CVS commit: src/sys/arch/usermode

["Reinoud Zandijk" <reinoud%netbsd.org@localhost>]

Module Name:    src
Committed By:   reinoud
Date:           Sun Nov 27 21:38:17 UTC 2011

Modified Files:
        src/sys/arch/usermode/dev: cpu.c
        src/sys/arch/usermode/include: machdep.h param.h pcb.h
        src/sys/arch/usermode/usermode: machdep.c syscall.c trap.c urkelvisor.c

Log Message:
Big patch that changes the signal stack usage of urkel significantly.

Formerly, all signals came on the signal stack and the two important ones were
then forwared to either the system call or the pagefault handler. This worked
fine but the signal stack remains that, a stack. When we go multi-process this
stack gets corrupted and out-of-order with all kind of nastyness since a
userland process switch can occure when a system call is called or when a
process gets a page fault.

The new scheme only uses the signal stack as a jumpboard. It swaps states and
then returns from the signal, clearing the stack but instead of returning to
the code it now jumpt to the handler and that handler then returns to the code
when its finished.


To generate a diff of this commit:
cvs rdiff -u -r1.46 -r1.47 src/sys/arch/usermode/dev/cpu.c
cvs rdiff -u -r1.3 -r1.4 src/sys/arch/usermode/include/machdep.h
cvs rdiff -u -r1.4 -r1.5 src/sys/arch/usermode/include/param.h
cvs rdiff -u -r1.12 -r1.13 src/sys/arch/usermode/include/pcb.h
cvs rdiff -u -r1.32 -r1.33 src/sys/arch/usermode/usermode/machdep.c
cvs rdiff -u -r1.10 -r1.11 src/sys/arch/usermode/usermode/syscall.c
cvs rdiff -u -r1.41 -r1.42 src/sys/arch/usermode/usermode/trap.c
cvs rdiff -u -r1.8 -r1.9 src/sys/arch/usermode/usermode/urkelvisor.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.