"Naveen N. Rao" <naveen.n....@linux.vnet.ibm.com> writes: > As pointed out in x86 setjmp_pre_handler(), we need to save and restore > the parameter save area since the jprobe hook might overwrite it. Since > there is no easy way to identify the size of the parameter save area, > we choose to save/restore a fixed 16 [double]word-sized area including > the stack frame header. > > We introduce STACK_FRAME_PARM_SAVE to encode the offset of the parameter > save area from the stack frame pointer. Remove the similarly named > PARAMETER_SAVE_AREA_OFFSET in ptrace.c as those are currently not used > anywhere. > > Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com> > --- > Michael, > I've set the limit to 16 parameters as being a "reasonable" number, but > we could very well make this 24 or 32 if we want to be sure. Let me > know what you prefer.
That sounds incredibly fragile. Are we really just guessing at the size required? What happens if we under estimate, do we crash, silently corrupt data .. ? cheers