Messages in this thread Patch in this message | | | From | qiaochong <> | Subject | [PATCH 1/2] fix vc->vc_origin on take_over_console. | Date | Thu, 17 Jun 2010 08:41:24 +0800 |
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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; }
... }
Signed-off-by: qiaochong <qiaochong@loongson.cn> --- 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 50faa1f..29a5bdc 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -3063,7 +3063,8 @@ 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); -- 1.5.6.5
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