perf/x86: Use scoped user access for the user callchain frames

The user callchain walkers read each two-word stack frame with
__get_user(), after checking the frame with valid_user_frame(), which is
just __access_ok().  They run with page faults disabled, since they can
be called from NMI context.

Read each frame inside a scoped_user_read_access() instead, which does
the range check itself and needs only a single stac/clac pair for both
loads.  That leaves valid_user_frame() unused, so remove it.

This is part of getting rid of __get_user() and __put_user() entirely.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions