Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964834AbVJMAyY (ORCPT ); Wed, 12 Oct 2005 20:54:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932494AbVJMAyY (ORCPT ); Wed, 12 Oct 2005 20:54:24 -0400 Received: from gold.veritas.com ([143.127.12.110]:27154 "EHLO gold.veritas.com") by vger.kernel.org with ESMTP id S932483AbVJMAyX (ORCPT ); Wed, 12 Oct 2005 20:54:23 -0400 Date: Thu, 13 Oct 2005 01:53:38 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@goblin.wat.veritas.com To: Andrew Morton cc: Tony Luck , linux-kernel@vger.kernel.org Subject: [PATCH 08/21] mm: ia64 use expand_upwards In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 13 Oct 2005 00:54:23.0102 (UTC) FILETIME=[A6D319E0:01C5CF90] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5267 Lines: 131 ia64 has expand_backing_store function for growing its Register Backing Store vma upwards. But more complete code for this purpose is found in the CONFIG_STACK_GROWSUP part of mm/mmap.c. Uglify its #ifdefs further to provide expand_upwards for ia64 as well as expand_stack for parisc. The Register Backing Store vma should be marked VM_ACCOUNT. Implement the intention of growing it only a page at a time, instead of passing an address outside of the vma to handle_mm_fault, with unknown consequences. Signed-off-by: Hugh Dickins --- arch/ia64/mm/fault.c | 34 +++++++--------------------------- arch/ia64/mm/init.c | 2 +- include/linux/mm.h | 3 ++- mm/mmap.c | 17 ++++++++++++++--- 4 files changed, 24 insertions(+), 32 deletions(-) --- mm07/arch/ia64/mm/fault.c 2005-09-30 11:58:53.000000000 +0100 +++ mm08/arch/ia64/mm/fault.c 2005-10-11 23:55:38.000000000 +0100 @@ -20,32 +20,6 @@ extern void die (char *, struct pt_regs *, long); /* - * This routine is analogous to expand_stack() but instead grows the - * register backing store (which grows towards higher addresses). - * Since the register backing store is access sequentially, we - * disallow growing the RBS by more than a page at a time. Note that - * the VM_GROWSUP flag can be set on any VM area but that's fine - * because the total process size is still limited by RLIMIT_STACK and - * RLIMIT_AS. - */ -static inline long -expand_backing_store (struct vm_area_struct *vma, unsigned long address) -{ - unsigned long grow; - - grow = PAGE_SIZE >> PAGE_SHIFT; - if (address - vma->vm_start > current->signal->rlim[RLIMIT_STACK].rlim_cur - || (((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) > current->signal->rlim[RLIMIT_AS].rlim_cur)) - return -ENOMEM; - vma->vm_end += PAGE_SIZE; - vma->vm_mm->total_vm += grow; - if (vma->vm_flags & VM_LOCKED) - vma->vm_mm->locked_vm += grow; - vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, grow); - return 0; -} - -/* * Return TRUE if ADDRESS points at a page in the kernel's mapped segment * (inside region 5, on ia64) and that page is present. */ @@ -185,7 +159,13 @@ ia64_do_page_fault (unsigned long addres if (REGION_NUMBER(address) != REGION_NUMBER(vma->vm_start) || REGION_OFFSET(address) >= RGN_MAP_LIMIT) goto bad_area; - if (expand_backing_store(vma, address)) + /* + * Since the register backing store is accessed sequentially, + * we disallow growing it by more than a page at a time. + */ + if (address > vma->vm_end + PAGE_SIZE - sizeof(long)) + goto bad_area; + if (expand_upwards(vma, address)) goto bad_area; } goto good_area; --- mm07/arch/ia64/mm/init.c 2005-09-21 12:16:14.000000000 +0100 +++ mm08/arch/ia64/mm/init.c 2005-10-11 23:55:38.000000000 +0100 @@ -158,7 +158,7 @@ ia64_init_addr_space (void) vma->vm_start = current->thread.rbs_bot & PAGE_MASK; vma->vm_end = vma->vm_start + PAGE_SIZE; vma->vm_page_prot = protection_map[VM_DATA_DEFAULT_FLAGS & 0x7]; - vma->vm_flags = VM_DATA_DEFAULT_FLAGS | VM_GROWSUP; + vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT; down_write(¤t->mm->mmap_sem); if (insert_vm_struct(current->mm, vma)) { up_write(¤t->mm->mmap_sem); --- mm07/include/linux/mm.h 2005-10-11 23:54:33.000000000 +0100 +++ mm08/include/linux/mm.h 2005-10-11 23:55:38.000000000 +0100 @@ -904,7 +904,8 @@ void handle_ra_miss(struct address_space unsigned long max_sane_readahead(unsigned long nr); /* Do stack extension */ -extern int expand_stack(struct vm_area_struct * vma, unsigned long address); +extern int expand_stack(struct vm_area_struct *vma, unsigned long address); +extern int expand_upwards(struct vm_area_struct *vma, unsigned long address); /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr); --- mm07/mm/mmap.c 2005-10-11 23:54:33.000000000 +0100 +++ mm08/mm/mmap.c 2005-10-11 23:55:38.000000000 +0100 @@ -1504,11 +1504,15 @@ static int acct_stack_growth(struct vm_a return 0; } -#ifdef CONFIG_STACK_GROWSUP +#if defined(CONFIG_STACK_GROWSUP) || defined(CONFIG_IA64) /* - * vma is the first one with address > vma->vm_end. Have to extend vma. + * PA-RISC uses this for its stack; IA64 for its Register Backing Store. + * vma is the last one with address > vma->vm_end. Have to extend vma. */ -int expand_stack(struct vm_area_struct * vma, unsigned long address) +#ifdef CONFIG_STACK_GROWSUP +static inline +#endif +int expand_upwards(struct vm_area_struct *vma, unsigned long address) { int error; @@ -1546,6 +1550,13 @@ int expand_stack(struct vm_area_struct * anon_vma_unlock(vma); return error; } +#endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */ + +#ifdef CONFIG_STACK_GROWSUP +int expand_stack(struct vm_area_struct *vma, unsigned long address) +{ + return expand_upwards(vma, address); +} struct vm_area_struct * find_extend_vma(struct mm_struct *mm, unsigned long addr) - 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/