kernel/compat.c

Source file repositories/reference/linux-study-clean/kernel/compat.c

File Facts

System
Linux kernel
Corpus path
kernel/compat.c
Extension
.c
Size
6980 bytes
Lines
272
Domain
Core OS
Bucket
Scheduler, Processes, Timers, Sync, And Syscalls
Inferred role
Core OS: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

switch (how) {
		case SIG_BLOCK:
			sigaddsetmask(&new_blocked, new_set);
			break;
		case SIG_UNBLOCK:
			sigdelsetmask(&new_blocked, new_set);
			break;
		case SIG_SETMASK:
			compat_sig_setmask(&new_blocked, new_set);
			break;
		default:
			return -EINVAL;
		}

		set_current_blocked(&new_blocked);
	}

	if (oset) {
		if (put_user(old_set, oset))
			return -EFAULT;
	}

	return 0;
}

#endif

int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
{
	struct compat_rusage r32;
	memset(&r32, 0, sizeof(r32));
	r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
	r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
	r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
	r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
	r32.ru_maxrss = r->ru_maxrss;
	r32.ru_ixrss = r->ru_ixrss;
	r32.ru_idrss = r->ru_idrss;
	r32.ru_isrss = r->ru_isrss;
	r32.ru_minflt = r->ru_minflt;
	r32.ru_majflt = r->ru_majflt;
	r32.ru_nswap = r->ru_nswap;
	r32.ru_inblock = r->ru_inblock;
	r32.ru_oublock = r->ru_oublock;
	r32.ru_msgsnd = r->ru_msgsnd;
	r32.ru_msgrcv = r->ru_msgrcv;
	r32.ru_nsignals = r->ru_nsignals;
	r32.ru_nvcsw = r->ru_nvcsw;
	r32.ru_nivcsw = r->ru_nivcsw;
	if (copy_to_user(ru, &r32, sizeof(r32)))
		return -EFAULT;
	return 0;
}

static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
				    unsigned len, struct cpumask *new_mask)
{
	unsigned long *k;

	if (len < cpumask_size())
		memset(new_mask, 0, cpumask_size());
	else if (len > cpumask_size())
		len = cpumask_size();

	k = cpumask_bits(new_mask);
	return compat_get_bitmap(k, user_mask_ptr, len * 8);
}

COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
		       unsigned int, len,
		       compat_ulong_t __user *, user_mask_ptr)
{
	cpumask_var_t new_mask;
	int retval;

	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
		return -ENOMEM;

	retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
	if (retval)
		goto out;

	retval = sched_setaffinity(pid, new_mask);
out:
	free_cpumask_var(new_mask);
	return retval;
}

COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t,  pid, unsigned int, len,
		       compat_ulong_t __user *, user_mask_ptr)

Annotation

Implementation Notes