From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f172.google.com (mail-pf1-f172.google.com [209.85.210.172]) (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 499753AF647 for ; Fri, 7 Aug 2026 08:15:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786090527; cv=none; b=qTZuM5aM0almRixMOVmtJRy26f8PTzjbiEdAR5tJdSxWb+MTaOHurj+EB2fHOSteaNBqE1b7MBqZNpWF5pHO+uBj19XROCGG03+IR6bxUwwlVfsNQ27wFebea9shWyCMiaO73H1kt3MLp0rOxFAN9YvKjydKi2fsckvEwTrHlYg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786090527; c=relaxed/simple; bh=tkCwiHM5Yy8VAsIhHkzjtBVNSBo5NUMgLP0Eb1hegXA=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=p1GXIx09OY/b0fBbeULItVpfqKPt41sXSlf/sHK4RKrRZe+Fjb9k51IE/WeR60qzjneDsPU0S4+RzVdEiW33+P1NVLcQ/yfpFsahgkc0uR/FshVcRAsjA7OR+/I+QlShu1bNDTDjR8rCfkKJEaZDk+Xaq7QwWnElniWumu44RnA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.210.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-84867f07d63so3686386b3a.2 for ; Fri, 07 Aug 2026 01:15:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786090516; x=1786695316; h=cc:to:content-transfer-encoding:content-type:mime-version :message-id:date:subject:from:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to:content-type; bh=7q8/nVQpkj9Gz+H2J6fGGvF/z4vNpglfJyg/OIloQY4=; b=eub5ciyzN3+oXek7jUCFP/ci5nt7LCz6V3IaCTVrQWagOmEmw3dONzV3SrWSoCHtvV xJFDGkGP/SgtiSdq5STd0AEg2EWLnrdH7uJ9he6kkkgcKx6B/xkBc2gbDJhgtWHL4RUG c6vlRh0WJ+ufw1RMBzf9oi6Xw/pl46+3dfiX29Dkb0yWP5MNmWlmRXxDtl0VBkVp6yyd Zv5nL80Ygx/DiSnTGuTBRJ8mobcG1J1sDQ1sWZNa2yKmWo+C/l/nStvg5S8u+pzPRekb zx955A1xJm7JBirsX7cf8QSeY9ZNyJDRFuHAkakDKB5JBogoRD7rbOhd0pcyPhh/kULt 5g+Q== X-Gm-Message-State: AOJu0Yxf5FGWn+E+AlihIDGT/dNrRaqZnPt6zXbs1UzLGfi7b7iaGaAd +umcZzhIs94VPVIYrdcaf96FTIS4eQ59J5U5ZXKjrKfoQAQiC7aZeRqG X-Gm-Gg: AR+sD11W25D31hOC1gtJCuA3G2VWzvqPaj42ZbAYDEU9gV2hRu0jTs0Oh7frQBY61MD itAp482ZBq29z6CwiF+g5hlNBsMIcsuxsqigVIbf1WqQc/E5+qAdCp8RLd2jBTbbNV/wWLP4jck YGSL8RdOWxBRio2+Ug/0j9kL6wJOq3selVPYe8LRsETIWeaUDJ0eCGRyM65s4du2JopMLtttfO1 MS+++OiZEHWhac8UISNNx1hUMuIb+ArFGoo0KgmIzmOsKsgsVe3mk6ypSJmY3CHaJrAZGbcjZv4 bbVPdP++Wvh6AZI1bbEdxkcFv9RNq5z9F/68kFMFPgQGSBxEFr6Uax/gTEf7xmFVygBx7E4luJu C5x8m6yNBgBsJURkyUpv4Mifvgu346tjMrV1VeQegYBp5wYqyPa5oR/moE8cjgq+cdKu+uO6F/m ZJ7Ld9PbRQkXLJoVIy2OZcptRdYID1kg== X-Received: by 2002:a05:6a00:4294:b0:83e:b443:965e with SMTP id d2e1a72fcca58-84f2dfc5413mr24095892b3a.3.1786090516334; Fri, 07 Aug 2026 01:15:16 -0700 (PDT) Received: from [127.0.1.1] ([2a11:3:200::10a9]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-84f5a3c948bsm630035b3a.17.2026.08.07.01.15.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Aug 2026 01:15:14 -0700 (PDT) From: Ke Sun Subject: [PATCH v14 0/2] rust: Add safe pointer formatting support Date: Fri, 07 Aug 2026 16:14:52 +0800 Message-Id: <20260807-hashedptr-v14-0-817009769ffb@kylinos.cn> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAPyTdWoC/22QQW7DIBBFr2KxLhEz2GBn1XtEXdgwFNTaToFYj aLcvdhZJKmynGH+4+lfWKIYKLF9dWGRlpDCPJUB6reKGd9Pn8SDLQuGApVoALnvkyd7zJEj1qo bOikAJCv3x0gu/G6ww0eZXZxHnn2k/k5A0TwQFgAOfLDCkdGOlIP3r/N3mOa0M9OK9CHlOZ43v QVwJb8yKU9ccAW2MVq3qm27R87qshTFexjVU1iWsMRaNqhB0dD9k9gyWrzIaN0L7dDp1j59eL2 1EennVBrNt0rY0CfiZh7HkPfVonfIo6nL8fUPvwD1A4YBAAA= X-Change-ID: 20260512-hashedptr-22469b930113 To: Miguel Ojeda , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich Cc: rust-for-linux@vger.kernel.org, Ke Sun X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1786090507; l=6644; i=sunke@kylinos.cn; s=20260317; h=from:subject:message-id; bh=tkCwiHM5Yy8VAsIhHkzjtBVNSBo5NUMgLP0Eb1hegXA=; b=Rn4Jc3I10vS+6s5ow6VTa/Gdptkxbso7prDx77MxL+sphkp2XeeAY3dhi9h/wU5Vi/GSXSfXd LkhSP1hqES8Dz4BmsXf0wx5dSAlwshptBdNR4jVoGXo7r+86qJeUlmx X-Developer-Key: i=sunke@kylinos.cn; a=ed25519; pk=CHcwQp8GSoj25V/L1ZWNSQjWp9eSIb0s9LKr0Nm3WuE= This series fixes two issues with {:p} pointer formatting: - The impl_fmt_adapter_forward! macro destructures self into a local variable, causing {:p} to print a stack address instead of the actual pointer - Kernel address leak - {:p} prints raw pointer values, exposing kernel address space layout --- Changes in v14: - Use `%#0*p` for `0x` prefix and zero-padding (Gary); this also avoids "0x(...)" for placeholder tokens like "(____ptrval____)" (Alice) - Simplify pointer impls per Gary - Link to v13: https://lore.kernel.org/r/20260706-hashedptr-v13-0-377a07f2f78d@kylinos.cn Changes in v13: - Add NonNull pointer formatting support - Add #[inline] to all Pointer impl methods - Support zero-padding format ({:0width$p}) - Simplify SAFETY comments - Rewrite tests: remove NoHashPointersGuard - modifying no_hash_pointers after boot panics since it's __ro_after_init; read current value and branch instead; expand format coverage - Link to v12: https://lore.kernel.org/r/20260512-hashedptr-v12-0-61d5c7786889@kylinos.cn Changes in v12: - Split into 2 patches: fix {:p} printing stack addresses -> route {:p} through HashedPtr - Test cleanup: NoHashPointersGuard RAII guard replaces raw save/restore; mod expected consolidates 32/64-bit constants - Impl delegation: &T, &mut T, *mut T all forward to *const T (matching core library conventions), replacing v11's blanket impl + macro - Link to v11: https://lore.kernel.org/r/20260205-hashedptr-v11-1-bd0fec7fe6f1@kylinos.cn Changes in v11: - Fix inaccurate or inappropriate descriptions in comments - Use as_char_ptr instead of as_ptr so that a *const u8 pointer is always passed to scnprintf on all architectures - Per Tamir's suggestion, replace doctests with mod tests and adjust test content to make the tests more meaningful - Remove the RawPtr wrapper type: it and HashedPtr use different formatting mechanisms (HashedPtr uses scnprintf and pad; RawPtr would call core's Pointer impl directly). This series focuses on fixing the issue that without it {:p} would output the pointer's stack address, and on using HashedPtr to safely format raw pointers and avoid leaking kernel address space layout information - Link to v10: https://lore.kernel.org/r/20260121050059.2315091-1-sunke@kylinos.cn Changes in v10: - Merge all patches into a single patch - Improve `kernel::fmt::Pointer` trait implementation Link to v9: https://lore.kernel.org/r/20260119033006.1453006-1-sunke@kylinos.cn Changes in v9: https://lore.kernel.org/r/20260119033006.1453006-1-sunke@kylinos.cn - Refactor implementation to use Pointer trait and Adapter pattern instead of exporting ptr_to_hashval() from lib/vsprintf.c. Use scnprintf directly in Rust for pointer hashing, eliminating the need for C function export - Move pointer wrapper types from rust/kernel/ptr.rs to rust/kernel/fmt.rs - Split implementation into more granular patches: Pointer trait foundation, HashedPtr type, raw pointer default behavior, and RawPtr type - Remove documentation patch, integrate examples into code doctests - Simplify API and improve code organization following Display trait pattern - Link to v8: https://lore.kernel.org/r/20260101081605.1300953-1-sunke@kylinos.cn Changes in v8: - Remove RestrictedPtr (%pK) support: only export ptr_to_hashval() with EXPORT_SYMBOL_NS_GPL using "RUST_INTERNAL" namespace, provide only two pointer wrapper types (HashedPtr, RawPtr) for %p and %px - Change API from HashedPtr::from(ptr) to HashedPtr(ptr) for direct construction - Link to v7: https://lore.kernel.org/r/20251229072157.3857053-1-sunke@kylinos.cn Changes in v7: - Refactor kptr_restrict handling: extract kptr_restrict_value() from restricted_pointer() in lib/vsprintf.c and export it for Rust use, and improve RestrictedPtr::fmt() implementation to directly handle kptr_restrict_value() return values (0, 1, 2, -1) for better code clarity - Remove Debug derive from pointer wrapper types (HashedPtr, RestrictedPtr, RawPtr) - Link to v6: https://lore.kernel.org/r/20251227033958.3713232-1-sunke@kylinos.cn Changes in v6: - Fix placeholder formatting to use `f.pad()` instead of `f.write_str()` in format_hashed_ptr(), ensuring width, alignment, and padding options are correctly applied to PTR_PLACEHOLDER - Link to v5: https://lore.kernel.org/r/20251226140751.2215563-1-sunke@kylinos.cn Changes in v5: https://lore.kernel.org/r/20251226140751.2215563-1-sunke@kylinos.cn - Format use statements in rust/kernel/ptr.rs and rust/kernel/fmt.rs using kernel vertical style with alphabetical ordering - Remove unnecessary SAFETY comment in rust/kernel/ptr.rs (addressed Clippy warning) - Update type ordering to alphabetical (HashedPtr, RawPtr, RestrictedPtr) in fmt.rs macro invocation - Link to v4: https://lore.kernel.org/r/20251225225709.3944255-1-sunke@kylinos.cn Changes in v4: - Use Pointer::fmt() instead of write!(f, "{:p}", ...) to preserve formatting options (width, alignment, padding characters) - Improve code structure: reduce unsafe block scope, use early return pattern - Add doctests with formatting option tests for all pointer wrapper types - Enhance documentation with detailed formatting options section, including examples for width, alignment, and padding - Fix RestrictedPtr example to use pr_info! instead of seq_print! in docs - Link to v3: https://lore.kernel.org/r/20251224081315.729684-1-sunke@kylinos.cn Changes in v3: - Export ptr_to_hashval() from lib/vsprintf.c for Rust pointer hashing - Add three pointer wrapper types (HashedPtr, RestrictedPtr, RawPtr) in rust/kernel/ptr.rs corresponding to %p, %pK, and %px - Make raw pointers automatically use HashedPtr when formatted with {:p} - Add documentation for pointer wrapper types - Link to v2: https://lore.kernel.org/r/20251223033018.2814732-1-sunke@kylinos.cn Changes in v2: - Disabled {:p} raw pointer printing by default to prevent accidental information leaks - Link to v1: https://lore.kernel.org/r/20251218032709.2184890-1-sunke@kylinos.cn Signed-off-by: Ke Sun --- Ke Sun (2): rust: fmt: fix {:p} printing stack addresses rust: fmt: route {:p} through HashedPtr to prevent address leaks rust/kernel/fmt.rs | 173 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 171 insertions(+), 2 deletions(-) --- base-commit: 6946cd5d0aa4dd10a414ddcb7a10844fdb0ad345 change-id: 20260512-hashedptr-22469b930113 Best regards, -- Ke Sun