On Mon, Apr 06, 2015 at 10:51:42AM -0400, Sasha Levin wrote:
> > Btw, what's happening to that user pointer in %rdi, is it kosher?
>
> Probably not. Trinity passes random addresses into that syscall, so it's
> probably one of it's magic
> values.
So what is the expectation? If that pointer goes away from under us,
userspace is supposed to get some signal instead of hanging?
> I've attached dmesg with debug-alternative, and my .config. vmlinux is pretty
> large (1GB compressed) so hopefully the config would be enough - let me know
> if it isn't.
Thanks, I'll give it a try and do some staring tomorrow. Still a holiday
today here :-)
> > Btw, that zerorest is being tested on every loop iteration! AFAICT,
> >
> > if (!zerorest) {
> > clac();
> > return len;
> > }
> >
> > before the loop should be nicer. Or am I missing something?
>
> Looks good to me. I suspect the compiler optimizes that anyway though.
Yeah, doesn't look like it. See the
e: 85 c9 test %ecx,%ecx
?
That's:
---
testl %esi, %esi # __pu_err
je .L34 #,
.L21:
testl %ecx, %ecx # zerorest <---
je .L33 #,
movl %edx, %eax # len, len
xorl %r8d, %r8d # tmp194
jmp .L27 #
.p2align 4,,7
.p2align 3
.L35:
decl %eax # len
movq %rsi, %rdi # to, to
je .L33 #,
.L27:
leaq 1(%rdi), %rsi #, to
---
and my asm is not so different from yours so that I can match your asm
with the .s output here.
Anyway, that's a different story, I'll do a fix for it.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
--
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/
