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[PATCH] mm: ia64 use expand_upwards
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 <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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4 changed files with 24 additions and 32 deletions
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@ -19,32 +19,6 @@
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extern void die (char *, struct pt_regs *, long);
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/*
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* This routine is analogous to expand_stack() but instead grows the
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* register backing store (which grows towards higher addresses).
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* Since the register backing store is access sequentially, we
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* disallow growing the RBS by more than a page at a time. Note that
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* the VM_GROWSUP flag can be set on any VM area but that's fine
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* because the total process size is still limited by RLIMIT_STACK and
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* RLIMIT_AS.
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*/
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static inline long
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expand_backing_store (struct vm_area_struct *vma, unsigned long address)
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{
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unsigned long grow;
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grow = PAGE_SIZE >> PAGE_SHIFT;
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if (address - vma->vm_start > current->signal->rlim[RLIMIT_STACK].rlim_cur
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|| (((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) > current->signal->rlim[RLIMIT_AS].rlim_cur))
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return -ENOMEM;
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vma->vm_end += PAGE_SIZE;
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vma->vm_mm->total_vm += grow;
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if (vma->vm_flags & VM_LOCKED)
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vma->vm_mm->locked_vm += grow;
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vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, grow);
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return 0;
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}
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/*
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* Return TRUE if ADDRESS points at a page in the kernel's mapped segment
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* (inside region 5, on ia64) and that page is present.
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@ -185,7 +159,13 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
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if (REGION_NUMBER(address) != REGION_NUMBER(vma->vm_start)
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|| REGION_OFFSET(address) >= RGN_MAP_LIMIT)
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goto bad_area;
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if (expand_backing_store(vma, address))
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/*
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* Since the register backing store is accessed sequentially,
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* we disallow growing it by more than a page at a time.
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*/
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if (address > vma->vm_end + PAGE_SIZE - sizeof(long))
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goto bad_area;
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if (expand_upwards(vma, address))
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goto bad_area;
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}
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goto good_area;
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@ -158,7 +158,7 @@ ia64_init_addr_space (void)
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vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
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vma->vm_end = vma->vm_start + PAGE_SIZE;
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vma->vm_page_prot = protection_map[VM_DATA_DEFAULT_FLAGS & 0x7];
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vma->vm_flags = VM_DATA_DEFAULT_FLAGS | VM_GROWSUP;
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vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
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down_write(¤t->mm->mmap_sem);
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if (insert_vm_struct(current->mm, vma)) {
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up_write(¤t->mm->mmap_sem);
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@ -896,7 +896,8 @@ void handle_ra_miss(struct address_space *mapping,
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unsigned long max_sane_readahead(unsigned long nr);
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/* Do stack extension */
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extern int expand_stack(struct vm_area_struct * vma, unsigned long address);
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extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
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extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
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/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
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extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
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17
mm/mmap.c
17
mm/mmap.c
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@ -1508,11 +1508,15 @@ static int acct_stack_growth(struct vm_area_struct * vma, unsigned long size, un
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return 0;
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}
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#ifdef CONFIG_STACK_GROWSUP
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#if defined(CONFIG_STACK_GROWSUP) || defined(CONFIG_IA64)
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/*
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* vma is the first one with address > vma->vm_end. Have to extend vma.
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* PA-RISC uses this for its stack; IA64 for its Register Backing Store.
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* vma is the last one with address > vma->vm_end. Have to extend vma.
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*/
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int expand_stack(struct vm_area_struct * vma, unsigned long address)
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#ifdef CONFIG_STACK_GROWSUP
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static inline
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#endif
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int expand_upwards(struct vm_area_struct *vma, unsigned long address)
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{
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int error;
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@ -1550,6 +1554,13 @@ int expand_stack(struct vm_area_struct * vma, unsigned long address)
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anon_vma_unlock(vma);
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return error;
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}
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#endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
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#ifdef CONFIG_STACK_GROWSUP
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int expand_stack(struct vm_area_struct *vma, unsigned long address)
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{
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return expand_upwards(vma, address);
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}
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struct vm_area_struct *
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find_extend_vma(struct mm_struct *mm, unsigned long addr)
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