* Question about kimage_alloc_page in kexec.c, bug?
@ 2010-10-11 14:46 wilbur.chan
2010-10-18 10:26 ` Américo Wang
0 siblings, 1 reply; 5+ messages in thread
From: wilbur.chan @ 2010-10-11 14:46 UTC (permalink / raw)
To: linux-kernel; +Cc: Linux MIPS Mailing List
Hi all !
I have a question on kimage_alloc_page:
page = kimage_alloc_pages(gfp_mask, 0);
...
/* If the page cannot be used file it away */
if (page_to_pfn(page) > (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
list_add(&page->lru, &image->unuseable_pages);
continue;
}
If a page frame is right at physical address 0x20000000 , then when calling
machine_kexec , the following code:
*ptr = (unsigned long) phys_to_virt(*ptr);
will generate an virtual address of 0xa0000000 = 0x20000000+0x80000000 , which
results in physical address 0.
should it be like this? :
--- kexec.c 2010-08-27 07:47:12.000000000 +0800
+++ kexec.changed.c 2010-10-11 22:04:08.000000000 +0800
@@ -723,7 +723,7 @@
if (!page)
return NULL;
/* If the page cannot be used file it away */
- if (page_to_pfn(page) >
+ if (page_to_pfn(page) >=
(KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
list_add(&page->lru, &image->unuseable_pages);
continue;
Thank you
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: Question about kimage_alloc_page in kexec.c, bug?
2010-10-11 14:46 Question about kimage_alloc_page in kexec.c, bug? wilbur.chan
@ 2010-10-18 10:26 ` Américo Wang
2010-10-18 10:40 ` Bernhard Walle
0 siblings, 1 reply; 5+ messages in thread
From: Américo Wang @ 2010-10-18 10:26 UTC (permalink / raw)
To: wilbur.chan; +Cc: linux-kernel, Linux MIPS Mailing List
On Mon, Oct 11, 2010 at 10:46:59PM +0800, wilbur.chan wrote:
>Hi all !
>
>I have a question on kimage_alloc_page:
>
...
You can Cc me on kexec/kdump issues. :)
>
>
>If a page frame is right at physical address 0x20000000 , then when calling
>
>machine_kexec , the following code:
>
>*ptr = (unsigned long) phys_to_virt(*ptr);
>
>will generate an virtual address of 0xa0000000 = 0x20000000+0x80000000 , which
>
>results in physical address 0.
>
>
>
>should it be like this? :
>
>--- kexec.c 2010-08-27 07:47:12.000000000 +0800
>+++ kexec.changed.c 2010-10-11 22:04:08.000000000 +0800
>@@ -723,7 +723,7 @@
> if (!page)
> return NULL;
> /* If the page cannot be used file it away */
>- if (page_to_pfn(page) >
>+ if (page_to_pfn(page) >=
> (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
> list_add(&page->lru, &image->unuseable_pages);
> continue;
>
No, this could break x86_64.
IMHO, what needs to fix is the definition of KEXEC_SOURCE_MEMORY_LIMIT
on MIPS, something like:
- #define KEXEC_SOURCE_MEMORY_LIMIT (0x20000000)
+ #define KEXEC_SOURCE_MEMORY_LIMIT (0x1FFFFFFF)
Thanks.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Question about kimage_alloc_page in kexec.c, bug?
@ 2010-10-11 15:02 ` wilbur.chan
0 siblings, 0 replies; 5+ messages in thread
From: wilbur.chan @ 2010-10-11 15:02 UTC (permalink / raw)
To: Linux MIPS Mailing List; +Cc: kexec
Hi all !
I have a question on kimage_alloc_page:
page = kimage_alloc_pages(gfp_mask, 0);
...
/* If the page cannot be used file it away */
if (page_to_pfn(page) > (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
list_add(&page->lru, &image->unuseable_pages);
continue;
}
If a page frame is right at physical address 0x20000000 , then when calling
machine_kexec , the following code:
*ptr = (unsigned long) phys_to_virt(*ptr);
will generate an virtual address of 0xa0000000 = 0x20000000+0x80000000 , which
results in physical address 0.
should it be like this? :
--- kexec.c 2010-08-27 07:47:12.000000000 +0800
+++ kexec.changed.c 2010-10-11 22:04:08.000000000 +0800
@@ -723,7 +723,7 @@
if (!page)
return NULL;
/* If the page cannot be used file it away */
- if (page_to_pfn(page) >
+ if (page_to_pfn(page) >=
(KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
list_add(&page->lru, &image->unuseable_pages);
continue;
Thank you
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kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 5+ messages in thread* Question about kimage_alloc_page in kexec.c, bug?
@ 2010-10-11 15:02 ` wilbur.chan
0 siblings, 0 replies; 5+ messages in thread
From: wilbur.chan @ 2010-10-11 15:02 UTC (permalink / raw)
To: Linux MIPS Mailing List; +Cc: kexec
Hi all !
I have a question on kimage_alloc_page:
page = kimage_alloc_pages(gfp_mask, 0);
...
/* If the page cannot be used file it away */
if (page_to_pfn(page) > (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
list_add(&page->lru, &image->unuseable_pages);
continue;
}
If a page frame is right at physical address 0x20000000 , then when calling
machine_kexec , the following code:
*ptr = (unsigned long) phys_to_virt(*ptr);
will generate an virtual address of 0xa0000000 = 0x20000000+0x80000000 , which
results in physical address 0.
should it be like this? :
--- kexec.c 2010-08-27 07:47:12.000000000 +0800
+++ kexec.changed.c 2010-10-11 22:04:08.000000000 +0800
@@ -723,7 +723,7 @@
if (!page)
return NULL;
/* If the page cannot be used file it away */
- if (page_to_pfn(page) >
+ if (page_to_pfn(page) >=
(KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
list_add(&page->lru, &image->unuseable_pages);
continue;
Thank you
^ permalink raw reply [flat|nested] 5+ messages in thread
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2010-10-11 14:46 Question about kimage_alloc_page in kexec.c, bug? wilbur.chan
2010-10-18 10:26 ` Américo Wang
2010-10-18 10:40 ` Bernhard Walle
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2010-10-11 15:02 wilbur.chan
2010-10-11 15:02 ` wilbur.chan
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