On Tue, Apr 28, 2015 at 09:21:05AM -0500, Josh Poimboeuf wrote: > > > I tried that, but I discovered that gcc's usage of frame pointers would > > > be a lot harder to validate. It only sets up the frame pointer in code > > > paths which have call instructions. There are a lot of functions which > > > have conditional jumps at the beginning which can jump straight to a > > > return instruction without first doing the frame pointer setup. > > > > Hmm, would not such code break your patching? > > No, because we'll also do some runtime stack validation (which will be a > future patch set). If we detect preemption or an irq frame on the > stack, we'll assume the stack is unreliable and delay the patching of > the task (*). Ah, which fixes your second issue too (the interrupt before frame setup). OK. -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
