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 1cjNDp-0007p7-JK for kexec@lists.infradead.org; Thu, 02 Mar 2017 09:40:30 +0000 From: Baoquan He Subject: [PATCH v2] Fix the false positive error message when search /proc/kallsyms for kernel symbol Date: Thu, 2 Mar 2017 17:39:41 +0800 Message-Id: <1488447581-16465-1-git-send-email-bhe@redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: horms@verge.net.au Cc: dyoung@redhat.com, kexec@lists.infradead.org, Baoquan He Function get_kernel_sym in kexec will search /proc/kallsyms for kernel symbol and print error message anyway if expected symbol is not found. While page_offset_base definition and exporting codes are only available when mm KASLR code is compiled in kernel. Otherwise search will fail and print out error message, obviously this is false positive warning. So in this patch take out the error message from get_kernel_sym and put it where get_kernel_sym is called and expected symbol is not found. Signed-off-by: Baoquan He --- kexec/arch/i386/crashdump-x86.c | 41 +++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 18 deletions(-) diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c index 88aeee3..b9adc8c 100644 --- a/kexec/arch/i386/crashdump-x86.c +++ b/kexec/arch/i386/crashdump-x86.c @@ -127,7 +127,6 @@ static unsigned long long get_kernel_sym(const char *symbol) } } - fprintf(stderr, "Cannot get kernel %s symbol address\n", symbol); return 0; } @@ -193,30 +192,36 @@ static int get_kernel_vaddr_and_size(struct kexec_info *UNUSED(info), } if (lowest_vaddr != 0) elf_info->page_offset = lowest_vaddr; + } else { + fprintf(stderr, "Cannot get kernel page_offset_base symbol address\n"); } /* Traverse through the Elf headers and find the region where * _stext symbol is located in. That's where kernel is mapped */ stext_sym = get_kernel_sym("_stext"); - for(phdr = ehdr.e_phdr; stext_sym && phdr != end_phdr; phdr++) { - if (phdr->p_type == PT_LOAD) { - unsigned long long saddr = phdr->p_vaddr; - unsigned long long eaddr = phdr->p_vaddr + phdr->p_memsz; - unsigned long long size; - - /* Look for kernel text mapping header. */ - if (saddr <= stext_sym && eaddr > stext_sym) { - saddr = _ALIGN_DOWN(saddr, X86_64_KERN_VADDR_ALIGN); - elf_info->kern_vaddr_start = saddr; - size = eaddr - saddr; - /* Align size to page size boundary. */ - size = _ALIGN(size, align); - elf_info->kern_size = size; - dbgprintf("kernel vaddr = 0x%llx size = 0x%llx\n", - saddr, size); - return 0; + if (stext_sym) { + for(phdr = ehdr.e_phdr; stext_sym && phdr != end_phdr; phdr++) { + if (phdr->p_type == PT_LOAD) { + unsigned long long saddr = phdr->p_vaddr; + unsigned long long eaddr = phdr->p_vaddr + phdr->p_memsz; + unsigned long long size; + + /* Look for kernel text mapping header. */ + if (saddr <= stext_sym && eaddr > stext_sym) { + saddr = _ALIGN_DOWN(saddr, X86_64_KERN_VADDR_ALIGN); + elf_info->kern_vaddr_start = saddr; + size = eaddr - saddr; + /* Align size to page size boundary. */ + size = _ALIGN(size, align); + elf_info->kern_size = size; + dbgprintf("kernel vaddr = 0x%llx size = 0x%llx\n", + saddr, size); + return 0; + } } } + } else { + fprintf(stderr, "Cannot get kernel _stext symbol address\n"); } /* If failed to retrieve kernel text mapping through -- 2.5.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec