From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from burns.conectiva (burns.conectiva [10.0.0.4]) by perninha.conectiva.com.br (Postfix) with SMTP id 1C88948653 for ; Thu, 5 Dec 2002 14:31:06 -0200 (BRST) Date: Thu, 5 Dec 2002 14:30:51 -0200 (BRST) From: Rik van Riel Subject: [PATCH] bugfix for HIGHMEM_DEBUG Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Marcelo Tosatti Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Hi Marcelo, I found a bug in the HIGHMEM_DEBUG code, in kunmap_atomic() to be specific. The problem is that kunmap_atomic() can get called with an address which isn't page aligned, but we compare that address to a page aligned address and bug if the two aren't equal. The obvious fix is to page-align the address before doing the check, we're not doing anything else with it anyway since kunmap_atomic() is a nop if HIGHMEM_DEBUG is off. please apply, Rik -- A: No. Q: Should I include quotations after my reply? http://www.surriel.com/ http://guru.conectiva.com/ --- include/asm/highmem.h.orig 2002-12-05 13:23:31.000000000 -0200 +++ include/asm/highmem.h 2002-12-05 13:13:18.000000000 -0200 @@ -106,7 +106,7 @@ static inline void kunmap_atomic(void *kvaddr, enum km_type type) { #if HIGHMEM_DEBUG - unsigned long vaddr = (unsigned long) kvaddr; + unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); if (vaddr < FIXADDR_START) // FIXME -- 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/