diff mbox series

[bpf,2/2] bpf: selftest: Trigger a DCE on the whole subprog

Message ID 20211106014020.651638-1-kafai@fb.com (mailing list archive)
State Accepted
Delegated to: BPF
Headers show
Series bpf: Fix out-of-bound issue when jit-ing bpf_pseudo_func | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 6 maintainers not CCed: songliubraving@fb.com linux-kselftest@vger.kernel.org shuah@kernel.org john.fastabend@gmail.com kpsingh@kernel.org netdev@vger.kernel.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: Use of volatile is usually wrong: see Documentation/process/volatile-considered-harmful.rst
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf fail VM_Test
bpf/vmtest-bpf-PR fail PR summary

Commit Message

Martin KaFai Lau Nov. 6, 2021, 1:40 a.m. UTC 
This patch adds a test to trigger the DCE to remove
the whole subprog to ensure the verifier  does not
depend on a stable subprog index.  The DCE is done
by testing a global const.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 .../selftests/bpf/progs/for_each_array_map_elem.c    | 12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/progs/for_each_array_map_elem.c b/tools/testing/selftests/bpf/progs/for_each_array_map_elem.c
index df918b2469da..52f6995ff29c 100644
--- a/tools/testing/selftests/bpf/progs/for_each_array_map_elem.c
+++ b/tools/testing/selftests/bpf/progs/for_each_array_map_elem.c
@@ -23,6 +23,16 @@  struct callback_ctx {
 	int output;
 };
 
+const volatile int bypass_unused = 1;
+
+static __u64
+unused_subprog(struct bpf_map *map, __u32 *key, __u64 *val,
+	       struct callback_ctx *data)
+{
+	data->output = 0;
+	return 1;
+}
+
 static __u64
 check_array_elem(struct bpf_map *map, __u32 *key, __u64 *val,
 		 struct callback_ctx *data)
@@ -54,6 +64,8 @@  int test_pkt_access(struct __sk_buff *skb)
 
 	data.output = 0;
 	bpf_for_each_map_elem(&arraymap, check_array_elem, &data, 0);
+	if (!bypass_unused)
+		bpf_for_each_map_elem(&arraymap, unused_subprog, &data, 0);
 	arraymap_output = data.output;
 
 	bpf_for_each_map_elem(&percpu_map, check_percpu_elem, (void *)0, 0);