From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935887AbeCBFj4 (ORCPT ); Fri, 2 Mar 2018 00:39:56 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:57618 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750750AbeCBFjy (ORCPT ); Fri, 2 Mar 2018 00:39:54 -0500 Date: Fri, 2 Mar 2018 13:39:45 +0800 From: Dave Young To: AKASHI Takahiro Cc: vgoyal@redhat.com, bhe@redhat.com, mpe@ellerman.id.au, bauerman@linux.vnet.ibm.com, prudo@linux.vnet.ibm.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: Re: [PATCH 6/7] x86: kexec_file: clean up prepare_elf64_headers() Message-ID: <20180302053945.GD2952@dhcp-128-65.nay.redhat.com> References: <20180227044814.24808-1-takahiro.akashi@linaro.org> <20180227044814.24808-7-takahiro.akashi@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180227044814.24808-7-takahiro.akashi@linaro.org> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/27/18 at 01:48pm, AKASHI Takahiro wrote: > removing bufp variable in prepare_elf64_headers() makes the code simpler > and more understandable. > > Signed-off-by: AKASHI Takahiro > Cc: Dave Young > Cc: Vivek Goyal > Cc: Baoquan He > --- > arch/x86/kernel/crash.c | 18 +++++++----------- > 1 file changed, 7 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c > index bfc37ad20d4a..a842fd847684 100644 > --- a/arch/x86/kernel/crash.c > +++ b/arch/x86/kernel/crash.c > @@ -334,7 +334,7 @@ static int prepare_elf64_headers(struct crash_mem *cmem, int kernel_map, > Elf64_Ehdr *ehdr; > Elf64_Phdr *phdr; > unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz; > - unsigned char *buf, *bufp; > + unsigned char *buf; > unsigned int cpu, i; > unsigned long long notes_addr; > unsigned long mstart, mend; > @@ -359,9 +359,8 @@ static int prepare_elf64_headers(struct crash_mem *cmem, int kernel_map, > if (!buf) > return -ENOMEM; > > - bufp = buf; > - ehdr = (Elf64_Ehdr *)bufp; > - bufp += sizeof(Elf64_Ehdr); > + ehdr = (Elf64_Ehdr *)buf; > + phdr = (Elf64_Phdr *)(ehdr + 1); phdr should start with ehdr + sizeof(Elf64_Ehdr); > memcpy(ehdr->e_ident, ELFMAG, SELFMAG); > ehdr->e_ident[EI_CLASS] = ELFCLASS64; > ehdr->e_ident[EI_DATA] = ELFDATA2LSB; > @@ -377,33 +376,30 @@ static int prepare_elf64_headers(struct crash_mem *cmem, int kernel_map, > > /* Prepare one phdr of type PT_NOTE for each present cpu */ > for_each_present_cpu(cpu) { > - phdr = (Elf64_Phdr *)bufp; > - bufp += sizeof(Elf64_Phdr); > phdr->p_type = PT_NOTE; > notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); > phdr->p_offset = phdr->p_paddr = notes_addr; > phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t); > (ehdr->e_phnum)++; > + phdr++; > } > > /* Prepare one PT_NOTE header for vmcoreinfo */ > - phdr = (Elf64_Phdr *)bufp; > - bufp += sizeof(Elf64_Phdr); > phdr->p_type = PT_NOTE; > phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note(); > phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE; > (ehdr->e_phnum)++; > + phdr++; > > /* Prepare PT_LOAD type program header for kernel text region */ > if (kernel_map) { > - phdr = (Elf64_Phdr *)bufp; > - bufp += sizeof(Elf64_Phdr); > phdr->p_type = PT_LOAD; > phdr->p_flags = PF_R|PF_W|PF_X; > phdr->p_vaddr = (Elf64_Addr)_text; > phdr->p_filesz = phdr->p_memsz = _end - _text; > phdr->p_offset = phdr->p_paddr = __pa_symbol(_text); > - (ehdr->e_phnum)++; > + ehdr->e_phnum++; > + phdr++; > } > > /* Go through all the ranges in cmem->ranges[] and prepare phdr */ > -- > 2.16.2 > Thanks Dave