From a45185d2d7108b01b90b9e0293377be4d6346dde Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 1 Jan 2009 10:12:24 +1030 Subject: [PATCH] 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: Rusty Russell --- kernel/compat.c | 49 ++++++++++++++++++++++++++++++------------------- 1 file changed, 30 insertions(+), 19 deletions(-) diff --git a/kernel/compat.c b/kernel/compat.c index 8eafe3eb50d9..d52e2ec1deb5 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -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, -- 2.20.1