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authorDaniel Kurtz <djkurtz@chromium.org>2011-10-06 15:43:20 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2011-10-06 19:41:52 -0700
commit626af8611211c55595cd316103abd2419cd4d861 (patch)
tree51e0230b67bd204f66288329c572a3fdd2b772bb
parent04c59abd3c053f9a42437d5db3af4383cf68659c (diff)
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 <djkurtz@chromium.org> Acked-by: Nick Dyer <nick.dyer@itdev.co.uk> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
-rw-r--r--drivers/input/touchscreen/atmel_mxt_ts.c21
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index f5d66859f23..a596c2775d1 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;