tree dbadd9fa746a1a4f091bc7e240ca8d787188a913
parent 224dc50ece1b40f8cff5ecadd42a6b2691e231de
author Ralf Baechle <ralf@linux-mips.org> 1161469055 +0100
committer Ralf Baechle <ralf@linux-mips.org> 1161469055 +0100

[MIPS] Fix aliasing bug in copy_to_user_page / copy_from_user_page

The current implementation uses a sequence of a cacheflush and a copy.
This is racy in case of a multithreaded debuggee and renders GDB
virtually unusable.

Aside this fixes a performance hog rendering access to /proc/cmdline very
slow and resulting in a enough cache stalls for the 34K AP/SP programming
model to make the bare metal code on the non-Linux VPE miss RT deadlines.

The main part of this patch was originally written by Ralf Baechle;
Atushi Nemoto did the the debugging.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>