From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id AA4036B005A for ; Tue, 7 Jul 2009 12:52:23 -0400 (EDT) Date: Tue, 7 Jul 2009 18:53:50 +0200 From: Johannes Weiner Subject: Re: [RFC PATCH 2/3] kmemleak: Add callbacks to the bootmem allocator Message-ID: <20090707165350.GA2782@cmpxchg.org> References: <20090706104654.16051.44029.stgit@pc1117.cambridge.arm.com> <20090706105155.16051.59597.stgit@pc1117.cambridge.arm.com> <1246950530.24285.7.camel@penberg-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1246950530.24285.7.camel@penberg-laptop> Sender: owner-linux-mm@kvack.org To: Pekka Enberg Cc: Catalin Marinas , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ingo Molnar List-ID: On Tue, Jul 07, 2009 at 10:08:50AM +0300, Pekka Enberg wrote: > On Mon, 2009-07-06 at 11:51 +0100, Catalin Marinas wrote: > > This patch adds kmemleak_alloc/free callbacks to the bootmem allocator. > > This would allow scanning of such blocks and help avoiding a whole class > > of false positives and more kmemleak annotations. > > > > Signed-off-by: Catalin Marinas > > Cc: Ingo Molnar > > Cc: Pekka Enberg > > Looks good to me! > > Acked-by: Pekka Enberg > > But lets cc Johannes on this too. > > @@ -597,7 +601,9 @@ restart: > > void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align, > > unsigned long goal) > > { > > - return ___alloc_bootmem_nopanic(size, align, goal, 0); > > + void *ptr = ___alloc_bootmem_nopanic(size, align, goal, 0); > > + kmemleak_alloc(ptr, size, 1, GFP_KERNEL); > > + return ptr; You may get an object from kzalloc() here, I don't think you want to track that (again), right? Pekka already worked out all the central places to catch 'slab already available' allocations, they can probably help you place the hooks. > > static void * __init ___alloc_bootmem(unsigned long size, unsigned long align, > > @@ -631,7 +637,9 @@ static void * __init ___alloc_bootmem(unsigned long size, unsigned long align, > > void * __init __alloc_bootmem(unsigned long size, unsigned long align, > > unsigned long goal) > > { > > - return ___alloc_bootmem(size, align, goal, 0); > > + void *ptr = ___alloc_bootmem(size, align, goal, 0); > > + kmemleak_alloc(ptr, size, 1, GFP_KERNEL); > > + return ptr; Same here. > > #ifdef CONFIG_SPARSEMEM > > @@ -707,14 +719,18 @@ void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size, > > return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id); > > > > ptr = alloc_arch_preferred_bootmem(pgdat->bdata, size, align, goal, 0); > > + kmemleak_alloc(ptr, size, 1, GFP_KERNEL); > > if (ptr) > > return ptr; > > > > ptr = alloc_bootmem_core(pgdat->bdata, size, align, goal, 0); > > + kmemleak_alloc(ptr, size, 1, GFP_KERNEL); > > if (ptr) > > return ptr; > > > > - return __alloc_bootmem_nopanic(size, align, goal); > > + ptr = __alloc_bootmem_nopanic(size, align, goal); > > + kmemleak_alloc(ptr, size, 1, GFP_KERNEL); > > + return ptr; > > } Can you use a central exit and goto? > > #ifndef ARCH_LOW_ADDRESS_LIMIT > > @@ -737,7 +753,9 @@ void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size, > > void * __init __alloc_bootmem_low(unsigned long size, unsigned long align, > > unsigned long goal) > > { > > - return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT); > > + void *ptr = ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT); > > + kmemleak_alloc(ptr, size, 1, GFP_KERNEL); > > + return ptr; > > } Possible slab object. > > @@ -758,9 +776,13 @@ void * __init __alloc_bootmem_low(unsigned long size, unsigned long align, > > void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size, > > unsigned long align, unsigned long goal) > > { > > + void *ptr; > > + > > if (WARN_ON_ONCE(slab_is_available())) > > return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id); > > > > - return ___alloc_bootmem_node(pgdat->bdata, size, align, > > - goal, ARCH_LOW_ADDRESS_LIMIT); > > + ptr = ___alloc_bootmem_node(pgdat->bdata, size, align, > > + goal, ARCH_LOW_ADDRESS_LIMIT); > > + kmemleak_alloc(ptr, size, 1, GFP_KERNEL); These GFP_KERNEL startled me. We know for sure that this code runs in earlylog mode only and gfp is unused, right? Can you perhaps just pass 0 for gfp instead? Hannes -- 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/ . Don't email: email@kvack.org