[LinuxPPS] 21 Oct 22:17 - [MIPS] Fix aliasing bug in copy_to_user_page / copy_from_user_page

[linuxpps, Ralf Baechle <>]

[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   
  
Signed-off-by: Ralf Baechle   
  
  
arch/mips/mm/init.c  
arch/mips/mm/pgtable-32.c  
arch/mips/mm/pgtable-64.c  
include/asm-mips/cacheflush.h  
include/asm-mips/fixmap.h

URL: http://gitweb.enneenne.com/?p=linuxpps;a=commit;h=f8829caee311207afbc882794bdc5aa0db5caf33