ci: run test_progs-cpuv4 flavor

.github/scripts/matrix.py

@@ -51,6 +51,8 @@ def get_tests(config):
         "test_maps",
         "test_verifier",
     ]
+    if int(config.get("llvm-version", 0)) >= 18:
+        tests.append("test_progs_cpuv4")
     if config.get("parallel_tests", False):
         return tests
     return [test for test in tests if not test.endswith("parallel")]

ci/diffs/0001-bpf-Fix-a-verifier-bug-due-to-incorrect-branch-offse.patch

@@ -0,0 +1,67 @@
+From dfce9cb3140592b886838e06f3e0c25fea2a9cae Mon Sep 17 00:00:00 2001
+From: Yonghong Song <[email protected]>
+Date: Thu, 30 Nov 2023 18:46:40 -0800
+Subject: [PATCH 1/1] bpf: Fix a verifier bug due to incorrect branch offset
+ comparison with cpu=v4
+
+Bpf cpu=v4 support is introduced in [1] and Commit 4cd58e9af8b9
+("bpf: Support new 32bit offset jmp instruction") added support for new
+32bit offset jmp instruction. Unfortunately, in function
+bpf_adj_delta_to_off(), for new branch insn with 32bit offset, the offset
+(plus/minor a small delta) compares to 16-bit offset bound
+[S16_MIN, S16_MAX], which caused the following verification failure:
+  $ ./test_progs-cpuv4 -t verif_scale_pyperf180
+  ...
+  insn 10 cannot be patched due to 16-bit range
+  ...
+  libbpf: failed to load object 'pyperf180.bpf.o'
+  scale_test:FAIL:expect_success unexpected error: -12 (errno 12)
+  #405     verif_scale_pyperf180:FAIL
+
+Note that due to recent llvm18 development, the patch [2] (already applied
+in bpf-next) needs to be applied to bpf tree for testing purpose.
+
+The fix is rather simple. For 32bit offset branch insn, the adjusted
+offset compares to [S32_MIN, S32_MAX] and then verification succeeded.
+
+  [1] https://lore.kernel.org/all/[email protected]
+  [2] https://lore.kernel.org/bpf/[email protected]
+
+Fixes: 4cd58e9af8b9 ("bpf: Support new 32bit offset jmp instruction")
+Signed-off-by: Yonghong Song <[email protected]>
+Signed-off-by: Andrii Nakryiko <[email protected]>
+Link: https://lore.kernel.org/bpf/[email protected]
+---
+ kernel/bpf/core.c | 12 ++++++++----
+ 1 file changed, 8 insertions(+), 4 deletions(-)
+
+diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
+index cd3afe57ece3..fe254ae035fe 100644
+--- a/kernel/bpf/core.c
++++ b/kernel/bpf/core.c
+@@ -371,14 +371,18 @@ static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
+ static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
+ 				s32 end_new, s32 curr, const bool probe_pass)
+ {
+-	const s32 off_min = S16_MIN, off_max = S16_MAX;
++	s64 off_min, off_max, off;
+ 	s32 delta = end_new - end_old;
+-	s32 off;
+
+-	if (insn->code == (BPF_JMP32 | BPF_JA))
++	if (insn->code == (BPF_JMP32 | BPF_JA)) {
+ 		off = insn->imm;
+-	else
++		off_min = S32_MIN;
++		off_max = S32_MAX;
++	} else {
+ 		off = insn->off;
++		off_min = S16_MIN;
++		off_max = S16_MAX;
++	}
+
+ 	if (curr < pos && curr + off + 1 >= end_old)
+ 		off += delta;
+-- 
+2.34.1
+

ci/diffs/0001-selftests-bpf-work-around-latest-Clang-smartness.patch

@@ -0,0 +1,31 @@
+From d31a7125891994681503770cff46a119692fb2b9 Mon Sep 17 00:00:00 2001
+From: Andrii Nakryiko <[email protected]>
+Date: Mon, 11 Dec 2023 17:09:38 -0800
+Subject: [PATCH 1/1] selftests/bpf: work around latest Clang smartness
+
+Work around the issue while we deal with it in the Clang itself.
+See [0].
+
+  [0] https://github.com/llvm/llvm-project/pull/73662#issuecomment-1849281758
+
+Signed-off-by: Andrii Nakryiko <[email protected]>
+---
+ tools/testing/selftests/bpf/progs/iters.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/tools/testing/selftests/bpf/progs/iters.c b/tools/testing/selftests/bpf/progs/iters.c
+index 3aca3dc145b5..929ba6fa2105 100644
+--- a/tools/testing/selftests/bpf/progs/iters.c
++++ b/tools/testing/selftests/bpf/progs/iters.c
+@@ -1420,7 +1420,7 @@ SEC("raw_tp")
+ __success
+ int iter_arr_with_actual_elem_count(const void *ctx)
+ {
+-	int i, n = loop_data.n, sum = 0;
++	unsigned i, n = loop_data.n, sum = 0;
+
+ 	if (n > ARRAY_SIZE(loop_data.data))
+ 		return 0;
+-- 
+2.34.1
+

ci/vmtest/run_selftests.sh

@@ -101,6 +101,10 @@ test_progs_no_alu32_parallel() {
   test_progs_helper "-no_alu32" "-j"
 }
 
+test_progs_cpuv4() {
+  test_progs_helper "-cpuv4" ""
+}
+
 test_maps() {
   foldable start test_maps "Testing test_maps"
   taskset 0xF ./test_maps && true
@@ -179,6 +183,7 @@ read_test_names "$@"
 if [ ${#TEST_NAMES[@]} -eq 0 ]; then
 	test_progs
 	test_progs_no_alu32
+	test_progs_cpuv4
 	test_maps
 	test_verifier
 else