Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755481Ab3DTPen (ORCPT ); Sat, 20 Apr 2013 11:34:43 -0400 Received: from mail-da0-f53.google.com ([209.85.210.53]:64917 "EHLO mail-da0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755419Ab3DTPem (ORCPT ); Sat, 20 Apr 2013 11:34:42 -0400 Message-ID: <5172B58A.3090006@gmail.com> Date: Sat, 20 Apr 2013 23:34:34 +0800 From: Jiang Liu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Russell King - ARM Linux CC: Andrew Morton , linux-arch@vger.kernel.org, James Bottomley , David Howells , Jiang Liu , Wen Congyang , linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, Mark Salter , linux-kernel@vger.kernel.org, Michal Hocko , Minchan Kim , Mel Gorman , David Rientjes , Sergei Shtylyov , KAMEZAWA Hiroyuki , Jianguo Wu Subject: Re: [PATCH v4, part3 01/15] mm: fix build warnings caused by free_reserved_area() References: <1365256509-29024-1-git-send-email-jiang.liu@huawei.com> <1365256509-29024-2-git-send-email-jiang.liu@huawei.com> <20130419165208.GZ14496@n2100.arm.linux.org.uk> In-Reply-To: <20130419165208.GZ14496@n2100.arm.linux.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4029 Lines: 87 On 04/20/2013 12:52 AM, Russell King - ARM Linux wrote: > On Sat, Apr 06, 2013 at 09:54:55PM +0800, Jiang Liu wrote: >> Fix following build warnings cuased by free_reserved_area(): >> >> arch/arm/mm/init.c: In function 'mem_init': >> arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default] >> free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL); >> ^ >> In file included from include/linux/mman.h:4:0, >> from arch/arm/mm/init.c:15: >> include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *' >> extern unsigned long free_reserved_area(unsigned long start, unsigned long end, >> >> mm/page_alloc.c: In function 'free_reserved_area': >>>> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default] >> In file included from arch/mips/include/asm/page.h:49:0, >> from include/linux/mmzone.h:20, >> from include/linux/gfp.h:4, >> from include/linux/mm.h:8, >> from mm/page_alloc.c:18: >> arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int' >> mm/page_alloc.c: In function 'free_area_init_nodes': >> mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds] >> >> Signed-off-by: Jiang Liu >> Reported-by: Arnd Bergmann >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: linux-kernel@vger.kernel.org >> Cc: linux-mm@kvack.org >> --- >> arch/arm/mm/init.c | 6 ++++-- >> mm/page_alloc.c | 2 +- >> 2 files changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c >> index 9a5cdc0..7a82fcd 100644 >> --- a/arch/arm/mm/init.c >> +++ b/arch/arm/mm/init.c >> @@ -600,7 +600,8 @@ void __init mem_init(void) >> >> #ifdef CONFIG_SA1111 >> /* now that our DMA memory is actually so designated, we can free it */ >> - free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL); >> + free_reserved_area((unsigned long)__va(PHYS_PFN_OFFSET), >> + (unsigned long)swapper_pg_dir, 0, NULL); >> #endif >> >> free_highpages(); >> @@ -728,7 +729,8 @@ void free_initmem(void) >> extern char __tcm_start, __tcm_end; >> >> poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start); >> - free_reserved_area(&__tcm_start, &__tcm_end, 0, "TCM link"); >> + free_reserved_area((unsigned long)&__tcm_start, >> + (unsigned long)&__tcm_end, 0, "TCM link"); >> #endif >> >> poison_init_mem(__init_begin, __init_end - __init_begin); >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index e4923e9..8bf7956 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -5196,7 +5196,7 @@ unsigned long free_reserved_area(unsigned long start, unsigned long end, >> for (pages = 0; pos < end; pos += PAGE_SIZE, pages++) { >> if (poison) >> memset((void *)pos, poison, PAGE_SIZE); >> - free_reserved_page(virt_to_page(pos)); >> + free_reserved_page(virt_to_page((void *)pos)); > > Don't all these casts suggest to you that you may have the type wrong > in the first place? > Hi Russell, Good question! Originally free_reserved_area() is designed to simplify free_initrd_mem(), and free_initrd_mem() is declared as: void free_initrd_mem(unsigned long start, unsigned long end) So I have chosen "unsigned long" for free_reserved_area()'s first and second parameters, otherwise it will cause much more type casts in function free_initrd_mem(). For code purity, we should use "void *" instead. So should we change to "void *" here? Regards! Gerry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/