[PATCH][2.6.0-test9] fix 32/64 bits for input events

From: Andrey Borzenkov
Date: Sun Nov 09 2003 - 14:11:19 EST


Input bits are kept as array of unsigned long and when no bit is set the whole
"unsigned long" is represented as single 0 in hotplug events and /proc files.
It makes rather hard for user-level programs to guess which bits are set -
programs need to know size of kernel long to correctly interpret output.

One possibility is attached patch. It makes sure every long is always output
in full. Another possibility (I like it more frankly speaking) is to always
use 32 bit type for arrays. But it needs more than two lines of trivial
changes.

regards

-andrey

PS do I miss something or input /proc functions really never check for buffer
overflow?
--- linux-2.6.0-test9/drivers/input/input.c 2003-11-09 21:17:59.000000000 +0300
+++ ../tmp/linux-2.6.0-test9/drivers/input/input.c 2003-10-25 22:21:42.000000000 +0400
@@ -330,8 +330,7 @@ static struct input_device_id *input_mat
for (j = NBITS(max) - 1; j >= 0; j--) \
if (dev->bit[j]) break; \
for (; j >= 0; j--) \
- scratch += sprintf(scratch, "%0*lx ", \
- BITS_PER_LONG/4, dev->bit[j]); \
+ scratch += sprintf(scratch, "%lx ", dev->bit[j]); \
scratch++; \
} while (0)

@@ -584,8 +583,7 @@ static struct file_operations input_fops
for (i = NBITS(max) - 1; i >= 0; i--) \
if (dev->bit[i]) break; \
for (; i >= 0; i--) \
- len += sprintf(buf + len, "%0*lx ", \
- BITS_PER_LONG/4, dev->bit[i]); \
+ len += sprintf(buf + len, "%lx ", dev->bit[i]); \
len += sprintf(buf + len, "\n"); \
} while (0)