selftests/bpf: verifier/map_ret_val.c converted to inline assembly

Test verifier/map_ret_val.c automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexei Starovoitov <[e-mail]>

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

···
 #include "verifier_ld_ind.skel.h"
 #include "verifier_leak_ptr.skel.h"
 #include "verifier_map_ptr.skel.h"
+#include "verifier_map_ret_val.skel.h"
 
 __maybe_unused
 static void run_tests_aux(const char *skel_name, skel_elf_bytes_fn elf_bytes_factory)
···
 void test_verifier_ld_ind(void)               { RUN(verifier_ld_ind); }
 void test_verifier_leak_ptr(void)             { RUN(verifier_leak_ptr); }
 void test_verifier_map_ptr(void)              { RUN(verifier_map_ptr); }
+void test_verifier_map_ret_val(void)          { RUN(verifier_map_ret_val); }

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

···
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/map_ret_val.c */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "../../../include/linux/filter.h"
+#include "bpf_misc.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 1);
+	__type(key, long long);
+	__type(value, long long);
+} map_hash_8b SEC(".maps");
+
+SEC("socket")
+__description("invalid map_fd for function call")
+__failure __msg("fd 0 is not pointing to valid bpf_map")
+__failure_unpriv
+__naked void map_fd_for_function_call(void)
+{
+	asm volatile ("					\
+	r2 = 0;						\
+	*(u64*)(r10 - 8) = r2;				\
+	r2 = r10;					\
+	r2 += -8;					\
+	.8byte %[ld_map_fd];				\
+	.8byte 0;					\
+	call %[bpf_map_delete_elem];			\
+	exit;						\
+"	:
+	: __imm(bpf_map_delete_elem),
+	  __imm_insn(ld_map_fd, BPF_RAW_INSN(BPF_LD | BPF_DW | BPF_IMM, BPF_REG_1, BPF_PSEUDO_MAP_FD, 0, 0))
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("don't check return value before access")
+__failure __msg("R0 invalid mem access 'map_value_or_null'")
+__failure_unpriv
+__naked void check_return_value_before_access(void)
+{
+	asm volatile ("					\
+	r1 = 0;						\
+	*(u64*)(r10 - 8) = r1;				\
+	r2 = r10;					\
+	r2 += -8;					\
+	r1 = %[map_hash_8b] ll;				\
+	call %[bpf_map_lookup_elem];			\
+	r1 = 0;						\
+	*(u64*)(r0 + 0) = r1;				\
+	exit;						\
+"	:
+	: __imm(bpf_map_lookup_elem),
+	  __imm_addr(map_hash_8b)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("access memory with incorrect alignment")
+__failure __msg("misaligned value access")
+__failure_unpriv
+__flag(BPF_F_STRICT_ALIGNMENT)
+__naked void access_memory_with_incorrect_alignment_1(void)
+{
+	asm volatile ("					\
+	r1 = 0;						\
+	*(u64*)(r10 - 8) = r1;				\
+	r2 = r10;					\
+	r2 += -8;					\
+	r1 = %[map_hash_8b] ll;				\
+	call %[bpf_map_lookup_elem];			\
+	if r0 == 0 goto l0_%=;				\
+	r1 = 0;						\
+	*(u64*)(r0 + 4) = r1;				\
+l0_%=:	exit;						\
+"	:
+	: __imm(bpf_map_lookup_elem),
+	  __imm_addr(map_hash_8b)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("sometimes access memory with incorrect alignment")
+__failure __msg("R0 invalid mem access")
+__msg_unpriv("R0 leaks addr")
+__flag(BPF_F_STRICT_ALIGNMENT)
+__naked void access_memory_with_incorrect_alignment_2(void)
+{
+	asm volatile ("					\
+	r1 = 0;						\
+	*(u64*)(r10 - 8) = r1;				\
+	r2 = r10;					\
+	r2 += -8;					\
+	r1 = %[map_hash_8b] ll;				\
+	call %[bpf_map_lookup_elem];			\
+	if r0 == 0 goto l0_%=;				\
+	r1 = 0;						\
+	*(u64*)(r0 + 0) = r1;				\
+	exit;						\
+l0_%=:	r1 = 1;						\
+	*(u64*)(r0 + 0) = r1;				\
+	exit;						\
+"	:
+	: __imm(bpf_map_lookup_elem),
+	  __imm_addr(map_hash_8b)
+	: __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";

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

···
-{
-	"invalid map_fd for function call",
-	.insns = {
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
-	BPF_ALU64_REG(BPF_MOV, BPF_REG_2, BPF_REG_10),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-	BPF_LD_MAP_FD(BPF_REG_1, 0),
-	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_delete_elem),
-	BPF_EXIT_INSN(),
-	},
-	.errstr = "fd 0 is not pointing to valid bpf_map",
-	.result = REJECT,
-},
-{
-	"don't check return value before access",
-	.insns = {
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
-	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-	BPF_LD_MAP_FD(BPF_REG_1, 0),
-	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-	BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.fixup_map_hash_8b = { 3 },
-	.errstr = "R0 invalid mem access 'map_value_or_null'",
-	.result = REJECT,
-},
-{
-	"access memory with incorrect alignment",
-	.insns = {
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
-	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-	BPF_LD_MAP_FD(BPF_REG_1, 0),
-	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
-	BPF_ST_MEM(BPF_DW, BPF_REG_0, 4, 0),
-	BPF_EXIT_INSN(),
-	},
-	.fixup_map_hash_8b = { 3 },
-	.errstr = "misaligned value access",
-	.result = REJECT,
-	.flags = F_LOAD_WITH_STRICT_ALIGNMENT,
-},
-{
-	"sometimes access memory with incorrect alignment",
-	.insns = {
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
-	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-	BPF_LD_MAP_FD(BPF_REG_1, 0),
-	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
-	BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0),
-	BPF_EXIT_INSN(),
-	BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 1),
-	BPF_EXIT_INSN(),
-	},
-	.fixup_map_hash_8b = { 3 },
-	.errstr = "R0 invalid mem access",
-	.errstr_unpriv = "R0 leaks addr",
-	.result = REJECT,
-	.flags = F_LOAD_WITH_STRICT_ALIGNMENT,
-},