Commit 01a3ee2b authored by Reinette Chatre's avatar Reinette Chatre Committed by Linus Torvalds
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[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: default avatarReinette Chatre <reinette.chatre@linux.intel.com>
Signed-off-by: default avatarInaky Perez-Gonzalez <inaky@linux.intel.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Joe Korty <joe.korty@ccur.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 39484e53

include/linux/bitmap.h

+11 −2
Original line number Diff line number Diff line
@@ -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_weight(const unsigned long *bitmap, int bits); 


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 @@ static inline void bitmap_shift_left(unsigned long *dst, 
		__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 */

include/linux/cpumask.h

+7 −7
Original line number Diff line number Diff line
@@ -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 @@ static inline int __cpumask_scnprintf(char *buf, int len, 
	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) \

include/linux/nodemask.h

+7 −7
Original line number Diff line number Diff line
@@ -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 @@ static inline int __nodemask_scnprintf(char *buf, int len, 
	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) \

kernel/irq/proc.c

+1 −1
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer, 
	if (!irq_desc[irq].chip->set_affinity || no_irq_affinity)

		return -EIO;



	err = cpumask_parse(buffer, count, new_value);

	err = cpumask_parse_user(buffer, count, new_value);

	if (err)

		return err;

kernel/profile.c

+1 −1
Original line number Diff line number Diff line
@@ -399,7 +399,7 @@ static int prof_cpu_mask_write_proc (struct file *file, const char __user *buffe 
	unsigned long full_count = count, err;

	cpumask_t new_value;



	err = cpumask_parse(buffer, count, new_value);

	err = cpumask_parse_user(buffer, count, new_value);

	if (err)

		return err;

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