On Thu, Jun 15, 2017 at 03:03:42PM +0100, Dave P Martin wrote: > This patch defines an extra_context signal frame record that can be > used to describe an expanded signal frame, and modifies the context > block allocator and signal frame setup and parsing code to create, > populate, parse and decode this block as necessary. > > To avoid abuse by userspace, parse_user_sigframe() attempts to > ensure that: > > * no more than one extra_context is accepted; > * the extra context data is a sensible size, and properly placed > and aligned. > > The extra_context data is required to start at the first 16-byte > aligned address immediately after the dummy terminator record > following extra_context in rt_sigframe.__reserved[] (as ensured > during signal delivery). This serves as a sanity-check that the > signal frame has not been moved or copied without taking the extra > data into account. > > Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
