From 0730ded5be28653675ed314fdd878b8db5f88aa4 Mon Sep 17 00:00:00 2001 From: Jesper Juhl Date: Tue, 6 Sep 2005 15:17:37 -0700 Subject: [PATCH] [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 system. 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sys.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/sys.c b/kernel/sys.c index 0bcaed6560ac..c80412be2302 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1711,7 +1711,6 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, 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, unsigned long arg2, unsigned long arg3, switch (option) { case PR_SET_PDEATHSIG: - sig = arg2; - if (!valid_signal(sig)) { + if (!valid_signal(arg2)) { error = -EINVAL; break; } - current->pdeath_signal = sig; + current->pdeath_signal = arg2; break; case PR_GET_PDEATHSIG: error = put_user(current->pdeath_signal, (int __user *)arg2); -- 2.20.1