From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F3960E77197 for ; Thu, 9 Jan 2025 04:12:39 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4YTBFy3VhFz2xWt; Thu, 9 Jan 2025 15:12:38 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=148.163.156.1 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1736395958; cv=none; b=ZK6yke0XCIfrJR/piaYmXVPhw3Exo/MgpK7M3wuiDcdR0FoecKFOPqzgfslGxhKJnWxy284IAcJV9J8VnNkU70YsQ76ccxYdPmnrXiyq4erC7erPWl+wjo0nfu0esI25KxHwDQfSinSAx92ctmlEH/d/qvblwR2OdXArFnn2SQYkkdwsCPV1HpDMbec7FCpwpV5oqgWDwZVcGnTDthRq+CAzwcOWM1envfj4jQvrjmeHRBkPHI3NAhiRuSzbwKW3HHm3yZYQUpgeUjlaI/WMV+wo/3Pe51sZd3ctrBZNjik82p+oqjqP+Xn5Izd61LRQZtV0xc5QpznulNjGtL4SxQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1736395958; c=relaxed/relaxed; bh=b2mjqvTGempTon9Ywa1jbwZqI26Px4SPJHG2UyEKJDU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=TEMPmLVK7zE5xA8OIcT8suIA4fOY3qUuiJHTxTbFqfkV6Lj/++7JF8b4PtUmYhUaP8EnPkSC1Qvel21dU7ty/AsRwl9fnW+SnKlmWO4Q1oiRdST+jSwzj+rxpjlcju0gjlq92eWgojQwio+CGVtm8o1T7qV24uBKjFUklxcDuCaHsXd8+sEjWMQTMoyo3D6jUsx659VNJZS4zOdss80Ge8UvXbl4kkrPWmnNWb5v6GEHavnYjuDk18WKp8CSdn3KEnZDmcQGqoyNH/2hCK4DDSYfH6HnZJyyAwfzoMzRBwfHvdWnhwyKxTvftI2B8qtF0DaJcT32StD15I5tBwqY/w== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; dkim=pass (2048-bit key; unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=AbCf7KV9; dkim-atps=neutral; spf=pass (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=sourabhjain@linux.ibm.com; receiver=lists.ozlabs.org) smtp.mailfrom=linux.ibm.com Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=AbCf7KV9; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=sourabhjain@linux.ibm.com; receiver=lists.ozlabs.org) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4YTBFw6h15z2xGF for ; Thu, 9 Jan 2025 15:12:36 +1100 (AEDT) Received: from pps.filterd (m0360083.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 5093r3Qi006598; Thu, 9 Jan 2025 04:12:25 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=b2mjqv TGempTon9Ywa1jbwZqI26Px4SPJHG2UyEKJDU=; b=AbCf7KV9MtHn9ZFW9MK/FL oCHMyrup5GM2mvCK8iJvPXaYrdKlKGHOuRTAUc3BtaD/JX0SyQXHqxpwS+J1fNAE N/1TFTuR74wc8CBaUZiQK3Zvxr1kH/QoAEE7mErsiSTR2lmvQxGQZZWg5KAJbnjq chF3vsMTwFZClVQQ4hNe6gPs1Gd10xCUjUb3O8v8zRXVbiCBrHPFOUKN9nc3CqhI DYvHGUWMeoxHQpXOg3s5gvuaWhqHEUxYzG+9COLkQ8ZHN32c2yiXK5fLpeYCvCOE z8bdHZOU99PrBJYzx34rPq6cKxktBvvlbGU3MCiT9Xbf43gUg1Su+xInf2sAlEFA == Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4426xc82dk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 09 Jan 2025 04:12:24 +0000 (GMT) Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 50910t6s013698; Thu, 9 Jan 2025 04:12:23 GMT Received: from smtprelay06.fra02v.mail.ibm.com ([9.218.2.230]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 43ygap39ca-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 09 Jan 2025 04:12:23 +0000 Received: from smtpav06.fra02v.mail.ibm.com (smtpav06.fra02v.mail.ibm.com [10.20.54.105]) by smtprelay06.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 5094CJYv18678034 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 9 Jan 2025 04:12:19 GMT Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5827E20049; Thu, 9 Jan 2025 04:12:19 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 46A4420040; Thu, 9 Jan 2025 04:12:16 +0000 (GMT) Received: from [9.43.18.121] (unknown [9.43.18.121]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 9 Jan 2025 04:12:15 +0000 (GMT) Message-ID: Date: Thu, 9 Jan 2025 09:42:14 +0530 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] kexec: Initialize ELF lowest address to ULONG_MAX To: Baoquan he , ebiederm@xmission.com Cc: Hari Bathini , akpm@linux-foundation.org, Madhavan Srinivasan , Michael Ellerman , kexec@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20241210091314.185785-1-sourabhjain@linux.ibm.com> Content-Language: en-US From: Sourabh Jain In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: BBvxfhqmZn0KHJqDL_jyalZewOdicwfn X-Proofpoint-ORIG-GUID: BBvxfhqmZn0KHJqDL_jyalZewOdicwfn X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-15_01,2024-10-11_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 priorityscore=1501 phishscore=0 suspectscore=0 adultscore=0 impostorscore=0 mlxscore=0 malwarescore=0 spamscore=0 bulkscore=0 mlxlogscore=999 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2411120000 definitions=main-2501090026 Hello Baoquan and Eric, On 12/12/24 08:25, Baoquan he wrote: > On 12/10/24 at 02:43pm, Sourabh Jain wrote: >> kexec_elf_load() loads an ELF executable and sets the address of the >> lowest PT_LOAD section to the address held by the lowest_load_addr >> function argument. >> >> To determine the lowest PT_LOAD address, a local variable lowest_addr >> (type unsigned long) is initialized to UINT_MAX. After loading each >> PT_LOAD, its address is compared to lowest_addr. If a loaded PT_LOAD >> address is lower, lowest_addr is updated. However, setting lowest_addr >> to UINT_MAX won't work when the kernel image is loaded above 4G, as the >> returned lowest PT_LOAD address would be invalid. This is resolved by >> initializing lowest_addr to ULONG_MAX instead. >> >> This issue was discovered while implementing crashkernel high/low >> reservation on the PowerPC architecture. >> >> Fixes: a0458284f062 ("powerpc: Add support code for kexec_file_load()") >> Cc: Baoquan he >> Cc: Hari Bathini >> CC: Madhavan Srinivasan >> Cc: Michael Ellerman >> Cc: kexec@lists.infradead.org >> Cc: linuxppc-dev@lists.ozlabs.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Sourabh Jain >> --- >> kernel/kexec_elf.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/kernel/kexec_elf.c b/kernel/kexec_elf.c >> index d3689632e8b9..3a5c25b2adc9 100644 >> --- a/kernel/kexec_elf.c >> +++ b/kernel/kexec_elf.c >> @@ -390,7 +390,7 @@ int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr, >> struct kexec_buf *kbuf, >> unsigned long *lowest_load_addr) >> { >> - unsigned long lowest_addr = UINT_MAX; >> + unsigned long lowest_addr = ULONG_MAX; > Great catch. > > Acked-by: Baoquan He Thank you for the Ack! The upcoming two patch series, which aim to enable generic crashkernel reservation, depends on this fix. One of them is already posted for upstream review: https://lore.kernel.org/all/20250108101458.406806-1-sourabhjain@linux.ibm.com/ I was wondering if you could guide us on how to get this fix pushed to the mainline tree. Thanks, Sourabh Jain