Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756455AbbGTPUn (ORCPT ); Mon, 20 Jul 2015 11:20:43 -0400 Received: from mail-lb0-f178.google.com ([209.85.217.178]:35171 "EHLO mail-lb0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752011AbbGTPUl (ORCPT ); Mon, 20 Jul 2015 11:20:41 -0400 MIME-Version: 1.0 In-Reply-To: <1433920870-3430-1-git-send-email-dongxing.zhang@intel.com> References: <1433920870-3430-1-git-send-email-dongxing.zhang@intel.com> Date: Mon, 20 Jul 2015 18:20:39 +0300 Message-ID: Subject: Re: [PATCH] tty/vt: Fix the memory leak in visual_init From: Konstantin Khlebnikov To: Dongxing Zhang Cc: Greg Kroah-Hartman , peter@hurleysoftware.com, alan@linux.intel.com, Linux Kernel Mailing List , Xiaoming Wang Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5647 Lines: 117 On Wed, Jun 10, 2015 at 10:21 AM, Dongxing Zhang wrote: > If vc->vc_uni_pagedir_loc is not NULL, its refcount needs to be > decreased before vc_uni_pagedir_loc is re-assigned. > > unreferenced object 0xffff88002cdd13b0 (size 512): > comm "setfont", pid 503, jiffies 4294896503 (age 722.828s) > hex dump (first 32 bytes): > 40 92 61 2b 00 88 ff ff 00 00 00 00 00 00 00 00 @.a+............ > 00 00 00 00 00 00 00 00 a0 ad 61 2b 00 88 ff ff ..........a+.... > backtrace: > [] kmemleak_alloc+0x4e/0xb0 > [] kmem_cache_alloc_trace+0x1c8/0x240 > [] con_do_clear_unimap.isra.2+0x83/0xe0 > [] con_clear_unimap+0x22/0x40 > [] vt_ioctl+0xeb8/0x1170 > [] tty_ioctl+0x208/0xca0 > [] do_vfs_ioctl+0x2f8/0x510 > [] SyS_ioctl+0x81/0xa0 > [] system_call_fastpath+0x16/0x75 > [] 0xffffffffffffffff > unreferenced object 0xffff88002b619240 (size 256): > comm "setfont", pid 503, jiffies 4294896503 (age 722.828s) > hex dump (first 32 bytes): > 90 bc 84 d5 00 88 ff ff 58 85 84 d5 00 88 ff ff ........X....... > 88 ac 84 d5 00 88 ff ff e0 b1 84 d5 00 88 ff ff ................ > backtrace: > [] kmemleak_alloc+0x4e/0xb0 > [] kmem_cache_alloc_trace+0x1c8/0x240 > [] con_insert_unipair+0x86/0x170 > [] con_set_unimap+0x1b7/0x280 > [] vt_ioctl+0xe65/0x1170 > [] tty_ioctl+0x208/0xca0 > [] do_vfs_ioctl+0x2f8/0x510 > [] SyS_ioctl+0x81/0xa0 > [] system_call_fastpath+0x16/0x75 > [] 0xffffffffffffffff > > Signed-off-by: Dongxing Zhang > Signed-off-by: Xiaoming Wang Looks like leak happens when kernel does this: [ 5.010152] fb: switching to cirrusdrmfb from EFI VGA Here: [ 5.010438] [] visual_init+0x149/0x150 [ 5.010441] [] do_bind_con_driver+0x159/0x310 [ 5.010443] [] do_unbind_con_driver+0x1b6/0x210 [ 5.010462] [] fbcon_event_notify+0x7cb/0x8b0 [ 5.010471] [] notifier_call_chain+0x65/0x90 [ 5.010475] [] __blocking_notifier_call_chain+0x5e/0x90 [ 5.010478] [] blocking_notifier_call_chain+0x16/0x20 [ 5.010480] [] fb_notifier_call_chain+0x1b/0x20 [ 5.010483] [] do_unregister_framebuffer+0x6c/0x130 [ 5.010487] [] do_remove_conflicting_framebuffers+0x153/0x180 [ 5.010491] [] remove_conflicting_framebuffers+0x3f/0x60 [ 5.010495] [] cirrus_pci_probe+0x91/0xd0 [cirrus] [ 5.010509] [] local_pci_probe+0x4e/0xa0 [ 5.010512] [] ? pci_match_device+0xe3/0x110 [ 5.010515] [] pci_device_probe+0xd9/0x120 [ 5.010525] [] driver_probe_device+0x155/0x430 [ 5.010528] [] __driver_attach+0xa1/0xb0 [ 5.010530] [] ? driver_probe_device+0x430/0x430 [ 5.010533] [] bus_for_each_dev+0x5e/0x90 [ 5.010535] [] driver_attach+0x1e/0x20 [ 5.010536] [] bus_add_driver+0x1be/0x290 [ 5.010538] [] driver_register+0x60/0xe0 [ 5.010540] [] __pci_register_driver+0x64/0x70 [ 5.010541] [] ? 0xffffffffa043f000 [ 5.010553] [] drm_pci_init+0xe0/0x110 [drm] [ 5.010556] [] ? 0xffffffffa043f000 [ 5.010560] [] cirrus_init+0x3c/0x1000 [cirrus] [ 5.010572] [] do_one_initcall+0xad/0x1d0 [ 5.010588] [] ? kmem_cache_alloc_trace+0x2b6/0x300 [ 5.010601] [] do_init_module+0x64/0x220 [ 5.010604] [] load_module+0x130a/0x1990 [ 5.010606] [] ? show_initstate+0x50/0x50 [ 5.010608] [] SyS_init_module+0x130/0x180 [ 5.010616] [] entry_SYSCALL_64_fastpath+0x12/0x76 This patch helps. Thanks. Tested-by: Konstantin Khlebnikov > --- > drivers/tty/vt/vt.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c > index 4a24eb2..334c502 100644 > --- a/drivers/tty/vt/vt.c > +++ b/drivers/tty/vt/vt.c > @@ -738,6 +738,8 @@ static void visual_init(struct vc_data *vc, int num, int init) > __module_get(vc->vc_sw->owner); > vc->vc_num = num; > vc->vc_display_fg = &master_display_fg; > + if (vc->vc_uni_pagedir_loc) > + con_free_unimap(vc); > vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir; > vc->vc_uni_pagedir = NULL; > vc->vc_hi_font_mask = 0; > -- > 1.9.1 > > -- > 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/ -- 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/