Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757432AbYBFRqQ (ORCPT ); Wed, 6 Feb 2008 12:46:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756700AbYBFRpq (ORCPT ); Wed, 6 Feb 2008 12:45:46 -0500 Received: from [198.99.130.12] ([198.99.130.12]:44521 "EHLO saraswathi.solana.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756638AbYBFRpo (ORCPT ); Wed, 6 Feb 2008 12:45:44 -0500 Date: Wed, 6 Feb 2008 12:44:48 -0500 From: Jeff Dike To: Andrew Morton Cc: LKML , uml-devel , Miklos Szeredi Subject: [PATCH 5/5] UML - Fix mm_context memory leak Message-ID: <20080206174448.GA7851@c2.user-mode-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.3i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2152 Lines: 61 [ Spotted by Miklos ] Fix a memory leak in init_new_context. The struct page ** buffer allocated for install_special_mapping was never recorded, and thus leaked when the mm_struct was freed. Fix it by saving the pointer in mm_context_t and freeing it in arch_exit_mmap. Signed-off-by: Jeff Dike Cc: Miklos Szeredi --- arch/um/include/um_mmu.h | 1 + arch/um/kernel/skas/mmu.c | 5 +++++ 2 files changed, 6 insertions(+) Index: linux-2.6-git/arch/um/include/um_mmu.h =================================================================== --- linux-2.6-git.orig/arch/um/include/um_mmu.h 2008-02-06 12:15:05.000000000 -0500 +++ linux-2.6-git/arch/um/include/um_mmu.h 2008-02-06 12:24:08.000000000 -0500 @@ -13,6 +13,7 @@ typedef struct mm_context { struct mm_id id; struct uml_ldt ldt; + struct page **stub_pages; } mm_context_t; extern void __switch_mm(struct mm_id * mm_idp); Index: linux-2.6-git/arch/um/kernel/skas/mmu.c =================================================================== --- linux-2.6-git.orig/arch/um/kernel/skas/mmu.c 2008-02-06 12:15:05.000000000 -0500 +++ linux-2.6-git/arch/um/kernel/skas/mmu.c 2008-02-06 12:24:31.000000000 -0500 @@ -91,6 +91,8 @@ int init_new_context(struct task_struct goto out_free; } + to_mm->stub_pages = NULL; + return 0; out_free: @@ -126,6 +128,7 @@ void arch_dup_mmap(struct mm_struct *old pages[0] = virt_to_page(&__syscall_stub_start); pages[1] = virt_to_page(mm->context.id.stack); + mm->context.stub_pages = pages; /* dup_mmap already holds mmap_sem */ err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START, @@ -147,6 +150,8 @@ void arch_exit_mmap(struct mm_struct *mm { pte_t *pte; + if (mm->context.stub_pages != NULL) + kfree(mm->context.stub_pages); pte = virt_to_pte(mm, STUB_CODE); if (pte != NULL) pte_clear(mm, STUB_CODE, pte); -- 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/