On Tue, 7 Jul 2015 17:18:40 -0400
Vivek Goyal <vgoyal at 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;
}
