[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 <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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5acd57936c
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0730ded5be
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@ -1711,7 +1711,6 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
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unsigned long arg4, unsigned long arg5)
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{
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long error;
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int sig;
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error = security_task_prctl(option, arg2, arg3, arg4, arg5);
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if (error)
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@ -1719,12 +1718,11 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
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switch (option) {
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case PR_SET_PDEATHSIG:
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sig = arg2;
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if (!valid_signal(sig)) {
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if (!valid_signal(arg2)) {
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error = -EINVAL;
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break;
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}
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current->pdeath_signal = sig;
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current->pdeath_signal = arg2;
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break;
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case PR_GET_PDEATHSIG:
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error = put_user(current->pdeath_signal, (int __user *)arg2);
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