From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (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 4A8883A782B for ; Tue, 21 Apr 2026 22:52:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776811947; cv=none; b=DH8JlzaxTBl9Jsc3ywl7dXEB1gjayRJw4E24v/Un6x7w/iqmadp7WXPtVAIr56/3qNwr0c64t6/kByxnEc6X6j+n6MMtAosZWw2SO6v8vY5jYqIdd2G8Js5cF+MBWjStbbw7U7GFLZN+DFO7ep9iDN8JYk1/3b+QfXPEIS0MBKk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776811947; c=relaxed/simple; bh=HcHbWf4But37GRlHHhJj2shggv7jUZ569KAsIFqpDcI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=PujhfKzEgRgTnAtWm8xho20Hp+gUj+zZE1YroiQMmX9zLbsTWciZn8uIh6bOzHtx7lviVyQPKnnKT8erzMH8EbA48+cw2/KFZ5Q+tsDBSwrE0I3Pb2rwsas9CGBPpVKZ2gVKbGLa4yxUN6qIMLzJssKqH0ySisn02vORwLV9Aus= 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=s7XcmSRB; arc=none smtp.client-ip=209.85.210.202 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="s7XcmSRB" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-82fa1c94b37so2795467b3a.0 for ; Tue, 21 Apr 2026 15:52:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1776811943; x=1777416743; 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=P5zH7mctwcDOEQHijpP6Dn53P2ryMqn8C5QEWnKsM/M=; b=s7XcmSRBQfgDCQGXlsAVvq9QJV4rTbdp4qr4VO+UpoXUt7JKU95py7OuChdzxjOYKK hld/CsPt3Bdv2mWP3JN5ermXrOV+Ec8q2hlPXRYRPFUT863vrEuMDfqsS/MMneR5ZKku MjLEBSA6WAF2kHG2LMgWyQ2RNzgQ4vVvlYj3dsnAXBznAzIsqzTLpPWuJvPORrcycCyO QNvZKbsO7+LaGcue30s1W1lIlTQw6NZEfeSli3GlW7SJ/WlNWhjIQadgXVuEWOQlcp65 JAPKEiPKs3Rso/CgXB/gvCMKVna9zEKOcioTzLGX0QFN/slvKrYkdCF9Yw+kgFTn0zDY 149g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776811943; x=1777416743; 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=P5zH7mctwcDOEQHijpP6Dn53P2ryMqn8C5QEWnKsM/M=; b=SnxAOED8XpoxgZ1t74Dd+ljmb/AOobi+iamlncgQ85jtkRf6QDpTT5iU2Cz9u1CPJN 9r2ZQPIuuG/cZWfiOUQ451bKeFHQYzcYFlNIiycNJG3NMCkRDoCnjnmu9yybz8Xa7mG9 l5kfyUfYPJ3EyWBwCGnES+PB0OwcO4ls+Mm8Pji4k/dN65hzSU/ANceHe43SUAeZB++g K4uELrVF2P/HdM0u79TzYxjJOzrK82Z7FM31JOJfAIYVxjlfReyy1dvJ/9acN+3t14SZ rxBSv8QgdWe4frBX0YnmHX3GmpwPs6f5nN1NNeIEmdC3O/IMLaEEOt8wV2GpR7kewJTf utdQ== X-Forwarded-Encrypted: i=1; AFNElJ/43Dl59N+IliIzzLzcL5BUHU2Jec64AQ9ALpgDNDfCgByz3wdpbta7V4+jG9nakdxl6Rf2rlTXuHvSjo9U@vger.kernel.org X-Gm-Message-State: AOJu0YxCQvh3I88fOvjNTIKfYJMdePUPn1WsxEF7bgiIm1cw5WKbbNgi QRqxdtylPPf89If9xSDNNtDqDwpETLq1xpU/W+lMrj1TLlsYNzxw15tPhUjtxHhZR0Se9hurDUs 2J26TiZySEO5NcQpgxgXV7KgoNQ== X-Received: from pfbjw25.prod.google.com ([2002:a05:6a00:9299:b0:82f:b709:3747]) (user=dylanbhatch job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:a247:b0:82c:1cd0:2f7e with SMTP id d2e1a72fcca58-82f8b553974mr15760811b3a.20.1776811942482; Tue, 21 Apr 2026 15:52:22 -0700 (PDT) Date: Tue, 21 Apr 2026 22:51:57 +0000 In-Reply-To: <20260421225200.1198447-1-dylanbhatch@google.com> Precedence: bulk X-Mailing-List: live-patching@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260421225200.1198447-1-dylanbhatch@google.com> X-Mailer: git-send-email 2.54.0.rc1.555.g9c883467ad-goog Message-ID: <20260421225200.1198447-6-dylanbhatch@google.com> Subject: [PATCH v4 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 fb3b6b2d8677..243027244854 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.rc1.555.g9c883467ad-goog