Test verifier/jeq_infer_not_null automatically converted to use inline assembly.
Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/verifier.c | 2 +
.../bpf/progs/verifier_jeq_infer_not_null.c | 213 ++++++++++++++++++
.../bpf/verifier/jeq_infer_not_null.c | 174 --------------
3 files changed, 215 insertions(+), 174 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/verifier_jeq_infer_not_null.c
delete mode 100644 tools/testing/selftests/bpf/verifier/jeq_infer_not_null.c
diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 2c9e61b9a83e..de5db0de98a1 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
@@ -29,6 +29,7 @@
#include "verifier_helper_restricted.skel.h"
#include "verifier_helper_value_access.skel.h"
#include "verifier_int_ptr.skel.h"
+#include "verifier_jeq_infer_not_null.skel.h"
#include "verifier_ld_ind.skel.h"
#include "verifier_leak_ptr.skel.h"
#include "verifier_map_ptr.skel.h"
@@ -109,6 +110,7 @@ void test_verifier_helper_packet_access(void) { RUN(verifier_helper_packet_acces
void test_verifier_helper_restricted(void) { RUN(verifier_helper_restricted); }
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_jeq_infer_not_null(void) { RUN(verifier_jeq_infer_not_null); }
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); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_jeq_infer_not_null.c b/tools/testing/selftests/bpf/progs/verifier_jeq_infer_not_null.c
new file mode 100644
index 000000000000..bf16b00502f2
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_jeq_infer_not_null.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/jeq_infer_not_null.c */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+struct {
+ __uint(type, BPF_MAP_TYPE_XSKMAP);
+ __uint(max_entries, 1);
+ __type(key, int);
+ __type(value, int);
+} map_xskmap SEC(".maps");
+
+/* This is equivalent to the following program:
+ *
+ * r6 = skb->sk;
+ * r7 = sk_fullsock(r6);
+ * r0 = sk_fullsock(r6);
+ * if (r0 == 0) return 0; (a)
+ * if (r0 != r7) return 0; (b)
+ * *r7->type; (c)
+ * return 0;
+ *
+ * It is safe to dereference r7 at point (c), because of (a) and (b).
+ * The test verifies that relation r0 == r7 is propagated from (b) to (c).
+ */
+SEC("cgroup/skb")
+__description("jne/jeq infer not null, PTR_TO_SOCKET_OR_NULL -> PTR_TO_SOCKET for JNE false branch")
+__success __failure_unpriv __msg_unpriv("R7 pointer comparison")
+__retval(0)
+__naked void socket_for_jne_false_branch(void)
+{
+ asm volatile (" \
+ /* r6 = skb->sk; */ \
+ r6 = *(u64*)(r1 + %[__sk_buff_sk]); \
+ /* if (r6 == 0) return 0; */ \
+ if r6 == 0 goto l0_%=; \
+ /* r7 = sk_fullsock(skb); */ \
+ r1 = r6; \
+ call %[bpf_sk_fullsock]; \
+ r7 = r0; \
+ /* r0 = sk_fullsock(skb); */ \
+ r1 = r6; \
+ call %[bpf_sk_fullsock]; \
+ /* if (r0 == null) return 0; */ \
+ if r0 == 0 goto l0_%=; \
+ /* if (r0 == r7) r0 = *(r7->type); */ \
+ if r0 != r7 goto l0_%=; /* Use ! JNE ! */\
+ r0 = *(u32*)(r7 + %[bpf_sock_type]); \
+l0_%=: /* return 0 */ \
+ r0 = 0; \
+ exit; \
+" :
+ : __imm(bpf_sk_fullsock),
+ __imm_const(__sk_buff_sk, offsetof(struct __sk_buff, sk)),
+ __imm_const(bpf_sock_type, offsetof(struct bpf_sock, type))
+ : __clobber_all);
+}
+
+/* Same as above, but verify that another branch of JNE still
+ * prohibits access to PTR_MAYBE_NULL.
+ */
+SEC("cgroup/skb")
+__description("jne/jeq infer not null, PTR_TO_SOCKET_OR_NULL unchanged for JNE true branch")
+__failure __msg("R7 invalid mem access 'sock_or_null'")
+__failure_unpriv __msg_unpriv("R7 pointer comparison")
+__naked void unchanged_for_jne_true_branch(void)
+{
+ asm volatile (" \
+ /* r6 = skb->sk */ \
+ r6 = *(u64*)(r1 + %[__sk_buff_sk]); \
+ /* if (r6 == 0) return 0; */ \
+ if r6 == 0 goto l0_%=; \
+ /* r7 = sk_fullsock(skb); */ \
+ r1 = r6; \
+ call %[bpf_sk_fullsock]; \
+ r7 = r0; \
+ /* r0 = sk_fullsock(skb); */ \
+ r1 = r6; \
+ call %[bpf_sk_fullsock]; \
+ /* if (r0 == null) return 0; */ \
+ if r0 != 0 goto l0_%=; \
+ /* if (r0 == r7) return 0; */ \
+ if r0 != r7 goto l1_%=; /* Use ! JNE ! */\
+ goto l0_%=; \
+l1_%=: /* r0 = *(r7->type); */ \
+ r0 = *(u32*)(r7 + %[bpf_sock_type]); \
+l0_%=: /* return 0 */ \
+ r0 = 0; \
+ exit; \
+" :
+ : __imm(bpf_sk_fullsock),
+ __imm_const(__sk_buff_sk, offsetof(struct __sk_buff, sk)),
+ __imm_const(bpf_sock_type, offsetof(struct bpf_sock, type))
+ : __clobber_all);
+}
+
+/* Same as a first test, but not null should be inferred for JEQ branch */
+SEC("cgroup/skb")
+__description("jne/jeq infer not null, PTR_TO_SOCKET_OR_NULL -> PTR_TO_SOCKET for JEQ true branch")
+__success __failure_unpriv __msg_unpriv("R7 pointer comparison")
+__retval(0)
+__naked void socket_for_jeq_true_branch(void)
+{
+ asm volatile (" \
+ /* r6 = skb->sk; */ \
+ r6 = *(u64*)(r1 + %[__sk_buff_sk]); \
+ /* if (r6 == null) return 0; */ \
+ if r6 == 0 goto l0_%=; \
+ /* r7 = sk_fullsock(skb); */ \
+ r1 = r6; \
+ call %[bpf_sk_fullsock]; \
+ r7 = r0; \
+ /* r0 = sk_fullsock(skb); */ \
+ r1 = r6; \
+ call %[bpf_sk_fullsock]; \
+ /* if (r0 == null) return 0; */ \
+ if r0 == 0 goto l0_%=; \
+ /* if (r0 != r7) return 0; */ \
+ if r0 == r7 goto l1_%=; /* Use ! JEQ ! */\
+ goto l0_%=; \
+l1_%=: /* r0 = *(r7->type); */ \
+ r0 = *(u32*)(r7 + %[bpf_sock_type]); \
+l0_%=: /* return 0; */ \
+ r0 = 0; \
+ exit; \
+" :
+ : __imm(bpf_sk_fullsock),
+ __imm_const(__sk_buff_sk, offsetof(struct __sk_buff, sk)),
+ __imm_const(bpf_sock_type, offsetof(struct bpf_sock, type))
+ : __clobber_all);
+}
+
+/* Same as above, but verify that another branch of JNE still
+ * prohibits access to PTR_MAYBE_NULL.
+ */
+SEC("cgroup/skb")
+__description("jne/jeq infer not null, PTR_TO_SOCKET_OR_NULL unchanged for JEQ false branch")
+__failure __msg("R7 invalid mem access 'sock_or_null'")
+__failure_unpriv __msg_unpriv("R7 pointer comparison")
+__naked void unchanged_for_jeq_false_branch(void)
+{
+ asm volatile (" \
+ /* r6 = skb->sk; */ \
+ r6 = *(u64*)(r1 + %[__sk_buff_sk]); \
+ /* if (r6 == null) return 0; */ \
+ if r6 == 0 goto l0_%=; \
+ /* r7 = sk_fullsock(skb); */ \
+ r1 = r6; \
+ call %[bpf_sk_fullsock]; \
+ r7 = r0; \
+ /* r0 = sk_fullsock(skb); */ \
+ r1 = r6; \
+ call %[bpf_sk_fullsock]; \
+ /* if (r0 == null) return 0; */ \
+ if r0 == 0 goto l0_%=; \
+ /* if (r0 != r7) r0 = *(r7->type); */ \
+ if r0 == r7 goto l0_%=; /* Use ! JEQ ! */\
+ r0 = *(u32*)(r7 + %[bpf_sock_type]); \
+l0_%=: /* return 0; */ \
+ r0 = 0; \
+ exit; \
+" :
+ : __imm(bpf_sk_fullsock),
+ __imm_const(__sk_buff_sk, offsetof(struct __sk_buff, sk)),
+ __imm_const(bpf_sock_type, offsetof(struct bpf_sock, type))
+ : __clobber_all);
+}
+
+/* Maps are treated in a different branch of `mark_ptr_not_null_reg`,
+ * so separate test for maps case.
+ */
+SEC("xdp")
+__description("jne/jeq infer not null, PTR_TO_MAP_VALUE_OR_NULL -> PTR_TO_MAP_VALUE")
+__success __retval(0)
+__naked void null_ptr_to_map_value(void)
+{
+ asm volatile (" \
+ /* r9 = &some stack to use as key */ \
+ r1 = 0; \
+ *(u32*)(r10 - 8) = r1; \
+ r9 = r10; \
+ r9 += -8; \
+ /* r8 = process local map */ \
+ r8 = %[map_xskmap] ll; \
+ /* r6 = map_lookup_elem(r8, r9); */ \
+ r1 = r8; \
+ r2 = r9; \
+ call %[bpf_map_lookup_elem]; \
+ r6 = r0; \
+ /* r7 = map_lookup_elem(r8, r9); */ \
+ r1 = r8; \
+ r2 = r9; \
+ call %[bpf_map_lookup_elem]; \
+ r7 = r0; \
+ /* if (r6 == 0) return 0; */ \
+ if r6 == 0 goto l0_%=; \
+ /* if (r6 != r7) return 0; */ \
+ if r6 != r7 goto l0_%=; \
+ /* read *r7; */ \
+ r0 = *(u32*)(r7 + %[bpf_xdp_sock_queue_id]); \
+l0_%=: /* return 0; */ \
+ r0 = 0; \
+ exit; \
+" :
+ : __imm(bpf_map_lookup_elem),
+ __imm_addr(map_xskmap),
+ __imm_const(bpf_xdp_sock_queue_id, offsetof(struct bpf_xdp_sock, queue_id))
+ : __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/verifier/jeq_infer_not_null.c b/tools/testing/selftests/bpf/verifier/jeq_infer_not_null.c
deleted file mode 100644
index 67a1c07ead34..000000000000
--- a/tools/testing/selftests/bpf/verifier/jeq_infer_not_null.c
+++ /dev/null
@@ -1,174 +0,0 @@
-{
- /* This is equivalent to the following program:
- *
- * r6 = skb->sk;
- * r7 = sk_fullsock(r6);
- * r0 = sk_fullsock(r6);
- * if (r0 == 0) return 0; (a)
- * if (r0 != r7) return 0; (b)
- * *r7->type; (c)
- * return 0;
- *
- * It is safe to dereference r7 at point (c), because of (a) and (b).
- * The test verifies that relation r0 == r7 is propagated from (b) to (c).
- */
- "jne/jeq infer not null, PTR_TO_SOCKET_OR_NULL -> PTR_TO_SOCKET for JNE false branch",
- .insns = {
- /* r6 = skb->sk; */
- BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, offsetof(struct __sk_buff, sk)),
- /* if (r6 == 0) return 0; */
- BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 8),
- /* r7 = sk_fullsock(skb); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
- BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
- BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
- /* r0 = sk_fullsock(skb); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
- BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
- /* if (r0 == null) return 0; */
- BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
- /* if (r0 == r7) r0 = *(r7->type); */
- BPF_JMP_REG(BPF_JNE, BPF_REG_0, BPF_REG_7, 1), /* Use ! JNE ! */
- BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, offsetof(struct bpf_sock, type)),
- /* return 0 */
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- },
- .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
- .result = ACCEPT,
- .result_unpriv = REJECT,
- .errstr_unpriv = "R7 pointer comparison",
-},
-{
- /* Same as above, but verify that another branch of JNE still
- * prohibits access to PTR_MAYBE_NULL.
- */
- "jne/jeq infer not null, PTR_TO_SOCKET_OR_NULL unchanged for JNE true branch",
- .insns = {
- /* r6 = skb->sk */
- BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, offsetof(struct __sk_buff, sk)),
- /* if (r6 == 0) return 0; */
- BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 9),
- /* r7 = sk_fullsock(skb); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
- BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
- BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
- /* r0 = sk_fullsock(skb); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
- BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
- /* if (r0 == null) return 0; */
- BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 3),
- /* if (r0 == r7) return 0; */
- BPF_JMP_REG(BPF_JNE, BPF_REG_0, BPF_REG_7, 1), /* Use ! JNE ! */
- BPF_JMP_IMM(BPF_JA, 0, 0, 1),
- /* r0 = *(r7->type); */
- BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, offsetof(struct bpf_sock, type)),
- /* return 0 */
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- },
- .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
- .result = REJECT,
- .errstr = "R7 invalid mem access 'sock_or_null'",
- .result_unpriv = REJECT,
- .errstr_unpriv = "R7 pointer comparison",
-},
-{
- /* Same as a first test, but not null should be inferred for JEQ branch */
- "jne/jeq infer not null, PTR_TO_SOCKET_OR_NULL -> PTR_TO_SOCKET for JEQ true branch",
- .insns = {
- /* r6 = skb->sk; */
- BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, offsetof(struct __sk_buff, sk)),
- /* if (r6 == null) return 0; */
- BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 9),
- /* r7 = sk_fullsock(skb); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
- BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
- BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
- /* r0 = sk_fullsock(skb); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
- BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
- /* if (r0 == null) return 0; */
- BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
- /* if (r0 != r7) return 0; */
- BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_7, 1), /* Use ! JEQ ! */
- BPF_JMP_IMM(BPF_JA, 0, 0, 1),
- /* r0 = *(r7->type); */
- BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, offsetof(struct bpf_sock, type)),
- /* return 0; */
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- },
- .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
- .result = ACCEPT,
- .result_unpriv = REJECT,
- .errstr_unpriv = "R7 pointer comparison",
-},
-{
- /* Same as above, but verify that another branch of JNE still
- * prohibits access to PTR_MAYBE_NULL.
- */
- "jne/jeq infer not null, PTR_TO_SOCKET_OR_NULL unchanged for JEQ false branch",
- .insns = {
- /* r6 = skb->sk; */
- BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, offsetof(struct __sk_buff, sk)),
- /* if (r6 == null) return 0; */
- BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 8),
- /* r7 = sk_fullsock(skb); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
- BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
- BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
- /* r0 = sk_fullsock(skb); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
- BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
- /* if (r0 == null) return 0; */
- BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
- /* if (r0 != r7) r0 = *(r7->type); */
- BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_7, 1), /* Use ! JEQ ! */
- BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, offsetof(struct bpf_sock, type)),
- /* return 0; */
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- },
- .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
- .result = REJECT,
- .errstr = "R7 invalid mem access 'sock_or_null'",
- .result_unpriv = REJECT,
- .errstr_unpriv = "R7 pointer comparison",
-},
-{
- /* Maps are treated in a different branch of `mark_ptr_not_null_reg`,
- * so separate test for maps case.
- */
- "jne/jeq infer not null, PTR_TO_MAP_VALUE_OR_NULL -> PTR_TO_MAP_VALUE",
- .insns = {
- /* r9 = &some stack to use as key */
- BPF_ST_MEM(BPF_W, BPF_REG_10, -8, 0),
- BPF_MOV64_REG(BPF_REG_9, BPF_REG_10),
- BPF_ALU64_IMM(BPF_ADD, BPF_REG_9, -8),
- /* r8 = process local map */
- BPF_LD_MAP_FD(BPF_REG_8, 0),
- /* r6 = map_lookup_elem(r8, r9); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
- BPF_MOV64_REG(BPF_REG_2, BPF_REG_9),
- BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
- BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
- /* r7 = map_lookup_elem(r8, r9); */
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
- BPF_MOV64_REG(BPF_REG_2, BPF_REG_9),
- BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
- BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
- /* if (r6 == 0) return 0; */
- BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 2),
- /* if (r6 != r7) return 0; */
- BPF_JMP_REG(BPF_JNE, BPF_REG_6, BPF_REG_7, 1),
- /* read *r7; */
- BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, offsetof(struct bpf_xdp_sock, queue_id)),
- /* return 0; */
- BPF_MOV64_IMM(BPF_REG_0, 0),
- BPF_EXIT_INSN(),
- },
- .fixup_map_xskmap = { 3 },
- .prog_type = BPF_PROG_TYPE_XDP,
- .result = ACCEPT,
-},
--
2.40.0
