diff options
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 70 |
1 files changed, 54 insertions, 16 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index d3d9a94ca031..d44bee96a5fe 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -25,6 +25,7 @@ #include <linux/personality.h> #include <linux/security.h> #include <linux/hugetlb.h> +#include <linux/shmem_fs.h> #include <linux/profile.h> #include <linux/export.h> #include <linux/mount.h> @@ -168,7 +169,7 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma) return next; } -static unsigned long do_brk(unsigned long addr, unsigned long len); +static int do_brk(unsigned long addr, unsigned long len); SYSCALL_DEFINE1(brk, unsigned long, brk) { @@ -224,7 +225,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) goto out; /* Ok, looks good - let it rip. */ - if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk) + if (do_brk(oldbrk, newbrk-oldbrk) < 0) goto out; set_brk: @@ -620,7 +621,6 @@ int vma_adjust(struct vm_area_struct *vma, unsigned long start, { struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *next = vma->vm_next; - struct vm_area_struct *importer = NULL; struct address_space *mapping = NULL; struct rb_root *root = NULL; struct anon_vma *anon_vma = NULL; @@ -630,17 +630,25 @@ int vma_adjust(struct vm_area_struct *vma, unsigned long start, int remove_next = 0; if (next && !insert) { - struct vm_area_struct *exporter = NULL; + struct vm_area_struct *exporter = NULL, *importer = NULL; if (end >= next->vm_end) { /* * vma expands, overlapping all the next, and * perhaps the one after too (mprotect case 6). */ -again: remove_next = 1 + (end > next->vm_end); + remove_next = 1 + (end > next->vm_end); end = next->vm_end; exporter = next; importer = vma; + + /* + * If next doesn't have anon_vma, import from vma after + * next, if the vma overlaps with it. + */ + if (remove_next == 2 && next && !next->anon_vma) + exporter = next->vm_next; + } else if (end > next->vm_start) { /* * vma expands, overlapping part of the next: @@ -674,6 +682,8 @@ again: remove_next = 1 + (end > next->vm_end); return error; } } +again: + vma_adjust_trans_huge(vma, start, end, adjust_next); if (file) { mapping = file->f_mapping; @@ -695,8 +705,6 @@ again: remove_next = 1 + (end > next->vm_end); } } - vma_adjust_trans_huge(vma, start, end, adjust_next); - anon_vma = vma->anon_vma; if (!anon_vma && adjust_next) anon_vma = next->anon_vma; @@ -795,8 +803,11 @@ again: remove_next = 1 + (end > next->vm_end); * up the code too much to do both in one go. */ next = vma->vm_next; - if (remove_next == 2) + if (remove_next == 2) { + remove_next = 1; + end = next->vm_end; goto again; + } else if (next) vma_gap_update(next); else @@ -1897,8 +1908,19 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, return -ENOMEM; get_area = current->mm->get_unmapped_area; - if (file && file->f_op->get_unmapped_area) - get_area = file->f_op->get_unmapped_area; + if (file) { + if (file->f_op->get_unmapped_area) + get_area = file->f_op->get_unmapped_area; + } else if (flags & MAP_SHARED) { + /* + * mmap_region() will call shmem_zero_setup() to create a file, + * so use shmem's get_unmapped_area in case it can be huge. + * do_mmap_pgoff() will clear pgoff, so match alignment. + */ + pgoff = 0; + get_area = shmem_get_unmapped_area; + } + addr = get_area(file, addr, len, pgoff, flags); if (IS_ERR_VALUE(addr)) return addr; @@ -2591,6 +2613,12 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, /* drop PG_Mlocked flag for over-mapped range */ for (tmp = vma; tmp->vm_start >= start + size; tmp = tmp->vm_next) { + /* + * Split pmd and munlock page on the border + * of the range. + */ + vma_adjust_trans_huge(tmp, start, start + size, 0); + munlock_vma_pages_range(tmp, max(tmp->vm_start, start), min(tmp->vm_end, start + size)); @@ -2625,7 +2653,7 @@ static inline void verify_mm_writelocked(struct mm_struct *mm) * anonymous maps. eventually we may be able to do some * brk-specific accounting here. */ -static unsigned long do_brk(unsigned long addr, unsigned long len) +static int do_brk(unsigned long addr, unsigned long len) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev; @@ -2636,7 +2664,7 @@ static unsigned long do_brk(unsigned long addr, unsigned long len) len = PAGE_ALIGN(len); if (!len) - return addr; + return 0; flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags; @@ -2703,13 +2731,13 @@ out: if (flags & VM_LOCKED) mm->locked_vm += (len >> PAGE_SHIFT); vma->vm_flags |= VM_SOFTDIRTY; - return addr; + return 0; } -unsigned long vm_brk(unsigned long addr, unsigned long len) +int vm_brk(unsigned long addr, unsigned long len) { struct mm_struct *mm = current->mm; - unsigned long ret; + int ret; bool populate; if (down_write_killable(&mm->mmap_sem)) @@ -2718,7 +2746,7 @@ unsigned long vm_brk(unsigned long addr, unsigned long len) ret = do_brk(addr, len); populate = ((mm->def_flags & VM_LOCKED) != 0); up_write(&mm->mmap_sem); - if (populate) + if (populate && !ret) mm_populate(addr, len); return ret; } @@ -2943,9 +2971,19 @@ static const char *special_mapping_name(struct vm_area_struct *vma) return ((struct vm_special_mapping *)vma->vm_private_data)->name; } +static int special_mapping_mremap(struct vm_area_struct *new_vma) +{ + struct vm_special_mapping *sm = new_vma->vm_private_data; + + if (sm->mremap) + return sm->mremap(sm, new_vma); + return 0; +} + static const struct vm_operations_struct special_mapping_vmops = { .close = special_mapping_close, .fault = special_mapping_fault, + .mremap = special_mapping_mremap, .name = special_mapping_name, }; |