tty: Fix memory leak in virtual console when enable unicode translation
Virtual console unicode translation map leaks with following
message when enable kmemleak:
unreferenced object 0xeb5ec450 (size 192):
comm "setfont", pid 665, jiffies 4294899028 (age 3696.220s)
hex dump (first 32 bytes):
e0 5b 9d eb 00 00 00 00 00 00 00 00 80 b9 ea eb .[..............
b0 5a 9d eb 00 00 00 00 00 00 00 00 00 00 00 00 .Z..............
backtrace:
[<c1533f8c>] kmemleak_alloc+0x3c/0xa0
[<c114acc2>] kmem_cache_alloc_trace+0xe2/0x250
[<c13498e8>] con_clear_unimap+0x78/0xd0
[<c1345552>] vt_ioctl+0x1562/0x1d00
[<c133aa00>] tty_ioctl+0x230/0x7c0
[<c1171519>] do_vfs_ioctl+0x79/0x2d0
[<c11717df>] sys_ioctl+0x6f/0x80
[<c156601f>] sysenter_do_call+0x12/0x38
[<ffffffff>] 0xffffffff
unreferenced object 0xeb9d5be0 (size 128):
comm "setfont", pid 660, jiffies 4294899030 (age 3696.212s)
hex dump (first 32 bytes):
60 c2 a6 eb 50 c8 a6 eb c0 54 9d eb 80 59 9d eb `...P....T...Y..
90 53 9d eb 60 52 9d eb 60 92 9b eb 00 00 00 00 .S..`R..`.......
backtrace:
[<c1533f8c>] kmemleak_alloc+0x3c/0xa0
[<c114acc2>] kmem_cache_alloc_trace+0xe2/0x250
[<c134938c>] con_insert_unipair+0x7c/0x150
[<c1349f8c>] con_set_unimap+0x15c/0x1f0
[<c13456fb>] vt_ioctl+0x170b/0x1d00
[<c133aa00>] tty_ioctl+0x230/0x7c0
[<c1171519>] do_vfs_ioctl+0x79/0x2d0
[<c11717df>] sys_ioctl+0x6f/0x80
[<c156601f>] sysenter_do_call+0x12/0x38
[<ffffffff>] 0xffffffff
The leak caused by con_set_default_unimap() not correct free the old map.
Signed-off-by: Zeng Zhaoming <zengzm.kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index 45d3e80..a0f3d6c 100644
--- a/drivers/tty/vt/consolemap.c
+++ b/drivers/tty/vt/consolemap.c
@@ -584,7 +584,7 @@
return 0;
dflt->refcount++;
*vc->vc_uni_pagedir_loc = (unsigned long)dflt;
- if (p && --p->refcount) {
+ if (p && !--p->refcount) {
con_release_unimap(p);
kfree(p);
}