Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752239Ab3CEHhm (ORCPT ); Tue, 5 Mar 2013 02:37:42 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:63745 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750781Ab3CEHhl convert rfc822-to-8bit (ORCPT ); Tue, 5 Mar 2013 02:37:41 -0500 X-IronPort-AV: E=Sophos;i="4.84,785,1355068800"; d="scan'208";a="6815568" Message-ID: <5135A054.7010401@cn.fujitsu.com> Date: Tue, 05 Mar 2013 15:35:48 +0800 From: Zhang Yanfei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.8) Gecko/20121012 Thunderbird/10.0.8 MIME-Version: 1.0 To: HATAYAMA Daisuke CC: vgoyal@redhat.com, ebiederm@xmission.com, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, heiko.carstens@de.ibm.com, akpm@linux-foundation.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 01/20] vmcore: refer to e_phoff member explicitly References: <20130302083447.31252.93914.stgit@localhost6.localdomain6> <20130302083554.31252.30615.stgit@localhost6.localdomain6> In-Reply-To: <20130302083554.31252.30615.stgit@localhost6.localdomain6> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/03/05 15:36:37, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/03/05 15:36:38 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7583 Lines: 187 于 2013年03月02日 16:35, HATAYAMA Daisuke 写道: > Code around /proc/vmcore currently assumes program header table is > next to ELF header. But future change can break the assumption on > kexec-tools and the 1st kernel. To avoid worst case, now refer to > e_phoff member that indicates position of program header table in > file-offset. Reviewed-by: Zhang Yanfei > > Signed-off-by: HATAYAMA Daisuke > --- > > fs/proc/vmcore.c | 40 ++++++++++++++++++++-------------------- > 1 files changed, 20 insertions(+), 20 deletions(-) > > diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c > index b870f74..abf4f01 100644 > --- a/fs/proc/vmcore.c > +++ b/fs/proc/vmcore.c > @@ -221,8 +221,8 @@ static u64 __init get_vmcore_size_elf64(char *elfptr) > Elf64_Phdr *phdr_ptr; > > ehdr_ptr = (Elf64_Ehdr *)elfptr; > - phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); > - size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr)); > + phdr_ptr = (Elf64_Phdr*)(elfptr + ehdr_ptr->e_phoff); > + size = ehdr_ptr->e_phoff + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr)); > for (i = 0; i < ehdr_ptr->e_phnum; i++) { > size += phdr_ptr->p_memsz; > phdr_ptr++; > @@ -238,8 +238,8 @@ static u64 __init get_vmcore_size_elf32(char *elfptr) > Elf32_Phdr *phdr_ptr; > > ehdr_ptr = (Elf32_Ehdr *)elfptr; > - phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); > - size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr)); > + phdr_ptr = (Elf32_Phdr*)(elfptr + ehdr_ptr->e_phoff); > + size = ehdr_ptr->e_phoff + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr)); > for (i = 0; i < ehdr_ptr->e_phnum; i++) { > size += phdr_ptr->p_memsz; > phdr_ptr++; > @@ -259,7 +259,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, > u64 phdr_sz = 0, note_off; > > ehdr_ptr = (Elf64_Ehdr *)elfptr; > - phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); > + phdr_ptr = (Elf64_Phdr*)(elfptr + ehdr_ptr->e_phoff); > for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { > int j; > void *notes_section; > @@ -305,7 +305,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, > /* Prepare merged PT_NOTE program header. */ > phdr.p_type = PT_NOTE; > phdr.p_flags = 0; > - note_off = sizeof(Elf64_Ehdr) + > + note_off = ehdr_ptr->e_phoff + > (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr); > phdr.p_offset = note_off; > phdr.p_vaddr = phdr.p_paddr = 0; > @@ -313,14 +313,14 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, > phdr.p_align = 0; > > /* Add merged PT_NOTE program header*/ > - tmp = elfptr + sizeof(Elf64_Ehdr); > + tmp = elfptr + ehdr_ptr->e_phoff; > memcpy(tmp, &phdr, sizeof(phdr)); > tmp += sizeof(phdr); > > /* Remove unwanted PT_NOTE program headers. */ > i = (nr_ptnote - 1) * sizeof(Elf64_Phdr); > *elfsz = *elfsz - i; > - memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr))); > + memmove(tmp, tmp+i, ((*elfsz)-ehdr_ptr->e_phoff-sizeof(Elf64_Phdr))); > > /* Modify e_phnum to reflect merged headers. */ > ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; > @@ -340,7 +340,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, > u64 phdr_sz = 0, note_off; > > ehdr_ptr = (Elf32_Ehdr *)elfptr; > - phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); > + phdr_ptr = (Elf32_Phdr*)(elfptr + ehdr_ptr->e_phoff); > for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { > int j; > void *notes_section; > @@ -386,7 +386,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, > /* Prepare merged PT_NOTE program header. */ > phdr.p_type = PT_NOTE; > phdr.p_flags = 0; > - note_off = sizeof(Elf32_Ehdr) + > + note_off = ehdr_ptr->e_phoff + > (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr); > phdr.p_offset = note_off; > phdr.p_vaddr = phdr.p_paddr = 0; > @@ -394,14 +394,14 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, > phdr.p_align = 0; > > /* Add merged PT_NOTE program header*/ > - tmp = elfptr + sizeof(Elf32_Ehdr); > + tmp = elfptr + ehdr_ptr->e_phoff; > memcpy(tmp, &phdr, sizeof(phdr)); > tmp += sizeof(phdr); > > /* Remove unwanted PT_NOTE program headers. */ > i = (nr_ptnote - 1) * sizeof(Elf32_Phdr); > *elfsz = *elfsz - i; > - memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr))); > + memmove(tmp, tmp+i, ((*elfsz)-ehdr_ptr->e_phoff-sizeof(Elf32_Phdr))); > > /* Modify e_phnum to reflect merged headers. */ > ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; > @@ -422,10 +422,10 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, > struct vmcore *new; > > ehdr_ptr = (Elf64_Ehdr *)elfptr; > - phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ > + phdr_ptr = (Elf64_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */ > > /* First program header is PT_NOTE header. */ > - vmcore_off = sizeof(Elf64_Ehdr) + > + vmcore_off = ehdr_ptr->e_phoff + > (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) + > phdr_ptr->p_memsz; /* Note sections */ > > @@ -459,10 +459,10 @@ static int __init process_ptload_program_headers_elf32(char *elfptr, > struct vmcore *new; > > ehdr_ptr = (Elf32_Ehdr *)elfptr; > - phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */ > + phdr_ptr = (Elf32_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */ > > /* First program header is PT_NOTE header. */ > - vmcore_off = sizeof(Elf32_Ehdr) + > + vmcore_off = ehdr_ptr->e_phoff + > (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) + > phdr_ptr->p_memsz; /* Note sections */ > > @@ -496,7 +496,7 @@ static void __init set_vmcore_list_offsets_elf64(char *elfptr, > ehdr_ptr = (Elf64_Ehdr *)elfptr; > > /* Skip Elf header and program headers. */ > - vmcore_off = sizeof(Elf64_Ehdr) + > + vmcore_off = ehdr_ptr->e_phoff + > (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr); > > list_for_each_entry(m, vc_list, list) { > @@ -516,7 +516,7 @@ static void __init set_vmcore_list_offsets_elf32(char *elfptr, > ehdr_ptr = (Elf32_Ehdr *)elfptr; > > /* Skip Elf header and program headers. */ > - vmcore_off = sizeof(Elf32_Ehdr) + > + vmcore_off = ehdr_ptr->e_phoff + > (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr); > > list_for_each_entry(m, vc_list, list) { > @@ -553,7 +553,7 @@ static int __init parse_crash_elf64_headers(void) > } > > /* Read in all elf headers. */ > - elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr); > + elfcorebuf_sz = ehdr.e_phoff + ehdr.e_phnum * sizeof(Elf64_Phdr); > elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL); > if (!elfcorebuf) > return -ENOMEM; > @@ -608,7 +608,7 @@ static int __init parse_crash_elf32_headers(void) > } > > /* Read in all elf headers. */ > - elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr); > + elfcorebuf_sz = ehdr.e_phoff + ehdr.e_phnum * sizeof(Elf32_Phdr); > elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL); > if (!elfcorebuf) > return -ENOMEM; > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/