From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx3-phx2.redhat.com ([209.132.183.24]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WmjVy-0007Ud-6H for kexec@lists.infradead.org; Tue, 20 May 2014 12:51:30 +0000 Date: Tue, 20 May 2014 08:51:04 -0400 (EDT) From: Dave Anderson Message-ID: <768772288.14234200.1400590264454.JavaMail.zimbra@redhat.com> In-Reply-To: <537AD0FC.1020202@huawei.com> References: <1809090930.13449697.1400528518027.JavaMail.zimbra@redhat.com> <537AD0FC.1020202@huawei.com> Subject: Re: [BUG REPORT] kexec and makedumpfile can't detect PAGE_OFFSET on arm (Wang Nan) MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Wang Nan Cc: Atsushi Kumagai , Simon Horman , kexec@lists.infradead.org ----- Original Message ----- > > On 2014/5/20 3:41, Dave Anderson wrote: > > > > > > ----- Original Message ----- > >> > >> Hi Atsushi and Simon, > >> > >> I find a problem about VMSPLIT on arm plarform, related to kexec and > >> makedumpfile. > >> > >> When CONFIG_VMSPLIT_1G/2G is selected by kernel, PAGE_OFFSET is actually > >> 0x40000000 or 0x80000000. However, kexec hard codes PAGE_OFFSET to > >> 0xc0000000 (in kexec/arch/arm/crashdump-arm.h), which is incorrect in > >> these situations. For example, on realview-pbx board with 1G/3G VMSPLIT, > >> PHDRs in generated /proc/vmcore is as follow: > >> > >> Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align > >> NOTE 0x001000 0x00000000 0x00000000 0x00690 0x00690 0 > >> LOAD 0x002000 0xc0000000 0x00000000 0x10000000 0x10000000 RWE > >> 0 > >> LOAD 0x10002000 0xe0000000 0x20000000 0x8000000 0x8000000 RWE > >> 0 > >> LOAD 0x18002000 0xf0000000 0x30000000 0x10000000 0x10000000 > >> RWE 0 > >> LOAD 0x28002000 0x40000000 0x80000000 0x10000000 0x10000000 > >> RWE 0 > >> > >> Which should be: > >> > >> Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align > >> ... > >> LOAD ... 0x40000000 0x00000000 0x10000000 0x10000000 RWE > >> 0 > >> LOAD ... 0x60000000 0x20000000 0x8000000 0x8000000 RWE 0 > >> LOAD ... 0x70000000 0x30000000 0x10000000 0x10000000 RWE > >> 0 > >> LOAD ... 0xc0000000 0x80000000 0x10000000 0x10000000 RWE > >> 0 > >> > >> I don't know why crash utility can deal with it without problem, > > > > For ARM the crash utility masks the symbol value of "_stext" with 0x1fffffff > > to determine the PAGE_OFFSET value, which was basically copied from the way > > it was done for i386. > > > > kexec-tools can do the same thing by reading /proc/kallsyms (crashdump-x86.c has already done this). > However, KALLSYMS and KALLSYMS_ALL are turned off on some embedded systems with memory limitation, > which is common on ARM. But you could use VMCOREINFO_SYMBOL(_stext), right? Dave _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec