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path: root/drivers/char/nvram.c
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Diffstat (limited to 'drivers/char/nvram.c')
-rw-r--r--drivers/char/nvram.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 88cee4099be9..71f0d72fc2f3 100644
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -265,10 +265,16 @@ static ssize_t nvram_write(struct file *file, const char __user *buf,
unsigned char contents[NVRAM_BYTES];
unsigned i = *ppos;
unsigned char *tmp;
- int len;
- len = (NVRAM_BYTES - i) < count ? (NVRAM_BYTES - i) : count;
- if (copy_from_user(contents, buf, len))
+ if (i >= NVRAM_BYTES)
+ return 0; /* Past EOF */
+
+ if (count > NVRAM_BYTES - i)
+ count = NVRAM_BYTES - i;
+ if (count > NVRAM_BYTES)
+ return -EFAULT; /* Can't happen, but prove it to gcc */
+
+ if (copy_from_user(contents, buf, count))
return -EFAULT;
spin_lock_irq(&rtc_lock);
@@ -276,7 +282,7 @@ static ssize_t nvram_write(struct file *file, const char __user *buf,
if (!__nvram_check_checksum())
goto checksum_err;
- for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
+ for (tmp = contents; count--; ++i, ++tmp)
__nvram_write_byte(*tmp, i);
__nvram_set_checksum();