uprobes: Add exports for module use

The original pull message for uprobes (commit 654443e) noted:

  This tree includes uprobes support in 'perf probe' - but SystemTap
  (and other tools) can take advantage of user probe points as well.

In order to actually be usable in module-based tools like SystemTap, the
interface needs to be exported.  This patch first adds the obvious
exports for uprobe_register and uprobe_unregister.  Then it also adds
one for task_user_regset_view, which is necessary to get the correct
state of userspace registers.

Signed-off-by: Josh Stone <jistone@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>

kernel/events/uprobes.c

@@ -27,6 +27,7 @@
 #include <linux/pagemap.h>	/* read_mapping_page */
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/export.h>
 #include <linux/rmap.h>		/* anon_vma_prepare */
 #include <linux/mmu_notifier.h>	/* set_pte_at_notify */
 #include <linux/swap.h>		/* try_to_free_swap */
@@ -851,6 +852,7 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
 		goto retry;
 	return ret;
 }
+EXPORT_SYMBOL_GPL(uprobe_register);
 
 /*
  * uprobe_unregister - unregister a already registered probe.
@@ -871,6 +873,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume
 	up_write(&uprobe->register_rwsem);
 	put_uprobe(uprobe);
 }
+EXPORT_SYMBOL_GPL(uprobe_unregister);
 
 static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm)
 {

kernel/ptrace.c

@@ -712,6 +712,12 @@ static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
 					     kiov->iov_len, kiov->iov_base);
 }
 
+/*
+ * This is declared in linux/regset.h and defined in machine-dependent
+ * code.  We put the export here, near the primary machine-neutral use,
+ * to ensure no machine forgets it.
+ */
+EXPORT_SYMBOL_GPL(task_user_regset_view);
 #endif
 
 int ptrace_request(struct task_struct *child, long request,