From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 2976A6B016C for ; Mon, 22 Aug 2011 12:27:28 -0400 (EDT) Received: by gxk23 with SMTP id 23so4939921gxk.14 for ; Mon, 22 Aug 2011 09:27:23 -0700 (PDT) From: Akinobu Mita Subject: [PATCH 2/4] debug-pagealloc: add support for highmem pages Date: Tue, 23 Aug 2011 01:29:06 +0900 Message-Id: <1314030548-21082-3-git-send-email-akinobu.mita@gmail.com> In-Reply-To: <1314030548-21082-1-git-send-email-akinobu.mita@gmail.com> References: <1314030548-21082-1-git-send-email-akinobu.mita@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org Cc: Akinobu Mita This adds support for highmem pages poisoning and verification to the debug-pagealloc feature for no-architecture support. Signed-off-by: Akinobu Mita --- mm/debug-pagealloc.c | 61 ++++++++++++++++++++++++------------------------- 1 files changed, 30 insertions(+), 31 deletions(-) diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c index a4b6d70..5afe80c 100644 --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -1,5 +1,6 @@ #include #include +#include #include #include #include @@ -19,28 +20,25 @@ static inline bool page_poison(struct page *page) return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags); } -static void poison_highpage(struct page *page) -{ - /* - * Page poisoning for highmem pages is not implemented. - * - * This can be called from interrupt contexts. - * So we need to create a new kmap_atomic slot for this - * application and it will need interrupt protection. - */ -} - static void poison_page(struct page *page) { void *addr; - - if (PageHighMem(page)) { - poison_highpage(page); - return; + unsigned long flags; + bool highmem = PageHighMem(page); + + if (highmem) { + local_irq_save(flags); + addr = kmap_atomic(page); + } else { + addr = page_address(page); } set_page_poison(page); - addr = page_address(page); memset(addr, PAGE_POISON, PAGE_SIZE); + + if (highmem) { + kunmap_atomic(addr); + local_irq_restore(flags); + } } static void poison_pages(struct page *page, int n) @@ -88,26 +86,27 @@ static void check_poison_mem(unsigned char *mem, size_t bytes) dump_stack(); } -static void unpoison_highpage(struct page *page) -{ - /* - * See comment in poison_highpage(). - * Highmem pages should not be poisoned for now - */ - BUG_ON(page_poison(page)); -} - static void unpoison_page(struct page *page) { - if (PageHighMem(page)) { - unpoison_highpage(page); + void *addr; + unsigned long flags; + bool highmem = PageHighMem(page); + + if (!page_poison(page)) return; + + if (highmem) { + local_irq_save(flags); + addr = kmap_atomic(page); + } else { + addr = page_address(page); } - if (page_poison(page)) { - void *addr = page_address(page); + check_poison_mem(addr, PAGE_SIZE); + clear_page_poison(page); - check_poison_mem(addr, PAGE_SIZE); - clear_page_poison(page); + if (highmem) { + kunmap_atomic(addr); + local_irq_restore(flags); } } -- 1.7.4.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org