Messages in this thread | | | Date | Tue, 15 Sep 2009 11:34:25 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH 1/3] vmalloc: ignore vmalloc area holes in vwrite() |
| |
On Tue, 15 Sep 2009 10:18:52 +0800 Wu Fengguang <fengguang.wu@intel.com> wrote:
> Siliently ignore all vmalloc area holes in vwrite(), > and report success to the caller even if nothing is written. > > CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Why don't you modify vread() at the same time ? Because /proc/kcore ignores return value of vread(), I think you can modify it without no side-effect.
Regards, -Kame
> --- > mm/vmalloc.c | 13 ++----------- > 1 file changed, 2 insertions(+), 11 deletions(-) > > --- linux-mm.orig/mm/vmalloc.c 2009-09-15 10:08:33.000000000 +0800 > +++ linux-mm/mm/vmalloc.c 2009-09-15 10:14:18.000000000 +0800 > @@ -1805,10 +1805,8 @@ finished: > * @addr: vm address. > * @count: number of bytes to be read. > * > - * Returns # of bytes which addr and buf should be incresed. > + * Returns # of bytes which addr and buf should be increased. > * (same number to @count). > - * If [addr...addr+count) doesn't includes any intersect with valid > - * vmalloc area, returns 0. > * > * This function checks that addr is a valid vmalloc'ed area, and > * copy data from a buffer to the given addr. If specified range of > @@ -1816,8 +1814,6 @@ finished: > * proper area of @buf. If there are memory holes, no copy to hole. > * IOREMAP area is treated as memory hole and no copy is done. > * > - * If [addr...addr+count) doesn't includes any intersects with alive > - * vm_struct area, returns 0. > * @buf should be kernel's buffer. Because this function uses KM_USER0, > * the caller should guarantee KM_USER0 is not used. > * > @@ -1834,7 +1830,6 @@ long vwrite(char *buf, char *addr, unsig > struct vm_struct *tmp; > char *vaddr; > unsigned long n, buflen; > - int copied = 0; > > /* Don't allow overflow */ > if ((unsigned long) addr + count < count) > @@ -1856,18 +1851,14 @@ long vwrite(char *buf, char *addr, unsig > n = vaddr + tmp->size - PAGE_SIZE - addr; > if (n > count) > n = count; > - if (!(tmp->flags & VM_IOREMAP)) { > + if (!(tmp->flags & VM_IOREMAP)) > aligned_vwrite(buf, addr, n); > - copied++; > - } > buf += n; > addr += n; > count -= n; > } > finished: > read_unlock(&vmlist_lock); > - if (!copied) > - return 0; > return buflen; > } > > > -- > >
| |