From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752061AbeBBNIO (ORCPT ); Fri, 2 Feb 2018 08:08:14 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:51298 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751835AbeBBNHg (ORCPT ); Fri, 2 Feb 2018 08:07:36 -0500 From: Philipp Rudo To: kexec@lists.infradead.org, linux-s390@vger.kernel.org Cc: prudo@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, Eric Biederman , Vivek Goyal , Michael Ellerman , Thiago Jung Bauermann , Martin Schwidefsky , Heiko Carstens Subject: [PATCH 07/17] kexec_file: Simplify kexec_purgatory_setup_sechdrs 1 Date: Fri, 2 Feb 2018 14:07:08 +0100 X-Mailer: git-send-email 2.13.5 In-Reply-To: <20180202130718.35509-1-prudo@linux.vnet.ibm.com> References: <20180202130718.35509-1-prudo@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18020213-0020-0000-0000-000003F1AF02 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18020213-0021-0000-0000-000042841C08 Message-Id: <20180202130718.35509-8-prudo@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-02-02_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802020162 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To update the entry point there is an extra loop over all section headers although this can be done in the main loop. So move it there and eliminate the extra loop and variable to store the 'entry section index'. Also, in the main loop, move the usual case, i.e. non-bss section, out of the extra if-block. Signed-off-by: Philipp Rudo Reviewed-by: Martin Schwidefsky --- kernel/kexec_file.c | 76 +++++++++++++++++++++-------------------------------- 1 file changed, 30 insertions(+), 46 deletions(-) diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index d1c3ec8dc6b1..bb31a3b627c2 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -731,7 +731,6 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, unsigned char *buf_addr; unsigned char *src; Elf_Shdr *sechdrs; - int entry_sidx = -1; int i; sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr)); @@ -763,32 +762,11 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, sechdrs[i].sh_offset; } - /* - * Identify entry point section and make entry relative to section - * start. - */ - kbuf->image->start = pi->ehdr->e_entry; - for (i = 0; i < pi->ehdr->e_shnum; i++) { - if (!(sechdrs[i].sh_flags & SHF_ALLOC)) - continue; - - if (!(sechdrs[i].sh_flags & SHF_EXECINSTR)) - continue; - - /* Make entry section relative */ - if (sechdrs[i].sh_addr <= pi->ehdr->e_entry && - ((sechdrs[i].sh_addr + sechdrs[i].sh_size) > - pi->ehdr->e_entry)) { - entry_sidx = i; - kbuf->image->start -= sechdrs[i].sh_addr; - break; - } - } - /* Load SHF_ALLOC sections */ buf_addr = kbuf->buffer; load_addr = curr_load_addr = kbuf->mem; bss_addr = load_addr + kbuf->bufsz; + kbuf->image->start = pi->ehdr->e_entry; for (i = 0; i < pi->ehdr->e_shnum; i++) { unsigned long align; @@ -797,34 +775,40 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, continue; align = sechdrs[i].sh_addralign; - if (sechdrs[i].sh_type != SHT_NOBITS) { - curr_load_addr = ALIGN(curr_load_addr, align); - offset = curr_load_addr - load_addr; - /* We already modifed ->sh_offset to keep src addr */ - src = (char *) sechdrs[i].sh_offset; - memcpy(buf_addr + offset, src, sechdrs[i].sh_size); - - /* Store load address and source address of section */ - sechdrs[i].sh_addr = curr_load_addr; - - /* - * This section got copied to temporary buffer. Update - * ->sh_offset accordingly. - */ - sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset); - - /* Advance to the next address */ - curr_load_addr += sechdrs[i].sh_size; - } else { + + if (sechdrs[i].sh_type == SHT_NOBITS) { bss_addr = ALIGN(bss_addr, align); sechdrs[i].sh_addr = bss_addr; bss_addr += sechdrs[i].sh_size; + continue; + } + + curr_load_addr = ALIGN(curr_load_addr, align); + offset = curr_load_addr - load_addr; + /* We already modifed ->sh_offset to keep src addr */ + src = (char *)sechdrs[i].sh_offset; + memcpy(buf_addr + offset, src, sechdrs[i].sh_size); + + if (sechdrs[i].sh_flags & SHF_EXECINSTR && + pi->ehdr->e_entry >= sechdrs[i].sh_addr && + pi->ehdr->e_entry < (sechdrs[i].sh_addr + + sechdrs[i].sh_size)) { + kbuf->image->start -= sechdrs[i].sh_addr; + kbuf->image->start += curr_load_addr } - } - /* Update entry point based on load address of text section */ - if (entry_sidx >= 0) - kbuf->image->start += sechdrs[entry_sidx].sh_addr; + /* Store load address and source address of section */ + sechdrs[i].sh_addr = curr_load_addr; + + /* + * This section got copied to temporary buffer. Update + * ->sh_offset accordingly. + */ + sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset); + + /* Advance to the next address */ + curr_load_addr += sechdrs[i].sh_size; + } return 0; } -- 2.13.5 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]) by bombadil.infradead.org with esmtps (Exim 4.89 #1 (Red Hat Linux)) id 1ehb4E-0007rh-Q2 for kexec@lists.infradead.org; Fri, 02 Feb 2018 13:07:54 +0000 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w12D6bLI036273 for ; Fri, 2 Feb 2018 08:07:35 -0500 Received: from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com [195.75.94.111]) by mx0a-001b2d01.pphosted.com with ESMTP id 2fvppwn6ng-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 02 Feb 2018 08:07:34 -0500 Received: from localhost by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 2 Feb 2018 13:07:32 -0000 From: Philipp Rudo Subject: [PATCH 07/17] kexec_file: Simplify kexec_purgatory_setup_sechdrs 1 Date: Fri, 2 Feb 2018 14:07:08 +0100 In-Reply-To: <20180202130718.35509-1-prudo@linux.vnet.ibm.com> References: <20180202130718.35509-1-prudo@linux.vnet.ibm.com> Message-Id: <20180202130718.35509-8-prudo@linux.vnet.ibm.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: kexec@lists.infradead.org, linux-s390@vger.kernel.org Cc: prudo@linux.vnet.ibm.com, Michael Ellerman , Heiko Carstens , linux-kernel@vger.kernel.org, Martin Schwidefsky , Eric Biederman , Thiago Jung Bauermann , Vivek Goyal To update the entry point there is an extra loop over all section headers although this can be done in the main loop. So move it there and eliminate the extra loop and variable to store the 'entry section index'. Also, in the main loop, move the usual case, i.e. non-bss section, out of the extra if-block. Signed-off-by: Philipp Rudo Reviewed-by: Martin Schwidefsky --- kernel/kexec_file.c | 76 +++++++++++++++++++++-------------------------------- 1 file changed, 30 insertions(+), 46 deletions(-) diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index d1c3ec8dc6b1..bb31a3b627c2 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -731,7 +731,6 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, unsigned char *buf_addr; unsigned char *src; Elf_Shdr *sechdrs; - int entry_sidx = -1; int i; sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr)); @@ -763,32 +762,11 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, sechdrs[i].sh_offset; } - /* - * Identify entry point section and make entry relative to section - * start. - */ - kbuf->image->start = pi->ehdr->e_entry; - for (i = 0; i < pi->ehdr->e_shnum; i++) { - if (!(sechdrs[i].sh_flags & SHF_ALLOC)) - continue; - - if (!(sechdrs[i].sh_flags & SHF_EXECINSTR)) - continue; - - /* Make entry section relative */ - if (sechdrs[i].sh_addr <= pi->ehdr->e_entry && - ((sechdrs[i].sh_addr + sechdrs[i].sh_size) > - pi->ehdr->e_entry)) { - entry_sidx = i; - kbuf->image->start -= sechdrs[i].sh_addr; - break; - } - } - /* Load SHF_ALLOC sections */ buf_addr = kbuf->buffer; load_addr = curr_load_addr = kbuf->mem; bss_addr = load_addr + kbuf->bufsz; + kbuf->image->start = pi->ehdr->e_entry; for (i = 0; i < pi->ehdr->e_shnum; i++) { unsigned long align; @@ -797,34 +775,40 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, continue; align = sechdrs[i].sh_addralign; - if (sechdrs[i].sh_type != SHT_NOBITS) { - curr_load_addr = ALIGN(curr_load_addr, align); - offset = curr_load_addr - load_addr; - /* We already modifed ->sh_offset to keep src addr */ - src = (char *) sechdrs[i].sh_offset; - memcpy(buf_addr + offset, src, sechdrs[i].sh_size); - - /* Store load address and source address of section */ - sechdrs[i].sh_addr = curr_load_addr; - - /* - * This section got copied to temporary buffer. Update - * ->sh_offset accordingly. - */ - sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset); - - /* Advance to the next address */ - curr_load_addr += sechdrs[i].sh_size; - } else { + + if (sechdrs[i].sh_type == SHT_NOBITS) { bss_addr = ALIGN(bss_addr, align); sechdrs[i].sh_addr = bss_addr; bss_addr += sechdrs[i].sh_size; + continue; + } + + curr_load_addr = ALIGN(curr_load_addr, align); + offset = curr_load_addr - load_addr; + /* We already modifed ->sh_offset to keep src addr */ + src = (char *)sechdrs[i].sh_offset; + memcpy(buf_addr + offset, src, sechdrs[i].sh_size); + + if (sechdrs[i].sh_flags & SHF_EXECINSTR && + pi->ehdr->e_entry >= sechdrs[i].sh_addr && + pi->ehdr->e_entry < (sechdrs[i].sh_addr + + sechdrs[i].sh_size)) { + kbuf->image->start -= sechdrs[i].sh_addr; + kbuf->image->start += curr_load_addr } - } - /* Update entry point based on load address of text section */ - if (entry_sidx >= 0) - kbuf->image->start += sechdrs[entry_sidx].sh_addr; + /* Store load address and source address of section */ + sechdrs[i].sh_addr = curr_load_addr; + + /* + * This section got copied to temporary buffer. Update + * ->sh_offset accordingly. + */ + sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset); + + /* Advance to the next address */ + curr_load_addr += sechdrs[i].sh_size; + } return 0; } -- 2.13.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec