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* [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage
@ 2026-08-24 21:01 Vineet Gupta
  2026-08-24 21:01 ` [PATCH bpf-next v2 1/3] selftests/bpf: name the remaining placeholder programs dummy_test [NFC] Vineet Gupta
                   ` (3 more replies)
  0 siblings, 4 replies; 8+ messages in thread
From: Vineet Gupta @ 2026-08-24 21:01 UTC (permalink / raw)
  To: bpf; +Cc: Vineet Gupta

When doing some unrelated testing, stumbled upon this. A lot of tests
are skipped under BPF_GCC due to clang only gate. On top, the test
harness declares them passing/OK.

Patch 1 renames a few placeholders a consistent dummy_test name [NFC].

A sample test with BPF_GCC used to say:

| #587/1 verifier_bswap/cpuv4 is not supported by compiler or jit, use a dummy test:OK
| #587	 verifier_bswap:OK

Patch 2 adds a __skip("reason") annotation so a compile-time gated file
reports SKIP rather than OK, making these gaps visible in test_progs
output.

Now the output changes to

| #587/1 verifier_bswap/cpuv4 is not supported by compiler or jit, use a dummy test:SKIP
| #587	 verifier_bswap:SKIP

Patch 3 augments the clang only gate with a per-feature gate supported
by both the compilers. FWIW the clang half has to stay: clang only
defines __BPF_FEATURE_MOVSX and friends at -mcpu=v4 but assembles the
inline asm at -mcpu=v3 too, so dropping it would remove these tests from
the default test_progs flavour where they run today.

And finally the output now is

| #587/1 verifier_bswap/BSWAP, 16:OK
| #587/2 verifier_bswap/BSWAP, 16 @unpriv:SKIP
| #587/3 verifier_bswap/BSWAP, 32:OK
| #587/4 verifier_bswap/BSWAP, 32 @unpriv:SKIP
| #587/5 verifier_bswap/BSWAP, 64:OK
| #587/6 verifier_bswap/BSWAP, 64 @unpriv:SKIP
| #587/7 verifier_bswap/bswap16_range:OK
| #587/8 verifier_bswap/bswap32_range:OK
| #587/9 verifier_bswap/bswap64_range:OK
| #587/10 verifier_bswap/be16_range:OK
| #587/11 verifier_bswap/be32_range:OK
| #587/12 verifier_bswap/be64_range:OK
| #587/13 verifier_bswap/le16_range:OK
| #587/14 verifier_bswap/le32_range:OK
| #587/15 verifier_bswap/le64_range:OK
| #587/16 verifier_bswap/BSWAP, reset reg id:OK
| #587	 verifier_bswap:OK (SKIP: 3/16)

Programs per object recovered under BPF_GCC, 124 in total:

  verifier_sdiv                  1 -> 80
  verifier_movsx                 1 -> 17
  verifier_ldsx                  1 -> 14
  verifier_bswap                 1 -> 13
  compute_live_registers        17 -> 19
  verifier_gotol                 1 -> 2
  verifier_iterating_callbacks  34 -> 35

Two things stay clang-only on purpose: the arena tests using
addr_space_cast, and verifier_load_acquire/verifier_store_release. gas
implements neither.

The increased coverage bore fruits right away as I stumbled into a gas
bug: PR gas/34558. Fix is posted however workaround is needed for the
time being.

Built for x86_64 with both clang and bpf-gcc; the per-object counts above
were read back from the generated objects.

Changes since v1:

 - 1/3: Nothing functional just Eduard's Ack.

 - 2/3: convert the two feature-gated placeholders that were missed.
   Spotted by the BPF CI AI reviewer.

 - 3/3: Fix comment to kernel-style, not netdev (Sashiko review).

 - Eduard's Acked-by carried over from v1. Note 2/3 grew two more
   placeholder conversions after he acked it.

v1:
https://lore.kernel.org/bpf/20260821201316.1059129-1-vineet.gupta@linux.dev/

Vineet Gupta (3):
  selftests/bpf: name the remaining placeholder programs dummy_test
    [NFC]
  selftests/bpf: report placeholder tests as SKIP, not OK
  selftests/bpf: Enable some of the blocked cpuv4 instruction tests for
    bpf-gcc

 .../testing/selftests/bpf/progs/arena_kfunc.c |  3 ++-
 tools/testing/selftests/bpf/progs/bpf_misc.h  | 10 ++++++++--
 .../bpf/progs/compute_live_registers.c        |  8 ++++++++
 .../selftests/bpf/progs/stack_arg_fail.c      |  3 ++-
 .../selftests/bpf/progs/stack_arg_precision.c |  1 +
 .../bpf/progs/verifier_aggregate_ret.c        |  1 +
 .../selftests/bpf/progs/verifier_bswap.c      |  3 ++-
 .../selftests/bpf/progs/verifier_gotol.c      |  1 +
 .../selftests/bpf/progs/verifier_ldsx.c       | 19 ++++++++++++-------
 .../bpf/progs/verifier_load_acquire.c         |  1 +
 .../selftests/bpf/progs/verifier_movsx.c      |  3 ++-
 .../bpf/progs/verifier_percpu_addr.c          |  1 +
 .../bpf/progs/verifier_private_stack.c        |  1 +
 .../selftests/bpf/progs/verifier_sdiv.c       |  3 ++-
 .../selftests/bpf/progs/verifier_stack_arg.c  |  1 +
 .../bpf/progs/verifier_stack_arg_order.c      |  1 +
 .../bpf/progs/verifier_store_release.c        |  1 +
 tools/testing/selftests/bpf/test_loader.c     |  9 +++++++++
 18 files changed, 56 insertions(+), 14 deletions(-)

-- 
2.53.0-Meta


^ permalink raw reply	[flat|nested] 8+ messages in thread
* [PATCH bpf-next v2 1/3] selftests/bpf: name the remaining placeholder programs dummy_test [NFC]
  2026-08-24 21:01 [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage Vineet Gupta
@ 2026-08-24 21:01 ` Vineet Gupta
  2026-08-24 21:01 ` [PATCH bpf-next v2 2/3] selftests/bpf: report placeholder tests as SKIP, not OK Vineet Gupta
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 8+ messages in thread
From: Vineet Gupta @ 2026-08-24 21:01 UTC (permalink / raw)
  To: bpf; +Cc: Vineet Gupta, Eduard Zingerman

Thirteen of the fifteen feature-gated placeholder programs are called
dummy_test. Two are not: hence this patch.

This is purely cosmetic as nothing depends on those names.
The non-compliant setups use RUN_TESTS(skel) which goes through all
programs normally. This is just more consistent and grep friendly.

Signed-off-by: Vineet Gupta <vineet.gupta@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
---
 tools/testing/selftests/bpf/progs/arena_kfunc.c    | 2 +-
 tools/testing/selftests/bpf/progs/stack_arg_fail.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/arena_kfunc.c b/tools/testing/selftests/bpf/progs/arena_kfunc.c
index bf0d304e0e59..47bed5c4c488 100644
--- a/tools/testing/selftests/bpf/progs/arena_kfunc.c
+++ b/tools/testing/selftests/bpf/progs/arena_kfunc.c
@@ -234,7 +234,7 @@ __arch_x86_64
 __arch_arm64
 __description("arena_arg_stack: not supported, dummy test")
 __success
-int arena_arg_stack(void *ctx)
+int dummy_test(void *ctx)
 {
 	return 0;
 }
diff --git a/tools/testing/selftests/bpf/progs/stack_arg_fail.c b/tools/testing/selftests/bpf/progs/stack_arg_fail.c
index ad9d4bfe15dc..6f6f59306d0e 100644
--- a/tools/testing/selftests/bpf/progs/stack_arg_fail.c
+++ b/tools/testing/selftests/bpf/progs/stack_arg_fail.c
@@ -104,7 +104,7 @@ __naked void r11_store_zero_off(void)
 SEC("tc")
 __description("stack_arg_fail: not supported, dummy test")
 __success
-int test_stack_arg_big(struct __sk_buff *skb)
+int dummy_test(struct __sk_buff *skb)
 {
 	return 0;
 }
-- 
2.53.0-Meta


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [PATCH bpf-next v2 2/3] selftests/bpf: report placeholder tests as SKIP, not OK
  2026-08-24 21:01 [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage Vineet Gupta
  2026-08-24 21:01 ` [PATCH bpf-next v2 1/3] selftests/bpf: name the remaining placeholder programs dummy_test [NFC] Vineet Gupta
@ 2026-08-24 21:01 ` Vineet Gupta
  2026-08-24 21:42   ` bot+bpf-ci
  2026-08-24 21:01 ` [PATCH bpf-next v2 3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc Vineet Gupta
  2026-08-26 16:40 ` [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage patchwork-bot+netdevbpf
  3 siblings, 1 reply; 8+ messages in thread
From: Vineet Gupta @ 2026-08-24 21:01 UTC (permalink / raw)
  To: bpf; +Cc: Vineet Gupta, Eduard Zingerman

Several verifier test files wrap their contents in a feature gate and provide
a one-line placeholder program in the #else arm, so the file still yields
something when the toolchain or JIT cannot support the tested instructions.

However the placeholder is annotated __success, so it reports as a pass,
whereas this is really a SKIP.

|  #318/1   verifier_ldsx/cpuv4 is not supported by compiler or jit, ...:OK
|  #318     verifier_ldsx:OK

This causes skipped coverage to be overlooked: see the next patch where
BPF_GCC builds miss a whole bunch of test due to clang only gate.

Add a __skip("reason") annotation for a compile-time gate, and use it for the
placeholders.

After this change, above tests reported as

|  #318/1   verifier_ldsx/cpuv4 is not supported by compiler or jit, ...:SKIP
|  #318     verifier_ldsx:SKIP

Signed-off-by: Vineet Gupta <vineet.gupta@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
---
 tools/testing/selftests/bpf/progs/arena_kfunc.c          | 1 +
 tools/testing/selftests/bpf/progs/bpf_misc.h             | 6 ++++++
 tools/testing/selftests/bpf/progs/stack_arg_fail.c       | 1 +
 tools/testing/selftests/bpf/progs/stack_arg_precision.c  | 1 +
 .../testing/selftests/bpf/progs/verifier_aggregate_ret.c | 1 +
 tools/testing/selftests/bpf/progs/verifier_bswap.c       | 1 +
 tools/testing/selftests/bpf/progs/verifier_gotol.c       | 1 +
 tools/testing/selftests/bpf/progs/verifier_ldsx.c        | 1 +
 .../testing/selftests/bpf/progs/verifier_load_acquire.c  | 1 +
 tools/testing/selftests/bpf/progs/verifier_movsx.c       | 1 +
 tools/testing/selftests/bpf/progs/verifier_percpu_addr.c | 1 +
 .../testing/selftests/bpf/progs/verifier_private_stack.c | 1 +
 tools/testing/selftests/bpf/progs/verifier_sdiv.c        | 1 +
 tools/testing/selftests/bpf/progs/verifier_stack_arg.c   | 1 +
 .../selftests/bpf/progs/verifier_stack_arg_order.c       | 1 +
 .../testing/selftests/bpf/progs/verifier_store_release.c | 1 +
 tools/testing/selftests/bpf/test_loader.c                | 9 +++++++++
 17 files changed, 30 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/arena_kfunc.c b/tools/testing/selftests/bpf/progs/arena_kfunc.c
index 47bed5c4c488..50609f3b0564 100644
--- a/tools/testing/selftests/bpf/progs/arena_kfunc.c
+++ b/tools/testing/selftests/bpf/progs/arena_kfunc.c
@@ -233,6 +233,7 @@ SEC("syscall")
 __arch_x86_64
 __arch_arm64
 __description("arena_arg_stack: not supported, dummy test")
+__skip("arena_arg_stack: not supported")
 __success
 int dummy_test(void *ctx)
 {
diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h
index 5eacf1b43252..88b0bfba83bb 100644
--- a/tools/testing/selftests/bpf/progs/bpf_misc.h
+++ b/tools/testing/selftests/bpf/progs/bpf_misc.h
@@ -106,6 +106,11 @@
  * __description     Text to be used for display and as an additional filter
  *                   alias, while the original program name stays matchable.
  *
+ * __skip            Report the test as SKIP with the given reason instead of
+ *                   running it. For placeholder programs that stand in for a
+ *                   feature the toolchain or JIT cannot provide, so a run does
+ *                   not report OK for coverage it never executed.
+ *
  * __log_level       Log level to use for the program, numeric value expected.
  *
  * __flag            Adds one flag use for the program, the following values are valid:
@@ -139,6 +144,7 @@
 #define __failure		__test_tag("test_expect_failure")
 #define __success		__test_tag("test_expect_success")
 #define __description(desc)	__test_tag("test_description=" desc)
+#define __skip(reason)		__test_tag("test_skip=" reason)
 #define __msg_unpriv(msg)	__test_tag("test_expect_msg_unpriv=" msg)
 #define __not_msg_unpriv(msg)	__test_tag("test_expect_not_msg_unpriv=" msg)
 #define __xlated_unpriv(msg)	__test_tag("test_expect_xlated_unpriv=" msg)
diff --git a/tools/testing/selftests/bpf/progs/stack_arg_fail.c b/tools/testing/selftests/bpf/progs/stack_arg_fail.c
index 6f6f59306d0e..eed97d582515 100644
--- a/tools/testing/selftests/bpf/progs/stack_arg_fail.c
+++ b/tools/testing/selftests/bpf/progs/stack_arg_fail.c
@@ -103,6 +103,7 @@ __naked void r11_store_zero_off(void)
 
 SEC("tc")
 __description("stack_arg_fail: not supported, dummy test")
+__skip("stack_arg_fail: not supported")
 __success
 int dummy_test(struct __sk_buff *skb)
 {
diff --git a/tools/testing/selftests/bpf/progs/stack_arg_precision.c b/tools/testing/selftests/bpf/progs/stack_arg_precision.c
index bee2eeec021d..ce0301a41fa9 100644
--- a/tools/testing/selftests/bpf/progs/stack_arg_precision.c
+++ b/tools/testing/selftests/bpf/progs/stack_arg_precision.c
@@ -124,6 +124,7 @@ __naked void stack_arg_precision_bpf2bpf(void)
 
 SEC("socket")
 __description("stack_arg_precision: not supported, dummy test")
+__skip("stack_arg_precision: not supported")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_aggregate_ret.c b/tools/testing/selftests/bpf/progs/verifier_aggregate_ret.c
index 7851bade2b40..f5c1166027a1 100644
--- a/tools/testing/selftests/bpf/progs/verifier_aggregate_ret.c
+++ b/tools/testing/selftests/bpf/progs/verifier_aggregate_ret.c
@@ -167,6 +167,7 @@ int aggregate_ret_kfunc_struct_c_test(struct __sk_buff *skb)
 
 SEC("socket")
 __description("verifier_aggregate_ret: needs LLVM 23, dummy test")
+__skip("needs LLVM 23")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_bswap.c b/tools/testing/selftests/bpf/progs/verifier_bswap.c
index cffaf36192bc..074faef5480e 100644
--- a/tools/testing/selftests/bpf/progs/verifier_bswap.c
+++ b/tools/testing/selftests/bpf/progs/verifier_bswap.c
@@ -117,6 +117,7 @@ l0_%=:							\
 
 SEC("socket")
 __description("cpuv4 is not supported by compiler or jit, use a dummy test")
+__skip("cpuv4 is not supported by compiler or jit")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_gotol.c b/tools/testing/selftests/bpf/progs/verifier_gotol.c
index d5d8f24df394..c0fd30a3a4c1 100644
--- a/tools/testing/selftests/bpf/progs/verifier_gotol.c
+++ b/tools/testing/selftests/bpf/progs/verifier_gotol.c
@@ -52,6 +52,7 @@ __naked void gotol_large_imm(void)
 
 SEC("socket")
 __description("cpuv4 is not supported by compiler or jit, use a dummy test")
+__skip("cpuv4 is not supported by compiler or jit")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
index 41340877dc9d..e58ea69e3854 100644
--- a/tools/testing/selftests/bpf/progs/verifier_ldsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
@@ -436,6 +436,7 @@ void kfunc_root(void)
 
 SEC("socket")
 __description("cpuv4 is not supported by compiler or jit, use a dummy test")
+__skip("cpuv4 is not supported by compiler or jit")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_load_acquire.c b/tools/testing/selftests/bpf/progs/verifier_load_acquire.c
index d17026d7480d..bcc34e798c63 100644
--- a/tools/testing/selftests/bpf/progs/verifier_load_acquire.c
+++ b/tools/testing/selftests/bpf/progs/verifier_load_acquire.c
@@ -267,6 +267,7 @@ __naked void load_acquire_with_invalid_reg(void)
 
 SEC("socket")
 __description("Clang version < 18, ENABLE_ATOMICS_TESTS not defined, and/or JIT doesn't support load-acquire, use a dummy test")
+__skip("Clang version < 18, ENABLE_ATOMICS_TESTS not defined, and/or JIT doesn't support load-acquire")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_movsx.c b/tools/testing/selftests/bpf/progs/verifier_movsx.c
index a4d8814eb5ed..5559c0583dd1 100644
--- a/tools/testing/selftests/bpf/progs/verifier_movsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_movsx.c
@@ -343,6 +343,7 @@ label_%=: 	                                        \
 
 SEC("socket")
 __description("cpuv4 is not supported by compiler or jit, use a dummy test")
+__skip("cpuv4 is not supported by compiler or jit")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_percpu_addr.c b/tools/testing/selftests/bpf/progs/verifier_percpu_addr.c
index 967f4e6e3a49..fd418f27996f 100644
--- a/tools/testing/selftests/bpf/progs/verifier_percpu_addr.c
+++ b/tools/testing/selftests/bpf/progs/verifier_percpu_addr.c
@@ -61,6 +61,7 @@ __naked void percpu_addr(void)
 
 SEC("raw_tp")
 __description("percpu addr dummy")
+__skip("percpu addr tests need x86")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_private_stack.c b/tools/testing/selftests/bpf/progs/verifier_private_stack.c
index ea0a7e73331d..3d9994a52464 100644
--- a/tools/testing/selftests/bpf/progs/verifier_private_stack.c
+++ b/tools/testing/selftests/bpf/progs/verifier_private_stack.c
@@ -377,6 +377,7 @@ int private_stack_max_depth(void)
 
 SEC("kprobe")
 __description("private stack is not supported, use a dummy test")
+__skip("private stack is not supported")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_sdiv.c b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
index 95f3239ce228..515644ace516 100644
--- a/tools/testing/selftests/bpf/progs/verifier_sdiv.c
+++ b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
@@ -1271,6 +1271,7 @@ __naked void smod32_int_min_mod_neg2_imm(void)
 
 SEC("socket")
 __description("cpuv4 is not supported by compiler or jit, use a dummy test")
+__skip("cpuv4 is not supported by compiler or jit")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_stack_arg.c b/tools/testing/selftests/bpf/progs/verifier_stack_arg.c
index 7e0ce5db28a0..51d22faf4559 100644
--- a/tools/testing/selftests/bpf/progs/verifier_stack_arg.c
+++ b/tools/testing/selftests/bpf/progs/verifier_stack_arg.c
@@ -436,6 +436,7 @@ __naked void stack_arg_sequential_calls(void)
 
 SEC("socket")
 __description("stack_arg is not supported by compiler or jit, use a dummy test")
+__skip("stack_arg is not supported by compiler or jit")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_stack_arg_order.c b/tools/testing/selftests/bpf/progs/verifier_stack_arg_order.c
index c9fe4857da3f..8e4325273b3d 100644
--- a/tools/testing/selftests/bpf/progs/verifier_stack_arg_order.c
+++ b/tools/testing/selftests/bpf/progs/verifier_stack_arg_order.c
@@ -174,6 +174,7 @@ __naked void stack_arg_read_without_write_2(void)
 
 SEC("socket")
 __description("stack_arg order is not supported by compiler or jit, use a dummy test")
+__skip("stack_arg order is not supported by compiler or jit")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/progs/verifier_store_release.c b/tools/testing/selftests/bpf/progs/verifier_store_release.c
index 72f1eb006074..0abbee5ce109 100644
--- a/tools/testing/selftests/bpf/progs/verifier_store_release.c
+++ b/tools/testing/selftests/bpf/progs/verifier_store_release.c
@@ -290,6 +290,7 @@ __naked void store_release_with_invalid_reg(void)
 
 SEC("socket")
 __description("Clang version < 18, ENABLE_ATOMICS_TESTS not defined, and/or JIT doesn't support store-release, use a dummy test")
+__skip("Clang version < 18, ENABLE_ATOMICS_TESTS not defined, and/or JIT doesn't support store-release")
 __success
 int dummy_test(void)
 {
diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c
index 07807757b518..794a7dfb0579 100644
--- a/tools/testing/selftests/bpf/test_loader.c
+++ b/tools/testing/selftests/bpf/test_loader.c
@@ -70,6 +70,7 @@ struct test_spec {
 	int arch_mask;
 	int load_mask;
 	int linear_sz;
+	const char *skip_reason;
 	bool auxiliary;
 	bool valid;
 };
@@ -456,6 +457,8 @@ static int parse_test_spec(struct test_loader *tester,
 			continue;
 		if ((val = str_has_pfx(s, "test_description="))) {
 			description = val;
+		} else if ((val = str_has_pfx(s, "test_skip="))) {
+			spec->skip_reason = val;
 		} else if (strcmp(s, "test_expect_failure") == 0) {
 			spec->priv.expect_failure = true;
 			spec->mode_mask |= PRIV;
@@ -1327,6 +1330,12 @@ void run_subtest(struct test_loader *tester,
 	if (!test__start_subtest_with_desc(subspec->name, subspec->description))
 		return;
 
+	if (spec->skip_reason) {
+		printf("%s:SKIP: %s\n", __func__, spec->skip_reason);
+		test__skip();
+		return;
+	}
+
 	if ((get_current_arch() & spec->arch_mask) == 0) {
 		test__skip();
 		return;
-- 
2.53.0-Meta


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [PATCH bpf-next v2 3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc
  2026-08-24 21:01 [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage Vineet Gupta
  2026-08-24 21:01 ` [PATCH bpf-next v2 1/3] selftests/bpf: name the remaining placeholder programs dummy_test [NFC] Vineet Gupta
  2026-08-24 21:01 ` [PATCH bpf-next v2 2/3] selftests/bpf: report placeholder tests as SKIP, not OK Vineet Gupta
@ 2026-08-24 21:01 ` Vineet Gupta
  2026-08-24 21:14   ` sashiko-bot
  2026-08-26 16:40 ` [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage patchwork-bot+netdevbpf
  3 siblings, 1 reply; 8+ messages in thread
From: Vineet Gupta @ 2026-08-24 21:01 UTC (permalink / raw)
  To: bpf; +Cc: Vineet Gupta, Eduard Zingerman

A bunch of tests are gated behind clang only __clang_major__ and thus
fail to build under BPF_GCC. What's worse is, before the prev patch they
were also declared as passing/OK.

This need not be because (a) bpf-gcc does support the feature in codegen
and (b) also advertises correctly with feature support preprocessor macros:

  __BPF_FEATURE_BSWAP, __BPF_FEATURE_GOTOL, __BPF_FEATURE_LDSX,
  __BPF_FEATURE_MOVSX, __BPF_FEATURE_SDIV_SMOD, __BPF_FEATURE_ST

So loosen up the gates to also add specific feature check.
clang >=18 has to stay, despite it being true for so long: clang only
defines __BPF_FEATURE_MOVSX and friends at -mcpu=v4, but assembles the
inline asm at -mcpu=v3 too, and dropping it would remove these tests from
the default test_progs flavour where they run today.

Since bpf-gcc doesn't support addr_space_cast, wrap the corresponding
tests under __BPF_FEATURE_ADDR_SPACE_CAST to skip under it.
And also move the map under that guard so that a bpf-gcc object does not
declare an arena map that no program in it references.

Recovered under BPF_GCC (programs per object, was 1 dummy each):

  verifier_sdiv    80
  verifier_movsx   17
  verifier_ldsx    14   (20 under clang; 5 arena tests,
                       kfunc_root and the arena map stay clang-only)
  verifier_bswap   13

CAN_USE_GOTOL and CAN_USE_BPF_ST only gate parts of a file, so those were
not dummies to begin with:

  compute_live_registers        17 -> 19  (21 under clang)
  verifier_gotol                 1 -> 2
  verifier_iterating_callbacks  34 -> 35

The clang builds are unchanged: verifier_ldsx still emits 20 programs under
the cpuv4 flavour.

One thing left alone: verifier_load_acquire.c and verifier_store_release.c
stay clang-only, and their gates are correct as gas doesn't implement
those (experimental -mxbpf not implemented at all). FWIW LLVM groups
those under -mcpu=v4 and defines __BPF_FEATURE_LOAD_ACQ_STORE_REL there.

Signed-off-by: Vineet Gupta <vineet.gupta@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
---
 tools/testing/selftests/bpf/progs/bpf_misc.h   |  4 ++--
 .../bpf/progs/compute_live_registers.c         |  8 ++++++++
 .../selftests/bpf/progs/verifier_bswap.c       |  2 +-
 .../selftests/bpf/progs/verifier_ldsx.c        | 18 +++++++++++-------
 .../selftests/bpf/progs/verifier_movsx.c       |  2 +-
 .../selftests/bpf/progs/verifier_sdiv.c        |  2 +-
 6 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h
index 88b0bfba83bb..eb88d9ce6c34 100644
--- a/tools/testing/selftests/bpf/progs/bpf_misc.h
+++ b/tools/testing/selftests/bpf/progs/bpf_misc.h
@@ -261,11 +261,11 @@
      (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) ||		\
      defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) ||	\
      defined(__TARGET_ARCH_loongarch)) &&				\
-	__clang_major__ >= 18
+	(__clang_major__ >= 18 || defined(__BPF_FEATURE_GOTOL))
 #define CAN_USE_GOTOL
 #endif
 
-#if __clang_major__ >= 18
+#if __clang_major__ >= 18 || defined(__BPF_FEATURE_ST)
 #define CAN_USE_BPF_ST
 #endif
 
diff --git a/tools/testing/selftests/bpf/progs/compute_live_registers.c b/tools/testing/selftests/bpf/progs/compute_live_registers.c
index 338e67cd8856..941b65fe7c07 100644
--- a/tools/testing/selftests/bpf/progs/compute_live_registers.c
+++ b/tools/testing/selftests/bpf/progs/compute_live_registers.c
@@ -299,7 +299,15 @@ __naked void gotol(void)
 		"r3 = 24;"
 		"if r1 > 0x7 goto +2;"
 		"r0 = r2;"
+#ifdef __clang__
 		"gotol +1;"
+#else
+		/*
+		 * gas mis-parses 'gotol +1' as 'goto l+1', same encoding
+		 * without the sign (binutils PR gas/34558).
+		 */
+		"gotol 1;"
+#endif
 		"r0 = r3;"
 		"exit;"
 		:
diff --git a/tools/testing/selftests/bpf/progs/verifier_bswap.c b/tools/testing/selftests/bpf/progs/verifier_bswap.c
index 074faef5480e..48ffb5b242d2 100644
--- a/tools/testing/selftests/bpf/progs/verifier_bswap.c
+++ b/tools/testing/selftests/bpf/progs/verifier_bswap.c
@@ -8,7 +8,7 @@
 	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
 	defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) || \
 	defined(__TARGET_ARCH_loongarch)) && \
-	__clang_major__ >= 18
+	(__clang_major__ >= 18 || defined(__BPF_FEATURE_BSWAP))
 
 SEC("socket")
 __description("BSWAP, 16")
diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
index e58ea69e3854..75762e11b443 100644
--- a/tools/testing/selftests/bpf/progs/verifier_ldsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
@@ -9,13 +9,7 @@
 	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
 	defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) || \
 	defined(__TARGET_ARCH_loongarch)) && \
-	__clang_major__ >= 18
-
-struct {
-	__uint(type, BPF_MAP_TYPE_ARENA);
-	__uint(map_flags, BPF_F_MMAPABLE);
-	__uint(max_entries, 1);
-} arena SEC(".maps");
+	(__clang_major__ >= 18 || defined(__BPF_FEATURE_LDSX))
 
 SEC("socket")
 __description("LDSX, S8")
@@ -263,6 +257,14 @@ __naked void ldsx_ctx_8(void)
 	: __clobber_all);
 }
 
+#ifdef __BPF_FEATURE_ADDR_SPACE_CAST
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARENA);
+	__uint(map_flags, BPF_F_MMAPABLE);
+	__uint(max_entries, 1);
+} arena SEC(".maps");
+
 SEC("syscall")
 __description("Arena LDSX Disasm")
 __success
@@ -432,6 +434,8 @@ void kfunc_root(void)
 	bpf_arena_alloc_pages(0, 0, 0, 0, 0);
 }
 
+#endif /* __BPF_FEATURE_ADDR_SPACE_CAST */
+
 #else
 
 SEC("socket")
diff --git a/tools/testing/selftests/bpf/progs/verifier_movsx.c b/tools/testing/selftests/bpf/progs/verifier_movsx.c
index 5559c0583dd1..195b27a51224 100644
--- a/tools/testing/selftests/bpf/progs/verifier_movsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_movsx.c
@@ -8,7 +8,7 @@
 	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
 	defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) || \
 	defined(__TARGET_ARCH_loongarch)) && \
-	__clang_major__ >= 18
+	(__clang_major__ >= 18 || defined(__BPF_FEATURE_MOVSX))
 
 SEC("socket")
 __description("MOV32SX, S8")
diff --git a/tools/testing/selftests/bpf/progs/verifier_sdiv.c b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
index 515644ace516..d6cbe1e27fd6 100644
--- a/tools/testing/selftests/bpf/progs/verifier_sdiv.c
+++ b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
@@ -9,7 +9,7 @@
 	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
 	defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) || \
 	defined(__TARGET_ARCH_loongarch)) && \
-	__clang_major__ >= 18
+	(__clang_major__ >= 18 || defined(__BPF_FEATURE_SDIV_SMOD))
 
 SEC("socket")
 __description("SDIV32, non-zero imm divisor, check 1")
-- 
2.53.0-Meta


^ permalink raw reply related	[flat|nested] 8+ messages in thread
* Re: [PATCH bpf-next v2 3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc
  2026-08-24 21:01 ` [PATCH bpf-next v2 3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc Vineet Gupta
@ 2026-08-24 21:14   ` sashiko-bot
  2026-08-24 21:30     ` Vineet Gupta
  0 siblings, 1 reply; 8+ messages in thread
From: sashiko-bot @ 2026-08-24 21:14 UTC (permalink / raw)
  To: Vineet Gupta; +Cc: bpf

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The newly added `#ifdef __BPF_FEATURE_ADDR_SPACE_CAST` guard unintentionally drops 5 arena tests from the default test_progs flavour for clang.
--

--- Patch [3]: [PATCH bpf-next v2 3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc ---
commit ad6608dfd47ddd6a7068cdc6e0e6d467ec3558b8
Author: Vineet Gupta <vineet.gupta@linux.dev>

selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc

This commit relaxes clang-only checks in BPF selftests by adding specific
feature checks like __BPF_FEATURE_LDSX to allow building under bpf-gcc.
It also wraps arena tests with __BPF_FEATURE_ADDR_SPACE_CAST to skip them
on bpf-gcc.

> diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
> index e58ea69e38549..75762e11b443f 100644
> --- a/tools/testing/selftests/bpf/progs/verifier_ldsx.c
> +++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
[ ... ]
> @@ -263,6 +257,14 @@ __naked void ldsx_ctx_8(void)
>  	: __clobber_all);
>  }
>  
> +#ifdef __BPF_FEATURE_ADDR_SPACE_CAST
> +
> +struct {
> +	__uint(type, BPF_MAP_TYPE_ARENA);
> +	__uint(map_flags, BPF_F_MMAPABLE);
> +	__uint(max_entries, 1);
> +} arena SEC(".maps");
> +

[Severity: Medium]
Does this inner guard unintentionally drop the arena tests for clang under
the default test_progs flavour?

The commit message notes that clang only defines feature macros like this at
-mcpu=v4, but successfully assembles the inline asm at -mcpu=v3. Because of
this, you kept the clang version checks on the file's main guard to avoid
removing tests where they run today.

However, since this inner guard lacks a || __clang_major__ >= 18 fallback,
clang at -mcpu=v3 evaluates this as false, silently dropping the arena map
and the subsequent 5 arena tests from the default test flavour.

>  SEC("syscall")
>  __description("Arena LDSX Disasm")
>  __success
[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260824210142.3933580-1-vineet.gupta@linux.dev?part=3

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH bpf-next v2 3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc
  2026-08-24 21:14   ` sashiko-bot
@ 2026-08-24 21:30     ` Vineet Gupta
  0 siblings, 0 replies; 8+ messages in thread
From: Vineet Gupta @ 2026-08-24 21:30 UTC (permalink / raw)
  To: sashiko-reviews; +Cc: bpf



On 8/24/26 2:14 PM, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] The newly added `#ifdef __BPF_FEATURE_ADDR_SPACE_CAST` guard unintentionally drops 5 arena tests from the default test_progs flavour for clang.
> --
>
> --- Patch [3]: [PATCH bpf-next v2 3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc ---
> commit ad6608dfd47ddd6a7068cdc6e0e6d467ec3558b8
> Author: Vineet Gupta <vineet.gupta@linux.dev>
>
> selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc
>
> This commit relaxes clang-only checks in BPF selftests by adding specific
> feature checks like __BPF_FEATURE_LDSX to allow building under bpf-gcc.
> It also wraps arena tests with __BPF_FEATURE_ADDR_SPACE_CAST to skip them
> on bpf-gcc.
>
>> diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
>> index e58ea69e38549..75762e11b443f 100644
>> --- a/tools/testing/selftests/bpf/progs/verifier_ldsx.c
>> +++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
> [ ... ]
>> @@ -263,6 +257,14 @@ __naked void ldsx_ctx_8(void)
>>   	: __clobber_all);
>>   }
>>   
>> +#ifdef __BPF_FEATURE_ADDR_SPACE_CAST
>> +
>> +struct {
>> +	__uint(type, BPF_MAP_TYPE_ARENA);
>> +	__uint(map_flags, BPF_F_MMAPABLE);
>> +	__uint(max_entries, 1);
>> +} arena SEC(".maps");
>> +
> [Severity: Medium]
> Does this inner guard unintentionally drop the arena tests for clang under
> the default test_progs flavour?
>
> The commit message notes that clang only defines feature macros like this at
> -mcpu=v4, but successfully assembles the inline asm at -mcpu=v3. Because of
> this, you kept the clang version checks on the file's main guard to avoid
> removing tests where they run today.
>
> However, since this inner guard lacks a || __clang_major__ >= 18 fallback,
> clang at -mcpu=v3 evaluates this as false,

Is this just by review or was it actually tested - I'm guessing former ...

> silently dropping the arena map
> and the subsequent 5 arena tests from the default test flavour.

... since clang (at least recent ones, I testet recent and a local jan 
build) defines this for all -mcpus

So this is invalid claim.

Thx,
-Vineet

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH bpf-next v2 2/3] selftests/bpf: report placeholder tests as SKIP, not OK
  2026-08-24 21:01 ` [PATCH bpf-next v2 2/3] selftests/bpf: report placeholder tests as SKIP, not OK Vineet Gupta
@ 2026-08-24 21:42   ` bot+bpf-ci
  0 siblings, 0 replies; 8+ messages in thread
From: bot+bpf-ci @ 2026-08-24 21:42 UTC (permalink / raw)
  To: vineet.gupta, bpf
  Cc: vineet.gupta, eddyz87, ast, andrii, daniel, martin.lau, eddyz87,
	yonghong.song, clm, ihor.solodrai

[-- Attachment #1: Type: text/plain, Size: 2766 bytes --]

> diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
> index 41340877dc9d..e58ea69e3854 100644
> --- a/tools/testing/selftests/bpf/progs/verifier_ldsx.c
> +++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
> @@ -436,6 +436,7 @@ void kfunc_root(void)
>
>  SEC("socket")
>  __description("cpuv4 is not supported by compiler or jit, use a dummy test")
> +__skip("cpuv4 is not supported by compiler or jit")
>  __success
>  int dummy_test(void)
>  {

This isn't a bug, but since the SKIP line is already labelled with the
__description text, would it read better for __skip(reason) to supply a
distinct message rather than repeating the same wording? Looking at all
15 converted placeholders (arena_kfunc.c, stack_arg_fail.c,
stack_arg_precision.c, verifier_aggregate_ret.c, verifier_bswap.c,
verifier_gotol.c, verifier_ldsx.c, verifier_load_acquire.c,
verifier_movsx.c, verifier_percpu_addr.c, verifier_private_stack.c,
verifier_sdiv.c, verifier_stack_arg.c, verifier_stack_arg_order.c,
verifier_store_release.c), each has __skip() repeating the adjacent
__description() nearly verbatim, differing only by a trailing clause like
", use a dummy test" or ", dummy test". This means each file now stores
the reason twice and the two strings can drift apart independently.

> diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c
> index 07807757b518..794a7dfb0579 100644
> --- a/tools/testing/selftests/bpf/test_loader.c
> +++ b/tools/testing/selftests/bpf/test_loader.c
> @@ -1327,6 +1330,12 @@ void run_subtest(struct test_loader *tester,
>  	if (!test__start_subtest_with_desc(subspec->name, subspec->description))
>  		return;
>
> +	if (spec->skip_reason) {
> +		printf("%s:SKIP: %s\n", __func__, spec->skip_reason);
> +		test__skip();
> +		return;
> +	}
> +
>  	if ((get_current_arch() & spec->arch_mask) == 0) {
>  		test__skip();
>  		return;

This isn't a bug, but is the extra reason line reachable in a normal
(non -v) run? Since test__start_subtest_with_desc() has already called
stdio_hijack_init(), this printf() goes into subtest_state->log_buf.
Looking at dump_test_log() in test_progs.c, the log_buf is only emitted
when verbose() || force_log || subtest_failed is true, which would be
false for a skipped subtest in a default run. Meanwhile the SKIP verdict
itself is printed by print_subtest_name() using the __description text,
so in the default output only the subtest name appears next to :SKIP.


---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md

CI run summary: https://github.com/kernel-patches/bpf/actions/runs/32778075708

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage
  2026-08-24 21:01 [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage Vineet Gupta
                   ` (2 preceding siblings ...)
  2026-08-24 21:01 ` [PATCH bpf-next v2 3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc Vineet Gupta
@ 2026-08-26 16:40 ` patchwork-bot+netdevbpf
  3 siblings, 0 replies; 8+ messages in thread
From: patchwork-bot+netdevbpf @ 2026-08-26 16:40 UTC (permalink / raw)
  To: Vineet Gupta; +Cc: bpf

Hello:

This series was applied to bpf/bpf-next.git (master)
by Daniel Borkmann <daniel@iogearbox.net>:

On Mon, 24 Aug 2026 14:01:39 -0700 you wrote:
> When doing some unrelated testing, stumbled upon this. A lot of tests
> are skipped under BPF_GCC due to clang only gate. On top, the test
> harness declares them passing/OK.
> 
> Patch 1 renames a few placeholders a consistent dummy_test name [NFC].
> 
> A sample test with BPF_GCC used to say:
> 
> [...]

Here is the summary with links:
  - [bpf-next,v2,1/3] selftests/bpf: name the remaining placeholder programs dummy_test [NFC]
    https://git.kernel.org/bpf/bpf-next/c/b0eeb9e0f548
  - [bpf-next,v2,2/3] selftests/bpf: report placeholder tests as SKIP, not OK
    https://git.kernel.org/bpf/bpf-next/c/8928f5ffdb65
  - [bpf-next,v2,3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc
    https://git.kernel.org/bpf/bpf-next/c/48b69cc8825d

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html



^ permalink raw reply	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2026-08-26 16:41 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-24 21:01 [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage Vineet Gupta
2026-08-24 21:01 ` [PATCH bpf-next v2 1/3] selftests/bpf: name the remaining placeholder programs dummy_test [NFC] Vineet Gupta
2026-08-24 21:01 ` [PATCH bpf-next v2 2/3] selftests/bpf: report placeholder tests as SKIP, not OK Vineet Gupta
2026-08-24 21:42   ` bot+bpf-ci
2026-08-24 21:01 ` [PATCH bpf-next v2 3/3] selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc Vineet Gupta
2026-08-24 21:14   ` sashiko-bot
2026-08-24 21:30     ` Vineet Gupta
2026-08-26 16:40 ` [PATCH bpf-next v2 0/3] selftests/bpf: unblock bpf-gcc test coverage patchwork-bot+netdevbpf

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