Currently when kdb_read() needs to reposition the cursor it uses copy and paste code that works by injecting an '\0' at the cursor position before delivering a carriage-return and reprinting the line (which stops at the '\0').
Tidy up the code by hoisting the copy and paste code into an appropriately named function. Additionally let's replace the '\0' injection with a proper field width parameter so that the string will be abridged during formatting instead.
Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes Signed-off-by: Daniel Thompson daniel.thompson@linaro.org --- kernel/debug/kdb/kdb_io.c | 34 ++++++++++++++-------------------- 1 file changed, 14 insertions(+), 20 deletions(-)
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c index 06dfbccb10336..a42607e4d1aba 100644 --- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -184,6 +184,13 @@ char kdb_getchar(void) unreachable(); }
+static void kdb_position_cursor(char *prompt, char *buffer, char *cp) +{ + kdb_printf("\r%s", kdb_prompt_str); + if (cp > buffer) + kdb_printf("%.*s", (int)(cp - buffer), buffer); +} + /* * kdb_read * @@ -249,12 +256,8 @@ static char *kdb_read(char *buffer, size_t bufsize) } *(--lastchar) = '\0'; --cp; - kdb_printf("\b%s \r", cp); - tmp = *cp; - *cp = '\0'; - kdb_printf(kdb_prompt_str); - kdb_printf("%s", buffer); - *cp = tmp; + kdb_printf("\b%s ", cp); + kdb_position_cursor(kdb_prompt_str, buffer, cp); } break; case 10: /* linefeed */ @@ -272,19 +275,14 @@ static char *kdb_read(char *buffer, size_t bufsize) memcpy(tmpbuffer, cp+1, lastchar - cp - 1); memcpy(cp, tmpbuffer, lastchar - cp - 1); *(--lastchar) = '\0'; - kdb_printf("%s \r", cp); - tmp = *cp; - *cp = '\0'; - kdb_printf(kdb_prompt_str); - kdb_printf("%s", buffer); - *cp = tmp; + kdb_printf("%s ", cp); + kdb_position_cursor(kdb_prompt_str, buffer, cp); } break; case 1: /* Home */ if (cp > buffer) { - kdb_printf("\r"); - kdb_printf(kdb_prompt_str); cp = buffer; + kdb_position_cursor(kdb_prompt_str, buffer, cp); } break; case 5: /* End */ @@ -390,13 +388,9 @@ static char *kdb_read(char *buffer, size_t bufsize) memcpy(cp+1, tmpbuffer, lastchar - cp); *++lastchar = '\0'; *cp = key; - kdb_printf("%s\r", cp); + kdb_printf("%s", cp); ++cp; - tmp = *cp; - *cp = '\0'; - kdb_printf(kdb_prompt_str); - kdb_printf("%s", buffer); - *cp = tmp; + kdb_position_cursor(kdb_prompt_str, buffer, cp); } else { *++lastchar = '\0'; *cp++ = key;