X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fnommu.c;h=7695dc850785e853f066e63992c242ffee14c30c;hb=5faff78904d9c07f38ac0e227b322e9f58d5447c;hp=9eef6a3985554fa9b69c54a0334865e54247e478;hpb=b50731732f926d6c49fd0724616a7344c31cd5cf;p=safe%2Fjmp%2Flinux-2.6 diff --git a/mm/nommu.c b/mm/nommu.c index 9eef6a39..7695dc8 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -10,8 +10,10 @@ * Copyright (c) 2000-2003 David McCullough * Copyright (c) 2000-2001 D Jeff Dionne * Copyright (c) 2002 Greg Ungerer + * Copyright (c) 2007 Paul Mundt */ +#include #include #include #include @@ -20,7 +22,7 @@ #include #include #include -#include +#include #include #include #include @@ -32,19 +34,20 @@ #include #include +#include "internal.h" + void *high_memory; struct page *mem_map; unsigned long max_mapnr; unsigned long num_physpages; unsigned long askedalloc, realalloc; -atomic_t vm_committed_space = ATOMIC_INIT(0); +atomic_long_t vm_committed_space = ATOMIC_LONG_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(__vm_enough_memory); EXPORT_SYMBOL(num_physpages); /* list of shareable VMAs */ @@ -104,32 +107,39 @@ unsigned int kobjsize(const void *objp) { struct page *page; - if (!objp || !((page = virt_to_page(objp)))) + /* + * If the object we have should not have ksize performed on it, + * return size of 0 + */ + if (!objp || !virt_addr_valid(objp)) return 0; + page = virt_to_head_page(objp); + + /* + * If the allocator sets PageSlab, we know the pointer came from + * kmalloc(). + */ if (PageSlab(page)) return ksize(objp); - BUG_ON(page->index < 0); - BUG_ON(page->index >= MAX_ORDER); - - return (PAGE_SIZE << page->index); + /* + * The ksize() function is only guaranteed to work for pointers + * returned by kmalloc(). So handle arbitrary pointers here. + */ + return PAGE_SIZE << compound_order(page); } -/* - * get a list of pages in an address range belonging to the specified process - * and indicate the VMA that covers each page - * - this is potentially dodgy as we may end incrementing the page count of a - * slab page or a secondary page from a compound page - * - don't permit access to VMAs that don't support it, such as I/O mappings - */ -int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, int len, int write, int force, - struct page **pages, struct vm_area_struct **vmas) +int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, int len, int flags, + struct page **pages, struct vm_area_struct **vmas) { struct vm_area_struct *vma; unsigned long vm_flags; int i; + int write = !!(flags & GUP_FLAGS_WRITE); + int force = !!(flags & GUP_FLAGS_FORCE); + int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS); /* calculate required read or write permissions. * - if 'force' is set, we only require the "MAY" flags. @@ -144,7 +154,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, /* protect what we can, including chardevs */ if (vma->vm_flags & (VM_IO | VM_PFNMAP) || - !(vm_flags & vma->vm_flags)) + (!ignore && !(vm_flags & vma->vm_flags))) goto finish_or_fault; if (pages) { @@ -162,12 +172,36 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, finish_or_fault: return i ? : -EFAULT; } + + +/* + * get a list of pages in an address range belonging to the specified process + * and indicate the VMA that covers each page + * - this is potentially dodgy as we may end incrementing the page count of a + * slab page or a secondary page from a compound page + * - don't permit access to VMAs that don't support it, such as I/O mappings + */ +int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, int len, int write, int force, + struct page **pages, struct vm_area_struct **vmas) +{ + int flags = 0; + + if (write) + flags |= GUP_FLAGS_WRITE; + if (force) + flags |= GUP_FLAGS_FORCE; + + return __get_user_pages(tsk, mm, + start, len, flags, + pages, vmas); +} EXPORT_SYMBOL(get_user_pages); DEFINE_RWLOCK(vmlist_lock); struct vm_struct *vmlist; -void vfree(void *addr) +void vfree(const void *addr) { kfree(addr); } @@ -176,19 +210,40 @@ EXPORT_SYMBOL(vfree); void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) { /* - * kmalloc doesn't like __GFP_HIGHMEM for some reason + * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() + * returns only a logical address. */ return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); } EXPORT_SYMBOL(__vmalloc); -struct page * vmalloc_to_page(void *addr) +void *vmalloc_user(unsigned long size) +{ + void *ret; + + ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, + PAGE_KERNEL); + if (ret) { + struct vm_area_struct *vma; + + down_write(¤t->mm->mmap_sem); + vma = find_vma(current->mm, (unsigned long)ret); + if (vma) + vma->vm_flags |= VM_USERMAP; + up_write(¤t->mm->mmap_sem); + } + + return ret; +} +EXPORT_SYMBOL(vmalloc_user); + +struct page *vmalloc_to_page(const void *addr) { return virt_to_page(addr); } EXPORT_SYMBOL(vmalloc_to_page); -unsigned long vmalloc_to_pfn(void *addr) +unsigned long vmalloc_to_pfn(const void *addr) { return page_to_pfn(virt_to_page(addr)); } @@ -233,6 +288,27 @@ void *vmalloc_node(unsigned long size, int node) } EXPORT_SYMBOL(vmalloc_node); +#ifndef PAGE_KERNEL_EXEC +# define PAGE_KERNEL_EXEC PAGE_KERNEL +#endif + +/** + * vmalloc_exec - allocate virtually contiguous, executable memory + * @size: allocation size + * + * Kernel-internal function to allocate enough pages to cover @size + * the page level allocator and map them into contiguous and + * executable kernel virtual space. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. + */ + +void *vmalloc_exec(unsigned long size) +{ + return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); +} + /** * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) * @size: allocation size @@ -252,10 +328,17 @@ EXPORT_SYMBOL(vmalloc_32); * * The resulting memory area is 32bit addressable and zeroed so it can be * mapped to userspace without leaking data. + * + * VM_USERMAP is set on the corresponding VMA so that subsequent calls to + * remap_vmalloc_range() are permissible. */ void *vmalloc_32_user(unsigned long size) { - return __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL); + /* + * We'll have to sort out the ZONE_DMA bits for 64-bit, + * but for now this can simply use vmalloc_user() directly. + */ + return vmalloc_user(size); } EXPORT_SYMBOL(vmalloc_32_user); @@ -266,7 +349,7 @@ void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_ } EXPORT_SYMBOL(vmap); -void vunmap(void *addr) +void vunmap(const void *addr) { BUG(); } @@ -705,7 +788,7 @@ static unsigned long determine_vm_flags(struct file *file, * it's being traced - otherwise breakpoints set in it may interfere * with another untraced process */ - if ((flags & MAP_PRIVATE) && (current->ptrace & PT_PTRACED)) + if ((flags & MAP_PRIVATE) && tracehook_expect_breakpoints(current)) vm_flags &= ~VM_MAYSHARE; return vm_flags; @@ -828,6 +911,9 @@ unsigned long do_mmap_pgoff(struct file *file, void *result; int ret; + if (!(flags & MAP_FIXED)) + addr = round_hint_to_min(addr); + /* decide whether we should attempt the mapping, and if so what sort of * mapping */ ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, @@ -930,8 +1016,13 @@ unsigned long do_mmap_pgoff(struct file *file, INIT_LIST_HEAD(&vma->anon_vma_node); atomic_set(&vma->vm_usage, 1); - if (file) + if (file) { get_file(file); + if (vm_flags & VM_EXECUTABLE) { + added_exe_file_vma(current->mm); + vma->vm_mm = current->mm; + } + } vma->vm_file = file; vma->vm_flags = vm_flags; vma->vm_start = addr; @@ -986,8 +1077,11 @@ unsigned long do_mmap_pgoff(struct file *file, up_write(&nommu_vma_sem); kfree(vml); if (vma) { - if (vma->vm_file) + if (vma->vm_file) { fput(vma->vm_file); + if (vma->vm_flags & VM_EXECUTABLE) + removed_exe_file_vma(vma->vm_mm); + } kfree(vma); } return ret; @@ -1017,7 +1111,7 @@ EXPORT_SYMBOL(do_mmap_pgoff); /* * handle mapping disposal for uClinux */ -static void put_vma(struct vm_area_struct *vma) +static void put_vma(struct mm_struct *mm, struct vm_area_struct *vma) { if (vma) { down_write(&nommu_vma_sem); @@ -1039,8 +1133,11 @@ static void put_vma(struct vm_area_struct *vma) realalloc -= kobjsize(vma); askedalloc -= sizeof(*vma); - if (vma->vm_file) + if (vma->vm_file) { fput(vma->vm_file); + if (vma->vm_flags & VM_EXECUTABLE) + removed_exe_file_vma(mm); + } kfree(vma); } @@ -1077,7 +1174,7 @@ int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len) found: vml = *parent; - put_vma(vml->vma); + put_vma(mm, vml->vma); *parent = vml->next; realalloc -= kobjsize(vml); @@ -1122,7 +1219,7 @@ void exit_mmap(struct mm_struct * mm) while ((tmp = mm->context.vmlist)) { mm->context.vmlist = tmp->next; - put_vma(tmp->vma); + put_vma(mm, tmp->vma); realalloc -= kobjsize(tmp); askedalloc -= sizeof(*tmp); @@ -1212,6 +1309,21 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, } EXPORT_SYMBOL(remap_pfn_range); +int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, + unsigned long pgoff) +{ + unsigned int size = vma->vm_end - vma->vm_start; + + if (!(vma->vm_flags & VM_USERMAP)) + return -EINVAL; + + vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); + vma->vm_end = vma->vm_start + size; + + return 0; +} +EXPORT_SYMBOL(remap_vmalloc_range); + void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) { } @@ -1270,7 +1382,7 @@ EXPORT_SYMBOL(get_unmapped_area); * 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) +int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) { unsigned long free, allowed; @@ -1342,13 +1454,14 @@ int __vm_enough_memory(long pages, int cap_sys_admin) /* 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 (mm) + allowed -= mm->total_vm / 32; /* * cast `allowed' as a signed long because vm_committed_space * sometimes has a negative value */ - if (atomic_read(&vm_committed_space) < (long)allowed) + if (atomic_long_read(&vm_committed_space) < (long)allowed) return 0; error: vm_unacct_memory(pages);