tree e224523373424f4402b70d351caa48e94133a9ab
parent 5acd57936c3224fd86e838201e528e0169373e9b
author Jesper Juhl <[EMAIL PROTECTED]> Wed, 07 Sep 2005 05:17:37 -0700
committer Linus Torvalds <[EMAIL PROTECTED]> Thu, 08 Sep 2005 06:57:32 -0700

[PATCH] remove a redundant variable in sys_prctl()

The patch removes a redundant variable `sig' from sys_prctl().

For some reason, when sys_prctl is called with option == PR_SET_PDEATHSIG
then the value of arg2 is assigned to an int variable named sig.  Then sig
is tested with valid_signal() and later used to set the value of
current->pdeath_signal .

There is no reason to use this intermediate variable since valid_signal()
takes a unsigned long argument, so it can handle being passed arg2
directly, and if the call to valid_signal is OK, then we know the value of
arg2 is in the range zero to _NSIG and thus it'll easily fit in a plain int
and thus there's no problem assigning it later to current->pdeath_signal
(which is an int).

The patch gets rid of the pointless variable `sig'.
This reduces the size of kernel/sys.o in 2.6.13-rc6-mm1 by 32 bytes on my

Patch has been compile tested, boot tested, and just to make damn sure I
didn't break anything I wrote a quick test app that calls
prctl(PR_SET_PDEATHSIG ...) with the entire range of values for a
unsigned long, and it behaves as expected with and without the patch.

Signed-off-by: Jesper Juhl <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>

 kernel/sys.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/sys.c b/kernel/sys.c
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1711,7 +1711,6 @@ asmlinkage long sys_prctl(int option, un
                          unsigned long arg4, unsigned long arg5)
        long error;
-       int sig;
        error = security_task_prctl(option, arg2, arg3, arg4, arg5);
        if (error)
@@ -1719,12 +1718,11 @@ asmlinkage long sys_prctl(int option, un
        switch (option) {
                case PR_SET_PDEATHSIG:
-                       sig = arg2;
-                       if (!valid_signal(sig)) {
+                       if (!valid_signal(arg2)) {
                                error = -EINVAL;
-                       current->pdeath_signal = sig;
+                       current->pdeath_signal = arg2;
                case PR_GET_PDEATHSIG:
                        error = put_user(current->pdeath_signal, (int __user 
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