#ifndef _ASM_POWERPC_VAS_H
#define _ASM_POWERPC_VAS_H
+#include <linux/sched/mm.h>
+#include <linux/mmu_context.h>
+#include <asm/icswx.h>
#include <uapi/asm/vas-api.h>
struct vas_window;
VAS_COP_TYPE_MAX,
};
+/*
+ * User space VAS windows are opened by tasks and take references
+ * to pid and mm until windows are closed.
+ * Stores pid, mm, and tgid for each window.
+ */
+struct vas_user_win_ref {
+ struct pid *pid; /* PID of owner */
+ struct pid *tgid; /* Thread group ID of owner */
+ struct mm_struct *mm; /* Linux process mm_struct */
+};
+
/*
* User space window operations used for powernv and powerVM
*/
int (*close_win)(struct vas_window *);
};
+static inline void put_vas_user_win_ref(struct vas_user_win_ref *ref)
+{
+ /* Drop references to pid, tgid, and mm */
+ put_pid(ref->pid);
+ put_pid(ref->tgid);
+ if (ref->mm)
+ mmdrop(ref->mm);
+}
+
+static inline void vas_user_win_add_mm_context(struct vas_user_win_ref *ref)
+{
+ mm_context_add_vas_window(ref->mm);
+ /*
+ * Even a process that has no foreign real address mapping can
+ * use an unpaired COPY instruction (to no real effect). Issue
+ * CP_ABORT to clear any pending COPY and prevent a covert
+ * channel.
+ *
+ * __switch_to() will issue CP_ABORT on future context switches
+ * if process / thread has any open VAS window (Use
+ * current->mm->context.vas_windows).
+ */
+ asm volatile(PPC_CP_ABORT);
+}
+
/*
* Receive window attributes specified by the (in-kernel) owner of window.
*/
const struct vas_user_win_ops *vops);
void vas_unregister_coproc_api(void);
+int get_vas_user_win_ref(struct vas_user_win_ref *task_ref);
#endif /* __ASM_POWERPC_VAS_H */
return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
}
+/*
+ * Take reference to pid and mm
+ */
+int get_vas_user_win_ref(struct vas_user_win_ref *task_ref)
+{
+ /*
+ * Window opened by a child thread may not be closed when
+ * it exits. So take reference to its pid and release it
+ * when the window is free by parent thread.
+ * Acquire a reference to the task's pid to make sure
+ * pid will not be re-used - needed only for multithread
+ * applications.
+ */
+ task_ref->pid = get_task_pid(current, PIDTYPE_PID);
+ /*
+ * Acquire a reference to the task's mm.
+ */
+ task_ref->mm = get_task_mm(current);
+ if (!task_ref->mm) {
+ put_pid(task_ref->pid);
+ pr_err("VAS: pid(%d): mm_struct is not found\n",
+ current->pid);
+ return -EPERM;
+ }
+
+ mmgrab(task_ref->mm);
+ mmput(task_ref->mm);
+ /*
+ * Process closes window during exit. In the case of
+ * multithread application, the child thread can open
+ * window and can exit without closing it. So takes tgid
+ * reference until window closed to make sure tgid is not
+ * reused.
+ */
+ task_ref->tgid = find_get_pid(task_tgid_vnr(current));
+
+ return 0;
+}
+
static int coproc_open(struct inode *inode, struct file *fp)
{
struct coproc_instance *cp_inst;
* NX user space windows can not be opened for task->mm=NULL
* and faults will not be generated for kernel requests.
*/
- if (WARN_ON_ONCE(!window->mm || !window->user_win))
+ if (WARN_ON_ONCE(!window->task_ref.mm || !window->user_win))
return;
csb_addr = (void __user *)be64_to_cpu(crb->csb_addr);
csb.address = crb->stamp.nx.fault_storage_addr;
csb.flags = 0;
- pid = window->pid;
+ pid = window->task_ref.pid;
tsk = get_pid_task(pid, PIDTYPE_PID);
/*
* Process closes send window after all pending NX requests are
* a window and exits without closing it.
*/
if (!tsk) {
- pid = window->tgid;
+ pid = window->task_ref.tgid;
tsk = get_pid_task(pid, PIDTYPE_PID);
/*
* Parent thread (tgid) will be closing window when it
return;
}
- kthread_use_mm(window->mm);
+ kthread_use_mm(window->task_ref.mm);
rc = copy_to_user(csb_addr, &csb, sizeof(csb));
/*
* User space polls on csb.flags (first byte). So add barrier
smp_mb();
rc = copy_to_user(csb_addr, &csb, sizeof(u8));
}
- kthread_unuse_mm(window->mm);
+ kthread_unuse_mm(window->task_ref.mm);
put_task_struct(tsk);
/* Success */
rc = -ENODEV;
goto free_window;
}
-
- /*
- * Window opened by a child thread may not be closed when
- * it exits. So take reference to its pid and release it
- * when the window is free by parent thread.
- * Acquire a reference to the task's pid to make sure
- * pid will not be re-used - needed only for multithread
- * applications.
- */
- txwin->pid = get_task_pid(current, PIDTYPE_PID);
- /*
- * Acquire a reference to the task's mm.
- */
- txwin->mm = get_task_mm(current);
-
- if (!txwin->mm) {
- put_pid(txwin->pid);
- pr_err("VAS: pid(%d): mm_struct is not found\n",
- current->pid);
- rc = -EPERM;
+ rc = get_vas_user_win_ref(&txwin->task_ref);
+ if (rc)
goto free_window;
- }
- mmgrab(txwin->mm);
- mmput(txwin->mm);
- mm_context_add_vas_window(txwin->mm);
- /*
- * Process closes window during exit. In the case of
- * multithread application, the child thread can open
- * window and can exit without closing it. so takes tgid
- * reference until window closed to make sure tgid is not
- * reused.
- */
- txwin->tgid = find_get_pid(task_tgid_vnr(current));
- /*
- * Even a process that has no foreign real address mapping can
- * use an unpaired COPY instruction (to no real effect). Issue
- * CP_ABORT to clear any pending COPY and prevent a covert
- * channel.
- *
- * __switch_to() will issue CP_ABORT on future context switches
- * if process / thread has any open VAS window (Use
- * current->mm->context.vas_windows).
- */
- asm volatile(PPC_CP_ABORT);
+ vas_user_win_add_mm_context(&txwin->task_ref);
}
set_vinst_win(vinst, txwin);
/* if send window, drop reference to matching receive window */
if (window->tx_win) {
if (window->user_win) {
- /* Drop references to pid. tgid and mm */
- put_pid(window->pid);
- put_pid(window->tgid);
- if (window->mm) {
- mm_context_remove_vas_window(window->mm);
- mmdrop(window->mm);
- }
+ put_vas_user_win_ref(&window->task_ref);
+ mm_context_remove_vas_window(window->task_ref.mm);
}
put_rx_win(window->rxwin);
}
bool user_win; /* True if user space window */
void *hvwc_map; /* HV window context */
void *uwc_map; /* OS/User window context */
- struct pid *pid; /* Linux process id of owner */
- struct pid *tgid; /* Thread group ID of owner */
- struct mm_struct *mm; /* Linux process mm_struct */
int wcreds_max; /* Window credits */
+ struct vas_user_win_ref task_ref;
char *dbgname;
struct dentry *dbgdir;
static inline int vas_window_pid(struct vas_window *window)
{
- return pid_vnr(window->pid);
+ return pid_vnr(window->task_ref.pid);
}
static inline void vas_log_write(struct vas_window *win, char *name,
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