[PATCH] bitmap: parse input from kernel and user buffers
lib/bitmap.c:bitmap_parse() is a library function that received as input a
user buffer. This seemed to have originated from the way the write_proc
function of the /proc filesystem operates.
This has been reworked to not use kmalloc and eliminates a lot of
get_user() overhead by performing one access_ok before using __get_user().
We need to test if we are in kernel or user space (is_user) and access the
buffer differently. We cannot use __get_user() to access kernel addresses
in all cases, for example in architectures with separate address space for
kernel and user.
This function will be useful for other uses as well; for example, taking
input for /sysfs instead of /proc, so it was changed to accept kernel
buffers. We have this use for the Linux UWB project, as part as the
upcoming bandwidth allocator code.
Only a few routines used this function and they were changed too.
Signed-off-by: Reinette Chatre <reinette.chatre@linux.intel.com>
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Joe Korty <joe.korty@ccur.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index dcc5de7..64b4641 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -46,7 +46,8 @@
* bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
* bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
* bitmap_scnprintf(buf, len, src, nbits) Print bitmap src to buf
- * bitmap_parse(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
+ * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
+ * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
* bitmap_scnlistprintf(buf, len, src, nbits) Print bitmap src as list to buf
* bitmap_parselist(buf, dst, nbits) Parse bitmap dst from list
* bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
@@ -106,7 +107,9 @@
extern int bitmap_scnprintf(char *buf, unsigned int len,
const unsigned long *src, int nbits);
-extern int bitmap_parse(const char __user *ubuf, unsigned int ulen,
+extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
+ unsigned long *dst, int nbits);
+extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
unsigned long *dst, int nbits);
extern int bitmap_scnlistprintf(char *buf, unsigned int len,
const unsigned long *src, int nbits);
@@ -270,6 +273,12 @@
__bitmap_shift_left(dst, src, n, nbits);
}
+static inline int bitmap_parse(const char *buf, unsigned int buflen,
+ unsigned long *maskp, int nmaskbits)
+{
+ return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
+}
+
#endif /* __ASSEMBLY__ */
#endif /* __LINUX_BITMAP_H */
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index b268a3c..d0e8c8b 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -8,8 +8,8 @@
* See detailed comments in the file linux/bitmap.h describing the
* data type on which these cpumasks are based.
*
- * For details of cpumask_scnprintf() and cpumask_parse(),
- * see bitmap_scnprintf() and bitmap_parse() in lib/bitmap.c.
+ * For details of cpumask_scnprintf() and cpumask_parse_user(),
+ * see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
* For details of cpulist_scnprintf() and cpulist_parse(), see
* bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
* For details of cpu_remap(), see bitmap_bitremap in lib/bitmap.c
@@ -49,7 +49,7 @@
* unsigned long *cpus_addr(mask) Array of unsigned long's in mask
*
* int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
- * int cpumask_parse(ubuf, ulen, mask) Parse ascii string as cpumask
+ * int cpumask_parse_user(ubuf, ulen, mask) Parse ascii string as cpumask
* int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
* int cpulist_parse(buf, map) Parse ascii string as cpulist
* int cpu_remap(oldbit, old, new) newbit = map(old, new)(oldbit)
@@ -273,12 +273,12 @@
return bitmap_scnprintf(buf, len, srcp->bits, nbits);
}
-#define cpumask_parse(ubuf, ulen, dst) \
- __cpumask_parse((ubuf), (ulen), &(dst), NR_CPUS)
-static inline int __cpumask_parse(const char __user *buf, int len,
+#define cpumask_parse_user(ubuf, ulen, dst) \
+ __cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS)
+static inline int __cpumask_parse_user(const char __user *buf, int len,
cpumask_t *dstp, int nbits)
{
- return bitmap_parse(buf, len, dstp->bits, nbits);
+ return bitmap_parse_user(buf, len, dstp->bits, nbits);
}
#define cpulist_scnprintf(buf, len, src) \
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 5dce5c2..b1063e9 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -8,8 +8,8 @@
* See detailed comments in the file linux/bitmap.h describing the
* data type on which these nodemasks are based.
*
- * For details of nodemask_scnprintf() and nodemask_parse(),
- * see bitmap_scnprintf() and bitmap_parse() in lib/bitmap.c.
+ * For details of nodemask_scnprintf() and nodemask_parse_user(),
+ * see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
* For details of nodelist_scnprintf() and nodelist_parse(), see
* bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
* For details of node_remap(), see bitmap_bitremap in lib/bitmap.c.
@@ -51,7 +51,7 @@
* unsigned long *nodes_addr(mask) Array of unsigned long's in mask
*
* int nodemask_scnprintf(buf, len, mask) Format nodemask for printing
- * int nodemask_parse(ubuf, ulen, mask) Parse ascii string as nodemask
+ * int nodemask_parse_user(ubuf, ulen, mask) Parse ascii string as nodemask
* int nodelist_scnprintf(buf, len, mask) Format nodemask as list for printing
* int nodelist_parse(buf, map) Parse ascii string as nodelist
* int node_remap(oldbit, old, new) newbit = map(old, new)(oldbit)
@@ -288,12 +288,12 @@
return bitmap_scnprintf(buf, len, srcp->bits, nbits);
}
-#define nodemask_parse(ubuf, ulen, dst) \
- __nodemask_parse((ubuf), (ulen), &(dst), MAX_NUMNODES)
-static inline int __nodemask_parse(const char __user *buf, int len,
+#define nodemask_parse_user(ubuf, ulen, dst) \
+ __nodemask_parse_user((ubuf), (ulen), &(dst), MAX_NUMNODES)
+static inline int __nodemask_parse_user(const char __user *buf, int len,
nodemask_t *dstp, int nbits)
{
- return bitmap_parse(buf, len, dstp->bits, nbits);
+ return bitmap_parse_user(buf, len, dstp->bits, nbits);
}
#define nodelist_scnprintf(buf, len, src) \