Make alloc_and_copy_ftrace_hash to copy also direct address
for each hash entry.

Signed-off-by: Jiri Olsa <[email protected]>

We are going to use these functions in following changes.

Signed-off-by: Jiri Olsa <[email protected]>

Adding update_ftrace_direct_add function that adds all entries
(ip -> addr) provided in hash argument to direct ftrace ops
and updates its attachments.

The difference to current register_ftrace_direct is
 - hash argument that allows to register multiple ip -> direct
   entries at once
 - we can call update_ftrace_direct_add multiple times on the
   same ftrace_ops object, becase after first registration with
   register_ftrace_function_nolock, it uses ftrace_update_ops to
   update the ftrace_ops object

This change will allow us to have simple ftrace_ops for all bpf
direct interface users in following changes.

Signed-off-by: Jiri Olsa <[email protected]>

Adding update_ftrace_direct_del function that removes all entries
(ip -> addr) provided in hash argument to direct ftrace ops and
updates its attachments.

The difference to current unregister_ftrace_direct is
 - hash argument that allows to unregister multiple ip -> direct
   entries at once
 - we can call update_ftrace_direct_del multiple times on the
   same ftrace_ops object, becase we do not need to unregister
   all entries at once, we can do it gradualy with the help of
   ftrace_update_ops function

This change will allow us to have simple ftrace_ops for all bpf
direct interface users in following changes.

Signed-off-by: Jiri Olsa <[email protected]>

Adding update_ftrace_direct_mod function that modifies all entries
(ip -> direct) provided in hash argument to direct ftrace ops and
updates its attachments.

The difference to current modify_ftrace_direct is:
- hash argument that allows to modify multiple ip -> direct
  entries at once

This change will allow us to have simple ftrace_ops for all bpf
direct interface users in following changes.

Signed-off-by: Jiri Olsa <[email protected]>

Following changes need to lookup trampoline based on its ip address,
adding hash table for that.

Signed-off-by: Jiri Olsa <[email protected]>

Using single ftrace_ops for direct calls update instead of allocating
ftrace_ops object for each trampoline.

With single ftrace_ops object we can use update_ftrace_direct_* api
that allows multiple ip sites updates on single ftrace_ops object.

Adding HAVE_SINGLE_FTRACE_DIRECT_OPS config option to be enabled on
each arch that supports this.

At the moment we can enable this only on x86 arch, because arm relies
on ftrace_ops object representing just single trampoline image (stored
in ftrace_ops::direct_call). Ach that do not support this will continue
to use *_ftrace_direct api.

Signed-off-by: Jiri Olsa <[email protected]>