s390/ptrace: Preserve previous registers for short regset write
commit 9dce990d2cf57b5ed4e71a9cdbd7eae4335111ff upstream.
Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.
convert_vx_to_fp() is adapted to handle only a specified number of
registers rather than unconditionally handling all of them: other
callers of this function are adapted appropriately.
Based on an initial patch by Dave Martin.
Reported-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed