Commit a45185d2 authored by Rusty Russell's avatar Rusty Russell
Browse files

cpumask: convert kernel/compat.c 



Impact: Reduce stack usage, use new cpumask API.

Straightforward conversion; cpumasks' size is given by cpumask_size() (now
a variable rather than fixed) and on-stack cpu masks use cpumask_var_t.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 3e597945

kernel/compat.c

+30 −19
Original line number Diff line number Diff line
@@ -454,16 +454,16 @@ asmlinkage long compat_sys_waitid(int which, compat_pid_t pid, 
}



static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,

				    unsigned len, cpumask_t *new_mask)

				    unsigned len, struct cpumask *new_mask)

{

	unsigned long *k;



	if (len < sizeof(cpumask_t))

		memset(new_mask, 0, sizeof(cpumask_t));

	else if (len > sizeof(cpumask_t))

		len = sizeof(cpumask_t);

	if (len < cpumask_size())

		memset(new_mask, 0, cpumask_size());

	else if (len > cpumask_size())

		len = cpumask_size();



	k = cpus_addr(*new_mask);

	k = cpumask_bits(new_mask);

	return compat_get_bitmap(k, user_mask_ptr, len * 8);

}
@@ -471,40 +471,51 @@ asmlinkage long compat_sys_sched_setaffinity(compat_pid_t pid, 
					     unsigned int len,

					     compat_ulong_t __user *user_mask_ptr)

{

	cpumask_t new_mask;

	cpumask_var_t new_mask;

	int retval;



	retval = compat_get_user_cpu_mask(user_mask_ptr, len, &new_mask);

	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))

		return -ENOMEM;



	retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);

	if (retval)

		return retval;

		goto out;



	return sched_setaffinity(pid, &new_mask);

	retval = sched_setaffinity(pid, new_mask);

out:

	free_cpumask_var(new_mask);

	return retval;

}



asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,

					     compat_ulong_t __user *user_mask_ptr)

{

	int ret;

	cpumask_t mask;

	cpumask_var_t mask;

	unsigned long *k;

	unsigned int min_length = sizeof(cpumask_t);

	unsigned int min_length = cpumask_size();



	if (NR_CPUS <= BITS_PER_COMPAT_LONG)

	if (nr_cpu_ids <= BITS_PER_COMPAT_LONG)

		min_length = sizeof(compat_ulong_t);



	if (len < min_length)

		return -EINVAL;



	ret = sched_getaffinity(pid, &mask);

	if (!alloc_cpumask_var(&mask, GFP_KERNEL))

		return -ENOMEM;



	ret = sched_getaffinity(pid, mask);

	if (ret < 0)

		return ret;

		goto out;



	k = cpus_addr(mask);

	k = cpumask_bits(mask);

	ret = compat_put_bitmap(user_mask_ptr, k, min_length * 8);

	if (ret)

		return ret;

	if (ret == 0)

		ret = min_length;



	return min_length;

out:

	free_cpumask_var(mask);

	return ret;

}



int get_compat_itimerspec(struct itimerspec *dst,

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