From 626af8611211c55595cd316103abd2419cd4d861 Mon Sep 17 00:00:00 2001 From: Daniel Kurtz Date: Thu, 6 Oct 2011 15:43:20 -0700 Subject: [PATCH] Input: atmel_mxt_ts - use snprintf for sysfs attribute show method Sysfs attribute show methods are always passed a buffer of length PAGE_SIZE. To keep from overwriting this buffer and causing havoc, use snprintf() to guarantee we never write more than the buffer can hold. In addition, at least for my touchscreen, the number and size of objects was far too big to fit in a single 4K page. Therefore, this patch also trims some redundant framing text to leave more room for actual data. Signed-off-by: Daniel Kurtz Acked-by: Nick Dyer Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/atmel_mxt_ts.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c index f5d66859f232..a596c2775d1a 100644 --- a/drivers/input/touchscreen/atmel_mxt_ts.c +++ b/drivers/input/touchscreen/atmel_mxt_ts.c @@ -910,12 +910,17 @@ static ssize_t mxt_object_show(struct device *dev, for (i = 0; i < data->info.object_num; i++) { object = data->object_table + i; - count += sprintf(buf + count, - "Object Table Element %d(Type %d)\n", + count += snprintf(buf + count, PAGE_SIZE - count, + "Object[%d] (Type %d)\n", i + 1, object->type); + if (count >= PAGE_SIZE) + return PAGE_SIZE - 1; if (!mxt_object_readable(object->type)) { - count += sprintf(buf + count, "\n"); + count += snprintf(buf + count, PAGE_SIZE - count, + "\n"); + if (count >= PAGE_SIZE) + return PAGE_SIZE - 1; continue; } @@ -925,11 +930,15 @@ static ssize_t mxt_object_show(struct device *dev, if (error) return error; - count += sprintf(buf + count, - " Byte %d: 0x%x (%d)\n", j, val, val); + count += snprintf(buf + count, PAGE_SIZE - count, + "\t[%2d]: %02x (%d)\n", j, val, val); + if (count >= PAGE_SIZE) + return PAGE_SIZE - 1; } - count += sprintf(buf + count, "\n"); + count += snprintf(buf + count, PAGE_SIZE - count, "\n"); + if (count >= PAGE_SIZE) + return PAGE_SIZE - 1; } return count; -- 2.20.1