From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by merlin.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1ciawR-0001It-A4 for kexec@lists.infradead.org; Tue, 28 Feb 2017 06:07:20 +0000 Date: Tue, 28 Feb 2017 14:06:25 +0800 From: Dave Young Subject: Re: [PATCH] Only search page_offset_base when KASLR mm code is compiled in Message-ID: <20170228060625.GA4872@dhcp-128-65.nay.redhat.com> References: <1487932732-24539-1-git-send-email-bhe@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1487932732-24539-1-git-send-email-bhe@redhat.com> 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: Baoquan He Cc: horms@verge.net.au, kexec@lists.infradead.org, piliu@redhat.com On 02/24/17 at 06:38pm, Baoquan He wrote: > Otherwise it will print false positve message as below. So add > a check when do the search. > > "Cannot get kernel page_offset_base symbol address" > > Signed-off-by: Baoquan He > --- > kexec/arch/i386/crashdump-x86.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c > index 88aeee3..b2c1be5 100644 > --- a/kexec/arch/i386/crashdump-x86.c > +++ b/kexec/arch/i386/crashdump-x86.c > @@ -150,8 +150,6 @@ static int get_kernel_vaddr_and_size(struct kexec_info *UNUSED(info), > off_t size; > uint32_t elf_flags = 0; > uint64_t stext_sym; > - const unsigned long long pud_mask = ~((1 << 30) - 1); > - unsigned long long vaddr, lowest_vaddr = 0; > > if (elf_info->machine != EM_X86_64) > return 0; > @@ -181,8 +179,11 @@ static int get_kernel_vaddr_and_size(struct kexec_info *UNUSED(info), > > end_phdr = &ehdr.e_phdr[ehdr.e_phnum]; > > +#ifdef CONFIG_RANDOMIZE_MEMORY It does not work in userspace code. Maybe mute the error message or move it to kexec --debug is more reasonable.. > /* Search for the real PAGE_OFFSET when KASLR memory randomization > * is enabled */ > + const unsigned long long pud_mask = ~((1 << 30) - 1); > + unsigned long long vaddr, lowest_vaddr = 0; > if (get_kernel_sym("page_offset_base") != 0) { > for(phdr = ehdr.e_phdr; phdr != end_phdr; phdr++) { > if (phdr->p_type == PT_LOAD) { > @@ -194,6 +195,7 @@ static int get_kernel_vaddr_and_size(struct kexec_info *UNUSED(info), > if (lowest_vaddr != 0) > elf_info->page_offset = lowest_vaddr; > } > +#endif > > /* Traverse through the Elf headers and find the region where > * _stext symbol is located in. That's where kernel is mapped */ > -- > 2.5.5 > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec Thanks Dave _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec