[PATCH v2 bpf-next 2/2] selftests/bpf: Add selftests for verifying return values of fmod_ret.

[Feng Yang]

From: Feng Yang <yangfeng@xxxxxxxxxx>

Add selftests for verifying return values of fmod_ret.
test_progs -t verifier_fmod_ret_return
569/1   verifier_fmod_ret_return/fmod_task_alloc_1:OK
569/2   verifier_fmod_ret_return/fmod_task_alloc_2:OK
569/3   verifier_fmod_ret_return/fmod_ret_sys_open_1:OK
569/4   verifier_fmod_ret_return/fmod_ret_sys_open_2:OK
569/5   verifier_fmod_ret_return/fmod_ret_sys_open_3:OK
569/6   verifier_fmod_ret_return/fmod_page_pool_alloc_netmems_1:OK
569/7   verifier_fmod_ret_return/fmod_page_pool_alloc_netmems_2:OK
569     verifier_fmod_ret_return:OK
Summary: 1/7 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Feng Yang <yangfeng@xxxxxxxxxx>
---
 .../selftests/bpf/prog_tests/verifier.c       |  2 +
 .../bpf/progs/verifier_fmod_ret_return.c      | 60 +++++++++++++++++++
 2 files changed, 62 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/progs/verifier_fmod_ret_return.c

diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 169cf7fbf40f..6e67f69d88fa 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
@@ -37,6 +37,7 @@
 #include "verifier_div0.skel.h"
 #include "verifier_div_mod_bounds.skel.h"
 #include "verifier_div_overflow.skel.h"
+#include "verifier_fmod_ret_return.skel.h"
 #include "verifier_global_subprogs.skel.h"
 #include "verifier_global_ptr_args.skel.h"
 #include "verifier_gotol.skel.h"
@@ -184,6 +185,7 @@ void test_verifier_direct_stack_access_wraparound(void) { RUN(verifier_direct_st
 void test_verifier_div0(void)                 { RUN(verifier_div0); }
 void test_verifier_div_mod_bounds(void)       { RUN(verifier_div_mod_bounds); }
 void test_verifier_div_overflow(void)         { RUN(verifier_div_overflow); }
+void test_verifier_fmod_ret_return(void)      { RUN(verifier_fmod_ret_return); }
 void test_verifier_global_subprogs(void)      { RUN(verifier_global_subprogs); }
 void test_verifier_global_ptr_args(void)      { RUN(verifier_global_ptr_args); }
 void test_verifier_gotol(void)                { RUN(verifier_gotol); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_fmod_ret_return.c b/tools/testing/selftests/bpf/progs/verifier_fmod_ret_return.c
new file mode 100644
index 000000000000..11d303b01c80
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_fmod_ret_return.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <bpf/bpf_tracing.h>
+#include "bpf_misc.h"
+
+SEC("fmod_ret/security_task_alloc")
+__success
+int BPF_PROG(fmod_task_alloc_1)
+{
+	return -1;
+}
+
+SEC("fmod_ret/security_task_alloc")
+__failure __log_level(2)
+__msg("At program exit the register R0 has smin=1 smax=1 should have been in [-4095, 0]")
+int BPF_PROG(fmod_task_alloc_2)
+{
+	return 1;
+}
+
+SEC("fmod_ret/" SYS_PREFIX "sys_open")
+__failure __log_level(2)
+__msg("At program exit the register R0 has smin=0 smax=0 should have been in [-4095, -1]")
+int BPF_PROG(fmod_ret_sys_open_1)
+{
+	return 0;
+}
+
+SEC("fmod_ret/" SYS_PREFIX "sys_open")
+__failure __log_level(2)
+__msg("At program exit the register R0 has smin=1 smax=1 should have been in [-4095, -1]")
+int BPF_PROG(fmod_ret_sys_open_2)
+{
+	return 1;
+}
+
+SEC("fmod_ret/" SYS_PREFIX "sys_open")
+__success
+int BPF_PROG(fmod_ret_sys_open_3)
+{
+	return -1;
+}
+
+SEC("fmod_ret/page_pool_alloc_netmems")
+__failure __log_level(2)
+__msg("At program exit the register R0 has smin=1 smax=1 should have been in [0, 0]")
+int BPF_PROG(fmod_page_pool_alloc_netmems_1)
+{
+	return 1;
+}
+
+SEC("fmod_ret/page_pool_alloc_netmems")
+__success
+int BPF_PROG(fmod_page_pool_alloc_netmems_2)
+{
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
-- 
2.43.0