X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=mm%2Fnommu.c;h=ef55210e550888212c9fba9876942338a2490d14;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=dd4b66b8c9a6dff09e59a33cda029a035521f65f;hpb=87fc8d1bb10cd459024a742c6a10961fefcef18f;p=linux-2.6.git diff --git a/mm/nommu.c b/mm/nommu.c index dd4b66b8c..ef55210e5 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -4,6 +4,9 @@ * Replacement code for mm functions to support CPU's that don't * have any form of memory management unit (thus no virtual memory). * + * See Documentation/nommu-mmap.txt + * + * Copyright (c) 2004-2005 David Howells * Copyright (c) 2000-2003 David McCullough * Copyright (c) 2000-2001 D Jeff Dionne * Copyright (c) 2002 Greg Ungerer @@ -12,13 +15,18 @@ #include #include #include -#include +#include #include #include #include #include +#include #include #include +#include +#include +#include +#include #include #include @@ -32,9 +40,22 @@ unsigned long askedalloc, realalloc; atomic_t vm_committed_space = ATOMIC_INIT(0); int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ int sysctl_overcommit_ratio = 50; /* default is 50% */ - int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; +int heap_stack_gap = 0; + +EXPORT_SYMBOL(mem_map); EXPORT_SYMBOL(sysctl_max_map_count); +EXPORT_SYMBOL(sysctl_overcommit_memory); +EXPORT_SYMBOL(sysctl_overcommit_ratio); +EXPORT_SYMBOL(vm_committed_space); +EXPORT_SYMBOL(__vm_enough_memory); + +/* list of shareable VMAs */ +struct rb_root nommu_vma_tree = RB_ROOT; +DECLARE_RWSEM(nommu_vma_sem); + +struct vm_operations_struct generic_file_vm_ops = { +}; /* * Handle all mappings that got truncated by a "truncate()" @@ -57,7 +78,7 @@ int vmtruncate(struct inode *inode, loff_t offset) goto out_truncate; do_expand: - limit = current->rlim[RLIMIT_FSIZE].rlim_cur; + limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; if (limit != RLIM_INFINITY && offset > limit) goto out_sig; if (offset > inode->i_sb->s_maxbytes) @@ -74,6 +95,8 @@ out: return -EFBIG; } +EXPORT_SYMBOL(vmtruncate); + /* * Return the total memory allocated for this pointer, not * just what the caller asked for. @@ -119,7 +142,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, return(i); } -rwlock_t vmlist_lock = RW_LOCK_UNLOCKED; +DEFINE_RWLOCK(vmlist_lock); struct vm_struct *vmlist; void vfree(void *addr) @@ -140,6 +163,12 @@ struct page * vmalloc_to_page(void *addr) return virt_to_page(addr); } +unsigned long vmalloc_to_pfn(void *addr) +{ + return page_to_pfn(virt_to_page(addr)); +} + + long vread(char *buf, char *addr, unsigned long count) { memcpy(buf, addr, count); @@ -151,7 +180,7 @@ long vwrite(char *buf, char *addr, unsigned long count) /* Don't allow overflow */ if ((unsigned long) addr + count < count) count = -(unsigned long) addr; - + memcpy(addr, buf, count); return(count); } @@ -207,7 +236,7 @@ asmlinkage unsigned long sys_brk(unsigned long brk) { struct mm_struct *mm = current->mm; - if (brk < mm->end_code || brk < mm->start_brk || brk > mm->context.end_brk) + if (brk < mm->start_brk || brk > mm->context.end_brk) return mm->brk; if (mm->brk == brk) @@ -253,49 +282,127 @@ static inline unsigned long calc_vm_flags(unsigned long prot, unsigned long flag #ifdef DEBUG static void show_process_blocks(void) { - struct mm_tblock_struct *tblock; + struct vm_list_struct *vml; printk("Process blocks %d:", current->pid); - for (tblock = ¤t->mm->context.tblock; tblock; tblock = tblock->next) { - printk(" %p: %p", tblock, tblock->rblock); - if (tblock->rblock) - printk(" (%d @%p #%d)", kobjsize(tblock->rblock->kblock), tblock->rblock->kblock, tblock->rblock->refcount); - printk(tblock->next ? " ->" : ".\n"); + for (vml = ¤t->mm->context.vmlist; vml; vml = vml->next) { + printk(" %p: %p", vml, vml->vma); + if (vml->vma) + printk(" (%d @%lx #%d)", + kobjsize((void *) vml->vma->vm_start), + vml->vma->vm_start, + atomic_read(&vml->vma->vm_usage)); + printk(vml->next ? " ->" : ".\n"); } } #endif /* DEBUG */ -unsigned long do_mmap_pgoff( - struct file * file, - unsigned long addr, - unsigned long len, - unsigned long prot, - unsigned long flags, - unsigned long pgoff) +static inline struct vm_area_struct *find_nommu_vma(unsigned long start) { - void * result; - struct mm_tblock_struct * tblock; - unsigned int vm_flags; + struct vm_area_struct *vma; + struct rb_node *n = nommu_vma_tree.rb_node; + + while (n) { + vma = rb_entry(n, struct vm_area_struct, vm_rb); + + if (start < vma->vm_start) + n = n->rb_left; + else if (start > vma->vm_start) + n = n->rb_right; + else + return vma; + } - /* - * Get the !CONFIG_MMU specific checks done first - */ - if ((flags & MAP_SHARED) && (prot & PROT_WRITE) && (file)) { - printk("MAP_SHARED not supported (cannot write mappings to disk)\n"); - return -EINVAL; + return NULL; +} + +static void add_nommu_vma(struct vm_area_struct *vma) +{ + struct vm_area_struct *pvma; + struct address_space *mapping; + struct rb_node **p = &nommu_vma_tree.rb_node; + struct rb_node *parent = NULL; + + /* add the VMA to the mapping */ + if (vma->vm_file) { + mapping = vma->vm_file->f_mapping; + + flush_dcache_mmap_lock(mapping); + vma_prio_tree_insert(vma, &mapping->i_mmap); + flush_dcache_mmap_unlock(mapping); } - - if ((prot & PROT_WRITE) && (flags & MAP_PRIVATE)) { - printk("Private writable mappings not supported\n"); + + /* add the VMA to the master list */ + while (*p) { + parent = *p; + pvma = rb_entry(parent, struct vm_area_struct, vm_rb); + + if (vma->vm_start < pvma->vm_start) { + p = &(*p)->rb_left; + } + else if (vma->vm_start > pvma->vm_start) { + p = &(*p)->rb_right; + } + else { + /* mappings are at the same address - this can only + * happen for shared-mem chardevs and shared file + * mappings backed by ramfs/tmpfs */ + BUG_ON(!(pvma->vm_flags & VM_SHARED)); + + if (vma < pvma) + p = &(*p)->rb_left; + else if (vma > pvma) + p = &(*p)->rb_right; + else + BUG(); + } + } + + rb_link_node(&vma->vm_rb, parent, p); + rb_insert_color(&vma->vm_rb, &nommu_vma_tree); +} + +static void delete_nommu_vma(struct vm_area_struct *vma) +{ + struct address_space *mapping; + + /* remove the VMA from the mapping */ + if (vma->vm_file) { + mapping = vma->vm_file->f_mapping; + + flush_dcache_mmap_lock(mapping); + vma_prio_tree_remove(vma, &mapping->i_mmap); + flush_dcache_mmap_unlock(mapping); + } + + /* remove from the master list */ + rb_erase(&vma->vm_rb, &nommu_vma_tree); +} + +/* + * handle mapping creation for uClinux + */ +unsigned long do_mmap_pgoff(struct file *file, + unsigned long addr, + unsigned long len, + unsigned long prot, + unsigned long flags, + unsigned long pgoff) +{ + struct vm_list_struct *vml = NULL; + struct vm_area_struct *vma = NULL; + struct rb_node *rb; + unsigned int vm_flags; + void *result; + int ret, membacked; + + /* do the simple checks first */ + if (flags & MAP_FIXED || addr) { + printk(KERN_DEBUG "%d: Can't do fixed-address/overlay mmap of RAM\n", + current->pid); return -EINVAL; } - - /* - * now all the standard checks - */ - if (file && (!file->f_op || !file->f_op->mmap)) - return -ENODEV; if (PAGE_ALIGN(len) == 0) return addr; @@ -307,147 +414,380 @@ unsigned long do_mmap_pgoff( if ((pgoff + (len >> PAGE_SHIFT)) < pgoff) return -EINVAL; - /* Do simple checking here so the lower-level routines won't have + /* validate file mapping requests */ + membacked = 0; + if (file) { + /* files must support mmap */ + if (!file->f_op || !file->f_op->mmap) + return -ENODEV; + + if ((prot & PROT_EXEC) && + (file->f_vfsmnt->mnt_flags & MNT_NOEXEC)) + return -EPERM; + + /* work out if what we've got could possibly be shared + * - we support chardevs that provide their own "memory" + * - we support files/blockdevs that are memory backed + */ + if (S_ISCHR(file->f_dentry->d_inode->i_mode)) { + membacked = 1; + } + else { + struct address_space *mapping = file->f_mapping; + if (!mapping) + mapping = file->f_dentry->d_inode->i_mapping; + if (mapping && mapping->backing_dev_info) + membacked = mapping->backing_dev_info->memory_backed; + } + + if (flags & MAP_SHARED) { + /* do checks for writing, appending and locking */ + if ((prot & PROT_WRITE) && !(file->f_mode & FMODE_WRITE)) + return -EACCES; + + if (IS_APPEND(file->f_dentry->d_inode) && + (file->f_mode & FMODE_WRITE)) + return -EACCES; + + if (locks_verify_locked(file->f_dentry->d_inode)) + return -EAGAIN; + + if (!membacked) { + printk("MAP_SHARED not completely supported on !MMU\n"); + return -EINVAL; + } + + /* we require greater support from the driver or + * filesystem - we ask it to tell us what memory to + * use */ + if (!file->f_op->get_unmapped_area) + return -ENODEV; + } + else { + /* we read private files into memory we allocate */ + if (!file->f_op->read) + return -ENODEV; + } + } + + /* handle PROT_EXEC implication by PROT_READ */ + if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC)) + if (!(file && (file->f_vfsmnt->mnt_flags & MNT_NOEXEC))) + prot |= PROT_EXEC; + + /* do simple checking here so the lower-level routines won't have * to. we assume access permissions have been handled by the open * of the memory object, so we don't do any here. */ - vm_flags = calc_vm_flags(prot,flags) /* | mm->def_flags */ | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; + vm_flags = calc_vm_flags(prot,flags) /* | mm->def_flags */ + | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; + + if (!membacked) { + /* share any file segment that's mapped read-only */ + if (((flags & MAP_PRIVATE) && !(prot & PROT_WRITE) && file) || + ((flags & MAP_SHARED) && !(prot & PROT_WRITE) && file)) + vm_flags |= VM_MAYSHARE; + + /* refuse to let anyone share files with this process if it's being traced - + * otherwise breakpoints set in it may interfere with another untraced process + */ + if (current->ptrace & PT_PTRACED) + vm_flags &= ~(VM_SHARED | VM_MAYSHARE); + } + else { + /* permit sharing of character devices and ramfs files at any time for + * anything other than a privately writable mapping + */ + if (!(flags & MAP_PRIVATE) || !(prot & PROT_WRITE)) { + vm_flags |= VM_MAYSHARE; + if (flags & MAP_SHARED) + vm_flags |= VM_SHARED; + } + } - /* - * determine the object being mapped and call the appropriate - * specific mapper. + /* allow the security API to have its say */ + ret = security_file_mmap(file, prot, flags); + if (ret) + return ret; + + /* we're going to need to record the mapping if it works */ + vml = kmalloc(sizeof(struct vm_list_struct), GFP_KERNEL); + if (!vml) + goto error_getting_vml; + memset(vml, 0, sizeof(*vml)); + + down_write(&nommu_vma_sem); + + /* if we want to share, we need to search for VMAs created by another + * mmap() call that overlap with our proposed mapping + * - we can only share with an exact match on most regular files + * - shared mappings on character devices and memory backed files are + * permitted to overlap inexactly as far as we are concerned for in + * these cases, sharing is handled in the driver or filesystem rather + * than here */ - if (file) { - struct vm_area_struct vma; - int error; + if (vm_flags & VM_MAYSHARE) { + unsigned long pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned long vmpglen; - if (!file->f_op) - return -ENODEV; + for (rb = rb_first(&nommu_vma_tree); rb; rb = rb_next(rb)) { + vma = rb_entry(rb, struct vm_area_struct, vm_rb); + + if (!(vma->vm_flags & VM_MAYSHARE)) + continue; - vma.vm_start = addr; - vma.vm_end = addr + len; - vma.vm_flags = vm_flags; - vma.vm_pgoff = pgoff; + /* search for overlapping mappings on the same file */ + if (vma->vm_file->f_dentry->d_inode != file->f_dentry->d_inode) + continue; + + if (vma->vm_pgoff >= pgoff + pglen) + continue; + + vmpglen = (vma->vm_end - vma->vm_start + PAGE_SIZE - 1) >> PAGE_SHIFT; + if (pgoff >= vma->vm_pgoff + vmpglen) + continue; + + /* handle inexact matches between mappings */ + if (vmpglen != pglen || vma->vm_pgoff != pgoff) { + if (!membacked) + goto sharing_violation; + continue; + } + + /* we've found a VMA we can share */ + atomic_inc(&vma->vm_usage); + + vml->vma = vma; + result = (void *) vma->vm_start; + goto shared; + } + } + + vma = NULL; + + /* obtain the address to map to. we verify (or select) it and ensure + * that it represents a valid section of the address space + * - this is the hook for quasi-memory character devices + */ + if (file && file->f_op->get_unmapped_area) { + addr = file->f_op->get_unmapped_area(file, addr, len, pgoff, flags); + if (IS_ERR((void *) addr)) { + ret = addr; + if (ret == (unsigned long) -ENOSYS) + ret = (unsigned long) -ENODEV; + goto error; + } + } + /* we're going to need a VMA struct as well */ + vma = kmalloc(sizeof(struct vm_area_struct), GFP_KERNEL); + if (!vma) + goto error_getting_vma; + + memset(vma, 0, sizeof(*vma)); + INIT_LIST_HEAD(&vma->anon_vma_node); + atomic_set(&vma->vm_usage, 1); + if (file) + get_file(file); + vma->vm_file = file; + vma->vm_flags = vm_flags; + vma->vm_start = addr; + vma->vm_end = addr + len; + vma->vm_pgoff = pgoff; + + vml->vma = vma; + + /* determine the object being mapped and call the appropriate specific + * mapper. + */ + if (file) { #ifdef MAGIC_ROM_PTR /* First, try simpler routine designed to give us a ROM pointer. */ - if (file->f_op->romptr && !(prot & PROT_WRITE)) { - error = file->f_op->romptr(file, &vma); + ret = file->f_op->romptr(file, vma); #ifdef DEBUG - printk("romptr mmap returned %d, start 0x%.8x\n", error, - vma.vm_start); + printk("romptr mmap returned %d (st=%lx)\n", + ret, vma->vm_start); #endif - if (!error) - return vma.vm_start; - else if (error != -ENOSYS) - return error; + result = (void *) vma->vm_start; + if (!ret) + goto done; + else if (ret != -ENOSYS) + goto error; } else #endif /* MAGIC_ROM_PTR */ - /* Then try full mmap routine, which might return a RAM pointer, - or do something truly complicated. */ - + /* Then try full mmap routine, which might return a RAM + * pointer, or do something truly complicated + */ if (file->f_op->mmap) { - error = file->f_op->mmap(file, &vma); - + ret = file->f_op->mmap(file, vma); + #ifdef DEBUG - printk("f_op->mmap() returned %d/%lx\n", error, vma.vm_start); + printk("f_op->mmap() returned %d (st=%lx)\n", + ret, vma->vm_start); #endif - if (!error) - return vma.vm_start; - else if (error != -ENOSYS) - return error; - } else - return -ENODEV; /* No mapping operations defined */ - - /* An ENOSYS error indicates that mmap isn't possible (as opposed to - tried but failed) so we'll fall through to the copy. */ - } - - tblock = (struct mm_tblock_struct *) - kmalloc(sizeof(struct mm_tblock_struct), GFP_KERNEL); - if (!tblock) { - printk("Allocation of tblock for %lu byte allocation from process %d failed\n", len, current->pid); - show_free_areas(); - return -ENOMEM; - } - - tblock->rblock = (struct mm_rblock_struct *) - kmalloc(sizeof(struct mm_rblock_struct), GFP_KERNEL); + result = (void *) vma->vm_start; + if (!ret) + goto done; + else if (ret != -ENOSYS) + goto error; + } else { + ret = -ENODEV; /* No mapping operations defined */ + goto error; + } - if (!tblock->rblock) { - printk("Allocation of rblock for %lu byte allocation from process %d failed\n", len, current->pid); - show_free_areas(); - kfree(tblock); - return -ENOMEM; + /* An ENOSYS error indicates that mmap isn't possible (as + * opposed to tried but failed) so we'll fall through to the + * copy. */ } + /* allocate some memory to hold the mapping + * - note that this may not return a page-aligned address if the object + * we're allocating is smaller than a page + */ + ret = -ENOMEM; result = kmalloc(len, GFP_KERNEL); if (!result) { - printk("Allocation of length %lu from process %d failed\n", len, - current->pid); + printk("Allocation of length %lu from process %d failed\n", + len, current->pid); show_free_areas(); - kfree(tblock->rblock); - kfree(tblock); - return -ENOMEM; + goto error; } - tblock->rblock->refcount = 1; - tblock->rblock->kblock = result; - tblock->rblock->size = len; - - realalloc += kobjsize(result); - askedalloc += len; + vma->vm_start = (unsigned long) result; + vma->vm_end = vma->vm_start + len; -#ifdef WARN_ON_SLACK - if ((len+WARN_ON_SLACK) <= kobjsize(result)) - printk("Allocation of %lu bytes from process %d has %lu bytes of slack\n", len, current->pid, kobjsize(result)-len); +#ifdef WARN_ON_SLACK + if (len + WARN_ON_SLACK <= kobjsize(result)) + printk("Allocation of %lu bytes from process %d has %lu bytes of slack\n", + len, current->pid, kobjsize(result) - len); #endif - + if (file) { - int error; mm_segment_t old_fs = get_fs(); + loff_t fpos; + + fpos = pgoff; + fpos <<= PAGE_SHIFT; + set_fs(KERNEL_DS); - error = file->f_op->read(file, (char *) result, len, &file->f_pos); + ret = file->f_op->read(file, (char *) result, len, &fpos); set_fs(old_fs); - if (error < 0) { - kfree(result); - kfree(tblock->rblock); - kfree(tblock); - return error; - } - if (error < len) - memset(result+error, '\0', len-error); + + if (ret < 0) + goto error2; + if (ret < len) + memset(result + ret, 0, len - ret); } else { - memset(result, '\0', len); + memset(result, 0, len); + } + + if (prot & PROT_EXEC) + flush_icache_range((unsigned long) result, (unsigned long) result + len); + + done: + if (!(vma->vm_flags & VM_SHARED)) { + realalloc += kobjsize(result); + askedalloc += len; } - realalloc += kobjsize(tblock); - askedalloc += sizeof(struct mm_tblock_struct); + realalloc += kobjsize(vma); + askedalloc += sizeof(*vma); + + // current->mm->total_vm += len >> PAGE_SHIFT; + vx_vmpages_add(current->mm, len >> PAGE_SHIFT); - realalloc += kobjsize(tblock->rblock); - askedalloc += sizeof(struct mm_rblock_struct); + add_nommu_vma(vma); + shared: + realalloc += kobjsize(vml); + askedalloc += sizeof(*vml); - tblock->next = current->mm->context.tblock.next; - current->mm->context.tblock.next = tblock; + vml->next = current->mm->context.vmlist; + current->mm->context.vmlist = vml; + + up_write(&nommu_vma_sem); #ifdef DEBUG printk("do_mmap:\n"); show_process_blocks(); -#endif +#endif + + return (unsigned long) result; + + error2: + kfree(result); + error: + up_write(&nommu_vma_sem); + kfree(vml); + if (vma) { + fput(vma->vm_file); + kfree(vma); + } + return ret; + + sharing_violation: + up_write(&nommu_vma_sem); + printk("Attempt to share mismatched mappings\n"); + kfree(vml); + return -EINVAL; + + error_getting_vma: + up_write(&nommu_vma_sem); + kfree(vml); + printk("Allocation of vml for %lu byte allocation from process %d failed\n", + len, current->pid); + show_free_areas(); + return -ENOMEM; - return (unsigned long)result; + error_getting_vml: + printk("Allocation of vml for %lu byte allocation from process %d failed\n", + len, current->pid); + show_free_areas(); + return -ENOMEM; } -int do_munmap(struct mm_struct * mm, unsigned long addr, size_t len) +/* + * handle mapping disposal for uClinux + */ +static void put_vma(struct vm_area_struct *vma) { - struct mm_tblock_struct * tblock, *tmp; + if (vma) { + down_write(&nommu_vma_sem); + + if (atomic_dec_and_test(&vma->vm_usage)) { + delete_nommu_vma(vma); + + if (vma->vm_ops && vma->vm_ops->close) + vma->vm_ops->close(vma); + + /* IO memory and memory shared directly out of the pagecache from + * ramfs/tmpfs mustn't be released here */ + if (!(vma->vm_flags & (VM_IO | VM_SHARED)) && vma->vm_start) { + realalloc -= kobjsize((void *) vma->vm_start); + askedalloc -= vma->vm_end - vma->vm_start; + kfree((void *) vma->vm_start); + } + + realalloc -= kobjsize(vma); + askedalloc -= sizeof(*vma); + + if (vma->vm_file) + fput(vma->vm_file); + kfree(vma); + } + + up_write(&nommu_vma_sem); + } +} + +int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len) +{ + struct vm_list_struct *vml, **parent; + unsigned long end = addr + len; #ifdef MAGIC_ROM_PTR - /* - * For efficiency's sake, if the pointer is obviously in ROM, - * don't bother walking the lists to free it. - */ + /* For efficiency's sake, if the pointer is obviously in ROM, + don't bother walking the lists to free it */ if (is_in_rom(addr)) return 0; #endif @@ -456,37 +796,30 @@ int do_munmap(struct mm_struct * mm, unsigned long addr, size_t len) printk("do_munmap:\n"); #endif - tmp = &mm->context.tblock; /* dummy head */ - while ((tblock=tmp->next) && tblock->rblock && - tblock->rblock->kblock != (void*)addr) - tmp = tblock; - - if (!tblock) { - printk("munmap of non-mmaped memory by process %d (%s): %p\n", - current->pid, current->comm, (void*)addr); - return -EINVAL; - } - if (tblock->rblock) { - if (!--tblock->rblock->refcount) { - if (tblock->rblock->kblock) { - realalloc -= kobjsize(tblock->rblock->kblock); - askedalloc -= tblock->rblock->size; - kfree(tblock->rblock->kblock); - } - - realalloc -= kobjsize(tblock->rblock); - askedalloc -= sizeof(struct mm_rblock_struct); - kfree(tblock->rblock); - } - } - tmp->next = tblock->next; - realalloc -= kobjsize(tblock); - askedalloc -= sizeof(struct mm_tblock_struct); - kfree(tblock); + for (parent = &mm->context.vmlist; *parent; parent = &(*parent)->next) + if ((*parent)->vma->vm_start == addr && + (*parent)->vma->vm_end == end) + goto found; + + printk("munmap of non-mmaped memory by process %d (%s): %p\n", + current->pid, current->comm, (void *) addr); + return -EINVAL; + + found: + vml = *parent; + + put_vma(vml->vma); + + *parent = vml->next; + realalloc -= kobjsize(vml); + askedalloc -= sizeof(*vml); + kfree(vml); + // mm->total_vm -= len >> PAGE_SHIFT; + vx_vmpages_sub(mm, len >> PAGE_SHIFT); #ifdef DEBUG show_process_blocks(); -#endif +#endif return 0; } @@ -494,38 +827,29 @@ int do_munmap(struct mm_struct * mm, unsigned long addr, size_t len) /* Release all mmaps. */ void exit_mmap(struct mm_struct * mm) { - struct mm_tblock_struct *tmp; - - if (!mm) - return; + struct vm_list_struct *tmp; + if (mm) { #ifdef DEBUG - printk("Exit_mmap:\n"); + printk("Exit_mmap:\n"); #endif - while((tmp = mm->context.tblock.next)) { - if (tmp->rblock) { - if (!--tmp->rblock->refcount) { - if (tmp->rblock->kblock) { - realalloc -= kobjsize(tmp->rblock->kblock); - askedalloc -= tmp->rblock->size; - kfree(tmp->rblock->kblock); - } - realalloc -= kobjsize(tmp->rblock); - askedalloc -= sizeof(struct mm_rblock_struct); - kfree(tmp->rblock); - } - tmp->rblock = 0; + // mm->total_vm = 0; + vx_vmpages_sub(mm, mm->total_vm); + + while ((tmp = mm->context.vmlist)) { + mm->context.vmlist = tmp->next; + put_vma(tmp->vma); + + realalloc -= kobjsize(tmp); + askedalloc -= sizeof(*tmp); + kfree(tmp); } - mm->context.tblock.next = tmp->next; - realalloc -= kobjsize(tmp); - askedalloc -= sizeof(struct mm_tblock_struct); - kfree(tmp); - } #ifdef DEBUG - show_process_blocks(); -#endif + show_process_blocks(); +#endif + } } asmlinkage long sys_munmap(unsigned long addr, size_t len) @@ -544,11 +868,70 @@ unsigned long do_brk(unsigned long addr, unsigned long len) return -ENOMEM; } -struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr) +/* + * Expand (or shrink) an existing mapping, potentially moving it at the + * same time (controlled by the MREMAP_MAYMOVE flag and available VM space) + * + * MREMAP_FIXED option added 5-Dec-1999 by Benjamin LaHaise + * This option implies MREMAP_MAYMOVE. + * + * on uClinux, we only permit changing a mapping's size, and only as long as it stays within the + * hole allocated by the kmalloc() call in do_mmap_pgoff() and the block is not shareable + */ +unsigned long do_mremap(unsigned long addr, + unsigned long old_len, unsigned long new_len, + unsigned long flags, unsigned long new_addr) { + struct vm_list_struct *vml = NULL; + + /* insanity checks first */ + if (new_len == 0) + return (unsigned long) -EINVAL; + + if (flags & MREMAP_FIXED && new_addr != addr) + return (unsigned long) -EINVAL; + + for (vml = current->mm->context.vmlist; vml; vml = vml->next) + if (vml->vma->vm_start == addr) + goto found; + + return (unsigned long) -EINVAL; + + found: + if (vml->vma->vm_end != vml->vma->vm_start + old_len) + return (unsigned long) -EFAULT; + + if (vml->vma->vm_flags & VM_MAYSHARE) + return (unsigned long) -EPERM; + + if (new_len > kobjsize((void *) addr)) + return (unsigned long) -ENOMEM; + + /* all checks complete - do it */ + vml->vma->vm_end = vml->vma->vm_start + new_len; + + askedalloc -= old_len; + askedalloc += new_len; + + return vml->vma->vm_start; +} + +/* + * Look up the first VMA which satisfies addr < vm_end, NULL if none + */ +struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) +{ + struct vm_list_struct *vml; + + for (vml = mm->context.vmlist; vml; vml = vml->next) + if (addr >= vml->vma->vm_start && addr < vml->vma->vm_end) + return vml->vma; + return NULL; } +EXPORT_SYMBOL(find_vma); + struct page * follow_page(struct mm_struct *mm, unsigned long addr, int write) { return NULL; @@ -559,18 +942,127 @@ struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) return NULL; } -int remap_page_range(struct vm_area_struct *vma, unsigned long from, +int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long to, unsigned long size, pgprot_t prot) { return -EPERM; } -unsigned long get_unmapped_area(struct file *file, unsigned long addr, +void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) +{ +} + +unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { return -ENOMEM; } -void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) +void arch_unmap_area(struct vm_area_struct *area) +{ +} + +void update_mem_hiwater(void) +{ + struct task_struct *tsk = current; + + if (likely(tsk->mm)) { + if (tsk->mm->hiwater_rss < tsk->mm->rss) + tsk->mm->hiwater_rss = tsk->mm->rss; + if (tsk->mm->hiwater_vm < tsk->mm->total_vm) + tsk->mm->hiwater_vm = tsk->mm->total_vm; + } +} + +void unmap_mapping_range(struct address_space *mapping, + loff_t const holebegin, loff_t const holelen, + int even_cows) +{ +} + +/* + * Check that a process has enough memory to allocate a new virtual + * mapping. 0 means there is enough memory for the allocation to + * succeed and -ENOMEM implies there is not. + * + * We currently support three overcommit policies, which are set via the + * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting + * + * Strict overcommit modes added 2002 Feb 26 by Alan Cox. + * Additional code 2002 Jul 20 by Robert Love. + * + * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. + * + * Note this is a helper function intended to be used by LSMs which + * wish to use this logic. + */ +int __vm_enough_memory(long pages, int cap_sys_admin) { + unsigned long free, allowed; + + vm_acct_memory(pages); + + /* + * Sometimes we want to use more memory than we have + */ + if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) + return 0; + + if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { + unsigned long n; + + free = get_page_cache_size(); + free += nr_swap_pages; + + /* + * Any slabs which are created with the + * SLAB_RECLAIM_ACCOUNT flag claim to have contents + * which are reclaimable, under pressure. The dentry + * cache and most inode caches should fall into this + */ + free += atomic_read(&slab_reclaim_pages); + + /* + * Leave the last 3% for root + */ + if (!cap_sys_admin) + free -= free / 32; + + if (free > pages) + return 0; + + /* + * nr_free_pages() is very expensive on large systems, + * only call if we're about to fail. + */ + n = nr_free_pages(); + if (!cap_sys_admin) + n -= n / 32; + free += n; + + if (free > pages) + return 0; + vm_unacct_memory(pages); + return -ENOMEM; + } + + allowed = totalram_pages * sysctl_overcommit_ratio / 100; + /* + * Leave the last 3% for root + */ + if (!cap_sys_admin) + allowed -= allowed / 32; + allowed += total_swap_pages; + + /* Don't let a single process grow too big: + leave 3% of the size of this process for other processes */ + allowed -= current->mm->total_vm / 32; + + if (atomic_read(&vm_committed_space) < allowed) + return 0; + + vm_unacct_memory(pages); + + return -ENOMEM; } +