selftests/bpf: verifier/unpriv converted to inline assembly

Test verifier/unpriv semi-automatically converted to use inline assembly.

The verifier/unpriv.c had to be split in two parts:
- the bulk of the tests is in the progs/verifier_unpriv.c;
- the single test that needs `struct bpf_perf_event_data`
  definition is in the progs/verifier_unpriv_perf.c.

The tests above can't be in a single file because:
- first requires inclusion of the filter.h header
  (to get access to BPF_ST_MEM macro, inline assembler does
   not support this isntruction);
- the second requires vmlinux.h, which contains definitions
  conflicting with filter.h.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-23-eddyz87@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

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

@@ -56,6 +56,8 @@
 #include "verifier_stack_ptr.skel.h"
 #include "verifier_subreg.skel.h"
 #include "verifier_uninit.skel.h"
+#include "verifier_unpriv.skel.h"
+#include "verifier_unpriv_perf.skel.h"
 #include "verifier_value_adj_spill.skel.h"
 #include "verifier_value.skel.h"
 #include "verifier_value_or_null.skel.h"
@@ -150,6 +152,8 @@ void test_verifier_spin_lock(void)            { RUN(verifier_spin_lock); }
 void test_verifier_stack_ptr(void)            { RUN(verifier_stack_ptr); }
 void test_verifier_subreg(void)               { RUN(verifier_subreg); }
 void test_verifier_uninit(void)               { RUN(verifier_uninit); }
+void test_verifier_unpriv(void)               { RUN(verifier_unpriv); }
+void test_verifier_unpriv_perf(void)          { RUN(verifier_unpriv_perf); }
 void test_verifier_value_adj_spill(void)      { RUN(verifier_value_adj_spill); }
 void test_verifier_value(void)                { RUN(verifier_value); }
 void test_verifier_value_or_null(void)        { RUN(verifier_value_or_null); }

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

+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/unpriv.c */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+SEC("perf_event")
+__description("unpriv: spill/fill of different pointers ldx")
+__failure __msg("same insn cannot be used with different pointers")
+__naked void fill_of_different_pointers_ldx(void)
+{
+	asm volatile ("					\
+	r6 = r10;					\
+	r6 += -8;					\
+	if r1 == 0 goto l0_%=;				\
+	r2 = r10;					\
+	r2 += %[__imm_0];				\
+	*(u64*)(r6 + 0) = r2;				\
+l0_%=:	if r1 != 0 goto l1_%=;				\
+	*(u64*)(r6 + 0) = r1;				\
+l1_%=:	r1 = *(u64*)(r6 + 0);				\
+	r1 = *(u64*)(r1 + %[sample_period]);		\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__imm_0,
+		      -(__s32) offsetof(struct bpf_perf_event_data, sample_period) - 8),
+	  __imm_const(sample_period,
+		      offsetof(struct bpf_perf_event_data, sample_period))
+	: __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";