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 A1CAD39658B for ; Mon, 6 Apr 2026 18:50:28 +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=1775501429; cv=none; b=gU4FUZ9AsE3vMYrZgpP5ChYlG/zz9dC/+qyyTjCC/wXNjNsPkP7RwBmROouXEvbTi0XeClACsBBbrXgoPWfVspY3oKREFVnJNjfFzjInrR/h3Jj7sB5lME6jixbY8xskk060kk8rKZrkX1GEoRBF2xqnpzdPjh0xfe//JPlCges= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775501429; c=relaxed/simple; bh=02IiNGebjj9T3GiLIb7uKCtJskYIhB5w0FLa54z1BU4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=bKMYe5OZJpxhDnN3eVQOzVo+k6eDy3Q0Us3UpM6iAPQfU3xVNlCJ64QibQo3tobBlEARTeQOZUe8nVahMUp1r9gSUWxHXfnNCL1W24opt31S132rudEAnBSf+cwCZquB3XE/QCngJIX+JExIOPrTTsBbWTitOSfoJ2Spm4MdQG0= 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=XCsWdMtI; 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="XCsWdMtI" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-82c675116f1so6177847b3a.2 for ; Mon, 06 Apr 2026 11:50:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1775501428; x=1776106228; 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=/itz4DVMHOse/koMe29mOhSeC8aYBjPMHAwpbzHRlRM=; b=XCsWdMtIyYWPkfogzDOpwlG9w3sEVxM0stkgl1qjY6p/LAWpcPYxzMWnhzvpDRizk8 oWfzk0gop6im7F7rrf2WZcPbYfEpfSn08eWL+cOplrR2Gix4/QkpWXlxYyJgzWdlj7+z sKvKoABZgn+hlmQSjKFhF8qk5d6/+JDXX4bql/NYW4U2XN3+4xobHqv6g55qMQksnzOW ZfXwVx8P1brrDI2ktVKRjMCUaMct8WPT1iRVAf7wEwvDLdAx9QIzzPmzIl3BkZMmU5M2 M2AlSn/oCGyGeLFAJgvp3/o+hHMEsj9xbXnHmWQNRxzm0nIuurOq1R6XBEZk9VEiDHw7 nhOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775501428; x=1776106228; 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=/itz4DVMHOse/koMe29mOhSeC8aYBjPMHAwpbzHRlRM=; b=ixLnN1MZGVdoo8XK8GLdZVAykId1SdybD5b0P0LWYWMgSJR9fcT+O65QGScSYJHV3S puVoH7CjcUVAUKBT64NsC54Qyzo8+bfvN6UxkFAcxLDVifw8j+oaaliGbbS7YPc1lMG2 DGPwK8s61c8cGYDDSYRS2XyOitFKH7/N2umVlMAmJIwxUeoKOXLsc3alvjvaU/Cc9uEq EtVZaUzc2mpqHA6v4a4EFa0jiA/cYQsIVSSN4V6pqzhmf8lklsBgfvbgCDEb8qH33YNe mFQP5+7FGXJyDNtoqHjdQsG41kikqSH5nLfZ8EUyc1bWHpWjlw9BTL5Kf4v4LJSDLz02 cQdA== X-Forwarded-Encrypted: i=1; AJvYcCUOp79JeChwaibLciSsSHUdv01P6YW6+Mc4uMymJo8kEyRiaq9cog9xRM3n9SfTmpAU1YFIt5hoa/of5LxnKQpb@vger.kernel.org X-Gm-Message-State: AOJu0Yzx23BOuvcR4aOWiYnltpfRMLSp+VvMcIBuFt0AlKCyijUOWy6y Yjr98ssbkYt7xF///tP4G891MjVY5XTtiDwlXw4+bOruKriDgTn6zSuDZmVI2HFwjvj7gVavrQC nPSal+m5PvHN7e8uza9qHCLm3KA== X-Received: from pfbbj11.prod.google.com ([2002:a05:6a00:318b:b0:82c:de4c:2172]) (user=dylanbhatch job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:4397:b0:823:9c6:1985 with SMTP id d2e1a72fcca58-82d0da8a9bbmr13916077b3a.16.1775501427782; Mon, 06 Apr 2026 11:50:27 -0700 (PDT) Date: Mon, 6 Apr 2026 18:49:57 +0000 In-Reply-To: <20260406185000.1378082-1-dylanbhatch@google.com> Precedence: bulk X-Mailing-List: linux-toolchains@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260406185000.1378082-1-dylanbhatch@google.com> X-Mailer: git-send-email 2.53.0.1213.gd9a14994de-goog Message-ID: <20260406185000.1378082-6-dylanbhatch@google.com> Subject: [PATCH v3 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 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, Jens Remus , linux-arm-kernel@lists.infradead.org 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. Signed-off-by: Dylan Hatch --- include/linux/sframe.h | 1 + kernel/unwind/sframe.c | 44 +++++++++++++++++++++++++++++++++++++----- 2 files changed, 40 insertions(+), 5 deletions(-) diff --git a/include/linux/sframe.h b/include/linux/sframe.h index 905775c3fde2..593b60715cd6 100644 --- a/include/linux/sframe.h +++ b/include/linux/sframe.h @@ -64,6 +64,7 @@ struct sframe_section { unsigned long text_start; unsigned long text_end; + bool fdes_sorted; unsigned long fdes_start; unsigned long fres_start; unsigned long fres_end; diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c index 321d0615aec7..4dd3612f9e7a 100644 --- a/kernel/unwind/sframe.c +++ b/kernel/unwind/sframe.c @@ -179,9 +179,34 @@ 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); + } +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; @@ -236,6 +261,15 @@ 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; \ @@ -660,7 +694,7 @@ 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; } @@ -739,7 +773,6 @@ 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"); @@ -769,6 +802,7 @@ 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; -- 2.53.0.1213.gd9a14994de-goog