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selftests/bpf: verifier/prevent_map_lookup converted to inline assembly
authorEduard Zingerman <eddyz87@gmail.com>
Fri, 21 Apr 2023 20:45:14 +0000 (23:45 +0300)
committerAlexei Starovoitov <ast@kernel.org>
Sat, 22 Apr 2023 15:26:58 +0000 (08:26 -0700)
Test verifier/prevent_map_lookup automatically converted to use inline assembly.

This was a part of a series [1] but could not be applied becuase
another patch from a series had to be witheld.

[1] https://lore.kernel.org/bpf/20230421174234.2391278-1-eddyz87@gmail.com/

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421204514.2450907-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
tools/testing/selftests/bpf/prog_tests/verifier.c
tools/testing/selftests/bpf/progs/verifier_prevent_map_lookup.c [new file with mode: 0644]
tools/testing/selftests/bpf/verifier/prevent_map_lookup.c [deleted file]

index c8bab8b..2497716 100644 (file)
@@ -42,6 +42,7 @@
 #include "verifier_meta_access.skel.h"
 #include "verifier_netfilter_ctx.skel.h"
 #include "verifier_netfilter_retcode.skel.h"
+#include "verifier_prevent_map_lookup.skel.h"
 #include "verifier_raw_stack.skel.h"
 #include "verifier_raw_tp_writable.skel.h"
 #include "verifier_reg_equal.skel.h"
@@ -140,6 +141,7 @@ void test_verifier_masking(void)              { RUN(verifier_masking); }
 void test_verifier_meta_access(void)          { RUN(verifier_meta_access); }
 void test_verifier_netfilter_ctx(void)        { RUN(verifier_netfilter_ctx); }
 void test_verifier_netfilter_retcode(void)    { RUN(verifier_netfilter_retcode); }
+void test_verifier_prevent_map_lookup(void)   { RUN(verifier_prevent_map_lookup); }
 void test_verifier_raw_stack(void)            { RUN(verifier_raw_stack); }
 void test_verifier_raw_tp_writable(void)      { RUN(verifier_raw_tp_writable); }
 void test_verifier_reg_equal(void)            { RUN(verifier_reg_equal); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_prevent_map_lookup.c b/tools/testing/selftests/bpf/progs/verifier_prevent_map_lookup.c
new file mode 100644 (file)
index 0000000..8d27c78
--- /dev/null
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/prevent_map_lookup.c */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+struct {
+       __uint(type, BPF_MAP_TYPE_STACK_TRACE);
+       __uint(max_entries, 1);
+       __type(key, __u32);
+       __type(value, __u64);
+} map_stacktrace SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+       __uint(max_entries, 8);
+       __uint(key_size, sizeof(int));
+       __array(values, void (void));
+} map_prog2_socket SEC(".maps");
+
+SEC("perf_event")
+__description("prevent map lookup in stack trace")
+__failure __msg("cannot pass map_type 7 into func bpf_map_lookup_elem")
+__naked void map_lookup_in_stack_trace(void)
+{
+       asm volatile ("                                 \
+       r1 = 0;                                         \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_stacktrace] ll;                      \
+       call %[bpf_map_lookup_elem];                    \
+       exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_stacktrace)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("prevent map lookup in prog array")
+__failure __msg("cannot pass map_type 3 into func bpf_map_lookup_elem")
+__failure_unpriv
+__naked void map_lookup_in_prog_array(void)
+{
+       asm volatile ("                                 \
+       r1 = 0;                                         \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_prog2_socket] ll;                    \
+       call %[bpf_map_lookup_elem];                    \
+       exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_prog2_socket)
+       : __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/verifier/prevent_map_lookup.c b/tools/testing/selftests/bpf/verifier/prevent_map_lookup.c
deleted file mode 100644 (file)
index fc4e301..0000000
+++ /dev/null
@@ -1,29 +0,0 @@
-{
-       "prevent map lookup in stack trace",
-       .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_EXIT_INSN(),
-       },
-       .fixup_map_stacktrace = { 3 },
-       .result = REJECT,
-       .errstr = "cannot pass map_type 7 into func bpf_map_lookup_elem",
-       .prog_type = BPF_PROG_TYPE_PERF_EVENT,
-},
-{
-       "prevent map lookup in prog array",
-       .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_EXIT_INSN(),
-       },
-       .fixup_prog2 = { 3 },
-       .result = REJECT,
-       .errstr = "cannot pass map_type 3 into func bpf_map_lookup_elem",
-},