2012-05-30 15:24:18

by Sasikantha Babu

Subject: [PATCH v2] prctl: Removed redunant assignment of "error" to zero

Just setting the "error" to error number is enough on failure and
It doesn't require to set "error" variable to zero in each switch case, since
it was already initialized with zero. And also removed return 0 in switch case
with break statement

Signed-off-by: Sasikantha babu <[email protected]>
---
kernel/sys.c | 13 ++-----------
1 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/kernel/sys.c b/kernel/sys.c
index 6df4262..fd52619 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1920,7 +1920,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
break;
}
me->pdeath_signal = arg2;
- error = 0;
break;
case PR_GET_PDEATHSIG:
error = put_user(me->pdeath_signal, (int __user *)arg2);
@@ -1934,7 +1933,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
break;
}
set_dumpable(me->mm, arg2);
- error = 0;
break;

case PR_SET_UNALIGN:
@@ -1961,10 +1959,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
case PR_SET_TIMING:
if (arg2 != PR_TIMING_STATISTICAL)
error = -EINVAL;
- else
- error = 0;
break;
-
case PR_SET_NAME:
comm[sizeof(me->comm)-1] = 0;
if (strncpy_from_user(comm, (char __user *)arg2,
@@ -1972,20 +1967,19 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
return -EFAULT;
set_task_comm(me, comm);
proc_comm_connector(me);
- return 0;
+ break;
case PR_GET_NAME:
get_task_comm(comm, me);
if (copy_to_user((char __user *)arg2, comm,
sizeof(comm)))
return -EFAULT;
- return 0;
+ break;
case PR_GET_ENDIAN:
error = GET_ENDIAN(me, arg2);
break;
case PR_SET_ENDIAN:
error = SET_ENDIAN(me, arg2);
break;
-
case PR_GET_SECCOMP:
error = prctl_get_seccomp();
break;
@@ -2013,7 +2007,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
current->default_timer_slack_ns;
else
current->timer_slack_ns = arg2;
- error = 0;
break;
case PR_MCE_KILL:
if (arg4 | arg5)
@@ -2039,7 +2032,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
default:
return -EINVAL;
}
- error = 0;
break;
case PR_MCE_KILL_GET:
if (arg2 | arg3 | arg4 | arg5)
@@ -2055,7 +2047,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
break;
case PR_SET_CHILD_SUBREAPER:
me->signal->is_child_subreaper = !!arg2;
- error = 0;
break;
case PR_GET_CHILD_SUBREAPER:
error = put_user(me->signal->is_child_subreaper,
--
1.7.3.4

2012-05-30 17:53:45

by Kees Cook

Subject: Re: [PATCH v2] prctl: Removed redunant assignment of "error" to zero

On Wed, May 30, 2012 at 8:27 AM, Sasikantha babu
<[email protected]> wrote:
> Just setting the "error" to error number is enough on failure and
> It doesn't require to set "error" variable to zero in each switch case, since
> it was already initialized with zero. And also removed return 0 in switch case
> with break statement
>
> Signed-off-by: Sasikantha babu <[email protected]>

Acked-by: Kees Cook <[email protected]>

-Kees

--
Kees Cook
Chrome OS Security

2012-05-30 18:28:46

by Serge Hallyn

Subject: Re: [PATCH v2] prctl: Removed redunant assignment of "error" to zero

Quoting Kees Cook ([email protected]):
> On Wed, May 30, 2012 at 8:27 AM, Sasikantha babu
> <[email protected]> wrote:
> > Just setting the "error" to error number is enough on failure and
> > It doesn't require to set "error" variable to zero in each switch case, since
> > it was already initialized with zero. And also removed return 0 in switch case
> > with break statement
> >
> > Signed-off-by: Sasikantha babu <[email protected]>
>
> Acked-by: Kees Cook <[email protected]>

Acked-by: Serge E. Hallyn <[email protected]>

>
> -Kees
>
> --
> Kees Cook
> Chrome OS Security