Commit f11b478d authored by James Hogan's avatar James Hogan Committed by Linus Torvalds
Browse files

fbmem: fix fb_read, fb_write unaligned accesses 



fb_{read,write} access the framebuffer using lots of fb_{read,write}l's
but don't check that the file position is aligned which can cause problems
on some architectures which do not support unaligned accesses.

Since the operations are essentially memcpy_{from,to}io, new
fb_memcpy_{from,to}fb macros have been defined and these are used instead.

For Sparc, fb_{read,write} macros use sbus_{read,write}, so this defines
new sbus_memcpy_{from,to}io functions the same as memcpy_{from,to}io but
using sbus_{read,write}b instead of {read,write}b.

Signed-off-by: default avatarJames Hogan <james@albanarts.com>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c9c62dce

arch/sparc/include/asm/io_32.h

+31 −0
Original line number Diff line number Diff line
@@ -207,6 +207,21 @@ _memset_io(volatile void __iomem *dst, int c, __kernel_size_t n) 


#define memset_io(d,c,sz)	_memset_io(d,c,sz)



static inline void

_sbus_memcpy_fromio(void *dst, const volatile void __iomem *src,

		    __kernel_size_t n)

{

	char *d = dst;



	while (n--) {

		char tmp = sbus_readb(src);

		*d++ = tmp;

		src++;

	}

}



#define sbus_memcpy_fromio(d, s, sz)	_sbus_memcpy_fromio(d, s, sz)



static inline void

_memcpy_fromio(void *dst, const volatile void __iomem *src, __kernel_size_t n)

{
@@ -221,6 +236,22 @@ _memcpy_fromio(void *dst, const volatile void __iomem *src, __kernel_size_t n) 


#define memcpy_fromio(d,s,sz)	_memcpy_fromio(d,s,sz)



static inline void

_sbus_memcpy_toio(volatile void __iomem *dst, const void *src,

		  __kernel_size_t n)

{

	const char *s = src;

	volatile void __iomem *d = dst;



	while (n--) {

		char tmp = *s++;

		sbus_writeb(tmp, d);

		d++;

	}

}



#define sbus_memcpy_toio(d, s, sz)	_sbus_memcpy_toio(d, s, sz)



static inline void

_memcpy_toio(volatile void __iomem *dst, const void *src, __kernel_size_t n)

{

arch/sparc/include/asm/io_64.h

+31 −0
Original line number Diff line number Diff line
@@ -418,6 +418,21 @@ _memset_io(volatile void __iomem *dst, int c, __kernel_size_t n) 


#define memset_io(d,c,sz)	_memset_io(d,c,sz)



static inline void

_sbus_memcpy_fromio(void *dst, const volatile void __iomem *src,

		    __kernel_size_t n)

{

	char *d = dst;



	while (n--) {

		char tmp = sbus_readb(src);

		*d++ = tmp;

		src++;

	}

}



#define sbus_memcpy_fromio(d, s, sz)	_sbus_memcpy_fromio(d, s, sz)



static inline void

_memcpy_fromio(void *dst, const volatile void __iomem *src, __kernel_size_t n)

{
@@ -432,6 +447,22 @@ _memcpy_fromio(void *dst, const volatile void __iomem *src, __kernel_size_t n) 


#define memcpy_fromio(d,s,sz)	_memcpy_fromio(d,s,sz)



static inline void

_sbus_memcpy_toio(volatile void __iomem *dst, const void *src,

		  __kernel_size_t n)

{

	const char *s = src;

	volatile void __iomem *d = dst;



	while (n--) {

		char tmp = *s++;

		sbus_writeb(tmp, d);

		d++;

	}

}



#define sbus_memcpy_toio(d, s, sz)	_sbus_memcpy_toio(d, s, sz)



static inline void

_memcpy_toio(volatile void __iomem *dst, const void *src, __kernel_size_t n)

{

drivers/video/fbmem.c

+14 −32
Original line number Diff line number Diff line
@@ -697,9 +697,9 @@ fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) 
	struct inode *inode = file->f_path.dentry->d_inode;

	int fbidx = iminor(inode);

	struct fb_info *info = registered_fb[fbidx];

	u32 *buffer, *dst;

	u32 __iomem *src;

	int c, i, cnt = 0, err = 0;

	u8 *buffer, *dst;

	u8 __iomem *src;

	int c, cnt = 0, err = 0;

	unsigned long total_size;



	if (!info || ! info->screen_base)
@@ -730,7 +730,7 @@ fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) 
	if (!buffer)

		return -ENOMEM;



	src = (u32 __iomem *) (info->screen_base + p);

	src = (u8 __iomem *) (info->screen_base + p);



	if (info->fbops->fb_sync)

		info->fbops->fb_sync(info);
@@ -738,17 +738,9 @@ fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) 
	while (count) {

		c  = (count > PAGE_SIZE) ? PAGE_SIZE : count;

		dst = buffer;

		for (i = c >> 2; i--; )

			*dst++ = fb_readl(src++);

		if (c & 3) {

			u8 *dst8 = (u8 *) dst;

			u8 __iomem *src8 = (u8 __iomem *) src;



			for (i = c & 3; i--;)

				*dst8++ = fb_readb(src8++);



			src = (u32 __iomem *) src8;

		}

		fb_memcpy_fromfb(dst, src, c);

		dst += c;

		src += c;



		if (copy_to_user(buf, buffer, c)) {

			err = -EFAULT;
@@ -772,9 +764,9 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) 
	struct inode *inode = file->f_path.dentry->d_inode;

	int fbidx = iminor(inode);

	struct fb_info *info = registered_fb[fbidx];

	u32 *buffer, *src;

	u32 __iomem *dst;

	int c, i, cnt = 0, err = 0;

	u8 *buffer, *src;

	u8 __iomem *dst;

	int c, cnt = 0, err = 0;

	unsigned long total_size;



	if (!info || !info->screen_base)
@@ -811,7 +803,7 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) 
	if (!buffer)

		return -ENOMEM;



	dst = (u32 __iomem *) (info->screen_base + p);

	dst = (u8 __iomem *) (info->screen_base + p);



	if (info->fbops->fb_sync)

		info->fbops->fb_sync(info);
@@ -825,19 +817,9 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) 
			break;

		}



		for (i = c >> 2; i--; )

			fb_writel(*src++, dst++);



		if (c & 3) {

			u8 *src8 = (u8 *) src;

			u8 __iomem *dst8 = (u8 __iomem *) dst;



			for (i = c & 3; i--; )

				fb_writeb(*src8++, dst8++);



			dst = (u32 __iomem *) dst8;

		}



		fb_memcpy_tofb(dst, src, c);

		dst += c;

		src += c;

		*ppos += c;

		buf += c;

		cnt += c;

include/linux/fb.h

+6 −0
Original line number Diff line number Diff line
@@ -931,6 +931,8 @@ static inline struct apertures_struct *alloc_apertures(unsigned int max_num) { 
#define fb_writel sbus_writel

#define fb_writeq sbus_writeq

#define fb_memset sbus_memset_io

#define fb_memcpy_fromfb sbus_memcpy_fromio

#define fb_memcpy_tofb sbus_memcpy_toio



#elif defined(__i386__) || defined(__alpha__) || defined(__x86_64__) || defined(__hppa__) || defined(__sh__) || defined(__powerpc__) || defined(__avr32__) || defined(__bfin__)
@@ -943,6 +945,8 @@ static inline struct apertures_struct *alloc_apertures(unsigned int max_num) { 
#define fb_writel __raw_writel

#define fb_writeq __raw_writeq

#define fb_memset memset_io

#define fb_memcpy_fromfb memcpy_fromio

#define fb_memcpy_tofb memcpy_toio



#else
@@ -955,6 +959,8 @@ static inline struct apertures_struct *alloc_apertures(unsigned int max_num) { 
#define fb_writel(b,addr) (*(volatile u32 *) (addr) = (b))

#define fb_writeq(b,addr) (*(volatile u64 *) (addr) = (b))

#define fb_memset memset

#define fb_memcpy_fromfb memcpy

#define fb_memcpy_tofb memcpy



#endif

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