* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
@ 2015-07-07 21:18 ` Vivek Goyal
0 siblings, 0 replies; 16+ messages in thread
From: Vivek Goyal @ 2015-07-07 21:18 UTC (permalink / raw)
To: Minfei Huang
Cc: linux-s390, kexec, heiko.carstens, linux-kernel, ebiederm,
schwidefsky, linux390, holzheu
On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang 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.
>
> Make a pair of reserved pages in kdump starting path, whatever kexec
> fails or not.
>
> Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
> ---
> v2:
> - replace the "failure" label with "fail_unmap_pages"
> v1:
> - reconstruct the patch code
> ---
> kernel/kexec.c | 26 ++++++++++++++------------
> 1 file changed, 14 insertions(+), 12 deletions(-)
>
Hi Minfei,
I am thinking of moving kernel loading code in a separate function to
make things little simpler. Right now it is confusing.
Can you please test attached patch. I have only compile tested it. This
is primarily doing what you are doing but in a separate function. It
seems more readable now.
Thanks
Vivek
---
kernel/kexec.c | 90 +++++++++++++++++++++++++++++++++++----------------------
1 file changed, 56 insertions(+), 34 deletions(-)
Index: rhvgoyal-linux/kernel/kexec.c
===================================================================
--- rhvgoyal-linux.orig/kernel/kexec.c 2015-07-06 13:59:35.088129148 -0400
+++ rhvgoyal-linux/kernel/kexec.c 2015-07-07 17:14:23.593175644 -0400
@@ -1247,6 +1247,57 @@ int kexec_load_disabled;
static DEFINE_MUTEX(kexec_mutex);
+static int __kexec_load(struct kimage **rimage, unsigned long entry,
+ unsigned long nr_segments,
+ struct kexec_segment __user * segments,
+ unsigned long flags)
+{
+ unsigned long i;
+ int result;
+ struct kimage *image;
+
+ if (flags & KEXEC_ON_CRASH) {
+ /*
+ * Loading another kernel to switch to if this one
+ * crashes. Free any current crash dump kernel before
+ * we corrupt it.
+ */
+
+ kimage_free(xchg(&kexec_crash_image, NULL));
+ }
+
+ result = kimage_alloc_init(&image, entry, nr_segments, segments, flags);
+ if (result)
+ return result;
+
+ if (flags & KEXEC_ON_CRASH)
+ crash_map_reserved_pages();
+
+ if (flags & KEXEC_PRESERVE_CONTEXT)
+ image->preserve_context = 1;
+
+ result = machine_kexec_prepare(image);
+ if (result)
+ goto out;
+
+ for (i = 0; i < nr_segments; i++) {
+ result = kimage_load_segment(image, &image->segment[i]);
+ if (result)
+ goto out;
+ }
+
+ kimage_terminate(image);
+ *rimage = image;
+out:
+ if (flags & KEXEC_ON_CRASH)
+ crash_unmap_reserved_pages();
+
+ /* Free image if there was an error */
+ if (result)
+ kimage_free(image);
+ return result;
+}
+
SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
struct kexec_segment __user *, segments, unsigned long, flags)
{
@@ -1292,44 +1343,15 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
dest_image = &kexec_image;
if (flags & KEXEC_ON_CRASH)
dest_image = &kexec_crash_image;
- if (nr_segments > 0) {
- unsigned long i;
- if (flags & KEXEC_ON_CRASH) {
- /*
- * Loading another kernel to switch to if this one
- * crashes. Free any current crash dump kernel before
- * we corrupt it.
- */
-
- kimage_free(xchg(&kexec_crash_image, NULL));
- result = kimage_alloc_init(&image, entry, nr_segments,
- segments, flags);
- crash_map_reserved_pages();
- } else {
- /* Loading another kernel to reboot into. */
-
- result = kimage_alloc_init(&image, entry, nr_segments,
- segments, flags);
- }
- if (result)
- goto out;
-
- if (flags & KEXEC_PRESERVE_CONTEXT)
- image->preserve_context = 1;
- result = machine_kexec_prepare(image);
+ /* Load new kernel */
+ if (nr_segments > 0) {
+ result = __kexec_load(&image, entry, nr_segments, segments,
+ flags);
if (result)
goto out;
-
- for (i = 0; i < nr_segments; i++) {
- result = kimage_load_segment(image, &image->segment[i]);
- if (result)
- goto out;
- }
- kimage_terminate(image);
- if (flags & KEXEC_ON_CRASH)
- crash_unmap_reserved_pages();
}
+
/* Install the new kernel, and Uninstall the old */
image = xchg(dest_image, image);
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
2015-07-07 21:18 ` Vivek Goyal
@ 2015-07-08 12:06 ` Minfei Huang
-1 siblings, 0 replies; 16+ messages in thread
From: Minfei Huang @ 2015-07-08 12:06 UTC (permalink / raw)
To: Vivek Goyal
Cc: ebiederm, schwidefsky, heiko.carstens, linux390, holzheu,
linux-s390, kexec, linux-kernel
On 07/07/15 at 05:18P, Vivek Goyal wrote:
> On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang 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.
> >
> > Make a pair of reserved pages in kdump starting path, whatever kexec
> > fails or not.
> >
> > Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
> > ---
> > v2:
> > - replace the "failure" label with "fail_unmap_pages"
> > v1:
> > - reconstruct the patch code
> > ---
> > kernel/kexec.c | 26 ++++++++++++++------------
> > 1 file changed, 14 insertions(+), 12 deletions(-)
> >
>
> Hi Minfei,
>
> I am thinking of moving kernel loading code in a separate function to
> make things little simpler. Right now it is confusing.
In my patch, I think maybe the label confuses with the reviewer, which
does not express the intention clearly.
>
> Can you please test attached patch. I have only compile tested it. This
> is primarily doing what you are doing but in a separate function. It
> seems more readable now.
>
The patch passed the simple testcase. Since it does change the code
logic, I think there is no risky.
Thanks
Minfei
> Thanks
> Vivek
>
>
> ---
> kernel/kexec.c | 90 +++++++++++++++++++++++++++++++++++----------------------
> 1 file changed, 56 insertions(+), 34 deletions(-)
>
> Index: rhvgoyal-linux/kernel/kexec.c
> ===================================================================
> --- rhvgoyal-linux.orig/kernel/kexec.c 2015-07-06 13:59:35.088129148 -0400
> +++ rhvgoyal-linux/kernel/kexec.c 2015-07-07 17:14:23.593175644 -0400
> @@ -1247,6 +1247,57 @@ int kexec_load_disabled;
>
> static DEFINE_MUTEX(kexec_mutex);
>
> +static int __kexec_load(struct kimage **rimage, unsigned long entry,
> + unsigned long nr_segments,
> + struct kexec_segment __user * segments,
> + unsigned long flags)
> +{
> + unsigned long i;
> + int result;
> + struct kimage *image;
> +
> + if (flags & KEXEC_ON_CRASH) {
> + /*
> + * Loading another kernel to switch to if this one
> + * crashes. Free any current crash dump kernel before
> + * we corrupt it.
> + */
> +
> + kimage_free(xchg(&kexec_crash_image, NULL));
> + }
> +
> + result = kimage_alloc_init(&image, entry, nr_segments, segments, flags);
> + if (result)
> + return result;
> +
> + if (flags & KEXEC_ON_CRASH)
> + crash_map_reserved_pages();
> +
> + if (flags & KEXEC_PRESERVE_CONTEXT)
> + image->preserve_context = 1;
> +
> + result = machine_kexec_prepare(image);
> + if (result)
> + goto out;
> +
> + for (i = 0; i < nr_segments; i++) {
> + result = kimage_load_segment(image, &image->segment[i]);
> + if (result)
> + goto out;
> + }
> +
> + kimage_terminate(image);
> + *rimage = image;
> +out:
> + if (flags & KEXEC_ON_CRASH)
> + crash_unmap_reserved_pages();
> +
> + /* Free image if there was an error */
> + if (result)
> + kimage_free(image);
> + return result;
> +}
> +
> SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
> struct kexec_segment __user *, segments, unsigned long, flags)
> {
> @@ -1292,44 +1343,15 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> dest_image = &kexec_image;
> if (flags & KEXEC_ON_CRASH)
> dest_image = &kexec_crash_image;
> - if (nr_segments > 0) {
> - unsigned long i;
>
> - if (flags & KEXEC_ON_CRASH) {
> - /*
> - * Loading another kernel to switch to if this one
> - * crashes. Free any current crash dump kernel before
> - * we corrupt it.
> - */
> -
> - kimage_free(xchg(&kexec_crash_image, NULL));
> - result = kimage_alloc_init(&image, entry, nr_segments,
> - segments, flags);
> - crash_map_reserved_pages();
> - } else {
> - /* Loading another kernel to reboot into. */
> -
> - result = kimage_alloc_init(&image, entry, nr_segments,
> - segments, flags);
> - }
> - if (result)
> - goto out;
> -
> - if (flags & KEXEC_PRESERVE_CONTEXT)
> - image->preserve_context = 1;
> - result = machine_kexec_prepare(image);
> + /* Load new kernel */
> + if (nr_segments > 0) {
> + result = __kexec_load(&image, entry, nr_segments, segments,
> + flags);
> if (result)
> goto out;
> -
> - for (i = 0; i < nr_segments; i++) {
> - result = kimage_load_segment(image, &image->segment[i]);
> - if (result)
> - goto out;
> - }
> - kimage_terminate(image);
> - if (flags & KEXEC_ON_CRASH)
> - crash_unmap_reserved_pages();
> }
> +
> /* Install the new kernel, and Uninstall the old */
> image = xchg(dest_image, image);
>
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
@ 2015-07-08 12:06 ` Minfei Huang
0 siblings, 0 replies; 16+ messages in thread
From: Minfei Huang @ 2015-07-08 12:06 UTC (permalink / raw)
To: Vivek Goyal
Cc: linux-s390, kexec, heiko.carstens, linux-kernel, ebiederm,
schwidefsky, linux390, holzheu
On 07/07/15 at 05:18P, Vivek Goyal wrote:
> On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang 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.
> >
> > Make a pair of reserved pages in kdump starting path, whatever kexec
> > fails or not.
> >
> > Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
> > ---
> > v2:
> > - replace the "failure" label with "fail_unmap_pages"
> > v1:
> > - reconstruct the patch code
> > ---
> > kernel/kexec.c | 26 ++++++++++++++------------
> > 1 file changed, 14 insertions(+), 12 deletions(-)
> >
>
> Hi Minfei,
>
> I am thinking of moving kernel loading code in a separate function to
> make things little simpler. Right now it is confusing.
In my patch, I think maybe the label confuses with the reviewer, which
does not express the intention clearly.
>
> Can you please test attached patch. I have only compile tested it. This
> is primarily doing what you are doing but in a separate function. It
> seems more readable now.
>
The patch passed the simple testcase. Since it does change the code
logic, I think there is no risky.
Thanks
Minfei
> Thanks
> Vivek
>
>
> ---
> kernel/kexec.c | 90 +++++++++++++++++++++++++++++++++++----------------------
> 1 file changed, 56 insertions(+), 34 deletions(-)
>
> Index: rhvgoyal-linux/kernel/kexec.c
> ===================================================================
> --- rhvgoyal-linux.orig/kernel/kexec.c 2015-07-06 13:59:35.088129148 -0400
> +++ rhvgoyal-linux/kernel/kexec.c 2015-07-07 17:14:23.593175644 -0400
> @@ -1247,6 +1247,57 @@ int kexec_load_disabled;
>
> static DEFINE_MUTEX(kexec_mutex);
>
> +static int __kexec_load(struct kimage **rimage, unsigned long entry,
> + unsigned long nr_segments,
> + struct kexec_segment __user * segments,
> + unsigned long flags)
> +{
> + unsigned long i;
> + int result;
> + struct kimage *image;
> +
> + if (flags & KEXEC_ON_CRASH) {
> + /*
> + * Loading another kernel to switch to if this one
> + * crashes. Free any current crash dump kernel before
> + * we corrupt it.
> + */
> +
> + kimage_free(xchg(&kexec_crash_image, NULL));
> + }
> +
> + result = kimage_alloc_init(&image, entry, nr_segments, segments, flags);
> + if (result)
> + return result;
> +
> + if (flags & KEXEC_ON_CRASH)
> + crash_map_reserved_pages();
> +
> + if (flags & KEXEC_PRESERVE_CONTEXT)
> + image->preserve_context = 1;
> +
> + result = machine_kexec_prepare(image);
> + if (result)
> + goto out;
> +
> + for (i = 0; i < nr_segments; i++) {
> + result = kimage_load_segment(image, &image->segment[i]);
> + if (result)
> + goto out;
> + }
> +
> + kimage_terminate(image);
> + *rimage = image;
> +out:
> + if (flags & KEXEC_ON_CRASH)
> + crash_unmap_reserved_pages();
> +
> + /* Free image if there was an error */
> + if (result)
> + kimage_free(image);
> + return result;
> +}
> +
> SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
> struct kexec_segment __user *, segments, unsigned long, flags)
> {
> @@ -1292,44 +1343,15 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> dest_image = &kexec_image;
> if (flags & KEXEC_ON_CRASH)
> dest_image = &kexec_crash_image;
> - if (nr_segments > 0) {
> - unsigned long i;
>
> - if (flags & KEXEC_ON_CRASH) {
> - /*
> - * Loading another kernel to switch to if this one
> - * crashes. Free any current crash dump kernel before
> - * we corrupt it.
> - */
> -
> - kimage_free(xchg(&kexec_crash_image, NULL));
> - result = kimage_alloc_init(&image, entry, nr_segments,
> - segments, flags);
> - crash_map_reserved_pages();
> - } else {
> - /* Loading another kernel to reboot into. */
> -
> - result = kimage_alloc_init(&image, entry, nr_segments,
> - segments, flags);
> - }
> - if (result)
> - goto out;
> -
> - if (flags & KEXEC_PRESERVE_CONTEXT)
> - image->preserve_context = 1;
> - result = machine_kexec_prepare(image);
> + /* Load new kernel */
> + if (nr_segments > 0) {
> + result = __kexec_load(&image, entry, nr_segments, segments,
> + flags);
> if (result)
> goto out;
> -
> - for (i = 0; i < nr_segments; i++) {
> - result = kimage_load_segment(image, &image->segment[i]);
> - if (result)
> - goto out;
> - }
> - kimage_terminate(image);
> - if (flags & KEXEC_ON_CRASH)
> - crash_unmap_reserved_pages();
> }
> +
> /* Install the new kernel, and Uninstall the old */
> image = xchg(dest_image, image);
>
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
2015-07-08 12:06 ` Minfei Huang
@ 2015-07-08 12:09 ` Minfei Huang
-1 siblings, 0 replies; 16+ messages in thread
From: Minfei Huang @ 2015-07-08 12:09 UTC (permalink / raw)
To: Vivek Goyal
Cc: ebiederm, schwidefsky, heiko.carstens, linux390, holzheu,
linux-s390, kexec, linux-kernel
On 07/08/15 at 08:06P, Minfei Huang wrote:
> On 07/07/15 at 05:18P, Vivek Goyal wrote:
> > On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang 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.
> > >
> > > Make a pair of reserved pages in kdump starting path, whatever kexec
> > > fails or not.
> > >
> > > Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
> > > ---
> > > v2:
> > > - replace the "failure" label with "fail_unmap_pages"
> > > v1:
> > > - reconstruct the patch code
> > > ---
> > > kernel/kexec.c | 26 ++++++++++++++------------
> > > 1 file changed, 14 insertions(+), 12 deletions(-)
> > >
> >
> > Hi Minfei,
> >
> > I am thinking of moving kernel loading code in a separate function to
> > make things little simpler. Right now it is confusing.
>
> In my patch, I think maybe the label confuses with the reviewer, which
> does not express the intention clearly.
>
> >
> > Can you please test attached patch. I have only compile tested it. This
> > is primarily doing what you are doing but in a separate function. It
> > seems more readable now.
> >
>
> The patch passed the simple testcase. Since it does change the code
^^^^^
does not change
> logic, I think there is no risky.
>
> Thanks
> Minfei
>
> > Thanks
> > Vivek
> >
> >
> > ---
> > kernel/kexec.c | 90 +++++++++++++++++++++++++++++++++++----------------------
> > 1 file changed, 56 insertions(+), 34 deletions(-)
> >
> > Index: rhvgoyal-linux/kernel/kexec.c
> > ===================================================================
> > --- rhvgoyal-linux.orig/kernel/kexec.c 2015-07-06 13:59:35.088129148 -0400
> > +++ rhvgoyal-linux/kernel/kexec.c 2015-07-07 17:14:23.593175644 -0400
> > @@ -1247,6 +1247,57 @@ int kexec_load_disabled;
> >
> > static DEFINE_MUTEX(kexec_mutex);
> >
> > +static int __kexec_load(struct kimage **rimage, unsigned long entry,
> > + unsigned long nr_segments,
> > + struct kexec_segment __user * segments,
> > + unsigned long flags)
> > +{
> > + unsigned long i;
> > + int result;
> > + struct kimage *image;
> > +
> > + if (flags & KEXEC_ON_CRASH) {
> > + /*
> > + * Loading another kernel to switch to if this one
> > + * crashes. Free any current crash dump kernel before
> > + * we corrupt it.
> > + */
> > +
> > + kimage_free(xchg(&kexec_crash_image, NULL));
> > + }
> > +
> > + result = kimage_alloc_init(&image, entry, nr_segments, segments, flags);
> > + if (result)
> > + return result;
> > +
> > + if (flags & KEXEC_ON_CRASH)
> > + crash_map_reserved_pages();
> > +
> > + if (flags & KEXEC_PRESERVE_CONTEXT)
> > + image->preserve_context = 1;
> > +
> > + result = machine_kexec_prepare(image);
> > + if (result)
> > + goto out;
> > +
> > + for (i = 0; i < nr_segments; i++) {
> > + result = kimage_load_segment(image, &image->segment[i]);
> > + if (result)
> > + goto out;
> > + }
> > +
> > + kimage_terminate(image);
> > + *rimage = image;
> > +out:
> > + if (flags & KEXEC_ON_CRASH)
> > + crash_unmap_reserved_pages();
> > +
> > + /* Free image if there was an error */
> > + if (result)
> > + kimage_free(image);
> > + return result;
> > +}
> > +
> > SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
> > struct kexec_segment __user *, segments, unsigned long, flags)
> > {
> > @@ -1292,44 +1343,15 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> > dest_image = &kexec_image;
> > if (flags & KEXEC_ON_CRASH)
> > dest_image = &kexec_crash_image;
> > - if (nr_segments > 0) {
> > - unsigned long i;
> >
> > - if (flags & KEXEC_ON_CRASH) {
> > - /*
> > - * Loading another kernel to switch to if this one
> > - * crashes. Free any current crash dump kernel before
> > - * we corrupt it.
> > - */
> > -
> > - kimage_free(xchg(&kexec_crash_image, NULL));
> > - result = kimage_alloc_init(&image, entry, nr_segments,
> > - segments, flags);
> > - crash_map_reserved_pages();
> > - } else {
> > - /* Loading another kernel to reboot into. */
> > -
> > - result = kimage_alloc_init(&image, entry, nr_segments,
> > - segments, flags);
> > - }
> > - if (result)
> > - goto out;
> > -
> > - if (flags & KEXEC_PRESERVE_CONTEXT)
> > - image->preserve_context = 1;
> > - result = machine_kexec_prepare(image);
> > + /* Load new kernel */
> > + if (nr_segments > 0) {
> > + result = __kexec_load(&image, entry, nr_segments, segments,
> > + flags);
> > if (result)
> > goto out;
> > -
> > - for (i = 0; i < nr_segments; i++) {
> > - result = kimage_load_segment(image, &image->segment[i]);
> > - if (result)
> > - goto out;
> > - }
> > - kimage_terminate(image);
> > - if (flags & KEXEC_ON_CRASH)
> > - crash_unmap_reserved_pages();
> > }
> > +
> > /* Install the new kernel, and Uninstall the old */
> > image = xchg(dest_image, image);
> >
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
@ 2015-07-08 12:09 ` Minfei Huang
0 siblings, 0 replies; 16+ messages in thread
From: Minfei Huang @ 2015-07-08 12:09 UTC (permalink / raw)
To: Vivek Goyal
Cc: linux-s390, kexec, heiko.carstens, linux-kernel, ebiederm,
schwidefsky, linux390, holzheu
On 07/08/15 at 08:06P, Minfei Huang wrote:
> On 07/07/15 at 05:18P, Vivek Goyal wrote:
> > On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang 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.
> > >
> > > Make a pair of reserved pages in kdump starting path, whatever kexec
> > > fails or not.
> > >
> > > Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
> > > ---
> > > v2:
> > > - replace the "failure" label with "fail_unmap_pages"
> > > v1:
> > > - reconstruct the patch code
> > > ---
> > > kernel/kexec.c | 26 ++++++++++++++------------
> > > 1 file changed, 14 insertions(+), 12 deletions(-)
> > >
> >
> > Hi Minfei,
> >
> > I am thinking of moving kernel loading code in a separate function to
> > make things little simpler. Right now it is confusing.
>
> In my patch, I think maybe the label confuses with the reviewer, which
> does not express the intention clearly.
>
> >
> > Can you please test attached patch. I have only compile tested it. This
> > is primarily doing what you are doing but in a separate function. It
> > seems more readable now.
> >
>
> The patch passed the simple testcase. Since it does change the code
^^^^^
does not change
> logic, I think there is no risky.
>
> Thanks
> Minfei
>
> > Thanks
> > Vivek
> >
> >
> > ---
> > kernel/kexec.c | 90 +++++++++++++++++++++++++++++++++++----------------------
> > 1 file changed, 56 insertions(+), 34 deletions(-)
> >
> > Index: rhvgoyal-linux/kernel/kexec.c
> > ===================================================================
> > --- rhvgoyal-linux.orig/kernel/kexec.c 2015-07-06 13:59:35.088129148 -0400
> > +++ rhvgoyal-linux/kernel/kexec.c 2015-07-07 17:14:23.593175644 -0400
> > @@ -1247,6 +1247,57 @@ int kexec_load_disabled;
> >
> > static DEFINE_MUTEX(kexec_mutex);
> >
> > +static int __kexec_load(struct kimage **rimage, unsigned long entry,
> > + unsigned long nr_segments,
> > + struct kexec_segment __user * segments,
> > + unsigned long flags)
> > +{
> > + unsigned long i;
> > + int result;
> > + struct kimage *image;
> > +
> > + if (flags & KEXEC_ON_CRASH) {
> > + /*
> > + * Loading another kernel to switch to if this one
> > + * crashes. Free any current crash dump kernel before
> > + * we corrupt it.
> > + */
> > +
> > + kimage_free(xchg(&kexec_crash_image, NULL));
> > + }
> > +
> > + result = kimage_alloc_init(&image, entry, nr_segments, segments, flags);
> > + if (result)
> > + return result;
> > +
> > + if (flags & KEXEC_ON_CRASH)
> > + crash_map_reserved_pages();
> > +
> > + if (flags & KEXEC_PRESERVE_CONTEXT)
> > + image->preserve_context = 1;
> > +
> > + result = machine_kexec_prepare(image);
> > + if (result)
> > + goto out;
> > +
> > + for (i = 0; i < nr_segments; i++) {
> > + result = kimage_load_segment(image, &image->segment[i]);
> > + if (result)
> > + goto out;
> > + }
> > +
> > + kimage_terminate(image);
> > + *rimage = image;
> > +out:
> > + if (flags & KEXEC_ON_CRASH)
> > + crash_unmap_reserved_pages();
> > +
> > + /* Free image if there was an error */
> > + if (result)
> > + kimage_free(image);
> > + return result;
> > +}
> > +
> > SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
> > struct kexec_segment __user *, segments, unsigned long, flags)
> > {
> > @@ -1292,44 +1343,15 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> > dest_image = &kexec_image;
> > if (flags & KEXEC_ON_CRASH)
> > dest_image = &kexec_crash_image;
> > - if (nr_segments > 0) {
> > - unsigned long i;
> >
> > - if (flags & KEXEC_ON_CRASH) {
> > - /*
> > - * Loading another kernel to switch to if this one
> > - * crashes. Free any current crash dump kernel before
> > - * we corrupt it.
> > - */
> > -
> > - kimage_free(xchg(&kexec_crash_image, NULL));
> > - result = kimage_alloc_init(&image, entry, nr_segments,
> > - segments, flags);
> > - crash_map_reserved_pages();
> > - } else {
> > - /* Loading another kernel to reboot into. */
> > -
> > - result = kimage_alloc_init(&image, entry, nr_segments,
> > - segments, flags);
> > - }
> > - if (result)
> > - goto out;
> > -
> > - if (flags & KEXEC_PRESERVE_CONTEXT)
> > - image->preserve_context = 1;
> > - result = machine_kexec_prepare(image);
> > + /* Load new kernel */
> > + if (nr_segments > 0) {
> > + result = __kexec_load(&image, entry, nr_segments, segments,
> > + flags);
> > if (result)
> > goto out;
> > -
> > - for (i = 0; i < nr_segments; i++) {
> > - result = kimage_load_segment(image, &image->segment[i]);
> > - if (result)
> > - goto out;
> > - }
> > - kimage_terminate(image);
> > - if (flags & KEXEC_ON_CRASH)
> > - crash_unmap_reserved_pages();
> > }
> > +
> > /* Install the new kernel, and Uninstall the old */
> > image = xchg(dest_image, image);
> >
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
2015-07-07 21:18 ` Vivek Goyal
@ 2015-07-09 15:54 ` Michael Holzheu
-1 siblings, 0 replies; 16+ messages in thread
From: Michael Holzheu @ 2015-07-09 15:54 UTC (permalink / raw)
To: Vivek Goyal
Cc: Minfei Huang, ebiederm, schwidefsky, heiko.carstens, linux390,
linux-s390, kexec, linux-kernel
On Tue, 7 Jul 2015 17:18:40 -0400
Vivek Goyal <vgoyal@redhat.com> wrote:
> On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang wrote:
[snip]
> I am thinking of moving kernel loading code in a separate function to
> make things little simpler. Right now it is confusing.
>
> Can you please test attached patch. I have only compile tested it. This
> is primarily doing what you are doing but in a separate function. It
> seems more readable now.
The patch looks good to me. What about the following patch on top
to make things even more readable?
---
kernel/kexec.c | 50 +++++++++++++++++---------------------------------
1 file changed, 17 insertions(+), 33 deletions(-)
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1236,14 +1236,18 @@ int kexec_load_disabled;
static DEFINE_MUTEX(kexec_mutex);
-static int __kexec_load(struct kimage **rimage, unsigned long entry,
- unsigned long nr_segments,
+static int __kexec_load(unsigned long entry, unsigned long nr_segments,
struct kexec_segment __user * segments,
unsigned long flags)
{
+ struct kimage *image, **dest_image;
unsigned long i;
int result;
- struct kimage *image;
+
+ dest_image = (flags & KEXEC_ON_CRASH) ? &kexec_crash_image : &kexec_image;
+
+ if (nr_segments == 0)
+ return 0;
if (flags & KEXEC_ON_CRASH) {
/*
@@ -1251,7 +1255,6 @@ static int __kexec_load(struct kimage **
* crashes. Free any current crash dump kernel before
* we corrupt it.
*/
-
kimage_free(xchg(&kexec_crash_image, NULL));
}
@@ -1267,30 +1270,29 @@ static int __kexec_load(struct kimage **
result = machine_kexec_prepare(image);
if (result)
- goto out;
+ goto fail;
for (i = 0; i < nr_segments; i++) {
result = kimage_load_segment(image, &image->segment[i]);
if (result)
- goto out;
+ goto fail;
}
-
kimage_terminate(image);
- *rimage = image;
-out:
+ /* Install the new kernel, and uninstall the old */
+ kimage_free(xchg(dest_image, image));
if (flags & KEXEC_ON_CRASH)
crash_unmap_reserved_pages();
-
- /* Free image if there was an error */
- if (result)
- kimage_free(image);
+ return 0;
+fail:
+ if (flags & KEXEC_ON_CRASH)
+ crash_unmap_reserved_pages();
+ kimage_free(image);
return result;
}
SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
struct kexec_segment __user *, segments, unsigned long, flags)
{
- struct kimage **dest_image, *image;
int result;
/* We only trust the superuser with rebooting the system. */
@@ -1315,9 +1317,6 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
if (nr_segments > KEXEC_SEGMENT_MAX)
return -EINVAL;
- image = NULL;
- result = 0;
-
/* Because we write directly to the reserved memory
* region when loading crash kernels we need a mutex here to
* prevent multiple crash kernels from attempting to load
@@ -1329,24 +1328,9 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
if (!mutex_trylock(&kexec_mutex))
return -EBUSY;
- dest_image = &kexec_image;
- if (flags & KEXEC_ON_CRASH)
- dest_image = &kexec_crash_image;
-
/* Load new kernel */
- if (nr_segments > 0) {
- result = __kexec_load(&image, entry, nr_segments, segments,
- flags);
- if (result)
- goto out;
- }
-
- /* Install the new kernel, and Uninstall the old */
- image = xchg(dest_image, image);
-
-out:
+ result = __kexec_load(entry, nr_segments, segments, flags);
mutex_unlock(&kexec_mutex);
- kimage_free(image);
return result;
}
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
@ 2015-07-09 15:54 ` Michael Holzheu
0 siblings, 0 replies; 16+ messages in thread
From: Michael Holzheu @ 2015-07-09 15:54 UTC (permalink / raw)
To: Vivek Goyal
Cc: linux-s390, kexec, heiko.carstens, linux-kernel, Minfei Huang,
schwidefsky, linux390, ebiederm
On Tue, 7 Jul 2015 17:18:40 -0400
Vivek Goyal <vgoyal@redhat.com> wrote:
> On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang wrote:
[snip]
> I am thinking of moving kernel loading code in a separate function to
> make things little simpler. Right now it is confusing.
>
> Can you please test attached patch. I have only compile tested it. This
> is primarily doing what you are doing but in a separate function. It
> seems more readable now.
The patch looks good to me. What about the following patch on top
to make things even more readable?
---
kernel/kexec.c | 50 +++++++++++++++++---------------------------------
1 file changed, 17 insertions(+), 33 deletions(-)
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1236,14 +1236,18 @@ int kexec_load_disabled;
static DEFINE_MUTEX(kexec_mutex);
-static int __kexec_load(struct kimage **rimage, unsigned long entry,
- unsigned long nr_segments,
+static int __kexec_load(unsigned long entry, unsigned long nr_segments,
struct kexec_segment __user * segments,
unsigned long flags)
{
+ struct kimage *image, **dest_image;
unsigned long i;
int result;
- struct kimage *image;
+
+ dest_image = (flags & KEXEC_ON_CRASH) ? &kexec_crash_image : &kexec_image;
+
+ if (nr_segments == 0)
+ return 0;
if (flags & KEXEC_ON_CRASH) {
/*
@@ -1251,7 +1255,6 @@ static int __kexec_load(struct kimage **
* crashes. Free any current crash dump kernel before
* we corrupt it.
*/
-
kimage_free(xchg(&kexec_crash_image, NULL));
}
@@ -1267,30 +1270,29 @@ static int __kexec_load(struct kimage **
result = machine_kexec_prepare(image);
if (result)
- goto out;
+ goto fail;
for (i = 0; i < nr_segments; i++) {
result = kimage_load_segment(image, &image->segment[i]);
if (result)
- goto out;
+ goto fail;
}
-
kimage_terminate(image);
- *rimage = image;
-out:
+ /* Install the new kernel, and uninstall the old */
+ kimage_free(xchg(dest_image, image));
if (flags & KEXEC_ON_CRASH)
crash_unmap_reserved_pages();
-
- /* Free image if there was an error */
- if (result)
- kimage_free(image);
+ return 0;
+fail:
+ if (flags & KEXEC_ON_CRASH)
+ crash_unmap_reserved_pages();
+ kimage_free(image);
return result;
}
SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
struct kexec_segment __user *, segments, unsigned long, flags)
{
- struct kimage **dest_image, *image;
int result;
/* We only trust the superuser with rebooting the system. */
@@ -1315,9 +1317,6 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
if (nr_segments > KEXEC_SEGMENT_MAX)
return -EINVAL;
- image = NULL;
- result = 0;
-
/* Because we write directly to the reserved memory
* region when loading crash kernels we need a mutex here to
* prevent multiple crash kernels from attempting to load
@@ -1329,24 +1328,9 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
if (!mutex_trylock(&kexec_mutex))
return -EBUSY;
- dest_image = &kexec_image;
- if (flags & KEXEC_ON_CRASH)
- dest_image = &kexec_crash_image;
-
/* Load new kernel */
- if (nr_segments > 0) {
- result = __kexec_load(&image, entry, nr_segments, segments,
- flags);
- if (result)
- goto out;
- }
-
- /* Install the new kernel, and Uninstall the old */
- image = xchg(dest_image, image);
-
-out:
+ result = __kexec_load(entry, nr_segments, segments, flags);
mutex_unlock(&kexec_mutex);
- kimage_free(image);
return result;
}
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
2015-07-09 15:54 ` Michael Holzheu
@ 2015-07-09 23:37 ` Minfei Huang
-1 siblings, 0 replies; 16+ messages in thread
From: Minfei Huang @ 2015-07-09 23:37 UTC (permalink / raw)
To: Michael Holzheu
Cc: Vivek Goyal, ebiederm, schwidefsky, heiko.carstens, linux390,
linux-s390, kexec, linux-kernel
Hi, Michael.
Yes, The code is more readable after wrapping the all of function code
in a function. Since this is a small issue, I think it is better to use
one patch to fix it. I am glad to repost a patch to merge you and
Vivek's patches as one patch.
Thanks
Minfei
On 07/09/15 at 05:54P, Michael Holzheu wrote:
> On Tue, 7 Jul 2015 17:18:40 -0400
> Vivek Goyal <vgoyal@redhat.com> wrote:
>
> > On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang wrote:
>
> [snip]
>
> > I am thinking of moving kernel loading code in a separate function to
> > make things little simpler. Right now it is confusing.
> >
> > Can you please test attached patch. I have only compile tested it. This
> > is primarily doing what you are doing but in a separate function. It
> > seems more readable now.
>
> The patch looks good to me. What about the following patch on top
> to make things even more readable?
> ---
> kernel/kexec.c | 50 +++++++++++++++++---------------------------------
> 1 file changed, 17 insertions(+), 33 deletions(-)
>
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -1236,14 +1236,18 @@ int kexec_load_disabled;
>
> static DEFINE_MUTEX(kexec_mutex);
>
> -static int __kexec_load(struct kimage **rimage, unsigned long entry,
> - unsigned long nr_segments,
> +static int __kexec_load(unsigned long entry, unsigned long nr_segments,
> struct kexec_segment __user * segments,
> unsigned long flags)
> {
> + struct kimage *image, **dest_image;
> unsigned long i;
> int result;
> - struct kimage *image;
> +
> + dest_image = (flags & KEXEC_ON_CRASH) ? &kexec_crash_image : &kexec_image;
> +
> + if (nr_segments == 0)
> + return 0;
>
> if (flags & KEXEC_ON_CRASH) {
> /*
> @@ -1251,7 +1255,6 @@ static int __kexec_load(struct kimage **
> * crashes. Free any current crash dump kernel before
> * we corrupt it.
> */
> -
> kimage_free(xchg(&kexec_crash_image, NULL));
> }
>
> @@ -1267,30 +1270,29 @@ static int __kexec_load(struct kimage **
>
> result = machine_kexec_prepare(image);
> if (result)
> - goto out;
> + goto fail;
>
> for (i = 0; i < nr_segments; i++) {
> result = kimage_load_segment(image, &image->segment[i]);
> if (result)
> - goto out;
> + goto fail;
> }
> -
> kimage_terminate(image);
> - *rimage = image;
> -out:
> + /* Install the new kernel, and uninstall the old */
> + kimage_free(xchg(dest_image, image));
> if (flags & KEXEC_ON_CRASH)
> crash_unmap_reserved_pages();
> -
> - /* Free image if there was an error */
> - if (result)
> - kimage_free(image);
> + return 0;
> +fail:
> + if (flags & KEXEC_ON_CRASH)
> + crash_unmap_reserved_pages();
> + kimage_free(image);
> return result;
> }
>
> SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
> struct kexec_segment __user *, segments, unsigned long, flags)
> {
> - struct kimage **dest_image, *image;
> int result;
>
> /* We only trust the superuser with rebooting the system. */
> @@ -1315,9 +1317,6 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> if (nr_segments > KEXEC_SEGMENT_MAX)
> return -EINVAL;
>
> - image = NULL;
> - result = 0;
> -
> /* Because we write directly to the reserved memory
> * region when loading crash kernels we need a mutex here to
> * prevent multiple crash kernels from attempting to load
> @@ -1329,24 +1328,9 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> if (!mutex_trylock(&kexec_mutex))
> return -EBUSY;
>
> - dest_image = &kexec_image;
> - if (flags & KEXEC_ON_CRASH)
> - dest_image = &kexec_crash_image;
> -
> /* Load new kernel */
> - if (nr_segments > 0) {
> - result = __kexec_load(&image, entry, nr_segments, segments,
> - flags);
> - if (result)
> - goto out;
> - }
> -
> - /* Install the new kernel, and Uninstall the old */
> - image = xchg(dest_image, image);
> -
> -out:
> + result = __kexec_load(entry, nr_segments, segments, flags);
> mutex_unlock(&kexec_mutex);
> - kimage_free(image);
>
> return result;
> }
>
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
@ 2015-07-09 23:37 ` Minfei Huang
0 siblings, 0 replies; 16+ messages in thread
From: Minfei Huang @ 2015-07-09 23:37 UTC (permalink / raw)
To: Michael Holzheu
Cc: linux-s390, kexec, heiko.carstens, linux-kernel, ebiederm,
schwidefsky, linux390, Vivek Goyal
Hi, Michael.
Yes, The code is more readable after wrapping the all of function code
in a function. Since this is a small issue, I think it is better to use
one patch to fix it. I am glad to repost a patch to merge you and
Vivek's patches as one patch.
Thanks
Minfei
On 07/09/15 at 05:54P, Michael Holzheu wrote:
> On Tue, 7 Jul 2015 17:18:40 -0400
> Vivek Goyal <vgoyal@redhat.com> wrote:
>
> > On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang wrote:
>
> [snip]
>
> > I am thinking of moving kernel loading code in a separate function to
> > make things little simpler. Right now it is confusing.
> >
> > Can you please test attached patch. I have only compile tested it. This
> > is primarily doing what you are doing but in a separate function. It
> > seems more readable now.
>
> The patch looks good to me. What about the following patch on top
> to make things even more readable?
> ---
> kernel/kexec.c | 50 +++++++++++++++++---------------------------------
> 1 file changed, 17 insertions(+), 33 deletions(-)
>
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -1236,14 +1236,18 @@ int kexec_load_disabled;
>
> static DEFINE_MUTEX(kexec_mutex);
>
> -static int __kexec_load(struct kimage **rimage, unsigned long entry,
> - unsigned long nr_segments,
> +static int __kexec_load(unsigned long entry, unsigned long nr_segments,
> struct kexec_segment __user * segments,
> unsigned long flags)
> {
> + struct kimage *image, **dest_image;
> unsigned long i;
> int result;
> - struct kimage *image;
> +
> + dest_image = (flags & KEXEC_ON_CRASH) ? &kexec_crash_image : &kexec_image;
> +
> + if (nr_segments == 0)
> + return 0;
>
> if (flags & KEXEC_ON_CRASH) {
> /*
> @@ -1251,7 +1255,6 @@ static int __kexec_load(struct kimage **
> * crashes. Free any current crash dump kernel before
> * we corrupt it.
> */
> -
> kimage_free(xchg(&kexec_crash_image, NULL));
> }
>
> @@ -1267,30 +1270,29 @@ static int __kexec_load(struct kimage **
>
> result = machine_kexec_prepare(image);
> if (result)
> - goto out;
> + goto fail;
>
> for (i = 0; i < nr_segments; i++) {
> result = kimage_load_segment(image, &image->segment[i]);
> if (result)
> - goto out;
> + goto fail;
> }
> -
> kimage_terminate(image);
> - *rimage = image;
> -out:
> + /* Install the new kernel, and uninstall the old */
> + kimage_free(xchg(dest_image, image));
> if (flags & KEXEC_ON_CRASH)
> crash_unmap_reserved_pages();
> -
> - /* Free image if there was an error */
> - if (result)
> - kimage_free(image);
> + return 0;
> +fail:
> + if (flags & KEXEC_ON_CRASH)
> + crash_unmap_reserved_pages();
> + kimage_free(image);
> return result;
> }
>
> SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
> struct kexec_segment __user *, segments, unsigned long, flags)
> {
> - struct kimage **dest_image, *image;
> int result;
>
> /* We only trust the superuser with rebooting the system. */
> @@ -1315,9 +1317,6 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> if (nr_segments > KEXEC_SEGMENT_MAX)
> return -EINVAL;
>
> - image = NULL;
> - result = 0;
> -
> /* Because we write directly to the reserved memory
> * region when loading crash kernels we need a mutex here to
> * prevent multiple crash kernels from attempting to load
> @@ -1329,24 +1328,9 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> if (!mutex_trylock(&kexec_mutex))
> return -EBUSY;
>
> - dest_image = &kexec_image;
> - if (flags & KEXEC_ON_CRASH)
> - dest_image = &kexec_crash_image;
> -
> /* Load new kernel */
> - if (nr_segments > 0) {
> - result = __kexec_load(&image, entry, nr_segments, segments,
> - flags);
> - if (result)
> - goto out;
> - }
> -
> - /* Install the new kernel, and Uninstall the old */
> - image = xchg(dest_image, image);
> -
> -out:
> + result = __kexec_load(entry, nr_segments, segments, flags);
> mutex_unlock(&kexec_mutex);
> - kimage_free(image);
>
> return result;
> }
>
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
2015-07-09 15:54 ` Michael Holzheu
@ 2015-07-10 4:05 ` Minfei Huang
-1 siblings, 0 replies; 16+ messages in thread
From: Minfei Huang @ 2015-07-10 4:05 UTC (permalink / raw)
To: Michael Holzheu
Cc: Vivek Goyal, ebiederm, schwidefsky, heiko.carstens, linux390,
linux-s390, kexec, linux-kernel
On 07/09/15 at 05:54P, Michael Holzheu wrote:
> On Tue, 7 Jul 2015 17:18:40 -0400
> Vivek Goyal <vgoyal@redhat.com> wrote:
>
> > On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang wrote:
>
> [snip]
>
> > I am thinking of moving kernel loading code in a separate function to
> > make things little simpler. Right now it is confusing.
> >
> > Can you please test attached patch. I have only compile tested it. This
> > is primarily doing what you are doing but in a separate function. It
> > seems more readable now.
>
> The patch looks good to me. What about the following patch on top
> to make things even more readable?
> ---
> kernel/kexec.c | 50 +++++++++++++++++---------------------------------
> 1 file changed, 17 insertions(+), 33 deletions(-)
>
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -1236,14 +1236,18 @@ int kexec_load_disabled;
>
> static DEFINE_MUTEX(kexec_mutex);
>
> -static int __kexec_load(struct kimage **rimage, unsigned long entry,
> - unsigned long nr_segments,
> +static int __kexec_load(unsigned long entry, unsigned long nr_segments,
> struct kexec_segment __user * segments,
> unsigned long flags)
> {
> + struct kimage *image, **dest_image;
> unsigned long i;
> int result;
> - struct kimage *image;
> +
> + dest_image = (flags & KEXEC_ON_CRASH) ? &kexec_crash_image : &kexec_image;
> +
> + if (nr_segments == 0)
> + return 0;
It is fine, if nr_segments is 0. So we should deal with this case like
original kexec code.
>
> if (flags & KEXEC_ON_CRASH) {
> /*
> @@ -1251,7 +1255,6 @@ static int __kexec_load(struct kimage **
> * crashes. Free any current crash dump kernel before
> * we corrupt it.
> */
> -
> kimage_free(xchg(&kexec_crash_image, NULL));
> }
>
> @@ -1267,30 +1270,29 @@ static int __kexec_load(struct kimage **
>
> result = machine_kexec_prepare(image);
> if (result)
> - goto out;
> + goto fail;
>
> for (i = 0; i < nr_segments; i++) {
> result = kimage_load_segment(image, &image->segment[i]);
> if (result)
> - goto out;
> + goto fail;
> }
> -
> kimage_terminate(image);
> - *rimage = image;
> -out:
> + /* Install the new kernel, and uninstall the old */
> + kimage_free(xchg(dest_image, image));
> if (flags & KEXEC_ON_CRASH)
> crash_unmap_reserved_pages();
> -
> - /* Free image if there was an error */
> - if (result)
> - kimage_free(image);
> + return 0;
> +fail:
> + if (flags & KEXEC_ON_CRASH)
> + crash_unmap_reserved_pages();
> + kimage_free(image);
Kernel release image again, and will crash in here, since we do not
assign the image to NULL when we release the image above.
Thanks
Minfei
> return result;
> }
>
> SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
> struct kexec_segment __user *, segments, unsigned long, flags)
> {
> - struct kimage **dest_image, *image;
> int result;
>
> /* We only trust the superuser with rebooting the system. */
> @@ -1315,9 +1317,6 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> if (nr_segments > KEXEC_SEGMENT_MAX)
> return -EINVAL;
>
> - image = NULL;
> - result = 0;
> -
> /* Because we write directly to the reserved memory
> * region when loading crash kernels we need a mutex here to
> * prevent multiple crash kernels from attempting to load
> @@ -1329,24 +1328,9 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> if (!mutex_trylock(&kexec_mutex))
> return -EBUSY;
>
> - dest_image = &kexec_image;
> - if (flags & KEXEC_ON_CRASH)
> - dest_image = &kexec_crash_image;
> -
> /* Load new kernel */
> - if (nr_segments > 0) {
> - result = __kexec_load(&image, entry, nr_segments, segments,
> - flags);
> - if (result)
> - goto out;
> - }
> -
> - /* Install the new kernel, and Uninstall the old */
> - image = xchg(dest_image, image);
> -
> -out:
> + result = __kexec_load(entry, nr_segments, segments, flags);
> mutex_unlock(&kexec_mutex);
> - kimage_free(image);
>
> return result;
> }
>
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
@ 2015-07-10 4:05 ` Minfei Huang
0 siblings, 0 replies; 16+ messages in thread
From: Minfei Huang @ 2015-07-10 4:05 UTC (permalink / raw)
To: Michael Holzheu
Cc: linux-s390, kexec, heiko.carstens, linux-kernel, ebiederm,
schwidefsky, linux390, Vivek Goyal
On 07/09/15 at 05:54P, Michael Holzheu wrote:
> On Tue, 7 Jul 2015 17:18:40 -0400
> Vivek Goyal <vgoyal@redhat.com> wrote:
>
> > On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang wrote:
>
> [snip]
>
> > I am thinking of moving kernel loading code in a separate function to
> > make things little simpler. Right now it is confusing.
> >
> > Can you please test attached patch. I have only compile tested it. This
> > is primarily doing what you are doing but in a separate function. It
> > seems more readable now.
>
> The patch looks good to me. What about the following patch on top
> to make things even more readable?
> ---
> kernel/kexec.c | 50 +++++++++++++++++---------------------------------
> 1 file changed, 17 insertions(+), 33 deletions(-)
>
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -1236,14 +1236,18 @@ int kexec_load_disabled;
>
> static DEFINE_MUTEX(kexec_mutex);
>
> -static int __kexec_load(struct kimage **rimage, unsigned long entry,
> - unsigned long nr_segments,
> +static int __kexec_load(unsigned long entry, unsigned long nr_segments,
> struct kexec_segment __user * segments,
> unsigned long flags)
> {
> + struct kimage *image, **dest_image;
> unsigned long i;
> int result;
> - struct kimage *image;
> +
> + dest_image = (flags & KEXEC_ON_CRASH) ? &kexec_crash_image : &kexec_image;
> +
> + if (nr_segments == 0)
> + return 0;
It is fine, if nr_segments is 0. So we should deal with this case like
original kexec code.
>
> if (flags & KEXEC_ON_CRASH) {
> /*
> @@ -1251,7 +1255,6 @@ static int __kexec_load(struct kimage **
> * crashes. Free any current crash dump kernel before
> * we corrupt it.
> */
> -
> kimage_free(xchg(&kexec_crash_image, NULL));
> }
>
> @@ -1267,30 +1270,29 @@ static int __kexec_load(struct kimage **
>
> result = machine_kexec_prepare(image);
> if (result)
> - goto out;
> + goto fail;
>
> for (i = 0; i < nr_segments; i++) {
> result = kimage_load_segment(image, &image->segment[i]);
> if (result)
> - goto out;
> + goto fail;
> }
> -
> kimage_terminate(image);
> - *rimage = image;
> -out:
> + /* Install the new kernel, and uninstall the old */
> + kimage_free(xchg(dest_image, image));
> if (flags & KEXEC_ON_CRASH)
> crash_unmap_reserved_pages();
> -
> - /* Free image if there was an error */
> - if (result)
> - kimage_free(image);
> + return 0;
> +fail:
> + if (flags & KEXEC_ON_CRASH)
> + crash_unmap_reserved_pages();
> + kimage_free(image);
Kernel release image again, and will crash in here, since we do not
assign the image to NULL when we release the image above.
Thanks
Minfei
> return result;
> }
>
> SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
> struct kexec_segment __user *, segments, unsigned long, flags)
> {
> - struct kimage **dest_image, *image;
> int result;
>
> /* We only trust the superuser with rebooting the system. */
> @@ -1315,9 +1317,6 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> if (nr_segments > KEXEC_SEGMENT_MAX)
> return -EINVAL;
>
> - image = NULL;
> - result = 0;
> -
> /* Because we write directly to the reserved memory
> * region when loading crash kernels we need a mutex here to
> * prevent multiple crash kernels from attempting to load
> @@ -1329,24 +1328,9 @@ SYSCALL_DEFINE4(kexec_load, unsigned lon
> if (!mutex_trylock(&kexec_mutex))
> return -EBUSY;
>
> - dest_image = &kexec_image;
> - if (flags & KEXEC_ON_CRASH)
> - dest_image = &kexec_crash_image;
> -
> /* Load new kernel */
> - if (nr_segments > 0) {
> - result = __kexec_load(&image, entry, nr_segments, segments,
> - flags);
> - if (result)
> - goto out;
> - }
> -
> - /* Install the new kernel, and Uninstall the old */
> - image = xchg(dest_image, image);
> -
> -out:
> + result = __kexec_load(entry, nr_segments, segments, flags);
> mutex_unlock(&kexec_mutex);
> - kimage_free(image);
>
> return result;
> }
>
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
2015-07-10 4:05 ` Minfei Huang
@ 2015-07-10 8:28 ` Michael Holzheu
-1 siblings, 0 replies; 16+ messages in thread
From: Michael Holzheu @ 2015-07-10 8:28 UTC (permalink / raw)
To: Minfei Huang
Cc: Vivek Goyal, ebiederm, schwidefsky, heiko.carstens, linux390,
linux-s390, kexec, linux-kernel
On Fri, 10 Jul 2015 12:05:27 +0800
Minfei Huang <mnfhuang@gmail.com> wrote:
> On 07/09/15 at 05:54P, Michael Holzheu wrote:
> > On Tue, 7 Jul 2015 17:18:40 -0400
> > Vivek Goyal <vgoyal@redhat.com> wrote:
> >
> > > On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang wrote:
> >
> > [snip]
> >
> > > I am thinking of moving kernel loading code in a separate function to
> > > make things little simpler. Right now it is confusing.
> > >
> > > Can you please test attached patch. I have only compile tested it. This
> > > is primarily doing what you are doing but in a separate function. It
> > > seems more readable now.
> >
> > The patch looks good to me. What about the following patch on top
> > to make things even more readable?
> > ---
> > kernel/kexec.c | 50 +++++++++++++++++---------------------------------
> > 1 file changed, 17 insertions(+), 33 deletions(-)
> >
> > --- a/kernel/kexec.c
> > +++ b/kernel/kexec.c
> > @@ -1236,14 +1236,18 @@ int kexec_load_disabled;
> >
> > static DEFINE_MUTEX(kexec_mutex);
> >
> > -static int __kexec_load(struct kimage **rimage, unsigned long entry,
> > - unsigned long nr_segments,
> > +static int __kexec_load(unsigned long entry, unsigned long nr_segments,
> > struct kexec_segment __user * segments,
> > unsigned long flags)
> > {
> > + struct kimage *image, **dest_image;
> > unsigned long i;
> > int result;
> > - struct kimage *image;
> > +
> > + dest_image = (flags & KEXEC_ON_CRASH) ? &kexec_crash_image : &kexec_image;
> > +
> > + if (nr_segments == 0)
> > + return 0;
>
> It is fine, if nr_segments is 0. So we should deal with this case like
> original kexec code.
>
> >
> > if (flags & KEXEC_ON_CRASH) {
> > /*
> > @@ -1251,7 +1255,6 @@ static int __kexec_load(struct kimage **
> > * crashes. Free any current crash dump kernel before
> > * we corrupt it.
> > */
> > -
> > kimage_free(xchg(&kexec_crash_image, NULL));
> > }
> >
> > @@ -1267,30 +1270,29 @@ static int __kexec_load(struct kimage **
> >
> > result = machine_kexec_prepare(image);
> > if (result)
> > - goto out;
> > + goto fail;
> >
> > for (i = 0; i < nr_segments; i++) {
> > result = kimage_load_segment(image, &image->segment[i]);
> > if (result)
> > - goto out;
> > + goto fail;
> > }
> > -
> > kimage_terminate(image);
> > - *rimage = image;
> > -out:
> > + /* Install the new kernel, and uninstall the old */
> > + kimage_free(xchg(dest_image, image));
> > if (flags & KEXEC_ON_CRASH)
> > crash_unmap_reserved_pages();
> > -
> > - /* Free image if there was an error */
> > - if (result)
> > - kimage_free(image);
> > + return 0;
> > +fail:
> > + if (flags & KEXEC_ON_CRASH)
> > + crash_unmap_reserved_pages();
> > + kimage_free(image);
>
> Kernel release image again
Again? This is only done in the error case.
> , and will crash in here, since we do not
> assign the image to NULL when we release the image above.
Good catch, I should have set image=NULL at the beginning of __kexec_load().
Michael
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3] kexec: Make a pair of map and unmap reserved pages when kdump fails to start
@ 2015-07-10 8:28 ` Michael Holzheu
0 siblings, 0 replies; 16+ messages in thread
From: Michael Holzheu @ 2015-07-10 8:28 UTC (permalink / raw)
To: Minfei Huang
Cc: linux-s390, kexec, heiko.carstens, linux-kernel, ebiederm,
schwidefsky, linux390, Vivek Goyal
On Fri, 10 Jul 2015 12:05:27 +0800
Minfei Huang <mnfhuang@gmail.com> wrote:
> On 07/09/15 at 05:54P, Michael Holzheu wrote:
> > On Tue, 7 Jul 2015 17:18:40 -0400
> > Vivek Goyal <vgoyal@redhat.com> wrote:
> >
> > > On Thu, Jul 02, 2015 at 09:45:52AM +0800, Minfei Huang wrote:
> >
> > [snip]
> >
> > > I am thinking of moving kernel loading code in a separate function to
> > > make things little simpler. Right now it is confusing.
> > >
> > > Can you please test attached patch. I have only compile tested it. This
> > > is primarily doing what you are doing but in a separate function. It
> > > seems more readable now.
> >
> > The patch looks good to me. What about the following patch on top
> > to make things even more readable?
> > ---
> > kernel/kexec.c | 50 +++++++++++++++++---------------------------------
> > 1 file changed, 17 insertions(+), 33 deletions(-)
> >
> > --- a/kernel/kexec.c
> > +++ b/kernel/kexec.c
> > @@ -1236,14 +1236,18 @@ int kexec_load_disabled;
> >
> > static DEFINE_MUTEX(kexec_mutex);
> >
> > -static int __kexec_load(struct kimage **rimage, unsigned long entry,
> > - unsigned long nr_segments,
> > +static int __kexec_load(unsigned long entry, unsigned long nr_segments,
> > struct kexec_segment __user * segments,
> > unsigned long flags)
> > {
> > + struct kimage *image, **dest_image;
> > unsigned long i;
> > int result;
> > - struct kimage *image;
> > +
> > + dest_image = (flags & KEXEC_ON_CRASH) ? &kexec_crash_image : &kexec_image;
> > +
> > + if (nr_segments == 0)
> > + return 0;
>
> It is fine, if nr_segments is 0. So we should deal with this case like
> original kexec code.
>
> >
> > if (flags & KEXEC_ON_CRASH) {
> > /*
> > @@ -1251,7 +1255,6 @@ static int __kexec_load(struct kimage **
> > * crashes. Free any current crash dump kernel before
> > * we corrupt it.
> > */
> > -
> > kimage_free(xchg(&kexec_crash_image, NULL));
> > }
> >
> > @@ -1267,30 +1270,29 @@ static int __kexec_load(struct kimage **
> >
> > result = machine_kexec_prepare(image);
> > if (result)
> > - goto out;
> > + goto fail;
> >
> > for (i = 0; i < nr_segments; i++) {
> > result = kimage_load_segment(image, &image->segment[i]);
> > if (result)
> > - goto out;
> > + goto fail;
> > }
> > -
> > kimage_terminate(image);
> > - *rimage = image;
> > -out:
> > + /* Install the new kernel, and uninstall the old */
> > + kimage_free(xchg(dest_image, image));
> > if (flags & KEXEC_ON_CRASH)
> > crash_unmap_reserved_pages();
> > -
> > - /* Free image if there was an error */
> > - if (result)
> > - kimage_free(image);
> > + return 0;
> > +fail:
> > + if (flags & KEXEC_ON_CRASH)
> > + crash_unmap_reserved_pages();
> > + kimage_free(image);
>
> Kernel release image again
Again? This is only done in the error case.
> , and will crash in here, since we do not
> assign the image to NULL when we release the image above.
Good catch, I should have set image=NULL at the beginning of __kexec_load().
Michael
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 16+ messages in thread