static
void pid_tracker_del_node_rcu(struct lttng_pid_hash_node *e)
{
hlist_del_rcu(&e->hlist);
/*
* We choose to use a heavyweight synchronize on removal here,
* since removal of a PID from the tracker mask is a rare
* operation, and we don't want to use more cache lines than
* what we really need when doing the PID lookups, so we don't
* want to afford adding a rcu_head field to those pid hash
* node.
*/
synchronize_trace();
kfree(e);
}
/**
* lttng_ioctl - lttng syscall through ioctl
*
* @file: the file
* @cmd: the command
* @arg: command arg
*
* This ioctl implements lttng commands:
* LTTNG_KERNEL_SESSION
* Returns a LTTng trace session file descriptor
* LTTNG_KERNEL_TRACER_VERSION
* Returns the LTTng kernel tracer version
* LTTNG_KERNEL_TRACEPOINT_LIST
* Returns a file descriptor listing available tracepoints
* LTTNG_KERNEL_WAIT_QUIESCENT
* Returns after all previously running probes have completed
* LTTNG_KERNEL_TRACER_ABI_VERSION
* Returns the LTTng kernel tracer ABI version
*
* The returned session will be deleted when its file descriptor is closed.
*/
static
long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case LTTNG_KERNEL_OLD_SESSION:
case LTTNG_KERNEL_SESSION:
return lttng_abi_create_session();
case LTTNG_KERNEL_OLD_TRACER_VERSION:
{
struct lttng_kernel_tracer_version v;
struct lttng_kernel_old_tracer_version oldv;
struct lttng_kernel_old_tracer_version *uversion =
(struct lttng_kernel_old_tracer_version __user *) arg;
lttng_abi_tracer_version(&v);
oldv.major = v.major;
oldv.minor = v.minor;
oldv.patchlevel = v.patchlevel;
if (copy_to_user(uversion, &oldv, sizeof(oldv)))
return -EFAULT;
return 0;
}
case LTTNG_KERNEL_TRACER_VERSION:
{
struct lttng_kernel_tracer_version version;
struct lttng_kernel_tracer_version *uversion =
(struct lttng_kernel_tracer_version __user *) arg;
lttng_abi_tracer_version(&version);
if (copy_to_user(uversion, &version, sizeof(version)))
return -EFAULT;
return 0;
}
case LTTNG_KERNEL_TRACER_ABI_VERSION:
{
struct lttng_kernel_tracer_abi_version version;
struct lttng_kernel_tracer_abi_version *uversion =
(struct lttng_kernel_tracer_abi_version __user *) arg;
lttng_abi_tracer_abi_version(&version);
if (copy_to_user(uversion, &version, sizeof(version)))
return -EFAULT;
return 0;
}
case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
case LTTNG_KERNEL_TRACEPOINT_LIST:
return lttng_abi_tracepoint_list();
case LTTNG_KERNEL_SYSCALL_LIST:
return lttng_abi_syscall_list();
case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
case LTTNG_KERNEL_WAIT_QUIESCENT:
synchronize_trace();
return 0;
case LTTNG_KERNEL_OLD_CALIBRATE:
{
struct lttng_kernel_old_calibrate __user *ucalibrate =
(struct lttng_kernel_old_calibrate __user *) arg;
struct lttng_kernel_old_calibrate old_calibrate;
struct lttng_kernel_calibrate calibrate;
int ret;
if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
return -EFAULT;
calibrate.type = old_calibrate.type;
ret = lttng_calibrate(&calibrate);
if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
return -EFAULT;
return ret;
}
case LTTNG_KERNEL_CALIBRATE:
{
struct lttng_kernel_calibrate __user *ucalibrate =
(struct lttng_kernel_calibrate __user *) arg;
struct lttng_kernel_calibrate calibrate;
int ret;
if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
return -EFAULT;
ret = lttng_calibrate(&calibrate);
if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
return -EFAULT;
return ret;
}
default:
return -ENOIOCTLCMD;
}
}
