On 4/17/21 4:45 AM, Matthew Wilcox (Oracle) wrote:
> Move the PagePoisoned test into dump_page(). Skip the hex print
> for poisoned pages -- we know they're full of ffffffff. Move the
> reason printing from __dump_page() to dump_page().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> mm/debug.c | 25 +++++++------------------
> 1 file changed, 7 insertions(+), 18 deletions(-)
>
> diff --git a/mm/debug.c b/mm/debug.c
> index 84cdcd0f7bd3..e73fe0a8ec3d 100644
> --- a/mm/debug.c
> +++ b/mm/debug.c
> @@ -42,11 +42,10 @@ const struct trace_print_flags vmaflag_names[] = {
> {0, NULL}
> };
>
> -static void __dump_page(struct page *page, const char *reason)
> +static void __dump_page(struct page *page)
> {
> struct page *head = compound_head(page);
> struct address_space *mapping;
> - bool page_poisoned = PagePoisoned(page);
> bool compound = PageCompound(page);
> /*
> * Accessing the pageblock without the zone lock. It could change to
> @@ -58,16 +57,6 @@ static void __dump_page(struct page *page, const char *reason)
> int mapcount;
> char *type = "";
>
> - /*
> - * If struct page is poisoned don't access Page*() functions as that
> - * leads to recursive loop. Page*() check for poisoned pages, and calls
> - * dump_page() when detected.
> - */
> - if (page_poisoned) {
> - pr_warn("page:%px is uninitialized and poisoned", page);
> - goto hex_only;
> - }
> -
> if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) {
> /*
> * Corrupt page, so we cannot call page_mapping. Instead, do a
> @@ -173,8 +162,6 @@ static void __dump_page(struct page *page, const char *reason)
>
> pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags,
> page_cma ? " CMA" : "");
> -
> -hex_only:
> print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
> sizeof(unsigned long), page,
> sizeof(struct page), false);
> @@ -182,14 +169,16 @@ static void __dump_page(struct page *page, const char *reason)
> print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32,
> sizeof(unsigned long), head,
> sizeof(struct page), false);
> -
> - if (reason)
> - pr_warn("page dumped because: %s\n", reason);
> }
>
> void dump_page(struct page *page, const char *reason)
> {
> - __dump_page(page, reason);
> + if (PagePoisoned(page))
> + pr_warn("page:%p is uninitialized and poisoned", page);
> + else
> + __dump_page(page);
> + if (reason)
> + pr_warn("page dumped because: %s\n", reason);
> dump_page_owner(page);
> }
> EXPORT_SYMBOL(dump_page);
>
Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
