4.19-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Thompson daniel.thompson@linaro.org
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@lina... 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(+)
--- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -380,6 +380,8 @@ 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; @@ -393,6 +395,9 @@ 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 */