diff options
Diffstat (limited to 'tools/testing/selftests/bpf/bpf_experimental.h')
| -rw-r--r-- | tools/testing/selftests/bpf/bpf_experimental.h | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h index 1386baf9ae4a..19ed6c941c1c 100644 --- a/tools/testing/selftests/bpf/bpf_experimental.h +++ b/tools/testing/selftests/bpf/bpf_experimental.h @@ -254,6 +254,75 @@ extern void bpf_throw(u64 cookie) __ksym; } \ }) +#define __cmp_cannot_be_signed(x) \ + __builtin_strcmp(#x, "==") == 0 || __builtin_strcmp(#x, "!=") == 0 || \ + __builtin_strcmp(#x, "&") == 0 + +#define __is_signed_type(type) (((type)(-1)) < (type)1) + +#define __bpf_cmp(LHS, OP, SIGN, PRED, RHS, DEFAULT) \ + ({ \ + __label__ l_true; \ + bool ret = DEFAULT; \ + asm volatile goto("if %[lhs] " SIGN #OP " %[rhs] goto %l[l_true]" \ + :: [lhs] "r"((short)LHS), [rhs] PRED (RHS) :: l_true); \ + ret = !DEFAULT; \ +l_true: \ + ret; \ + }) + +/* C type conversions coupled with comparison operator are tricky. + * Make sure BPF program is compiled with -Wsign-compare then + * __lhs OP __rhs below will catch the mistake. + * Be aware that we check only __lhs to figure out the sign of compare. + */ +#define _bpf_cmp(LHS, OP, RHS, NOFLIP) \ + ({ \ + typeof(LHS) __lhs = (LHS); \ + typeof(RHS) __rhs = (RHS); \ + bool ret; \ + _Static_assert(sizeof(&(LHS)), "1st argument must be an lvalue expression"); \ + (void)(__lhs OP __rhs); \ + if (__cmp_cannot_be_signed(OP) || !__is_signed_type(typeof(__lhs))) { \ + if (sizeof(__rhs) == 8) \ + ret = __bpf_cmp(__lhs, OP, "", "r", __rhs, NOFLIP); \ + else \ + ret = __bpf_cmp(__lhs, OP, "", "i", __rhs, NOFLIP); \ + } else { \ + if (sizeof(__rhs) == 8) \ + ret = __bpf_cmp(__lhs, OP, "s", "r", __rhs, NOFLIP); \ + else \ + ret = __bpf_cmp(__lhs, OP, "s", "i", __rhs, NOFLIP); \ + } \ + ret; \ + }) + +#ifndef bpf_cmp_unlikely +#define bpf_cmp_unlikely(LHS, OP, RHS) _bpf_cmp(LHS, OP, RHS, true) +#endif + +#ifndef bpf_cmp_likely +#define bpf_cmp_likely(LHS, OP, RHS) \ + ({ \ + bool ret; \ + if (__builtin_strcmp(#OP, "==") == 0) \ + ret = _bpf_cmp(LHS, !=, RHS, false); \ + else if (__builtin_strcmp(#OP, "!=") == 0) \ + ret = _bpf_cmp(LHS, ==, RHS, false); \ + else if (__builtin_strcmp(#OP, "<=") == 0) \ + ret = _bpf_cmp(LHS, >, RHS, false); \ + else if (__builtin_strcmp(#OP, "<") == 0) \ + ret = _bpf_cmp(LHS, >=, RHS, false); \ + else if (__builtin_strcmp(#OP, ">") == 0) \ + ret = _bpf_cmp(LHS, <=, RHS, false); \ + else if (__builtin_strcmp(#OP, ">=") == 0) \ + ret = _bpf_cmp(LHS, <, RHS, false); \ + else \ + (void) "bug"; \ + ret; \ + }) +#endif + /* Description * Assert that a conditional expression is true. * Returns |