bpf: Sort subprogs in topological order after check_cfg()

Browse source

Add a pass that sorts subprogs in topological order so that iterating
subprog_topo_order[] walks leaf subprogs first, then their callers.
This is computed as a DFS post-order traversal of the CFG.

The pass runs after check_cfg() to ensure the CFG has been validated
before traversing and after postorder has been computed to avoid
walking dead code.

Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260403024422.87231-3-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

...

This commit is contained in:

Alexei Starovoitov 2026-04-02 19:44:17 -07:00

parent 503d21ef8e

commit e6898ec751

4 changed files with 98 additions and 5 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

2

include/linux/bpf_verifier.h

View file

92

kernel/bpf/verifier.c

View file

3

tools/testing/selftests/bpf/progs/verifier_loops1.c

View file

6

tools/testing/selftests/bpf/verifier/calls.c

View file