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

Test verifier/raw_tp_writable.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_masking.skel.h"
 #include "verifier_meta_access.skel.h"
 #include "verifier_raw_stack.skel.h"
+#include "verifier_raw_tp_writable.skel.h"
 
 __maybe_unused
 static void run_tests_aux(const char *skel_name, skel_elf_bytes_fn elf_bytes_factory)
···
 void test_verifier_masking(void)              { RUN(verifier_masking); }
 void test_verifier_meta_access(void)          { RUN(verifier_meta_access); }
 void test_verifier_raw_stack(void)            { RUN(verifier_raw_stack); }
+void test_verifier_raw_tp_writable(void)      { RUN(verifier_raw_tp_writable); }

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

···
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/raw_tp_writable.c */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.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("raw_tracepoint.w")
+__description("raw_tracepoint_writable: reject variable offset")
+__failure
+__msg("R6 invalid variable buffer offset: off=0, var_off=(0x0; 0xffffffff)")
+__flag(BPF_F_ANY_ALIGNMENT)
+__naked void tracepoint_writable_reject_variable_offset(void)
+{
+	asm volatile ("					\
+	/* r6 is our tp buffer */			\
+	r6 = *(u64*)(r1 + 0);				\
+	r1 = %[map_hash_8b] ll;				\
+	/* move the key (== 0) to r10-8 */		\
+	w0 = 0;						\
+	r2 = r10;					\
+	r2 += -8;					\
+	*(u64*)(r2 + 0) = r0;				\
+	/* lookup in the map */				\
+	call %[bpf_map_lookup_elem];			\
+	/* exit clean if null */			\
+	if r0 != 0 goto l0_%=;				\
+	exit;						\
+l0_%=:	/* shift the buffer pointer to a variable location */\
+	r0 = *(u32*)(r0 + 0);				\
+	r6 += r0;					\
+	/* clobber whatever's there */			\
+	r7 = 4242;					\
+	*(u64*)(r6 + 0) = r7;				\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm(bpf_map_lookup_elem),
+	  __imm_addr(map_hash_8b)
+	: __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";

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

···
-{
-	"raw_tracepoint_writable: reject variable offset",
-	.insns = {
-		/* r6 is our tp buffer */
-		BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
-
-		BPF_LD_MAP_FD(BPF_REG_1, 0),
-		/* move the key (== 0) to r10-8 */
-		BPF_MOV32_IMM(BPF_REG_0, 0),
-		BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-		BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-		BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_0, 0),
-		/* lookup in the map */
-		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
-			     BPF_FUNC_map_lookup_elem),
-
-		/* exit clean if null */
-		BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
-		BPF_EXIT_INSN(),
-
-		/* shift the buffer pointer to a variable location */
-		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0),
-		BPF_ALU64_REG(BPF_ADD, BPF_REG_6, BPF_REG_0),
-		/* clobber whatever's there */
-		BPF_MOV64_IMM(BPF_REG_7, 4242),
-		BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_7, 0),
-
-		BPF_MOV64_IMM(BPF_REG_0, 0),
-		BPF_EXIT_INSN(),
-	},
-	.fixup_map_hash_8b = { 1, },
-	.prog_type = BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
-	.errstr = "R6 invalid variable buffer offset: off=0, var_off=(0x0; 0xffffffff)",
-	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
-},