linux-kernel - Re: tlb_finish

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] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.64.0712261236390.15176@schroedinger.engr.sgi.com>
Date:	Wed, 26 Dec 2007 12:43:01 -0800 (PST)
From:	Christoph Lameter <clameter@....com>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
cc:	Al Viro <viro@....linux.org.uk>, linux-kernel@...r.kernel.org
Subject: Re: tlb_finish_mmu() bogisity

Argh. This is indeed bogus. The one reporting the problem states that the 
patch did not address the issue. The report was regarding pgd freeing 
which is handled slightly differently from pte frees.

[PATCH] Revert quicklist need->flush fix

Did not fix the reported issue. Apart from other weirdness this causes a 
bad link between the TLB flushing logic and the quicklists. If there is 
indeed an issue that an arch needs a tlb flush before free then the arch 
code needs to set tlb->need_flush before calling quicklist_free.

Signed-off-by: Christoph Lameter <clameter@....com>

Index: linux-2.6/include/asm-generic/tlb.h
===================================================================
--- linux-2.6.orig/include/asm-generic/tlb.h	2007-12-26 12:26:32.000000000 -0800
+++ linux-2.6/include/asm-generic/tlb.h	2007-12-26 12:26:39.000000000 -0800
@@ -86,9 +86,6 @@ tlb_flush_mmu(struct mmu_gather *tlb, un
 static inline void
 tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
 {
-#ifdef CONFIG_QUICKLIST
-	tlb->need_flush += &__get_cpu_var(quicklist)[0].nr_pages != 0;
-#endif
 	tlb_flush_mmu(tlb, start, end);
 
 	/* keep the page table cache within bounds */
--
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/