From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 DED7E47AF57 for ; Tue, 28 Apr 2026 18:37:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777401445; cv=none; b=AHdb+3hhHXwTwQg+NljDCHOKgnseaAMgHJffY3M4xAfhYCvExd1QPSV8tQ8LBOXhX7oEBrq03BFTG1hC2SBFLut9V07UHEoRLQHTn1vMgBNuzKhpFIuNFlETHaq66tOJhlaV/5hOCxsUcPilnPTGWmn4/DPK+jOaj+zK/pl8vMI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777401445; c=relaxed/simple; bh=zsbBPiSMTY+4JYf4sn3CPXmmxXgtYh5S3I+3ssE0e6M=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=cs1wY+aUfqyomPJnKHXz8RbNKyLx5F8bqUSKmaZd4I12+tDWrV0sD5hr750KmRylRbwVOOmq9/G7MZoQumH+58FCnKBTYOuGujM4Iu13vbxBr9yh595GNeU2HRTKVn48i8FJzMrZCqVjGsQ0GJrN8cYYjNz2OSBRIdMwVZ1XTGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--dylanbhatch.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=bWvTgcYK; arc=none smtp.client-ip=209.85.216.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--dylanbhatch.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bWvTgcYK" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-35842aa350fso22479067a91.0 for ; Tue, 28 Apr 2026 11:37:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777401442; x=1778006242; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=HEk4CM6KkrmWUN7H1Rd0LwOd0ZnJZhF5RnXyjlQj1vc=; b=bWvTgcYKtxjAm4s8vmwxCVHLZfs+YYh47l5rhwi6Xs8d+9FnMsVUaocvRuR4m+HzmH GFRfltfwTIUffp7zKkY97sdeNeec9gs6zzTAn/U/q6DGc9l4nTRsaLYkeq4v/WAXAhNb K5NMV3jlgu8y/KaGCkk9oEA/AUK9ua/iA1e+z1qQHpItwsPCYdIwu5xVlhrAk3915hXR FmN0km7W/WtXlkpnlvVgJ0XC1YK9bEenZY2anUWw5DDRqwaBqKJZRswcjl6FQEZQ7mkq lbNpztfLGQCrDPdonnqMg6Oa+PntzjUoK922lAyM+Ap8CT0iaRcdtv0jpwTrSn+H4Lg5 2oSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777401442; x=1778006242; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=HEk4CM6KkrmWUN7H1Rd0LwOd0ZnJZhF5RnXyjlQj1vc=; b=R4kwqUJnHdix3AgU85xYcKM3656fFnpqahdZ3U8szODZIk3TSSgLWs+wtPGfttx2eY IR4rO6eKqbalXBWv3MdBDnZTRgOL6Q9VkUPz+bPOyU2I90VCqGZfcjSQyKCkdXx2iYD1 xqPY9HBS3vp9RPvaesPvdbAEefs23au3e6/MJjBsHInfN+lkwR84pGWXg/oIxuaZwA8X sOGNmWSaQhhBq+g8ZvX/S23xt8ZsJzYktq+RJ9yCilg2nQNNAWR/N3YfFxvMJdyY+3fe H9LUOsaqIguDnzaKKE9Y+xF6bkKF3Rqf2QK28AIrXXEY8joJlGsQWSKoJs9iCLj3KW6K kSUg== X-Forwarded-Encrypted: i=1; AFNElJ/LFMbd9WMawLzZaCcc1c7gyAJ2AtQujj1fyN9JslzY0GdQWQXViKrPiMqcIG/b69YM1gJCT605pIow8xk=@vger.kernel.org X-Gm-Message-State: AOJu0Ywegke8xRxT3EIrcOeGabOFlRfAcYSLoL2TC4LnoEhyF5EUuGLx 26LUsgvUPuRoPt/oYMTBgxcoBi7yG7eZmqn8NCU1tFRJNZ3nq0E6YIT3tTqsgGtaV/1KQhFjPUW 7QBw3TDfncAif4IPLfFIuDeR1iw== X-Received: from plbjl20.prod.google.com ([2002:a17:903:1354:b0:2b0:b22a:e6ef]) (user=dylanbhatch job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:2ecd:b0:364:7467:53e5 with SMTP id 98e67ed59e1d1-36491ff60aamr4439314a91.2.1777401441910; Tue, 28 Apr 2026 11:37:21 -0700 (PDT) Date: Tue, 28 Apr 2026 18:36:40 +0000 In-Reply-To: <20260428183643.3796063-1-dylanbhatch@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260428183643.3796063-1-dylanbhatch@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260428183643.3796063-6-dylanbhatch@google.com> Subject: [PATCH v5 5/8] sframe: Allow unsorted FDEs From: Dylan Hatch To: Roman Gushchin , Weinan Liu , Will Deacon , Josh Poimboeuf , Indu Bhagat , Peter Zijlstra , Steven Rostedt , Catalin Marinas , Jiri Kosina , Jens Remus Cc: Dylan Hatch , Mark Rutland , Prasanna Kumar T S M , Puranjay Mohan , Song Liu , joe.lawrence@redhat.com, linux-toolchains@vger.kernel.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Randy Dunlap Content-Type: text/plain; charset="UTF-8" The .sframe in kernel modules is built without SFRAME_F_FDE_SORTED set. In order to allow sframe PC lookup in modules, add a code path to handle unsorted FDE tables by doing a simple linear search. Reviewed-by: Jens Remus Signed-off-by: Dylan Hatch --- include/linux/sframe.h | 1 + kernel/unwind/sframe.c | 45 +++++++++++++++++++++++++++++++++++++----- 2 files changed, 41 insertions(+), 5 deletions(-) diff --git a/include/linux/sframe.h b/include/linux/sframe.h index 5b7341b61a7c..8ae31ed36226 100644 --- a/include/linux/sframe.h +++ b/include/linux/sframe.h @@ -28,6 +28,7 @@ struct sframe_section { unsigned long fres_start; unsigned long fres_end; unsigned int num_fdes; + bool fdes_sorted; signed char ra_off; signed char fp_off; diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c index 430bff9533ee..dcf4deb378dc 100644 --- a/kernel/unwind/sframe.c +++ b/kernel/unwind/sframe.c @@ -176,9 +176,35 @@ static __always_inline int __read_fde(struct sframe_section *sec, return -EFAULT; } -static __always_inline int __find_fde(struct sframe_section *sec, - unsigned long ip, - struct sframe_fde_internal *fde) +static __always_inline int __find_fde_unsorted(struct sframe_section *sec, + unsigned long ip, + struct sframe_fde_internal *fde) +{ + struct sframe_fde_v3 *cur, *start, *end; + + start = (struct sframe_fde_v3 *)sec->fdes_start; + end = start + sec->num_fdes; + + for (cur = start; cur < end; cur++) { + s64 func_off; + u32 func_size; + unsigned long func_addr; + + DATA_GET(sec, func_off, &cur->func_start_off, s64, Efault); + DATA_GET(sec, func_size, &cur->func_size, u32, Efault); + func_addr = (unsigned long)cur + func_off; + + if (ip >= func_addr && ip < func_addr + func_size) + return __read_fde(sec, cur - start, fde); + } + return -EINVAL; +Efault: + return -EFAULT; +} + +static __always_inline int __find_fde_sorted(struct sframe_section *sec, + unsigned long ip, + struct sframe_fde_internal *fde) { unsigned long func_addr_low = 0, func_addr_high = ULONG_MAX; struct sframe_fde_v3 *first, *low, *high, *found = NULL; @@ -233,6 +259,15 @@ static __always_inline int __find_fde(struct sframe_section *sec, return -EFAULT; } +static __always_inline int __find_fde(struct sframe_section *sec, + unsigned long ip, + struct sframe_fde_internal *fde) +{ + if (sec->fdes_sorted) + return __find_fde_sorted(sec, ip, fde); + return __find_fde_unsorted(sec, ip, fde); +} + #define ____GET_INC(sec, to, from, type, label) \ ({ \ type __to; \ @@ -657,7 +692,7 @@ static int sframe_validate_section(struct sframe_section *sec) return ret; ip = fde.func_addr; - if (ip <= prev_ip) { + if (sec->fdes_sorted && ip <= prev_ip) { dbg_sec("fde %u not sorted\n", i); return -EFAULT; } @@ -736,7 +771,6 @@ static int sframe_read_header(struct sframe_section *sec) if (shdr.preamble.magic != SFRAME_MAGIC || shdr.preamble.version != SFRAME_VERSION_3 || - !(shdr.preamble.flags & SFRAME_F_FDE_SORTED) || !(shdr.preamble.flags & SFRAME_F_FDE_FUNC_START_PCREL) || shdr.auxhdr_len) { dbg_sec("bad/unsupported sframe header\n"); @@ -766,6 +800,7 @@ static int sframe_read_header(struct sframe_section *sec) return -EINVAL; } + sec->fdes_sorted = shdr.preamble.flags & SFRAME_F_FDE_SORTED; sec->num_fdes = num_fdes; sec->fdes_start = fdes_start; sec->fres_start = fres_start; -- 2.54.0.545.g6539524ca2-goog