selftests/bpf: verifier/d_path converted to inline assembly

Test verifier/d_path automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Author: eddyz87

tools/testing/selftests/bpf/prog_tests/verifier.c

@@ -19,6 +19,7 @@
 #include "verifier_const_or.skel.h"
 #include "verifier_ctx.skel.h"
 #include "verifier_ctx_sk_msg.skel.h"
+#include "verifier_d_path.skel.h"
 #include "verifier_direct_stack_access_wraparound.skel.h"
 #include "verifier_div0.skel.h"
 #include "verifier_div_overflow.skel.h"
@@ -99,6 +100,7 @@ void test_verifier_cgroup_storage(void)       { RUN(verifier_cgroup_storage); }
 void test_verifier_const_or(void)             { RUN(verifier_const_or); }
 void test_verifier_ctx(void)                  { RUN(verifier_ctx); }
 void test_verifier_ctx_sk_msg(void)           { RUN(verifier_ctx_sk_msg); }
+void test_verifier_d_path(void)               { RUN(verifier_d_path); }
 void test_verifier_direct_stack_access_wraparound(void) { RUN(verifier_direct_stack_access_wraparound); }
 void test_verifier_div0(void)                 { RUN(verifier_div0); }
 void test_verifier_div_overflow(void)         { RUN(verifier_div_overflow); }

tools/testing/selftests/bpf/progs/verifier_d_path.c

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/d_path.c */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+SEC("fentry/dentry_open")
+__description("d_path accept")
+__success __retval(0)
+__naked void d_path_accept(void)
+{
+	asm volatile ("					\
+	r1 = *(u32*)(r1 + 0);				\
+	r2 = r10;					\
+	r2 += -8;					\
+	r6 = 0;						\
+	*(u64*)(r2 + 0) = r6;				\
+	r3 = 8 ll;					\
+	call %[bpf_d_path];				\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm(bpf_d_path)
+	: __clobber_all);
+}
+
+SEC("fentry/d_path")
+__description("d_path reject")
+__failure __msg("helper call is not allowed in probe")
+__naked void d_path_reject(void)
+{
+	asm volatile ("					\
+	r1 = *(u32*)(r1 + 0);				\
+	r2 = r10;					\
+	r2 += -8;					\
+	r6 = 0;						\
+	*(u64*)(r2 + 0) = r6;				\
+	r3 = 8 ll;					\
+	call %[bpf_d_path];				\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm(bpf_d_path)
+	: __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";