From: Yonghong Song <yonghong.song@linux.dev>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Eduard Zingerman <eddyz87@gmail.com>,
kernel-team@fb.com
Subject: [PATCH bpf-next 04/12] bpf: Support __int128 as a by-value function argument
Date: Thu, 3 Sep 2026 22:10:18 -0700 [thread overview]
Message-ID: <20260904051018.3978585-1-yonghong.song@linux.dev> (raw)
In-Reply-To: <20260904050957.3976119-1-yonghong.song@linux.dev>
A 128-bit integer follows the same calling convention as a 16-byte
by-value struct: LLVM emits it as a 16-byte BTF_KIND_INT and passes it in
two consecutive argument registers. So a __int128 gets its two slots.
The test added at the start of the series, which recorded the wrong
register map as an R4 !read_ok rejection, now passes and is flipped to
__success.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
---
kernel/bpf/btf.c | 9 +++------
tools/testing/selftests/bpf/progs/verifier_int128_arg.c | 7 +------
2 files changed, 4 insertions(+), 12 deletions(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index dbd64cee1b27..6c391449e298 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -8235,11 +8235,7 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
bpf_log(log, "arg#%d has pointer tag, but is not a pointer type\n", i);
return -EINVAL;
}
- if (btf_type_is_int(t) || btf_is_any_enum(t)) {
- sub->args[slots_used++].arg_type = ARG_ANYTHING;
- continue;
- }
- if (btf_type_is_struct(t)) {
+ if (btf_type_is_int(t) || btf_is_any_enum(t) || btf_type_is_struct(t)) {
u32 nslots;
if (!t->size || t->size > 2 * BPF_REG_SIZE) {
@@ -8251,7 +8247,8 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
i, btf_type_str(t), tname, t->size, 2 * BPF_REG_SIZE);
return -EINVAL;
}
- if (!btf_struct_is_composed_of(env, btf, t, BTF_MEMBER_SCALAR)) {
+ if (btf_type_is_struct(t) &&
+ !btf_struct_is_composed_of(env, btf, t, BTF_MEMBER_SCALAR)) {
if (!is_global)
return -EINVAL;
bpf_log(log, "Arg#%d type %s in %s() is not composed of scalars\n",
diff --git a/tools/testing/selftests/bpf/progs/verifier_int128_arg.c b/tools/testing/selftests/bpf/progs/verifier_int128_arg.c
index 419851f2d8d0..044fc4a80055 100644
--- a/tools/testing/selftests/bpf/progs/verifier_int128_arg.c
+++ b/tools/testing/selftests/bpf/progs/verifier_int128_arg.c
@@ -15,12 +15,7 @@ __noinline __u64 take_i128_global(int a, u128 v, int c)
}
SEC("tc")
-/*
- * The verifier counts one argument register for the __int128 and marks only
- * R1 through R3 at the entry of take_i128_global(), while the compiler passed
- * a in R1, v in R2:R3 and c in R4.
- */
-__failure __msg("R4 !read_ok")
+__success __retval(0)
int aggregate_arg_int128_c_test(struct __sk_buff *skb)
{
__u64 a = skb->len ^ MIX_A;
--
2.53.0-Meta
next prev parent reply other threads:[~2026-09-04 5:10 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-04 5:09 [PATCH bpf-next 00/12] bpf: Support by-value struct and __int128 arguments Yonghong Song
2026-09-04 5:10 ` [PATCH bpf-next 01/12] selftests/bpf: Add a test for an __int128 by-value argument Yonghong Song
2026-09-04 5:10 ` [PATCH bpf-next 02/12] bpf: Index global function arguments by argument slot Yonghong Song
2026-09-04 5:10 ` [PATCH bpf-next 03/12] bpf: Support by-value struct arguments up to 16 bytes Yonghong Song
2026-09-04 5:23 ` sashiko-bot
2026-09-04 6:09 ` bot+bpf-ci
2026-09-04 5:10 ` Yonghong Song [this message]
2026-09-04 5:32 ` [PATCH bpf-next 04/12] bpf: Support __int128 as a by-value function argument sashiko-bot
2026-09-04 6:09 ` bot+bpf-ci
2026-09-04 5:10 ` [PATCH bpf-next 05/12] bpf: Support by-value struct and __int128 kfunc arguments Yonghong Song
2026-09-04 6:18 ` sashiko-bot
2026-09-04 6:24 ` bot+bpf-ci
2026-09-04 5:10 ` [PATCH bpf-next 06/12] bpf: Add a JIT helper for the outgoing stack of kfunc calls Yonghong Song
2026-09-04 5:25 ` sashiko-bot
2026-09-04 5:10 ` [PATCH bpf-next 07/12] bpf, x86: Place kfunc arguments per the SysV calling convention Yonghong Song
2026-09-04 5:36 ` sashiko-bot
2026-09-04 23:58 ` Alexei Starovoitov
2026-09-04 5:10 ` [PATCH bpf-next 08/12] bpf: Record a 16-byte argument alignment in the function model Yonghong Song
2026-09-04 6:09 ` bot+bpf-ci
2026-09-04 5:10 ` [PATCH bpf-next 09/12] bpf, arm64: Place kfunc arguments per AAPCS64 Yonghong Song
2026-09-04 6:09 ` bot+bpf-ci
2026-09-04 5:10 ` [PATCH bpf-next 10/12] selftests/bpf: Add C tests for by-value arguments up to 16 bytes Yonghong Song
2026-09-04 5:19 ` sashiko-bot
2026-09-04 6:09 ` bot+bpf-ci
2026-09-04 5:10 ` [PATCH bpf-next 11/12] selftests/bpf: Add inline-asm tests for by-value arguments Yonghong Song
2026-09-04 6:09 ` bot+bpf-ci
2026-09-04 5:11 ` [PATCH bpf-next 12/12] selftests/bpf: Add tests for by-value kfunc arguments Yonghong Song
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