Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754940Ab2KEWrl (ORCPT ); Mon, 5 Nov 2012 17:47:41 -0500 Received: from mail-pb0-f46.google.com ([209.85.160.46]:35034 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752356Ab2KEWrg (ORCPT ); Mon, 5 Nov 2012 17:47:36 -0500 From: Michel Lespinasse To: Andrew Morton , Rik van Riel , Hugh Dickins , linux-kernel@vger.kernel.org, Russell King , Ralf Baechle , Paul Mundt , "David S. Miller" , Chris Metcalf , x86@kernel.org, William Irwin Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org Subject: [PATCH 03/16] mm: check rb_subtree_gap correctness Date: Mon, 5 Nov 2012 14:47:00 -0800 Message-Id: <1352155633-8648-4-git-send-email-walken@google.com> X-Mailer: git-send-email 1.7.7.3 In-Reply-To: <1352155633-8648-1-git-send-email-walken@google.com> References: <1352155633-8648-1-git-send-email-walken@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3079 Lines: 90 When CONFIG_DEBUG_VM_RB is enabled, check that rb_subtree_gap is correctly set for every vma and that mm->highest_vm_end is also correct. Also add an explicit 'bug' variable to track if browse_rb() detected any invalid condition. Signed-off-by: Michel Lespinasse Reviewed-by: Rik van Riel --- mm/mmap.c | 24 ++++++++++++++++-------- 1 files changed, 16 insertions(+), 8 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 2de8bcfe859d..769a09cc71af 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -365,7 +365,7 @@ static void vma_rb_erase(struct vm_area_struct *vma, struct rb_root *root) #ifdef CONFIG_DEBUG_VM_RB static int browse_rb(struct rb_root *root) { - int i = 0, j; + int i = 0, j, bug = 0; struct rb_node *nd, *pn = NULL; unsigned long prev = 0, pend = 0; @@ -373,29 +373,33 @@ static int browse_rb(struct rb_root *root) struct vm_area_struct *vma; vma = rb_entry(nd, struct vm_area_struct, vm_rb); if (vma->vm_start < prev) - printk("vm_start %lx prev %lx\n", vma->vm_start, prev), i = -1; + printk("vm_start %lx prev %lx\n", vma->vm_start, prev), bug = 1; if (vma->vm_start < pend) - printk("vm_start %lx pend %lx\n", vma->vm_start, pend); + printk("vm_start %lx pend %lx\n", vma->vm_start, pend), bug = 1; if (vma->vm_start > vma->vm_end) - printk("vm_end %lx < vm_start %lx\n", vma->vm_end, vma->vm_start); + printk("vm_end %lx < vm_start %lx\n", vma->vm_end, vma->vm_start), bug = 1; + if (vma->rb_subtree_gap != vma_compute_subtree_gap(vma)) + printk("free gap %lx, correct %lx\n", + vma->rb_subtree_gap, + vma_compute_subtree_gap(vma)), bug = 1; i++; pn = nd; prev = vma->vm_start; pend = vma->vm_end; } j = 0; - for (nd = pn; nd; nd = rb_prev(nd)) { + for (nd = pn; nd; nd = rb_prev(nd)) j++; - } if (i != j) - printk("backwards %d, forwards %d\n", j, i), i = 0; - return i; + printk("backwards %d, forwards %d\n", j, i), bug = 1; + return bug ? -1 : i; } void validate_mm(struct mm_struct *mm) { int bug = 0; int i = 0; + unsigned long highest_address = 0; struct vm_area_struct *vma = mm->mmap; while (vma) { struct anon_vma_chain *avc; @@ -403,11 +407,15 @@ void validate_mm(struct mm_struct *mm) list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) anon_vma_interval_tree_verify(avc); anon_vma_unlock(vma->anon_vma); + highest_address = vma->vm_end; vma = vma->vm_next; i++; } if (i != mm->map_count) printk("map_count %d vm_next %d\n", mm->map_count, i), bug = 1; + if (highest_address != mm->highest_vm_end) + printk("mm->highest_vm_end %lx, found %lx\n", + mm->highest_vm_end, highest_address), bug = 1; i = browse_rb(&mm->mm_rb); if (i != mm->map_count) printk("map_count %d rb %d\n", mm->map_count, i), bug = 1; -- 1.7.7.3 -- 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/