Messages in this thread | | | Date | Mon, 8 Dec 2014 18:14:04 +0000 | From | Al Viro <> | Subject | Re: [RFC][PATCHES] iov_iter.c rewrite |
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On Mon, Dec 08, 2014 at 10:07:55AM -0800, Linus Torvalds wrote:
> Which is in the vmalloc address space. So somebody used a vmalloc'ed > address and tried to convert it to a physical address in order to look > up the page. > > Which is not a valid operation, and the BUG_ON() is definitely proper. > > Now *why* something tried to do a virt_to_page() on a vmalloc'ed > address, that I leave to others.
iov_iter_get_pages() in ITER_KVEC case, trying to avoid get_user_pages_fast() and getting it wrong. FWIW, the reproducer is finit_module(fd, ....) where fd has been opened with O_DIRECT. In that case we get kernel_read() on O_DIRECT and the buffer has just been vmalloc'ed.
What's the sane way to grab struct page * for a vmalloc'ed address?
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