On 07/10/15 at 10:54P, Michael Holzheu wrote:
> On Fri, 10 Jul 2015 13:12:17 +0800
> Minfei Huang <mnfhuang at gmail.com> wrote:
>
> > For some arch, kexec shall map the reserved pages, then use them, when
> > we try to start the kdump service.
> >
> > Now kexec will never unmap the reserved pages, once it fails to continue
> > starting the kdump service. So we make a pair of map/unmap reserved
> > pages whatever kexec fails or not in code path.
> >
> > In order to make code readable, wrap a new function __kexec_load which
> > contains all of the logic to deal with the image loading.
> >
> > Signed-off-by: Minfei Huang <mnfhuang at gmail.com>
> > ---
> > v3:
> > - reconstruct the patch, wrap a new function to deal with the code logic, based on Vivek and Michael's patch
> > v2:
> > - replace the "failure" label with "fail_unmap_pages"
> > v1:
> > - reconstruct the patch code
> > ---
> > kernel/kexec.c | 112 ++++++++++++++++++++++++++++++++-------------------------
> > 1 file changed, 63 insertions(+), 49 deletions(-)
> >
> > diff --git a/kernel/kexec.c b/kernel/kexec.c
> > index a785c10..2232c90 100644
> > --- a/kernel/kexec.c
> > +++ b/kernel/kexec.c
> > @@ -1247,10 +1247,71 @@ int kexec_load_disabled;
> >
> > static DEFINE_MUTEX(kexec_mutex);
> >
> > +static int __kexec_load(unsigned long entry, unsigned long nr_segments,
> > + struct kexec_segment __user *segments,
> > + unsigned long flags)
> > +{
> > + int result = 0;
> > + struct kimage **dest_image, *image;
> > +
> > + dest_image = &kexec_image;
> > +
> > + if (flags & KEXEC_ON_CRASH)
> > + dest_image = &kexec_crash_image;
> > +
> > + if (nr_segments == 0) {
> > + /* Install the new kernel, and Uninstall the old */
> > + image = xchg(dest_image, image);
> > + kimage_free(image);
>
> Well this is wrong and should probably be:
>
> if (nr_segments == 0) {
> /* Uninstall image */
> image = xchg(dest_image, NULL);
> kimage_free(image);
>
You are right. It should be what you commented.
> > + } else {
> > + unsigned long i;
> > +
> > + if (flags & KEXEC_ON_CRASH) {
> > + /*
>
> [snip]
>
> > + result = kimage_load_segment(image, &image->segment[i]);
> > + if (result)
> > + goto failure_unmap_mem;
> > + }
> > +
> > + kimage_terminate(image);
> > +
> > + /* Install the new kernel, and Uninstall the old */
>
> Perhaps fix the comment: Remove superfluous blank and lowercase "uninstall"?
>
Thanks.
Minfei
