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(unknown [202.112.238.121]) by web2 (Coremail) with SMTP id yQQGZQDX1bcGUF5q2kYhAA--.51004S2; Tue, 21 Jul 2026 00:42:49 +0800 (CST) From: Yiyang Chen To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi Cc: Yiyang Chen , John Fastabend , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Shuah Khan , Emil Tsalapatis , bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next 0/2] bpf: Preserve stack frame number for commuted stack arithmetic Date: Mon, 20 Jul 2026 16:37:43 +0000 Message-Id: X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:yQQGZQDX1bcGUF5q2kYhAA--.51004S2 X-Coremail-Antispam: 1UD129KBjvdXoW7GFW3Kr1kWFWrZFyxZw4fXwb_yoWDKwc_ua 9ava90ywsrAFs2gFy7CF1fZrW3Ca1fXryxAa1DtF13trn8Xrn8WF1kur15G3yIqF4jqrZx ZF9Yq34F9r1agjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb6AFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_JFI_Gr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr0_ Cr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gr0_Gr 1UM2vYz4IE04k24VAvwVAKI4IrM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8Jw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAG YxC7M4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14v26r1q6r43MxkIecxEwVAFwV WUMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_ Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXwCIc40Y0x 0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8 JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIx AIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUUsXo7UUUUU= = X-CM-SenderInfo: xfkh05r1stqzpdlo2hxwvl0wxkxdhvlgxou0/ The verifier uses reg->frameno to distinguish stack pointers that have the same offset but refer to different call frames. The scalar += pointer path copies pointer type and id to the destination register, but it also needs to preserve frameno when the source pointer is PTR_TO_STACK. Preserve the frame number for commuted stack pointer arithmetic and add a verifier regression test where a callee derives its frame pointer through scalar += fp before overwriting and reloading the same stack slot. Yiyang Chen (2): bpf: Preserve stack frame number for commuted arithmetic selftests/bpf: Cover stack frame number after scalar plus fp kernel/bpf/verifier.c | 7 +++- .../selftests/bpf/prog_tests/verifier.c | 2 - .../bpf/prog_tests/verifier_basic_stack.c | 28 +++++++++++++ .../bpf/progs/verifier_basic_stack.c | 41 +++++++++++++++++++ 4 files changed, 74 insertions(+), 4 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/verifier_basic_stack.c base-commit: cfce77b63375dac81d53f2f85593c548415206b7 -- 2.34.1