[PATCH 03/14] uprobes: kill write_opcode()->lock_page(new_page)

[Oleg Nesterov]

write_opcode() does lock_page(new_page) for no reason. Nobody can
see this page until __replace_page() exposes it under ptl lock, and
we do nothing with this page after pte_unmap_unlock().

If nothing else, the similar code in do_wp_page() doesn't lock the
new page for page_add_new_anon_rmap/set_pte_at_notify.

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com>
---
 kernel/events/uprobes.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index fbb4188..dff8da2 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -239,9 +239,7 @@ retry:
 	if (ret)
 		goto unlock_out;
 
-	lock_page(new_page);
 	ret = __replace_page(vma, vaddr, old_page, new_page);
-	unlock_page(new_page);
 
 unlock_out:
 	unlock_page(old_page);
-- 
1.5.5.1

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