NetBSD/sys/arch/atari
mhitch 9b0f085da1 68030 and 68040 processors consider the read portion of a read-modify-write
transfer as a write to ensure the memory is writable before starting any
transfer.  The fault status information does not reflect this in the 'read'
status bit (i.e. it shows up as a read access), so faults with a RMW access
to non-writable memory was not getting the correct protection.  The page would
be read-only and the instruction would fault over and over.

A specific example is when a process forks, and the child process attempts
to execute a RMW access to a data page, which is read-only because it's CoP
Copy-On-Write.

When checking if the page needs to be writablek, also check the locked transfer
and treat any locked transfer as a write.

68060 already handled this correctly, since it has separate read and write
fault bits, and both are set on a RMW access and the trap code was checking
the write status bit.

Fixes PR#36848.
2007-09-01 21:31:55 +00:00
..
atari 68030 and 68040 processors consider the read portion of a read-modify-write 2007-09-01 21:31:55 +00:00
compile
conf Remove iso(4) from GENERIC kernels, as discussed on tech-net@ 2007-08-06 21:26:53 +00:00
dev It's not a good idea for device drivers to modify b_flags, as they don't 2007-07-29 12:15:35 +00:00
include Add ci_cpuid where it's missing. 2007-08-04 09:49:51 +00:00
isa Pass (char *) to mtod(9) on pointer arith. 2007-03-06 14:12:10 +00:00
pci fix typos 2007-04-29 20:23:34 +00:00
stand
vme Kill caddr_t; there will be some MI fallout, but it will be fixed shortly. 2007-03-04 05:59:00 +00:00
Makefile