Re: [PATCH bpf-next v10 11/12] selftests/bpf: add testcases for fsession cookie
From: Andrii Nakryiko <hidden>
Date: 2026-01-22 00:08:10
Also in:
bpf, lkml
On Thu, Jan 15, 2026 at 3:24 AM Menglong Dong [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Test session cookie for fsession. Multiple fsession BPF progs is attached to bpf_fentry_test1() and session cookie is read and write in the testcase. Signed-off-by: Menglong Dong <redacted> --- v3: - restructure the testcase by combine the testcases for session cookie and get_func_ip into one patch --- .../selftests/bpf/progs/fsession_test.c | 53 +++++++++++++++++++ 1 file changed, 53 insertions(+)diff --git a/tools/testing/selftests/bpf/progs/fsession_test.c b/tools/testing/selftests/bpf/progs/fsession_test.c index f504984d42f2..4e55ca67db46 100644 --- a/tools/testing/selftests/bpf/progs/fsession_test.c +++ b/tools/testing/selftests/bpf/progs/fsession_test.c@@ -108,3 +108,56 @@ int BPF_PROG(test6, int a) test6_entry_result = (const void *) addr == &bpf_fentry_test1; return 0; } + +__u64 test7_entry_ok = 0; +__u64 test7_exit_ok = 0; +SEC("fsession/bpf_fentry_test1") +int BPF_PROG(test7, int a) +{ + __u64 *cookie = bpf_session_cookie(ctx); + + if (!bpf_session_is_return(ctx)) { + *cookie = 0xAAAABBBBCCCCDDDDull; + test7_entry_ok = *cookie == 0xAAAABBBBCCCCDDDDull;
you are trying to double-check that writing into *cookie preserves the written value, is that right? Do we need volatile read here to ensure that compiler doesn't optimize this?
+ return 0;
+ }
+
+ test7_exit_ok = *cookie == 0xAAAABBBBCCCCDDDDull;
+ return 0;
+}
+
+__u64 test8_entry_ok = 0;
+__u64 test8_exit_ok = 0;
+
+SEC("fsession/bpf_fentry_test1")
+int BPF_PROG(test8, int a)
+{
+ __u64 *cookie = bpf_session_cookie(ctx);
+
+ if (!bpf_session_is_return(ctx)) {
+ *cookie = 0x1111222233334444ull;
+ test8_entry_ok = *cookie == 0x1111222233334444ull;
+ return 0;
+ }
+
+ test8_exit_ok = *cookie == 0x1111222233334444ull;
+ return 0;
+}
+
+__u64 test9_entry_result = 0;
+__u64 test9_exit_result = 0;
+
+SEC("fsession/bpf_fentry_test1")
+int BPF_PROG(test9, int a, int ret)
+{
+ __u64 *cookie = bpf_session_cookie(ctx);
+
+ if (!bpf_session_is_return(ctx)) {
+ test9_entry_result = a == 1 && ret == 0;
+ *cookie = 0x123456ULL;
+ return 0;
+ }
+
+ test9_exit_result = a == 1 && ret == 2 && *cookie == 0x123456ULL;
+ return 0;
+}
--
2.52.0