hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

/dev/zero: avoid repeated access_ok() checks 

In read_zero, we check for access_ok() once for the count bytes.  It is
unnecessarily checked again in clear_user.  Use __clear_user, which does
not check for access_ok().

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nikanth Karthikesan 2009-09-23 15:57:09 -07:00 committed by Linus Torvalds
parent 0b8c78f2bf
commit bb521c5de0
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/char/mem.c
View File

@ -690,7 +690,7 @@ static ssize_t read_zero(struct file * file, char __user * buf,
if (chunk > PAGE_SIZE) if (chunk > PAGE_SIZE)
chunk = PAGE_SIZE; /* Just for latency reasons */ chunk = PAGE_SIZE; /* Just for latency reasons */
unwritten = clear_user(buf, chunk); unwritten = __clear_user(buf, chunk);
written += chunk - unwritten; written += chunk - unwritten;
if (unwritten) if (unwritten)
break; break;