diff options
Diffstat (limited to 'drivers/char')
-rw-r--r-- | drivers/char/mem.c | 34 |
1 files changed, 12 insertions, 22 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index c6b2fbc5ed47..192af59afc13 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c | |||
@@ -39,12 +39,9 @@ static inline unsigned long size_inside_page(unsigned long start, | |||
39 | { | 39 | { |
40 | unsigned long sz; | 40 | unsigned long sz; |
41 | 41 | ||
42 | if (-start & (PAGE_SIZE - 1)) | 42 | sz = PAGE_SIZE - (start & (PAGE_SIZE - 1)); |
43 | sz = -start & (PAGE_SIZE - 1); | ||
44 | else | ||
45 | sz = PAGE_SIZE; | ||
46 | 43 | ||
47 | return min_t(unsigned long, sz, size); | 44 | return min(sz, size); |
48 | } | 45 | } |
49 | 46 | ||
50 | /* | 47 | /* |
@@ -139,9 +136,7 @@ static ssize_t read_mem(struct file * file, char __user * buf, | |||
139 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | 136 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED |
140 | /* we don't have page 0 mapped on sparc and m68k.. */ | 137 | /* we don't have page 0 mapped on sparc and m68k.. */ |
141 | if (p < PAGE_SIZE) { | 138 | if (p < PAGE_SIZE) { |
142 | sz = PAGE_SIZE - p; | 139 | sz = size_inside_page(p, count); |
143 | if (sz > count) | ||
144 | sz = count; | ||
145 | if (sz > 0) { | 140 | if (sz > 0) { |
146 | if (clear_user(buf, sz)) | 141 | if (clear_user(buf, sz)) |
147 | return -EFAULT; | 142 | return -EFAULT; |
@@ -201,9 +196,7 @@ static ssize_t write_mem(struct file * file, const char __user * buf, | |||
201 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | 196 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED |
202 | /* we don't have page 0 mapped on sparc and m68k.. */ | 197 | /* we don't have page 0 mapped on sparc and m68k.. */ |
203 | if (p < PAGE_SIZE) { | 198 | if (p < PAGE_SIZE) { |
204 | unsigned long sz = PAGE_SIZE - p; | 199 | sz = size_inside_page(p, count); |
205 | if (sz > count) | ||
206 | sz = count; | ||
207 | /* Hmm. Do something? */ | 200 | /* Hmm. Do something? */ |
208 | buf += sz; | 201 | buf += sz; |
209 | p += sz; | 202 | p += sz; |
@@ -412,15 +405,14 @@ static ssize_t read_kmem(struct file *file, char __user *buf, | |||
412 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | 405 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED |
413 | /* we don't have page 0 mapped on sparc and m68k.. */ | 406 | /* we don't have page 0 mapped on sparc and m68k.. */ |
414 | if (p < PAGE_SIZE && low_count > 0) { | 407 | if (p < PAGE_SIZE && low_count > 0) { |
415 | size_t tmp = PAGE_SIZE - p; | 408 | sz = size_inside_page(p, low_count); |
416 | if (tmp > low_count) tmp = low_count; | 409 | if (clear_user(buf, sz)) |
417 | if (clear_user(buf, tmp)) | ||
418 | return -EFAULT; | 410 | return -EFAULT; |
419 | buf += tmp; | 411 | buf += sz; |
420 | p += tmp; | 412 | p += sz; |
421 | read += tmp; | 413 | read += sz; |
422 | low_count -= tmp; | 414 | low_count -= sz; |
423 | count -= tmp; | 415 | count -= sz; |
424 | } | 416 | } |
425 | #endif | 417 | #endif |
426 | while (low_count > 0) { | 418 | while (low_count > 0) { |
@@ -480,9 +472,7 @@ do_write_kmem(void *p, unsigned long realp, const char __user * buf, | |||
480 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | 472 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED |
481 | /* we don't have page 0 mapped on sparc and m68k.. */ | 473 | /* we don't have page 0 mapped on sparc and m68k.. */ |
482 | if (realp < PAGE_SIZE) { | 474 | if (realp < PAGE_SIZE) { |
483 | unsigned long sz = PAGE_SIZE - realp; | 475 | sz = size_inside_page(realp, count); |
484 | if (sz > count) | ||
485 | sz = count; | ||
486 | /* Hmm. Do something? */ | 476 | /* Hmm. Do something? */ |
487 | buf += sz; | 477 | buf += sz; |
488 | p += sz; | 478 | p += sz; |