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authorJason Wessel <jason.wessel@windriver.com>2012-08-26 22:37:03 -0500
committerJason Wessel <jason.wessel@windriver.com>2012-10-12 06:37:35 -0500
commit17b572e82032bc246324ce136696656b66d4e3f1 (patch)
treeff54f0141d8d9d60c9d8ea1f49842474aa882912 /drivers/tty
parentd1871b38fccdc4b6575b0cabdea9e06bc70167eb (diff)
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: <stable@vger.kernel.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/vt/vt.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 84cbf298c094..a13f7e158c5b 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;
}