From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f180.google.com (mail-pf1-f180.google.com [209.85.210.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B55FC3A962E for ; Fri, 10 Apr 2026 20:56:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775854581; cv=none; b=pNJtjc6tl6epx9wXyeCVpqiwi9Qcls8aBdiy7UhLId0M7TZTX+d+uHFiCRHU71QKlXvAKFxmcb0KocvYWTnJLvAZZYy9H6DccDFafvudiC1DxZUMFhtdkuAb+RQYhqpCUKCsL/Cb9cTv9Lu1CxUbdPUzwZL5X4CPUlxfPCrdiZ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775854581; c=relaxed/simple; bh=aiseS6TluHkxOT3dOKjkluKww20EbTchPRtuxMszWrM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=o0MypGgcfGO/3c26yHRMkKmMFDgxhMNnf90EhVpc2O+iYt/Ic57sVay3gNAozRfX7aXlEtb3RwspKnpQKxz4aHgowIlcKMYsF13A2N8Jv1qCLS9skKNBExA60/0A+mu9L2LylALvUDWHNlgkRqXk5BQZR/MsObhMajvKungyILw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=o3E46sMK; arc=none smtp.client-ip=209.85.210.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="o3E46sMK" Received: by mail-pf1-f180.google.com with SMTP id d2e1a72fcca58-82c28f0a4ecso1742591b3a.3 for ; Fri, 10 Apr 2026 13:56:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775854579; x=1776459379; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=01lWhu9Os65kPPSj9s6xaaMOMSReVlNtGElPCZmQfUY=; b=o3E46sMKqsU1KWH93CHP7OdRuwKLah34AjiGZ+FVMgr/85uHgCFLY5WcpYCz2JumBi rsgnasXKcDVQgCBHh9MuDxgmHRj6GNyPu9xNmkrq/VPzy2wbB0cDNWLNi2z1KDSrQZDF ssOWiHXCfxA6CSaGNGWDKINz6S/k9wqSPenxzXwqxsC4p2W4cZw7KB8wn5qQcpBBjmu4 IZ4Ib2W+lQogPIxsHLCbUsLbB6r5fx88Qg80EHETGp8PHwtRPUblWQolt+jTtD7UkX6B rfMc8H2WSILWYbCRiyB+vKDkEFJ1tgYGKeriDJpDxT5uezwzDhN/+AZMFTVPQaHXb7RE U47w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775854579; x=1776459379; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=01lWhu9Os65kPPSj9s6xaaMOMSReVlNtGElPCZmQfUY=; b=Y5eoDSG8VTBCWxbiO8kcuF5Pp4EB8SvFSBpHCiS4Mlrnkaqzyah+iv5YHZM/f4dtvV MZWn9x4jtzWW2SXzQJlZd/un+Z9F6qnEA4IdURvlM1sXYqrttSvafNjnYXoDFDAmTAZ6 ZkXG1PA6BmWftdtrukgcE0ccq4TpXFbervKuq2JlUhlShEfcR6wVKxDoqQb8CCPT/LAA ONAU6vwbaedGGhm4HQsXMKe9qfovWC01UUwBzWl+ytm4aLgTjffx/Dkj/V0+hlJiBMQS Lk5BxH8x50TmN7BQ97V9AKxNtIOaJ13tFgMB+ACZ5eWq9kPJwvYGVi9bModrUbdf90fP WVCQ== X-Gm-Message-State: AOJu0YzLFkooaOiMse13u7ZoC/EK5kKBc8RWPb7VZDIZIpJeEK5c/laY 0Us7fEZJrLgmHF4Xfghd2mRJAEm3aey1b+VqFy52wQbVT37ZqeI5GEL9JpMjn+OP X-Gm-Gg: AeBDietz391psfqJDRdnF7vWuKW7vPfNng12fi8XZmFD0jMzaOAMJBTzdmlOnl/Znci xSfrJwFGtcWqiwMxbgQqmHvU6HX1rPrsHwVWxZ6RLUTJinLjkYhjHsH2iEFoNzuG3o15s0eaY7H WJZwik+eGJ6duRrZAuR3t0vnbRihN4kPEx6utTOoZnNC2xGHJmcEUGoCA956RRV270TJLKur1EE K7gqP/dFUqlgHWebbZrZoibhY07Boxv86sF0FFk4zD4q+mUb+HPwXPxCTcMATa6nSIIWkxoq3gO m80h8mahwQHnvhytOETNTtrA0lcW8KCpss2OmJBA2N/cUlFXk7sPVt3NX5RMVV2P0rG7+AjuvDK UjmYuNW9YjjF6Fc1UyhpXaPr+A++rASmyqWCIJY66wEQbIIVVdS4WieU7qViqA7X1KkDu7b4aTD uJJ+Eoj3PxhXLLx2TDQVe0ei7Ge0BffQywADihnIoTf40KR9sMKuBY9lC4FjHloLqf07A= X-Received: by 2002:a05:6a00:35ce:b0:82c:6683:b866 with SMTP id d2e1a72fcca58-82f0c1d9b9fmr4937681b3a.4.1775854578816; Fri, 10 Apr 2026 13:56:18 -0700 (PDT) Received: from ezingerman-fedora-PF4V722J ([38.34.87.7]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82f0c50a8f7sm3551648b3a.56.2026.04.10.13.56.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Apr 2026 13:56:18 -0700 (PDT) From: Eduard Zingerman To: bpf@vger.kernel.org, ast@kernel.org, andrii@kernel.org Cc: daniel@iogearbox.net, martin.lau@linux.dev, kernel-team@fb.com, yonghong.song@linux.dev, eddyz87@gmail.com Subject: [PATCH bpf-next v4 03/14] bpf: Add spis_*() helpers for 4-byte stack slot bitmasks Date: Fri, 10 Apr 2026 13:55:54 -0700 Message-ID: <20260410-patch-set-v4-3-5d4eecb343db@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260410-patch-set-v4-0-5d4eecb343db@gmail.com> References: <20260410-patch-set-v4-0-5d4eecb343db@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit From: Alexei Starovoitov Add helper functions for manipulating u64[2] bitmasks that represent 4-byte stack slot liveness. The 512-byte BPF stack is divided into 128 4-byte slots, requiring 128 bits (two u64s) to track. These will be used by the static stack liveness analysis in the next commit. Signed-off-by: Alexei Starovoitov Signed-off-by: Eduard Zingerman --- include/linux/bpf_verifier.h | 67 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index cec6054d6333..f34e7a074a20 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -224,6 +224,73 @@ enum bpf_stack_slot_type { #define BPF_REG_SIZE 8 /* size of eBPF register in bytes */ +/* 4-byte stack slot granularity for liveness analysis */ +#define BPF_HALF_REG_SIZE 4 +#define STACK_SLOTS (MAX_BPF_STACK / BPF_HALF_REG_SIZE) /* 128 */ + +typedef struct { + u64 v[2]; +} spis_t; + +#define SPIS_ZERO ((spis_t){}) +#define SPIS_ALL ((spis_t){{ U64_MAX, U64_MAX }}) + +static inline bool spis_is_zero(spis_t s) +{ + return s.v[0] == 0 && s.v[1] == 0; +} + +static inline bool spis_equal(spis_t a, spis_t b) +{ + return a.v[0] == b.v[0] && a.v[1] == b.v[1]; +} + +static inline spis_t spis_or(spis_t a, spis_t b) +{ + return (spis_t){{ a.v[0] | b.v[0], a.v[1] | b.v[1] }}; +} + +static inline spis_t spis_and(spis_t a, spis_t b) +{ + return (spis_t){{ a.v[0] & b.v[0], a.v[1] & b.v[1] }}; +} + +static inline spis_t spis_xor(spis_t a, spis_t b) +{ + return (spis_t){{ a.v[0] ^ b.v[0], a.v[1] ^ b.v[1] }}; +} + +static inline spis_t spis_not(spis_t s) +{ + return (spis_t){{ ~s.v[0], ~s.v[1] }}; +} + +static inline bool spis_test_bit(spis_t s, u32 slot) +{ + return s.v[slot / 64] & BIT_ULL(slot % 64); +} + +static inline void spis_or_range(spis_t *mask, u32 lo, u32 hi) +{ + u32 w; + + for (w = lo; w <= hi && w < STACK_SLOTS; w++) + mask->v[w / 64] |= BIT_ULL(w % 64); +} + +static inline spis_t spis_one_bit(u32 slot) +{ + if (slot < 64) + return (spis_t){{ BIT_ULL(slot), 0 }}; + else + return (spis_t){{ 0, BIT_ULL(slot - 64) }}; +} + +static inline spis_t spis_single_slot(u32 spi) +{ + return spis_or(spis_one_bit(spi * 2), spis_one_bit(spi * 2 + 1)); +} + #define BPF_REGMASK_ARGS ((1 << BPF_REG_1) | (1 << BPF_REG_2) | \ (1 << BPF_REG_3) | (1 << BPF_REG_4) | \ (1 << BPF_REG_5)) -- 2.53.0