From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm/debug: factor PagePoisoned out of __dump_page 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(). Link: https://lkml.kernel.org/r/20210416231531.2521383-3-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/debug.c | 25 +++++++------------------ 1 file changed, 7 insertions(+), 18 deletions(-) --- a/mm/debug.c~mm-debug-factor-pagepoisoned-out-of-__dump_page +++ a/mm/debug.c @@ -42,11 +42,10 @@ const struct trace_print_flags vmaflag_n {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 *pag 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 @@ out_mapping: 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 @@ hex_only: 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); _
