From 17b572e82032bc246324ce136696656b66d4e3f1 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Sun, 26 Aug 2012 22:37:03 -0500 Subject: kdb,vt_console: Fix missed data due to pager overruns It is possible to miss data when using the kdb pager. The kdb pager does not pay attention to the maximum column constraint of the screen or serial terminal. This result is not incrementing the shown lines correctly and the pager will print more lines that fit on the screen. Obviously that is less than useful when using a VGA console where you cannot scroll back. The pager will now look at the kdb_buffer string to see how many characters are printed. It might not be perfect considering you can output ASCII that might move the cursor position, but it is a substantially better approximation for viewing dmesg and trace logs. This also means that the vt screen needs to set the kdb COLUMNS variable. Cc: Signed-off-by: Jason Wessel --- drivers/tty/vt/vt.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'drivers/tty/vt') diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 84cbf298c09..a13f7e158c5 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -3475,6 +3475,19 @@ int con_debug_enter(struct vc_data *vc) kdb_set(2, setargs); } } + if (vc->vc_cols < 999) { + int colcount; + char cols[4]; + const char *setargs[3] = { + "set", + "COLUMNS", + cols, + }; + if (kdbgetintenv(setargs[0], &colcount)) { + snprintf(cols, 4, "%i", vc->vc_cols); + kdb_set(2, setargs); + } + } #endif /* CONFIG_KGDB_KDB */ return ret; } -- cgit v1.2.3