In extreme situation kzalloc in con_init may
return NULL, so we should check it to prevent
OOPS!
Signed-off-by: Wang YanQing <udkni...@gmail.com>
Reported-by: rucsoft...@gmail.com
---
I don't think a system without memory to initialize
vt could do some useful things, but this patch could
make debug easier and improve kernel code's robustness
in theory.
drivers/tty/vt/vc_screen.c | 2 +-
drivers/tty/vt/vt.c | 12 ++++++++++++
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c
index 14a2b5f..2bc3987bc 100644
--- a/drivers/tty/vt/vc_screen.c
+++ b/drivers/tty/vt/vc_screen.c
@@ -648,6 +648,6 @@ int __init vcs_init(void)
device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs");
device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa");
for (i = 0; i < MIN_NR_CONSOLES; i++)
- vcs_make_sysfs(i);
+ if (vc_cons[i].d) vcs_make_sysfs(i);
return 0;
}
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 9a8e8c5..ef8b1aa 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2887,6 +2887,8 @@ static int __init con_init(void)
for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data),
GFP_NOWAIT);
+ if (vc == NULL)
+ break;
INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
tty_port_init(&vc->port);
visual_init(vc, currcons, 1);
@@ -2894,8 +2896,18 @@ static int __init con_init(void)
vc_init(vc, vc->vc_rows, vc->vc_cols,
currcons || !vc->vc_sw->con_save_screen);
}
+ if (currcons < MIN_NR_CONSOLES)
+ printk(KERN_WARNING "Console: vt %d-%d initialization
failed!\n",
+ currcons, MIN_NR_CONSOLES - 1);
+
currcons = fg_console = 0;
master_display_fg = vc = vc_cons[currcons].d;
+
+ if (vc == NULL) {
+ printk(KERN_WARNING "Console: no avaiable vt!\n");
+ console_unlock();
+ return 0;
+ }
set_origin(vc);
save_screen(vc);
gotoxy(vc, vc->vc_x, vc->vc_y);
--
1.7.12.4.dirty
--
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