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

Test verifier/leak_ptr.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_helper_value_access.skel.h"
 #include "verifier_int_ptr.skel.h"
 #include "verifier_ld_ind.skel.h"
+#include "verifier_leak_ptr.skel.h"
 
 __maybe_unused
 static void run_tests_aux(const char *skel_name, skel_elf_bytes_fn elf_bytes_factory)
···
 void test_verifier_helper_value_access(void)  { RUN(verifier_helper_value_access); }
 void test_verifier_int_ptr(void)              { RUN(verifier_int_ptr); }
 void test_verifier_ld_ind(void)               { RUN(verifier_ld_ind); }
+void test_verifier_leak_ptr(void)             { RUN(verifier_leak_ptr); }

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

···
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/leak_ptr.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("socket")
+__description("leak pointer into ctx 1")
+__failure __msg("BPF_ATOMIC stores into R1 ctx is not allowed")
+__failure_unpriv __msg_unpriv("R2 leaks addr into mem")
+__naked void leak_pointer_into_ctx_1(void)
+{
+	asm volatile ("					\
+	r0 = 0;						\
+	*(u64*)(r1 + %[__sk_buff_cb_0]) = r0;		\
+	r2 = %[map_hash_8b] ll;				\
+	lock *(u64 *)(r1 + %[__sk_buff_cb_0]) += r2;	\
+	exit;						\
+"	:
+	: __imm_addr(map_hash_8b),
+	  __imm_const(__sk_buff_cb_0, offsetof(struct __sk_buff, cb[0]))
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("leak pointer into ctx 2")
+__failure __msg("BPF_ATOMIC stores into R1 ctx is not allowed")
+__failure_unpriv __msg_unpriv("R10 leaks addr into mem")
+__naked void leak_pointer_into_ctx_2(void)
+{
+	asm volatile ("					\
+	r0 = 0;						\
+	*(u64*)(r1 + %[__sk_buff_cb_0]) = r0;		\
+	lock *(u64 *)(r1 + %[__sk_buff_cb_0]) += r10;	\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_cb_0, offsetof(struct __sk_buff, cb[0]))
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("leak pointer into ctx 3")
+__success __failure_unpriv __msg_unpriv("R2 leaks addr into ctx")
+__retval(0)
+__naked void leak_pointer_into_ctx_3(void)
+{
+	asm volatile ("					\
+	r0 = 0;						\
+	r2 = %[map_hash_8b] ll;				\
+	*(u64*)(r1 + %[__sk_buff_cb_0]) = r2;		\
+	exit;						\
+"	:
+	: __imm_addr(map_hash_8b),
+	  __imm_const(__sk_buff_cb_0, offsetof(struct __sk_buff, cb[0]))
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("leak pointer into map val")
+__success __failure_unpriv __msg_unpriv("R6 leaks addr into mem")
+__retval(0)
+__naked void leak_pointer_into_map_val(void)
+{
+	asm volatile ("					\
+	r6 = r1;					\
+	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_%=;				\
+	r3 = 0;						\
+	*(u64*)(r0 + 0) = r3;				\
+	lock *(u64 *)(r0 + 0) += r6;			\
+l0_%=:	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/leak_ptr.c

···
-{
-	"leak pointer into ctx 1",
-	.insns = {
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
-		    offsetof(struct __sk_buff, cb[0])),
-	BPF_LD_MAP_FD(BPF_REG_2, 0),
-	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_1, BPF_REG_2,
-		      offsetof(struct __sk_buff, cb[0])),
-	BPF_EXIT_INSN(),
-	},
-	.fixup_map_hash_8b = { 2 },
-	.errstr_unpriv = "R2 leaks addr into mem",
-	.result_unpriv = REJECT,
-	.result = REJECT,
-	.errstr = "BPF_ATOMIC stores into R1 ctx is not allowed",
-},
-{
-	"leak pointer into ctx 2",
-	.insns = {
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
-		    offsetof(struct __sk_buff, cb[0])),
-	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_1, BPF_REG_10,
-		      offsetof(struct __sk_buff, cb[0])),
-	BPF_EXIT_INSN(),
-	},
-	.errstr_unpriv = "R10 leaks addr into mem",
-	.result_unpriv = REJECT,
-	.result = REJECT,
-	.errstr = "BPF_ATOMIC stores into R1 ctx is not allowed",
-},
-{
-	"leak pointer into ctx 3",
-	.insns = {
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_LD_MAP_FD(BPF_REG_2, 0),
-	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_2,
-		      offsetof(struct __sk_buff, cb[0])),
-	BPF_EXIT_INSN(),
-	},
-	.fixup_map_hash_8b = { 1 },
-	.errstr_unpriv = "R2 leaks addr into ctx",
-	.result_unpriv = REJECT,
-	.result = ACCEPT,
-},
-{
-	"leak pointer into map val",
-	.insns = {
-	BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
-	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, 3),
-	BPF_MOV64_IMM(BPF_REG_3, 0),
-	BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_3, 0),
-	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_6, 0),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.fixup_map_hash_8b = { 4 },
-	.errstr_unpriv = "R6 leaks addr into mem",
-	.result_unpriv = REJECT,
-	.result = ACCEPT,
-},