On Wed, Mar 18, 2026 at 9:04 PM Sun Jian <[email protected]> wrote: > > trampoline_count fills all trampoline attachment slots for a single > target function and verifies that one extra attach fails with -E2BIG. > > It currently targets bpf_modify_return_test, which is also used by > other selftests such as modify_return, get_func_ip_test, and > get_func_args_test. When such tests run in parallel, they can contend > for the same per-function trampoline quota and cause unexpected attach > failures. This issue is currently masked by harness serialization. > > Move trampoline_count to a dedicated bpf_testmod target and register it > for fmod_ret attachment. This keeps the test semantics unchanged while > isolating it from other selftests, so it no longer needs to run in > serial mode. Remove the TODO comment as well. > > Tested: > ./test_progs -t trampoline_count -vv > ./test_progs -t modify_return -vv > ./test_progs -t get_func_ip_test -vv > ./test_progs -t get_func_args_test -vv > ./test_progs -j$(nproc) -t trampoline_count -vv > ./test_progs -j$(nproc) -t > trampoline_count,modify_return,get_func_ip_test,get_func_args_test,\ > kprobe_multi_test -vv > 20 runs of: > ./test_progs -j$(nproc) -t > trampoline_count,modify_return,get_func_ip_test,get_func_args_test,\ > kprobe_multi_test > > Signed-off-by: Sun Jian <[email protected]>
if you want to land these patches please participate in code reviews: https://lore.kernel.org/bpf/CAADnVQ+TKKptnNB25V3=bcdybh5g6c2dyw2sytxvyravnpn...@mail.gmail.com/
