Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932121Ab3CFPv7 (ORCPT ); Wed, 6 Mar 2013 10:51:59 -0500 Received: from mail-wg0-f46.google.com ([74.125.82.46]:59801 "EHLO mail-wg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755877Ab3CFPv5 (ORCPT ); Wed, 6 Mar 2013 10:51:57 -0500 MIME-Version: 1.0 In-Reply-To: <20130302083616.31252.73787.stgit@localhost6.localdomain6> References: <20130302083447.31252.93914.stgit@localhost6.localdomain6> <20130302083616.31252.73787.stgit@localhost6.localdomain6> Date: Wed, 6 Mar 2013 23:51:55 +0800 Message-ID: Subject: Re: [PATCH v2 05/20] vmcore: round up buffer size of ELF headers by PAGE_SIZE From: Yanfei Zhang 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 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4153 Lines: 94 2013/3/2 HATAYAMA Daisuke : > To satisfy mmap() page-size boundary requirement, round up buffer size > of ELF headers by PAGE_SIZE. The resulting value becomes offset of ELF ~~~~~~~~~~~ ELF header? or ELF program headers? > note segments and it's assigned in unique PT_NOTE program header > entry. > > Also, some part that assumes past ELF headers' size is replaced by > this new rounded-up value. Reviewed-by: Zhang Yanfei > > Signed-off-by: HATAYAMA Daisuke > --- > > fs/proc/vmcore.c | 16 ++++++++-------- > 1 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c > index 1b02d01..c511cf4 100644 > --- a/fs/proc/vmcore.c > +++ b/fs/proc/vmcore.c > @@ -340,7 +340,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, > phdr.p_flags = 0; > note_off = ehdr_ptr->e_phoff + > (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr); > - phdr.p_offset = note_off; > + phdr.p_offset = roundup(note_off, PAGE_SIZE); > phdr.p_vaddr = phdr.p_paddr = 0; > phdr.p_filesz = phdr.p_memsz = phdr_sz; > phdr.p_align = 0; > @@ -353,6 +353,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, > /* Modify e_phnum to reflect merged headers. */ > ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; > > + *elfsz = roundup(*elfsz, PAGE_SIZE); > out: > return 0; > } > @@ -449,7 +450,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, > phdr.p_flags = 0; > note_off = ehdr_ptr->e_phoff + > (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr); > - phdr.p_offset = note_off; > + phdr.p_offset = roundup(note_off, PAGE_SIZE); > phdr.p_vaddr = phdr.p_paddr = 0; > phdr.p_filesz = phdr.p_memsz = phdr_sz; > phdr.p_align = 0; > @@ -462,6 +463,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, > /* Modify e_phnum to reflect merged headers. */ > ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; > > + *elfsz = roundup(*elfsz, PAGE_SIZE); > out: > return 0; > } > @@ -482,9 +484,8 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, > phdr_ptr = (Elf64_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */ > > /* First program header is PT_NOTE header. */ > - vmcore_off = ehdr_ptr->e_phoff + > - (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) + > - phdr_ptr->p_memsz; /* Note sections */ > + vmcore_off = phdr_ptr->p_offset + roundup(phdr_ptr->p_memsz, > + PAGE_SIZE); > > for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { > if (phdr_ptr->p_type != PT_LOAD) > @@ -519,9 +520,8 @@ static int __init process_ptload_program_headers_elf32(char *elfptr, > phdr_ptr = (Elf32_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */ > > /* First program header is PT_NOTE header. */ > - vmcore_off = ehdr_ptr->e_phoff + > - (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) + > - phdr_ptr->p_memsz; /* Note sections */ > + vmcore_off = phdr_ptr->p_offset + roundup(phdr_ptr->p_memsz, > + PAGE_SIZE); > > for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { > if (phdr_ptr->p_type != PT_LOAD) > > -- > 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/ -- 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/