On Thu, Jun 1, 2017 at 7:28 AM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > On Thu, Jun 01, 2017 at 09:23:58AM -0500, Josh Poimboeuf wrote: >> On Thu, Jun 01, 2017 at 07:03:18AM -0700, Andy Lutomirski wrote: >> > On Wed, May 31, 2017 at 10:44 PM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: >> > Just to make sure I understand this, if we unwind from... >> > >> > > @@ -112,6 +114,7 @@ For 32-bit we have the following conventions - kernel is built with >> > > movq %rdx, 12*8+\offset(%rsp) >> > > movq %rsi, 13*8+\offset(%rsp) >> > >> > ...here..., will objtool think that rdx and rsi (etc) still live in >> > their respective regs, or will it find them in the on-stack data given >> > by CFI_REGS? If the former, how does undwarf deal with the >> > corresponding pops? >> >> It will find them in their respective registers, which is fine because >> they haven't been clobbered yet. > > Sorry, I hit send too soon. Which pops are you referring to? > If we do push, push, push, CFI_REGS, and then, later, we pop all those saved regs, how does undwarf figure out that those pops are moving a saved reg from the stack back to a register? Is objtool just that smart, or did I fail to notice an annotation somewhere, or does it not matter? -- 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
