From 2b5e1534dfc79ef68fa5fddb0a405dfa3fe8af89 Mon Sep 17 00:00:00 2001
From: Daniel Thompson <daniel.thompson@linaro.org>
Date: Wed, 24 Apr 2024 15:03:36 +0100
Subject: [PATCH] kdb: Fix console handling when editing and tab-completing
commands
commit db2f9c7dc29114f531df4a425d0867d01e1f1e28 upstream.
Currently, if the cursor position is not at the end of the command buffer
and the user uses the Tab-complete functions, then the console does not
leave the cursor in the correct position.
For example consider the following buffer with the cursor positioned
at the ^:
md kdb_pro 10
^
Pressing tab should result in:
md kdb_prompt_str 10
^
However this does not happen. Instead the cursor is placed at the end
(after then 10) and further cursor movement redraws incorrectly. The
same problem exists when we double-Tab but in a different part of the
code.
Fix this by sending a carriage return and then redisplaying the text to
the left of the cursor.
Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-3-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/debug/kdb/kdb_io.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 0f4b288185be..217124076c6c 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -370,6 +370,8 @@ poll_again:
kdb_printf("\n");
kdb_printf(kdb_prompt_str);
kdb_printf("%s", buffer);
+ if (cp != lastchar)
+ kdb_position_cursor(kdb_prompt_str, buffer, cp);
} else if (tab != 2 && count > 0) {
/* How many new characters do we want from tmpbuffer? */
len_tmp = strlen(p_tmp) - len;
@@ -383,6 +385,9 @@ poll_again:
kdb_printf("%s", cp);
cp += len_tmp;
lastchar += len_tmp;
+ if (cp != lastchar)
+ kdb_position_cursor(kdb_prompt_str,
+ buffer, cp);
}
}
kdb_nextline = 1; /* reset output line number */