_assert_op(LHS, op, RHS, VAL) \
+ _Static_assert(sizeof(&(LHS)), "1st argument must be an lvalue expression"); \
+ _Static_assert(__builtin_constant_p((RHS)), "2nd argument must be a constant expression"); \
+ asm volatile ("if %[lhs] " op " %[rhs] goto +2; r1 = %[value]; call bpf_throw" \
+ : : [lhs] "r"(LHS), [rhs] "i"(RHS), [value] "ri"(VAL) : )
+
+#define bpf_assert_eq(LHS, RHS) __bpf_assert_op(LHS, "==", RHS, 0)
+#define bpf_assert_ne(LHS, RHS) __bpf_assert_op(LHS, "!=", RHS, 0)
+#define bpf_assert_lt(LHS, RHS) __bpf_assert_op(LHS, "<", RHS, 0)
+#define bpf_assert_gt(LHS, RHS) __bpf_assert_op(LHS, ">", RHS, 0)
+#define bpf_assert_le(LHS, RHS) __bpf_assert_op(LHS, "<=", RHS, 0)
+#define bpf_assert_ge(LHS, RHS) __bpf_assert_op(LHS, ">=", RHS, 0)
+
+#define bpf_assert_eq_value(LHS, RHS, value) __bpf_assert_op(LHS, "==", RHS, value)
+#define bpf_assert_ne_value(LHS, RHS, value) __bpf_assert_op(LHS, "!=", RHS, value)
+#define bpf_assert_lt_value(LHS, RHS, value) __bpf_assert_op(LHS, "<", RHS, value)
+#define bpf_assert_gt_value(LHS, RHS, value) __bpf_assert_op(LHS, ">", RHS, value)
+#define bpf_assert_le_value(LHS, RHS, value) __bpf_assert_op(LHS, "<=", RHS, value)
+#define bpf_assert_ge_value(LHS, RHS, value) __bpf_assert_op(LHS, ">=", RHS, value)
+
#endif
--
2.40.1
