On Fri, Jul 24, 2015 at 9:25 AM, Willy Tarreau <w...@1wt.eu> wrote: > On Fri, Jul 24, 2015 at 08:48:57AM -0700, Andy Lutomirski wrote: >> So by the time we detect that we've hit a watchpoint, the instruction >> that tripped it is done and we don't need RF. Furthermore, after >> reading 17.3.1.1: I *think* that regs->flags withh have RF *clear* if >> we hit a watchpoint. > > Apparently after reading 17.3.1.1, it seems like RF can still be set > if a data breakpoint triggers in a repeated string instruction before > the last iteration. However I don't think we care because as long as > we return to the string instruction, since the data location was already > visited it won't trigger again so the loss of the flag should be safe. >
Oh, right. So my proposal is wrong: it'll clear a watchpoint incorrectly if we hit it in the middle of a string operation. So we should either parse dr0..dr3 (whichever one triggered) or do Peter's think and clear dr7 entirely. I still prefer just clearing the breakpoint that triggered. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
