linux-kernel - [PATCH CPA] [22/28] CPA: Only queue actually unused page table pages for freeing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu,  3 Jan 2008 16:24:37 +0100 (CET)
From:	Andi Kleen <ak@...e.de>
To:	linux-kernel@...r.kernel.org
Subject: [PATCH CPA] [22/28] CPA: Only queue actually unused page table pages for freeing


With the separate data structure added for flush earlier it is only
needed to call save_page() now on pte pages that have been already reverted.

Also move all freeing checks into the caller.

Signed-off-by: Andi Kleen <ak@...e.de>

---
 arch/x86/mm/pageattr_32.c |    4 +---
 arch/x86/mm/pageattr_64.c |    7 +++----
 2 files changed, 4 insertions(+), 7 deletions(-)

Index: linux/arch/x86/mm/pageattr_32.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr_32.c
+++ linux/arch/x86/mm/pageattr_32.c
@@ -270,9 +270,9 @@ __change_page_attr(struct page *page, pg
 	 * replace it with a largepage.
 	 */
 
-	save_page(kpte_page);
 	if (!PageReserved(kpte_page)) {
 		if (cpu_has_pse && (page_private(kpte_page) == 0)) {
+			save_page(kpte_page);
 			paravirt_release_pt(page_to_pfn(kpte_page));
 			revert_page(kpte_page, address);
 		}
@@ -333,8 +333,6 @@ void global_flush_tlb(void)
 	list_for_each_entry_safe(pg, next, &free_pages, lru) {
 		list_del(&pg->lru);
 		ClearPageDeferred(pg);
-		if (PageReserved(pg) || !cpu_has_pse || page_private(pg) != 0)
-			continue;
 		ClearPagePrivate(pg);
 		__free_page(pg);
 	}
Index: linux/arch/x86/mm/pageattr_64.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr_64.c
+++ linux/arch/x86/mm/pageattr_64.c
@@ -246,9 +246,10 @@ __change_page_attr(unsigned long address
 	/* on x86-64 the direct mapping set at boot is not using 4k pages */
  	BUG_ON(PageReserved(kpte_page));
 
-	save_page(kpte_page);
-	if (page_private(kpte_page) == 0)
+	if (page_private(kpte_page) == 0) {
+		save_page(kpte_page);
 		revert_page(address, ref_prot);
+	}
 	return 0;
 } 
 
@@ -336,8 +337,6 @@ void global_flush_tlb(void)
 	list_for_each_entry_safe(pg, next, &free_pages, lru) {
 		list_del(&pg->lru);
 		ClearPageDeferred(pg);
-		if (page_private(pg) != 0)
-			continue;
 		ClearPagePrivate(pg);
 		__free_page(pg);
 	} 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/