diff options
| author |   qiaochong <qiaochong@loongson.cn> | 2010-08-09 17:21:23 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-09 20:45:11 -0700 |
| commit | 02f0777a0d6560eb995aade34a1b82f95c0452da (patch) | |
| tree | 5d4b4f09c3345a4a84c5ebc85b037540c39c63fc /drivers/char | |
| parent | rwsem: smaller wrappers around rwsem_down_failed_common (diff) | |
| download | linux-dev-02f0777a0d6560eb995aade34a1b82f95c0452da.tar.xz linux-dev-02f0777a0d6560eb995aade34a1b82f95c0452da.zip | |
drivers/char/vt.c: fix vc->vc_origin on take_over_console()
kernel will die on some platform when switch from vga mode to framebuffer
mode. The reason of this bug is that bind_con_driver reset vc->vc_origin
to (unsigned long)vc->vc_screenbuf.
On vgacon vc->vc_origin is not releated to vc->vc_screenbuf,if set
vc->vc_origin to vc->vc_screenbuf,kernel will die on vc_do_resize.
static int vc_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
struct vc_data *vc, unsigned int cols, unsigned int lines)
{
unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
unsigned int old_cols, old_rows, old_row_size, old_screen_size;
unsigned int new_cols, new_rows, new_row_size, new_screen_size;
unsigned int end, user;
...
end = (old_rows > new_rows) ? old_origin +
(old_row_size * new_rows) :
vc->vc_scr_end;
...
/*
here for a test from vgacon to framebuffer:
old_origin=0x810814a0,end=0xb00b8fa0,vc->vc_origin=0x810814a0
the code bellow will copy memory from 0x810814a0 to 0xb00b8fa0,
this will cover kernel code,kernel died here.
*/
while (old_origin < end) {
scr_memcpyw((unsigned short *) new_origin,
(unsigned short *) old_origin, rlth);
if (rrem)
scr_memsetw((void *)(new_origin + rlth),
vc->vc_video_erase_char, rrem);
old_origin += old_row_size;
new_origin += new_row_size;
}
...
}
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: qiaochong <qiaochong@loongson.cn>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/vt.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/char/vt.c b/drivers/char/vt.c index 4a9eb3044e52..cff1d4bce21d 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -3065,7 +3065,8 @@ static int bind_con_driver(const struct consw *csw, int first, int last, old_was_color = vc->vc_can_do_color; vc->vc_sw->con_deinit(vc); - vc->vc_origin = (unsigned long)vc->vc_screenbuf; + if (!vc->vc_origin) + vc->vc_origin = (unsigned long)vc->vc_screenbuf; visual_init(vc, i, 0); set_origin(vc); update_attr(vc); |