Commit a45185d2 authored by Rusty Russell's avatar Rusty Russell

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 <>
parent 3e597945
......@@ -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);
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_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;
return ret;
int get_compat_itimerspec(struct itimerspec *dst,
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