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>,
"Jose E . Marchesi" <jose.marchesi@oracle.com>,
kernel-team@fb.com, Martin KaFai Lau <martin.lau@kernel.org>
Subject: [PATCH bpf-next v4 13/25] bpf: Enable r11 based insns
Date: Tue, 12 May 2026 21:50:59 -0700 [thread overview]
Message-ID: <20260513045059.2391192-1-yonghong.song@linux.dev> (raw)
In-Reply-To: <20260513044949.2382019-1-yonghong.song@linux.dev>
BPF_REG_PARAMS (r11) is used for stack argument accesses and
the following are only insns with r11 presence:
- load incoming stack arg
- store register to outgoing stack arg
- store immediate to outgoing stack arg
The detailed insn format can be found in is_stack_arg_ldx/st/stx()
helpers. After this patch, stack arg ldx/st/stx insns become valid
for kernel and these insns can be properly checked by verifier.
The LLVM compiler [1] implemented the above BPF_REG_PARAMS insns.
[1] https://github.com/llvm/llvm-project/pull/189060
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
---
kernel/bpf/verifier.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 30143bea6a86..18bbc5b6c2d2 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -18006,11 +18006,12 @@ static int check_and_resolve_insns(struct bpf_verifier_env *env)
return err;
for (i = 0; i < insn_cnt; i++, insn++) {
- if (insn->dst_reg >= MAX_BPF_REG) {
+ if (insn->dst_reg >= MAX_BPF_REG &&
+ !is_stack_arg_st(insn) && !is_stack_arg_stx(insn)) {
verbose(env, "R%d is invalid\n", insn->dst_reg);
return -EINVAL;
}
- if (insn->src_reg >= MAX_BPF_REG) {
+ if (insn->src_reg >= MAX_BPF_REG && !is_stack_arg_ldx(insn)) {
verbose(env, "R%d is invalid\n", insn->src_reg);
return -EINVAL;
}
--
2.53.0-Meta
next prev parent reply other threads:[~2026-05-13 4:51 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-13 4:49 [PATCH bpf-next v4 00/25] bpf: Support stack arguments for BPF functions and kfuncs Yonghong Song
2026-05-13 4:49 ` [PATCH bpf-next v4 01/25] bpf: Convert bpf_get_spilled_reg macro to static inline function Yonghong Song
2026-05-13 4:50 ` [PATCH bpf-next v4 02/25] bpf: Remove copy_register_state wrapper function Yonghong Song
2026-05-13 4:50 ` [PATCH bpf-next v4 03/25] bpf: Add helper functions for r11-based stack argument insns Yonghong Song
2026-05-13 4:50 ` [PATCH bpf-next v4 04/25] bpf: Set sub->arg_cnt earlier in btf_prepare_func_args() Yonghong Song
2026-05-13 4:50 ` [PATCH bpf-next v4 05/25] bpf: Support stack arguments for bpf functions Yonghong Song
2026-05-13 4:50 ` [PATCH bpf-next v4 06/25] bpf: Refactor jmp history to use dedicated spi/frame fields Yonghong Song
2026-05-13 4:50 ` [PATCH bpf-next v4 07/25] bpf: Add precision marking and backtracking for stack argument slots Yonghong Song
2026-05-13 5:44 ` bot+bpf-ci
2026-05-13 4:50 ` [PATCH bpf-next v4 08/25] bpf: Refactor record_call_access() to extract per-arg logic Yonghong Song
2026-05-13 4:50 ` [PATCH bpf-next v4 09/25] bpf: Use arg_is_fp() in has_fp_args() Yonghong Song
2026-05-13 4:50 ` [PATCH bpf-next v4 10/25] bpf: Extend liveness analysis to track stack argument slots Yonghong Song
2026-05-13 5:44 ` bot+bpf-ci
2026-05-13 4:50 ` [PATCH bpf-next v4 11/25] bpf: Reject stack arguments in non-JITed programs Yonghong Song
2026-05-13 5:33 ` bot+bpf-ci
2026-05-13 4:50 ` [PATCH bpf-next v4 12/25] bpf: Prepare architecture JIT support for stack arguments Yonghong Song
2026-05-13 5:33 ` bot+bpf-ci
2026-05-13 4:50 ` Yonghong Song [this message]
2026-05-13 4:51 ` [PATCH bpf-next v4 14/25] bpf: Support stack arguments for kfunc calls Yonghong Song
2026-05-13 4:51 ` [PATCH bpf-next v4 15/25] bpf: Reject stack arguments if tail call reachable Yonghong Song
2026-05-13 5:33 ` bot+bpf-ci
2026-05-13 4:51 ` [PATCH bpf-next v4 16/25] bpf: Disable private stack for x86_64 if stack arguments used Yonghong Song
2026-05-13 5:33 ` bot+bpf-ci
2026-05-13 4:51 ` [PATCH bpf-next v4 17/25] bpf,x86: Implement JIT support for stack arguments Yonghong Song
2026-05-13 4:51 ` [PATCH bpf-next v4 18/25] selftests/bpf: Add tests for BPF function " Yonghong Song
2026-05-13 4:51 ` [PATCH bpf-next v4 19/25] selftests/bpf: Add tests for stack argument validation Yonghong Song
2026-05-13 4:51 ` [PATCH bpf-next v4 20/25] selftests/bpf: Add BTF fixup for __naked subprog parameter names Yonghong Song
2026-05-13 4:51 ` [PATCH bpf-next v4 21/25] selftests/bpf: Add verifier tests for stack argument validation Yonghong Song
2026-05-13 4:51 ` [PATCH bpf-next v4 22/25] selftests/bpf: Add precision backtracking test for stack arguments Yonghong Song
2026-05-13 4:51 ` [PATCH bpf-next v4 23/25] bpf, arm64: Map BPF_REG_0 to x8 instead of x7 Yonghong Song
2026-05-13 4:51 ` [PATCH bpf-next v4 24/25] bpf, arm64: Add JIT support for stack arguments Yonghong Song
2026-05-13 4:52 ` [PATCH bpf-next v4 25/25] selftests/bpf: Enable stack argument tests for arm64 Yonghong Song
2026-05-13 16:33 ` [PATCH bpf-next v4 00/25] bpf: Support stack arguments for BPF functions and kfuncs Alexei Starovoitov
2026-05-13 17:41 ` Yonghong Song
2026-05-13 17:51 ` Alexei Starovoitov
2026-05-13 18:11 ` Yonghong Song
2026-05-13 16:40 ` patchwork-bot+netdevbpf
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