From 3855ae1c486a2d1b65a96fac8d504ef7197e62cd Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Sun, 4 Aug 2013 13:09:50 +0200 Subject: [PATCH] vt: make the default color configurable The virtual console has (undocumented) module parameters to set the colors for italic and underlined text, but the default text color was hardcoded for some reason. This made it impossible to change the color for startup messages, or to set the default for new virtual consoles. Add a module parameter for that, and document the entire bunch. Any hacker who thinks that a command prompt on a "black screen with white font" is not supicious enough can now use the kernel parameter vt.color=10 to get a nice, evil green. Signed-off-by: Clemens Ladisch Signed-off-by: Greg Kroah-Hartman --- Documentation/kernel-parameters.txt | 10 ++++++++++ drivers/tty/vt/vt.c | 4 +++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 15356aca938c..f6c8b417c652 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3322,6 +3322,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. them quite hard to use for exploits but might break your system. + vt.color= [VT] Default text color. + Format: 0xYX, X = foreground, Y = background. + Default: 0x07 = light gray on black. + vt.cur_default= [VT] Default cursor shape. Format: 0xCCBBAA, where AA, BB, and CC are the same as the parameters of the [?A;B;Cc escape sequence; @@ -3361,6 +3365,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. overridden by individual drivers. 0 will hide cursors, 1 will display them. + vt.italic= [VT] Default color for italic text; 0-15. + Default: 2 = green. + + vt.underline= [VT] Default color for underlined text; 0-15. + Default: 3 = cyan. + watchdog timers [HW,WDT] For information on watchdog timers, see Documentation/watchdog/watchdog-parameters.txt or other driver-specific files in the diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 02af6ccefe6a..9a8e8c5a0c73 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -2809,8 +2809,10 @@ static void con_shutdown(struct tty_struct *tty) console_unlock(); } +static int default_color = 7; /* white */ static int default_italic_color = 2; // green (ASCII) static int default_underline_color = 3; // cyan (ASCII) +module_param_named(color, default_color, int, S_IRUGO | S_IWUSR); module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR); module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR); @@ -2832,7 +2834,7 @@ static void vc_init(struct vc_data *vc, unsigned int rows, vc->vc_palette[k++] = default_grn[j] ; vc->vc_palette[k++] = default_blu[j] ; } - vc->vc_def_color = 0x07; /* white */ + vc->vc_def_color = default_color; vc->vc_ulcolor = default_underline_color; vc->vc_itcolor = default_italic_color; vc->vc_halfcolor = 0x08; /* grey */ -- GitLab