releases/2.6.25.19/fbcon_set_all_vcs-fix-kernel-crash-when-switching-the-rotated-consoles.patch

   1 From jejb@kernel.org  Thu Oct 16 14:54:47 2008
   2 From: Oleg Nesterov <oleg@tv-sign.ru>
   3 Date: Thu, 16 Oct 2008 19:05:07 GMT
   4 Subject: fbcon_set_all_vcs: fix kernel crash when switching the rotated consoles
   5 To: jejb@kernel.org, stable@kernel.org
   6 Message-ID: <200810161905.m9GJ57Ki013495@hera.kernel.org>
   7
   8 From: Oleg Nesterov <oleg@tv-sign.ru>
   9
  10 commit 232fb69a53a5ec3f22a8104d447abe4806848a8f upstream
  11
  12 echo 3 >> /sys/class/graphics/fbcon/rotate_all, then switch to another
  13 console. Result:
  14
  15         BUG: unable to handle kernel paging request at ffffc20005d00000
  16         IP: [bitfill_aligned+149/265] bitfill_aligned+0x95/0x109
  17         PGD 7e228067 PUD 7e229067 PMD 7bc1f067 PTE 0
  18         Oops: 0002 [1] SMP
  19         CPU 1
  20         Modules linked in: [...a lot...]
  21         Pid: 10, comm: events/1 Not tainted 2.6.26.5-45.fc9.x86_64 #1
  22         RIP: 0010:[bitfill_aligned+149/265]  [bitfill_aligned+149/265] bitfill_aligned+0x95/0x109
  23         RSP: 0018:ffff81007d811bc8  EFLAGS: 00010216
  24         RAX: ffffc20005d00000 RBX: 0000000000000000 RCX: 0000000000000400
  25         RDX: 0000000000000000 RSI: ffffc20005d00000 RDI: ffffffffffffffff
  26         RBP: ffff81007d811be0 R08: 0000000000000400 R09: 0000000000000040
  27         R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000010000
  28         R13: ffffffff811632f0 R14: 0000000000000006 R15: ffff81007cb85400
  29         FS:  0000000000000000(0000) GS:ffff81007e004780(0000) knlGS:0000000000000000
  30         CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
  31         CR2: ffffc20005d00000 CR3: 0000000000201000 CR4: 00000000000006e0
  32         DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  33         DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  34         Process events/1 (pid: 10, threadinfo ffff81007d810000, task ffff81007d808000)
  35         Stack:  ffff81007c9d75a0 0000000000000000 0000000000000000 ffff81007d811c80
  36          ffffffff81163a61 ffff810000000000 ffffffff8115f9c8 0000001000000000
  37          0000000100aaaaaa 000000007cd0d4a0 fffffd8a00000800 0001000000000000
  38         Call Trace:
  39          [cfb_fillrect+523/798] cfb_fillrect+0x20b/0x31e
  40          [soft_cursor+416/436] ? soft_cursor+0x1a0/0x1b4
  41          [ccw_clear_margins+205/263] ccw_clear_margins+0xcd/0x107
  42          [fbcon_clear_margins+59/61] fbcon_clear_margins+0x3b/0x3d
  43          [fbcon_switch+1291/1466] fbcon_switch+0x50b/0x5ba
  44          [redraw_screen+261/481] redraw_screen+0x105/0x1e1
  45          [ccw_cursor+0/1869] ? ccw_cursor+0x0/0x74d
  46          [complete_change_console+48/190] complete_change_console+0x30/0xbe
  47          [change_console+115/120] change_console+0x73/0x78
  48          [console_callback+0/292] ? console_callback+0x0/0x124
  49          [console_callback+97/292] console_callback+0x61/0x124
  50          [schedule_delayed_work+25/30] ? schedule_delayed_work+0x19/0x1e
  51          [run_workqueue+139/282] run_workqueue+0x8b/0x11a
  52          [worker_thread+221/238] worker_thread+0xdd/0xee
  53          [autoremove_wake_function+0/56] ? autoremove_wake_function+0x0/0x38
  54          [worker_thread+0/238] ? worker_thread+0x0/0xee
  55          [kthread+73/118] kthread+0x49/0x76
  56          [child_rip+10/18] child_rip+0xa/0x12
  57          [kthread+0/118] ? kthread+0x0/0x76
  58          [child_rip+0/18] ? child_rip+0x0/0x12
  59
  60 Because fbcon_set_all_vcs()->FBCON_SWAP() uses display->rotate == 0 instead
  61 of fbcon_ops->rotate, and vc_resize() has no effect because it is called with
  62 new_cols/rows == ->vc_cols/rows.
  63
  64 Tested on 2.6.26.5-45.fc9.x86_64, but
  65 http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git seems to
  66 have the same problem.
  67
  68 Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
  69 Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
  70 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  71 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  72 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  73
  74 ---
  75  drivers/video/console/fbcon.c |    4 ++--
  76  1 file changed, 2 insertions(+), 2 deletions(-)
  77
  78 --- a/drivers/video/console/fbcon.c
  79 +++ b/drivers/video/console/fbcon.c
  80 @@ -2974,8 +2974,8 @@ static void fbcon_set_all_vcs(struct fb_
  81                 p = &fb_display[vc->vc_num];
  82                 set_blitting_type(vc, info);
  83                 var_to_display(p, &info->var, info);
  84 -               cols = FBCON_SWAP(p->rotate, info->var.xres, info->var.yres);
  85 -               rows = FBCON_SWAP(p->rotate, info->var.yres, info->var.xres);
  86 +               cols = FBCON_SWAP(ops->rotate, info->var.xres, info->var.yres);
  87 +               rows = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
  88                 cols /= vc->vc_font.width;
  89                 rows /= vc->vc_font.height;
  90                 vc_resize(vc, cols, rows);