Increase the coverage of a test implemented in commit 301a62dfb0d0
("vsock/test: Add test for UAF due to socket unbinding"). Take this
opportunity to factor out some utility code, drop a redundant sync between
client and server, and introduce a /proc/kallsyms harvesting logic for
auto-detecting registered vsock transports.

Signed-off-by: Michal Luczaj <redacted>
---
Changes in v3:
- Drop "RFC" prefix, rebase, amend commit logs
- get_transports(): don't look for a symbol that was already found
- Expand testcase comments, clean up the code [Stefano]
- Streamline `enum transport` and `transport_ksyms` [Stefano]
- Move KALLSYMS_* defines from utils.h to utils.c [Stefano]
- Link to v2: https://lore.kernel.org/r/20250528-vsock-test-inc-cov-v2-0-8f655b40d57c@rbox.co (local)

Changes in v2:
- Speed up: don't bother checking EINTR or respecting timeout on connect()s
- Introduce get_transports(), warn on unsupported setup [Stefano]
- Comment the code, drop the sync, introduce vsock_bind_try() [Stefano]
- Link to v1: https://lore.kernel.org/r/20250523-vsock-test-inc-cov-v1-1-fa3507941bbd@rbox.co (local)

---
Michal Luczaj (3):
      vsock/test: Introduce vsock_bind_try() helper
      vsock/test: Introduce get_transports()
      vsock/test: Cover more CIDs in transport_uaf test

 tools/testing/vsock/util.c       | 80 ++++++++++++++++++++++++++++++++--
 tools/testing/vsock/util.h       | 30 +++++++++++++
 tools/testing/vsock/vsock_test.c | 93 ++++++++++++++++++++++++++++++++--------
 3 files changed, 181 insertions(+), 22 deletions(-)
---
base-commit: 0097c4195b1d0ca57d15979626c769c74747b5a0
change-id: 20250326-vsock-test-inc-cov-b823822bdb78

Best regards,
-- 
Michal Luczaj [off-list ref]