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 08/25] bpf: Refactor record_call_access() to extract per-arg logic
Date: Tue, 12 May 2026 21:50:30 -0700 [thread overview]
Message-ID: <20260513045030.2388067-1-yonghong.song@linux.dev> (raw)
In-Reply-To: <20260513044949.2382019-1-yonghong.song@linux.dev>
Extract the per-argument FP-derived pointer handling from
record_call_access() into a new record_arg_access() helper.
The existing loop body — checking arg_is_fp, querying stack access
bytes, and calling record_stack_access/record_imprecise — will be
reused for stack argument slots in the next patch. Factoring it out
now avoids duplicating the logic.
No functional change.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
---
kernel/bpf/liveness.c | 65 +++++++++++++++++++++++++------------------
1 file changed, 38 insertions(+), 27 deletions(-)
diff --git a/kernel/bpf/liveness.c b/kernel/bpf/liveness.c
index 58197d73b120..c81337dfbfc7 100644
--- a/kernel/bpf/liveness.c
+++ b/kernel/bpf/liveness.c
@@ -1343,6 +1343,42 @@ static int record_load_store_access(struct bpf_verifier_env *env,
return 0;
}
+static int record_arg_access(struct bpf_verifier_env *env,
+ struct func_instance *instance,
+ struct bpf_insn *insn,
+ struct arg_track *at, int arg_idx,
+ int insn_idx)
+{
+ int depth = instance->depth;
+ int frame = at->frame;
+ int err = 0;
+ s64 bytes;
+
+ if (!arg_is_fp(at))
+ return 0;
+
+ if (bpf_helper_call(insn)) {
+ bytes = bpf_helper_stack_access_bytes(env, insn, arg_idx, insn_idx);
+ } else if (bpf_pseudo_kfunc_call(insn)) {
+ bytes = bpf_kfunc_stack_access_bytes(env, insn, arg_idx, insn_idx);
+ } else {
+ for (int f = 0; f <= depth; f++) {
+ err = mark_stack_read(instance, f, insn_idx, SPIS_ALL);
+ if (err)
+ return err;
+ }
+ return 0;
+ }
+ if (bytes == 0)
+ return 0;
+
+ if (frame >= 0 && frame <= depth)
+ err = record_stack_access(instance, at, bytes, frame, insn_idx);
+ else if (frame == ARG_IMPRECISE)
+ err = record_imprecise(instance, at->mask, insn_idx);
+ return err;
+}
+
/* Record stack access for a given 'at' state of helper/kfunc 'insn' */
static int record_call_access(struct bpf_verifier_env *env,
struct func_instance *instance,
@@ -1350,9 +1386,8 @@ static int record_call_access(struct bpf_verifier_env *env,
int insn_idx)
{
struct bpf_insn *insn = &env->prog->insnsi[insn_idx];
- int depth = instance->depth;
struct bpf_call_summary cs;
- int r, err = 0, num_params = 5;
+ int r, err, num_params = 5;
if (bpf_pseudo_call(insn))
return 0;
@@ -1361,31 +1396,7 @@ static int record_call_access(struct bpf_verifier_env *env,
num_params = cs.num_params;
for (r = BPF_REG_1; r < BPF_REG_1 + num_params; r++) {
- int frame = at[r].frame;
- s64 bytes;
-
- if (!arg_is_fp(&at[r]))
- continue;
-
- if (bpf_helper_call(insn)) {
- bytes = bpf_helper_stack_access_bytes(env, insn, r - 1, insn_idx);
- } else if (bpf_pseudo_kfunc_call(insn)) {
- bytes = bpf_kfunc_stack_access_bytes(env, insn, r - 1, insn_idx);
- } else {
- for (int f = 0; f <= depth; f++) {
- err = mark_stack_read(instance, f, insn_idx, SPIS_ALL);
- if (err)
- return err;
- }
- return 0;
- }
- if (bytes == 0)
- continue;
-
- if (frame >= 0 && frame <= depth)
- err = record_stack_access(instance, &at[r], bytes, frame, insn_idx);
- else if (frame == ARG_IMPRECISE)
- err = record_imprecise(instance, at[r].mask, insn_idx);
+ err = record_arg_access(env, instance, insn, &at[r], r - 1, insn_idx);
if (err)
return err;
}
--
2.53.0-Meta
next prev parent reply other threads:[~2026-05-13 4:50 UTC|newest]
Thread overview: 32+ 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 ` Yonghong Song [this message]
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 ` [PATCH bpf-next v4 13/25] bpf: Enable r11 based insns Yonghong Song
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
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