On 10/17/2017 04:50 PM, Josh Poimboeuf wrote: > On Tue, Oct 17, 2017 at 04:36:00PM -0400, Boris Ostrovsky wrote: >> On 10/17/2017 04:17 PM, Josh Poimboeuf wrote: >>> On Tue, Oct 17, 2017 at 11:36:57AM -0400, Boris Ostrovsky wrote: >>>> On 10/17/2017 10:36 AM, Josh Poimboeuf wrote: >>>>> Maybe we can add a new field to the alternatives entry struct which >>>>> specifies the offset to the CALL instruction, so apply_alternatives() >>>>> can find it. >>>> We'd also have to assume that the restore part of an alternative entry >>>> is the same size as the save part. Which is true now. >>> Why? >>> >> Don't you need to know the size of the instruction without save and >> restore part? >> >> + if (a->replacementlen == 6 && *insnbuf == 0xff && *(insnbuf+1) == 0x15) >> >> Otherwise you'd need another field for the actual instruction length. > If we know where the CALL instruction starts, and can verify that it > starts with "ff 15", then we know the instruction length: 6 bytes. > Right? > Oh, OK. Then you shouldn't need a->replacementlen test(s?) in apply_alternatives()? -boris -- 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
