Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752819Ab2BRP6n (ORCPT ); Sat, 18 Feb 2012 10:58:43 -0500 Received: from smarthost01.mail.zen.net.uk ([212.23.3.140]:43184 "EHLO smarthost01.mail.zen.net.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752490Ab2BRP6l (ORCPT ); Sat, 18 Feb 2012 10:58:41 -0500 X-Greylist: delayed 625 seconds by postgrey-1.27 at vger.kernel.org; Sat, 18 Feb 2012 10:58:41 EST Message-ID: <1329580713.2448.17.camel@computer2.home> Subject: Re: [PATCH 2/2] ARM: dma-mapping: fix leak in consistent_init From: Tixy To: Ajeet Yadav Cc: Russell King , Nicolas Pitre , Catalin Marinas , Sumit Bhattacharya , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Date: Sat, 18 Feb 2012 15:58:33 +0000 In-Reply-To: <1329484195-26361-1-git-send-email-ajeet.yadav.77@gmail.com> References: <1329484195-26361-1-git-send-email-ajeet.yadav.77@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.2-1 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 X-Originating-Smarthost01-IP: [82.69.122.217] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2625 Lines: 94 On Fri, 2012-02-17 at 18:39 +0530, Ajeet Yadav wrote: > Although the error in this case is unlikely, but logically > if error occurs then we leak memory. > > Signed-off-by: Ajeet Yadav If you want to fix all the memory leaks then the page tables allocated by pte_alloc_kernel() need freeing as well, (and the pud and pmd tables?). However, if we run out of memory this early in boot, then the system is unusable anyway and it doesn't seem worth adding the extra code complexity to avoid any of these memory leaks. -- Tixy > --- > arch/arm/mm/dma-mapping.c | 24 ++++++++++++------------ > 1 files changed, 12 insertions(+), 12 deletions(-) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index 04bfa76..b8cf062 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -161,7 +161,6 @@ static struct arm_vmregion_head consistent_head = { > */ > static int __init consistent_init(void) > { > - int ret = 0; > pgd_t *pgd; > pud_t *pud; > pmd_t *pmd; > @@ -171,7 +170,7 @@ static int __init consistent_init(void) > unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT; > > consistent_pte = kmalloc(num_ptes * sizeof(pte_t *), GFP_KERNEL); > - if (!consistent_pte) { > + if (unlikely(!consistent_pte)) { > pr_err("%s: no memory\n", __func__); > return -ENOMEM; > } > @@ -183,32 +182,33 @@ static int __init consistent_init(void) > pgd = pgd_offset(&init_mm, base); > > pud = pud_alloc(&init_mm, pgd, base); > - if (!pud) { > + if (unlikely(!pud)) { > printk(KERN_ERR "%s: no pud tables\n", __func__); > - ret = -ENOMEM; > - break; > + goto err; > } > > pmd = pmd_alloc(&init_mm, pud, base); > - if (!pmd) { > + if (unlikely(!pmd)) { > printk(KERN_ERR "%s: no pmd tables\n", __func__); > - ret = -ENOMEM; > - break; > + goto err; > } > WARN_ON(!pmd_none(*pmd)); > > pte = pte_alloc_kernel(pmd, base); > - if (!pte) { > + if (unlikely(!pte)) { > printk(KERN_ERR "%s: no pte tables\n", __func__); > - ret = -ENOMEM; > - break; > + goto err; > } > > consistent_pte[i++] = pte; > base += PMD_SIZE; > } while (base < CONSISTENT_END); > > - return ret; > + return 0; > +err: > + kfree(consistent_pte); > + consistent_pte = NULL; > + return -ENOMEM; > } > > core_initcall(consistent_init); -- 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/