Messages in this thread Patch in this message | | | From | Robert Abel <> | Subject | [PATCH 3/4] auxdisplay: charlcd: fix x/y address commands | Date | Mon, 26 Feb 2018 00:54:31 +0100 |
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NUL-terminate each individual number to be parsed. To do this, the next command character and a pointer to its argument are found and stored. The command character is then overwritten by NUL before kstr* functions are called on the buffer.
Signed-off-by: Robert Abel <rabel@robertabel.eu> --- drivers/auxdisplay/charlcd.c | 53 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 44 insertions(+), 9 deletions(-)
diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c index a3d364e6c666..24cabe88c7f0 100644 --- a/drivers/auxdisplay/charlcd.c +++ b/drivers/auxdisplay/charlcd.c @@ -471,28 +471,63 @@ static inline int handle_lcd_special_code(struct charlcd *lcd) break; } case 'x': /* gotoxy : LxXXX[yYYY]; */ - case 'y': /* gotoxy : LyYYY[xXXX]; */ + case 'y': { /* gotoxy : LyYYY[xXXX]; */ + + char* nxt_esc; + char nxt_cmd; + char cmd; + struct charlcd_priv_addr tmp_addr; + if (!strchr(esc, ';')) break; - while (*esc) { - if (*esc == 'x') { - esc++; - if (kstrtoul(esc, 10, &priv->addr.x) < 0) + /* sequence is processed whether legal or illegal */ + processed = 1; + + /* copy current address to temporary buffer */ + tmp_addr = priv->addr; + + nxt_cmd = *esc++; + nxt_esc = esc; + + while ('\0' != *esc) { + + cmd = nxt_cmd; + esc = nxt_esc; + nxt_esc = strpbrk(esc, "xy;"); + if (NULL != nxt_esc) { + nxt_cmd = *nxt_esc; + /* terminate current sequence with NUL */ + *nxt_esc++ = '\0'; + } + + if ('x' == cmd) { + if (kstrtoul(esc, 10, &tmp_addr.x) < 0) break; - } else if (*esc == 'y') { - esc++; - if (kstrtoul(esc, 10, &priv->addr.y) < 0) + } else if ('y' == cmd) { + if (kstrtoul(esc, 10, &tmp_addr.y) < 0) break; } else { + /* break on unknown command or ';' */ break; } + } + /* unknown commands in sequence will be followed by at least ';' */ + if ('\0' != *esc) + break; + + /* clamp new x/y coordinates */ + if (tmp_addr.x >= lcd->width) + tmp_addr.x = lcd->width - 1; + tmp_addr.y %= lcd->height; + + priv->addr = tmp_addr; charlcd_gotoxy(lcd); - processed = 1; break; } + } /* TODO: This indent party here got ugly, clean it! */ /* Check whether one flag was changed */ -- 2.11.0
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