On 8/18/26 12:56 PM, Eduard Zingerman wrote:
On Tue, 2026-08-18 at 12:35 -0700, Vineet Gupta wrote:
On 8/16/26 4:36 PM, Eduard Zingerman wrote:
On Sun, 2026-08-16 at 16:17 -0700, Eduard Zingerman wrote:
On Sun, 2026-08-16 at 10:56 +0000, Yiyang Chen wrote:
Add a verifier test with one atomic RMW instruction reached through
PTR_TO_ARENA and PTR_TO_STACK paths. The verifier must reject the
shared instruction with the existing incompatible-pointer diagnostic.
Signed-off-by: Yiyang Chen <[email protected]>
---
tools/testing/selftests/bpf/progs/verifier_arena.c | 39
++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/verifier_arena.c
b/tools/testing/selftests/bpf/progs/verifier_arena.c
index b241bbcf54a8a..b22bab33301ab 100644
--- a/tools/testing/selftests/bpf/progs/verifier_arena.c
+++ b/tools/testing/selftests/bpf/progs/verifier_arena.c
@@ -637,6 +637,45 @@ int non_arena_ptr_add_to_arena_ptr(void *ctx)
#endif
+static const struct bpf_insn addr_space_cast_insn = {
+ .code = 0xbf,
+ .dst_reg = BPF_REG_7,
+ .src_reg = BPF_REG_7,
+ .off = 1,
+ .imm = 1,
+};
+
+SEC("socket")
+__description("arena and stack atomic at the same instruction")
+__failure __msg("same insn cannot be used with different pointers")
+__arch_x86_64
+__load_if_JITed()
+__naked void mixed_arena_stack_atomic(void)
+{
+ asm volatile (" \
+ r1 = %[arena] ll; \
+ r6 = r10; \
+ r6 += -8; \
+ r9 = 0; \
+ *(u64 *)(r6 + 0) = r9; \
+ r7 = 8192; \
+ .8byte %[addr_space_cast]; \
I'm going to fix this to:
r7 = addr_space_cast(r7, 0, 1); \
as in the test case above.
Waiting for CI [1].
[1] https://github.com/kernel-patches/bpf/pull/13325
A...and it requires another exception for GCC-BPF:
https://github.com/kernel-patches/bpf/blob/bpf-next_base/ci/vmtest/configs/DENYLIST.test_progs-bpf_gcc
Ihor, it's a third time GCC-BPF strikes this weekend.
What do people think about downgrading it to may-fail until the
DENYLIST decreases to something reasonable?
While bpf-gcc is improving, slowly, we can in parallel do alittle better
on test hygiene as well. In this case by correctly bracketing the tests
with _BPF_FEATURE_XXX.
Yes, that's what I ended up doing. Should have paid attention to the
#if .. #endif bracket used by the textually preceding test.
Sorry for lashing out.
No worries and I can sympathize with frustrations when someone's s*it is
not together and others have to suffer
-Vineet
