Simplfy use dump_page().
Signed-off-by: Kefeng Wang <[email protected]>
---
mm/page_alloc.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a2fe714aed93..f23702e7c564 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -658,8 +658,7 @@ static void bad_page(struct page *page, const char *reason)
pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
current->comm, page_to_pfn(page));
- __dump_page(page, reason);
- dump_page_owner(page);
+ dump_page(page, reason);
print_modules();
dump_stack();
--
2.26.2
If page is poisoned, it will crash when we call some page related
functions, so must check whether the page is poisoned or not firstly.
Fixes: 6197ab984b41 ("mm: improve dump_page() for compound pages")
Signed-off-by: Kefeng Wang <[email protected]>
---
mm/debug.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/mm/debug.c b/mm/debug.c
index 84cdcd0f7bd3..cf84cd9df527 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -44,20 +44,19 @@ const struct trace_print_flags vmaflag_names[] = {
static void __dump_page(struct page *page, const char *reason)
{
- struct page *head = compound_head(page);
+ struct page *head = NULL;
struct address_space *mapping;
- bool page_poisoned = PagePoisoned(page);
- bool compound = PageCompound(page);
+ bool compound;
/*
* Accessing the pageblock without the zone lock. It could change to
* "isolate" again in the meantime, but since we are just dumping the
* state for debugging, it should be fine to accept a bit of
* inaccuracy here due to racing.
*/
- bool page_cma = is_migrate_cma_page(page);
+ bool page_cma;
int mapcount;
char *type = "";
-
+ bool page_poisoned = PagePoisoned(page);
/*
* If struct page is poisoned don't access Page*() functions as that
* leads to recursive loop. Page*() check for poisoned pages, and calls
@@ -68,6 +67,10 @@ static void __dump_page(struct page *page, const char *reason)
goto hex_only;
}
+ head = compound_head(page);
+ page_poisoned = PagePoisoned(page);
+ page_cma = is_migrate_cma_page(page);
+
if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) {
/*
* Corrupt page, so we cannot call page_mapping. Instead, do a
@@ -178,7 +181,7 @@ static void __dump_page(struct page *page, const char *reason)
print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
sizeof(unsigned long), page,
sizeof(struct page), false);
- if (head != page)
+ if (head && head != page)
print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
sizeof(unsigned long), head,
sizeof(struct page), false);
--
2.26.2
On Wed, May 12, 2021 at 11:10:55AM +0800, Kefeng Wang wrote:
> Simplfy use dump_page().
https://lore.kernel.org/linux-mm/[email protected]/
> Signed-off-by: Kefeng Wang <[email protected]>
> ---
> mm/page_alloc.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index a2fe714aed93..f23702e7c564 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -658,8 +658,7 @@ static void bad_page(struct page *page, const char *reason)
>
> pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
> current->comm, page_to_pfn(page));
> - __dump_page(page, reason);
> - dump_page_owner(page);
> + dump_page(page, reason);
>
> print_modules();
> dump_stack();
> --
> 2.26.2
>
On Wed, May 12, 2021 at 11:10:57AM +0800, Kefeng Wang wrote:
> If page is poisoned, it will crash when we call some page related
> functions, so must check whether the page is poisoned or not firstly.
https://lore.kernel.org/linux-mm/[email protected]/
> Fixes: 6197ab984b41 ("mm: improve dump_page() for compound pages")
> Signed-off-by: Kefeng Wang <[email protected]>
> ---
> mm/debug.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/mm/debug.c b/mm/debug.c
> index 84cdcd0f7bd3..cf84cd9df527 100644
> --- a/mm/debug.c
> +++ b/mm/debug.c
> @@ -44,20 +44,19 @@ const struct trace_print_flags vmaflag_names[] = {
>
> static void __dump_page(struct page *page, const char *reason)
> {
> - struct page *head = compound_head(page);
> + struct page *head = NULL;
> struct address_space *mapping;
> - bool page_poisoned = PagePoisoned(page);
> - bool compound = PageCompound(page);
> + bool compound;
> /*
> * Accessing the pageblock without the zone lock. It could change to
> * "isolate" again in the meantime, but since we are just dumping the
> * state for debugging, it should be fine to accept a bit of
> * inaccuracy here due to racing.
> */
> - bool page_cma = is_migrate_cma_page(page);
> + bool page_cma;
> int mapcount;
> char *type = "";
> -
> + bool page_poisoned = PagePoisoned(page);
> /*
> * If struct page is poisoned don't access Page*() functions as that
> * leads to recursive loop. Page*() check for poisoned pages, and calls
> @@ -68,6 +67,10 @@ static void __dump_page(struct page *page, const char *reason)
> goto hex_only;
> }
>
> + head = compound_head(page);
> + page_poisoned = PagePoisoned(page);
> + page_cma = is_migrate_cma_page(page);
> +
> if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) {
> /*
> * Corrupt page, so we cannot call page_mapping. Instead, do a
> @@ -178,7 +181,7 @@ static void __dump_page(struct page *page, const char *reason)
> print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
> sizeof(unsigned long), page,
> sizeof(struct page), false);
> - if (head != page)
> + if (head && head != page)
> print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
> sizeof(unsigned long), head,
> sizeof(struct page), false);
> --
> 2.26.2
>
>
On 2021/5/12 11:15, Matthew Wilcox wrote:
> On Wed, May 12, 2021 at 11:10:57AM +0800, Kefeng Wang wrote:
>> If page is poisoned, it will crash when we call some page related
>> functions, so must check whether the page is poisoned or not firstly.
>
> https://lore.kernel.org/linux-mm/[email protected]/
OK, please ignore them, I found this when debug arm issue in lts5.10,
thanks.
>
>> Fixes: 6197ab984b41 ("mm: improve dump_page() for compound pages")
>> Signed-off-by: Kefeng Wang <[email protected]>
>> ---
>> mm/debug.c | 15 +++++++++------
>> 1 file changed, 9 insertions(+), 6 deletions(-)
>>
>> diff --git a/mm/debug.c b/mm/debug.c
>> index 84cdcd0f7bd3..cf84cd9df527 100644
>> --- a/mm/debug.c
>> +++ b/mm/debug.c
>> @@ -44,20 +44,19 @@ const struct trace_print_flags vmaflag_names[] = {
>>
>> static void __dump_page(struct page *page, const char *reason)
>> {
>> - struct page *head = compound_head(page);
>> + struct page *head = NULL;
>> struct address_space *mapping;
>> - bool page_poisoned = PagePoisoned(page);
>> - bool compound = PageCompound(page);
>> + bool compound;
>> /*
>> * Accessing the pageblock without the zone lock. It could change to
>> * "isolate" again in the meantime, but since we are just dumping the
>> * state for debugging, it should be fine to accept a bit of
>> * inaccuracy here due to racing.
>> */
>> - bool page_cma = is_migrate_cma_page(page);
>> + bool page_cma;
>> int mapcount;
>> char *type = "";
>> -
>> + bool page_poisoned = PagePoisoned(page);
>> /*
>> * If struct page is poisoned don't access Page*() functions as that
>> * leads to recursive loop. Page*() check for poisoned pages, and calls
>> @@ -68,6 +67,10 @@ static void __dump_page(struct page *page, const char *reason)
>> goto hex_only;
>> }
>>
>> + head = compound_head(page);
>> + page_poisoned = PagePoisoned(page);
>> + page_cma = is_migrate_cma_page(page);
>> +
>> if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) {
>> /*
>> * Corrupt page, so we cannot call page_mapping. Instead, do a
>> @@ -178,7 +181,7 @@ static void __dump_page(struct page *page, const char *reason)
>> print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
>> sizeof(unsigned long), page,
>> sizeof(struct page), false);
>> - if (head != page)
>> + if (head && head != page)
>> print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
>> sizeof(unsigned long), head,
>> sizeof(struct page), false);
>> --
>> 2.26.2
>>
>>
> .
>