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author | HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> | 2013-07-03 22:02:18 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-03 23:07:30 (GMT) |
commit | e69e9d4aee712a22665f008ae0550bb3d7c7f7c1 (patch) | |
tree | bb63cd5b881678c902f6b5e197a107022825be30 /mm/vmalloc.c | |
parent | cef2ac3f6c8ab532e49cf69d05f540931ad8ee64 (diff) | |
download | linux-e69e9d4aee712a22665f008ae0550bb3d7c7f7c1.tar.xz |
vmalloc: introduce remap_vmalloc_range_partial
We want to allocate ELF note segment buffer on the 2nd kernel in vmalloc
space and remap it to user-space in order to reduce the risk that memory
allocation fails on system with huge number of CPUs and so with huge ELF
note segment that exceeds 11-order block size.
Although there's already remap_vmalloc_range for the purpose of
remapping vmalloc memory to user-space, we need to specify user-space
range via vma.
Mmap on /proc/vmcore needs to remap range across multiple objects, so
the interface that requires vma to cover full range is problematic.
This patch introduces remap_vmalloc_range_partial that receives user-space
range as a pair of base address and size and can be used for mmap on
/proc/vmcore case.
remap_vmalloc_range is rewritten using remap_vmalloc_range_partial.
[akpm@linux-foundation.org: use PAGE_ALIGNED()]
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
-rw-r--r-- | mm/vmalloc.c | 67 |
1 files changed, 45 insertions, 22 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 3875fa2..b725990 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1476,10 +1476,9 @@ static void __vunmap(const void *addr, int deallocate_pages) if (!addr) return; - if ((PAGE_SIZE-1) & (unsigned long)addr) { - WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr); + if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n", + addr)); return; - } area = remove_vm_area(addr); if (unlikely(!area)) { @@ -2148,42 +2147,43 @@ finished: } /** - * remap_vmalloc_range - map vmalloc pages to userspace - * @vma: vma to cover (map full range of vma) - * @addr: vmalloc memory - * @pgoff: number of pages into addr before first page to map + * remap_vmalloc_range_partial - map vmalloc pages to userspace + * @vma: vma to cover + * @uaddr: target user address to start at + * @kaddr: virtual address of vmalloc kernel memory + * @size: size of map area * * Returns: 0 for success, -Exxx on failure * - * This function checks that addr is a valid vmalloc'ed area, and - * that it is big enough to cover the vma. Will return failure if - * that criteria isn't met. + * This function checks that @kaddr is a valid vmalloc'ed area, + * and that it is big enough to cover the range starting at + * @uaddr in @vma. Will return failure if that criteria isn't + * met. * * Similar to remap_pfn_range() (see mm/memory.c) */ -int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, - unsigned long pgoff) +int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, + void *kaddr, unsigned long size) { struct vm_struct *area; - unsigned long uaddr = vma->vm_start; - unsigned long usize = vma->vm_end - vma->vm_start; - if ((PAGE_SIZE-1) & (unsigned long)addr) + size = PAGE_ALIGN(size); + + if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr)) return -EINVAL; - area = find_vm_area(addr); + area = find_vm_area(kaddr); if (!area) return -EINVAL; if (!(area->flags & VM_USERMAP)) return -EINVAL; - if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE) + if (kaddr + size > area->addr + area->size) return -EINVAL; - addr += pgoff << PAGE_SHIFT; do { - struct page *page = vmalloc_to_page(addr); + struct page *page = vmalloc_to_page(kaddr); int ret; ret = vm_insert_page(vma, uaddr, page); @@ -2191,14 +2191,37 @@ int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, return ret; uaddr += PAGE_SIZE; - addr += PAGE_SIZE; - usize -= PAGE_SIZE; - } while (usize > 0); + kaddr += PAGE_SIZE; + size -= PAGE_SIZE; + } while (size > 0); vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; return 0; } +EXPORT_SYMBOL(remap_vmalloc_range_partial); + +/** + * remap_vmalloc_range - map vmalloc pages to userspace + * @vma: vma to cover (map full range of vma) + * @addr: vmalloc memory + * @pgoff: number of pages into addr before first page to map + * + * Returns: 0 for success, -Exxx on failure + * + * This function checks that addr is a valid vmalloc'ed area, and + * that it is big enough to cover the vma. Will return failure if + * that criteria isn't met. + * + * Similar to remap_pfn_range() (see mm/memory.c) + */ +int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, + unsigned long pgoff) +{ + return remap_vmalloc_range_partial(vma, vma->vm_start, + addr + (pgoff << PAGE_SHIFT), + vma->vm_end - vma->vm_start); +} EXPORT_SYMBOL(remap_vmalloc_range); /* |