diff options
author | Nicolas Pitre <nico@cam.org> | 2006-02-08 21:19:37 +0000 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-02-08 21:19:37 +0000 |
commit | 49bca4c2815feafd5f999bf43baf87e0dd8d1d08 (patch) | |
tree | 6bc9a59e2fa217d346841418fd45dd704cf61071 /Documentation/powerpc | |
parent | 99595d0237926b5aba1fe4c844a011a1ba1ee1f8 (diff) |
[ARM] 3309/1: disable the pre-ARMv5 NPTL kernel helper in the non MMU case
Patch from Nicolas Pitre
The cmpxchg emulation on pre-ARMv5 relies on user code executed from a
kernel address. If the operation cannot complete atomically, it is
aborted from the usr_entry macro by clearing the Z flag. This clearing
of the Z flag is done whenever the user pc is above TASK_SIZE.
However this "pc >= TASK_SIZE" test cannot work in the non MMU case.
Worse: the current code will corrupt the Z flag on every entry to the
kernel.
Let's disable it in the non MMU case for now. Using NPTL on non MMU
targets needs to be worked out anyway.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'Documentation/powerpc')
0 files changed, 0 insertions, 0 deletions