[bpf,2/2] selftests/bpf: Add test coverage for reg_set_min_max handling

Commit Message

Daniel Borkmann June 12, 2024, 10:14 p.m. UTC

Add a test case for the jmp32/k fix to ensure selftests have coverage.

Before fix:

  # ./vmtest.sh -- ./test_progs -t verifier_or_jmp32_k
  [...]
  ./test_progs -t verifier_or_jmp32_k
  tester_init:PASS:tester_log_buf 0 nsec
  process_subtest:PASS:obj_open_mem 0 nsec
  process_subtest:PASS:specs_alloc 0 nsec
  run_subtest:PASS:obj_open_mem 0 nsec
  run_subtest:FAIL:unexpected_load_success unexpected success: 0
  #492/1   verifier_or_jmp32_k/or_jmp32_k: bit ops + branch on unknown value:FAIL
  #492     verifier_or_jmp32_k:FAIL
  Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED

After fix:

  # ./vmtest.sh -- ./test_progs -t verifier_or_jmp32_k
  [...]
  ./test_progs -t verifier_or_jmp32_k
  #492/1   verifier_or_jmp32_k/or_jmp32_k: bit ops + branch on unknown value:OK
  #492     verifier_or_jmp32_k:OK
  Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <[e-mail]>
---
 .../selftests/bpf/prog_tests/verifier.c       |  2 +
 .../selftests/bpf/progs/verifier_or_jmp32_k.c | 43 +++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/progs/verifier_or_jmp32_k.c

Comments

John Fastabend June 12, 2024, 11:12 p.m. UTC | #1

Daniel Borkmann wrote:
> Add a test case for the jmp32/k fix to ensure selftests have coverage.
> 
> Before fix:
> 
>   # ./vmtest.sh -- ./test_progs -t verifier_or_jmp32_k
>   [...]
>   ./test_progs -t verifier_or_jmp32_k
>   tester_init:PASS:tester_log_buf 0 nsec
>   process_subtest:PASS:obj_open_mem 0 nsec
>   process_subtest:PASS:specs_alloc 0 nsec
>   run_subtest:PASS:obj_open_mem 0 nsec
>   run_subtest:FAIL:unexpected_load_success unexpected success: 0
>   #492/1   verifier_or_jmp32_k/or_jmp32_k: bit ops + branch on unknown value:FAIL
>   #492     verifier_or_jmp32_k:FAIL
>   Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED
> 
> After fix:
> 
>   # ./vmtest.sh -- ./test_progs -t verifier_or_jmp32_k
>   [...]
>   ./test_progs -t verifier_or_jmp32_k
>   #492/1   verifier_or_jmp32_k/or_jmp32_k: bit ops + branch on unknown value:OK
>   #492     verifier_or_jmp32_k:OK
>   Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED
> 
> Signed-off-by: Daniel Borkmann <[e-mail]>
> ---

Acked-by: John Fastabend <[e-mail]>

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 1c9c4ec1be11..98ef39efa77e 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
@@ -53,6 +53,7 @@ 
 #include "verifier_movsx.skel.h"
 #include "verifier_netfilter_ctx.skel.h"
 #include "verifier_netfilter_retcode.skel.h"
+#include "verifier_or_jmp32_k.skel.h"
 #include "verifier_precision.skel.h"
 #include "verifier_prevent_map_lookup.skel.h"
 #include "verifier_raw_stack.skel.h"
@@ -170,6 +171,7 @@  void test_verifier_meta_access(void)          { RUN(verifier_meta_access); }
 void test_verifier_movsx(void)                 { RUN(verifier_movsx); }
 void test_verifier_netfilter_ctx(void)        { RUN(verifier_netfilter_ctx); }
 void test_verifier_netfilter_retcode(void)    { RUN(verifier_netfilter_retcode); }
+void test_verifier_or_jmp32_k(void)           { RUN(verifier_or_jmp32_k); }
 void test_verifier_precision(void)            { RUN(verifier_precision); }
 void test_verifier_prevent_map_lookup(void)   { RUN(verifier_prevent_map_lookup); }
 void test_verifier_raw_stack(void)            { RUN(verifier_raw_stack); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_or_jmp32_k.c b/tools/testing/selftests/bpf/progs/verifier_or_jmp32_k.c
new file mode 100644
index 000000000000..c02c3a647e59
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_or_jmp32_k.c
@@ -0,0 +1,43 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+SEC("socket")
+__description("or_jmp32_k: bit ops + branch on unknown value")
+__failure
+__msg("R0 invalid mem access 'scalar'")
+__naked void or_jmp32_k(void)
+{
+	asm volatile ("					\
+	r0 = 0xffffffff;				\
+	r0 /= 1;					\
+	r1 = 0;						\
+	w1 = -1;					\
+	w1 >>= 1;					\
+	w0 &= w1;					\
+	w0 |= 2;					\
+	if w0 != 0x7ffffffd goto l2;			\
+	r0 = 1;						\
+	exit;						\
+l4:							\
+	r0 = 5;						\
+	*(u64*)(r0 - 8) = r0;				\
+	exit;						\
+l3:							\
+	w0 -= 0xe;					\
+	if w0 == 1 goto l4;				\
+	r0 = 4;						\
+	exit;						\
+l2:							\
+	w0 -= 0x7ffffff0;				\
+	if w0 s>= 0xe goto l3;				\
+	r0 = 3;						\
+	exit;						\
+"	:
+	:
+	: __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";