[PATCH V3] ia64/mm: fix a bad_page bug when crash kernel booting

Xishi Qiu
2013-02-07T06:09:16Z

> Sorry, this bug will be happen when use Sparse-Memory(section is valid, but last

> several pages are invalid). If use Flat-Memory, crash kernel will boot successfully.
> I think the following patch would be better.
>
> Hi Andrew, will you just ignore the earlier patch and consider the following one? :>
>
> Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
> ---
> arch/ia64/mm/init.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
> index 082e383..23f2ee3 100644
> --- a/arch/ia64/mm/init.c
> +++ b/arch/ia64/mm/init.c
> @@ -213,6 +213,8 @@ free_initrd_mem (unsigned long start, unsigned long end)
> for (; start < end; start += PAGE_SIZE) {
> if (!virt_addr_valid(start))
> continue;
> + if ((start >> PAGE_SHIFT) >= max_low_pfn)

I confused the vaddr and paddr, really sorry for it.

In efi_init() memory aligns in IA64_GRANULE_SIZE(16M). If set "crashkernel\x1024M-:600M"
and use sparse memory model, when crash kernel booting it changes [128M-728M] to [128M-720M].
But initrd memory is in [709M-727M], and virt_addr_valid() *can not* check the invalid pages
when freeing initrd memory. There are some pages missed at the end of the seciton.

ChangeLog V3:
fixed vaddr mistake
ChangeLog V2:
add invalid pages check when freeing initrd memory

Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
---
arch/ia64/mm/init.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 082e383..8a269f8 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -173,6 +173,7 @@ void __init
free_initrd_mem (unsigned long start, unsigned long end)
{
struct page *page;
+ unsigned long pfn;
/*
* EFI uses 4KB pages while the kernel can use 4KB or bigger.
* Thus EFI and the kernel may have different page sizes. It is
@@ -213,6 +214,9 @@ free_initrd_mem (unsigned long start, unsigned long end)
for (; start < end; start += PAGE_SIZE) {
if (!virt_addr_valid(start))
continue;
+ pfn = __pa(start) >> PAGE_SHIFT;
+ if (pfn >= max_low_pfn)
+ continue;
page = virt_to_page(start);
ClearPageReserved(page);
init_page_count(page);
--
1.7.6.1