sched: convert sys_sched_getaffinity() to cpumask_var_t.
Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space in the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Some jiggling here to make sure we always exit at the bottom (so we hit the free_cpumask_var there). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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@ -5499,19 +5499,24 @@ asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len,
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unsigned long __user *user_mask_ptr)
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unsigned long __user *user_mask_ptr)
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{
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{
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int ret;
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int ret;
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cpumask_t mask;
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cpumask_var_t mask;
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if (len < sizeof(cpumask_t))
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if (len < cpumask_size())
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return -EINVAL;
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return -EINVAL;
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ret = sched_getaffinity(pid, &mask);
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if (!alloc_cpumask_var(&mask, GFP_KERNEL))
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if (ret < 0)
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return -ENOMEM;
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return ret;
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if (copy_to_user(user_mask_ptr, &mask, sizeof(cpumask_t)))
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ret = sched_getaffinity(pid, mask);
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return -EFAULT;
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if (ret == 0) {
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if (copy_to_user(user_mask_ptr, mask, cpumask_size()))
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ret = -EFAULT;
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else
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ret = cpumask_size();
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}
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free_cpumask_var(mask);
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return sizeof(cpumask_t);
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return ret;
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}
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}
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/**
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/**
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