On Mon, Jun 20, 2016 at 9:14 AM, Oleg Nesterov wrote:
> On 06/20, Andy Lutomirski wrote:
>>
>> On Mon, Jun 20, 2016 at 8:24 AM, Oleg Nesterov wrote:
>> >
>> > How about the simple change below for now? IIRC 32-bit task can't use
>> > "syscall" so if syscall_get_nr() >= 0 then even the wrong TS_CO
On 06/20, Andy Lutomirski wrote:
>
> On Mon, Jun 20, 2016 at 8:24 AM, Oleg Nesterov wrote:
> >
> > How about the simple change below for now? IIRC 32-bit task can't use
> > "syscall" so if syscall_get_nr() >= 0 then even the wrong TS_COMPAT is
> > not that bad, even if it "leaks" to user-mode.
>
>
On Mon, Jun 20, 2016 at 8:24 AM, Oleg Nesterov wrote:
> On 06/19, Andy Lutomirski wrote:
>>
>> On Sat, Jun 18, 2016 at 10:02 AM, Andy Lutomirski
>> wrote:
>> Step 1: for 4.7 and for -stable, introduce TS_I386_REGS_POKED. Set it
>> in putreg32. Use it in syscall_get_error, get_nr_restart_syscal
On 06/19, Andy Lutomirski wrote:
>
> On Sat, Jun 18, 2016 at 10:02 AM, Andy Lutomirski wrote:
> Step 1: for 4.7 and for -stable, introduce TS_I386_REGS_POKED. Set it
> in putreg32. Use it in syscall_get_error, get_nr_restart_syscall,
> etc. Clear it in do_signal.
do_signal() won't be necessari
On 06/19, Andy Lutomirski wrote:
>
> On Sun, Jun 19, 2016 at 2:19 PM, Oleg Nesterov wrote:
> >
> > And this leads to another question, why do we actually need to set/clear
> > TS_COMPAT in set_personality_ia32() ??
>
> Something's clearly buggy there, considering that
> set_personality_64bit() doe
On Mon, 20 Jun 2016 12:07:56 +0200, Pedro Alves wrote:
> On 06/18/2016 06:02 PM, Andy Lutomirski wrote:
> > Yuck. I should have dug in to the history. Why not just
> > unconditionally sign-extend eax when set by a 32-bit tracer?
>
> No idea.
Roland McGrath knows why he wrote it that way, Cced.
On 06/19/2016 11:09 PM, Andy Lutomirski wrote:
>
> The latter bit is a mess and is probably broken on current kernels for
> 64-bit gdb attached to a 32-bit process. (Is it? All of this stuff
> is a bit of a pain to test.)
The testcase at:
https://sourceware.org/ml/gdb/2014-05/msg4.html
s
On 06/18/2016 06:02 PM, Andy Lutomirski wrote:
> Yuck. I should have dug in to the history. Why not just
> unconditionally sign-extend eax when set by a 32-bit tracer?
No idea.
>
> Do you know how to acquire a copy of erestartsys-trap.c? The old
> links appear to be broken.
That's part of t
On Sun, Jun 19, 2016 at 2:19 PM, Oleg Nesterov wrote:
> Let me first thank Pedro who has already replied!
>
> And I have to admit I will need to re-read his explanations after
> sleep to (try to) convince myself I fully understans the problems ;)
> Too late for me.
>
> Right now I have nothing to
On Sun, Jun 19, 2016 at 2:19 PM, Oleg Nesterov wrote:
> Let me first thank Pedro who has already replied!
>
> And I have to admit I will need to re-read his explanations after
> sleep to (try to) convince myself I fully understans the problems ;)
> Too late for me.
>
> Right now I have nothing to
Let me first thank Pedro who has already replied!
And I have to admit I will need to re-read his explanations after
sleep to (try to) convince myself I fully understans the problems ;)
Too late for me.
Right now I have nothing to add, but
On 06/18, Andy Lutomirski wrote:
>
> @@ -922,16 +922,7 @@
On Sat, Jun 18, 2016 at 10:02 AM, Andy Lutomirski wrote:
> On Jun 18, 2016 6:56 AM, "Pedro Alves" wrote:
>>
>> On 06/18/2016 11:21 AM, Andy Lutomirski wrote:
>> > A 32-bit tracer can set a tracee's TS_COMPAT flag by poking orig_ax.
>> >
>> > - If the tracee is stopped in a 32-bit syscall, this ha
On Sat, Jun 18, 2016 at 3:21 AM, Andy Lutomirski wrote:
> A 32-bit tracer can set a tracee's TS_COMPAT flag by poking orig_ax.
>
> - If the tracee is stopped in a 32-bit syscall, this has no effect
> as TS_COMPAT will already be set.
>
> - If the tracee is stopped on entry to a 64-bit syscall, t
On Jun 18, 2016 6:56 AM, "Pedro Alves" wrote:
>
> On 06/18/2016 11:21 AM, Andy Lutomirski wrote:
> > A 32-bit tracer can set a tracee's TS_COMPAT flag by poking orig_ax.
> >
> > - If the tracee is stopped in a 32-bit syscall, this has no effect
> > as TS_COMPAT will already be set.
> >
> > - If
On 06/18/2016 02:55 PM, Pedro Alves wrote:
> This hunk being mentioned in this thread a couple years ago too:
>
> https://www.sourceware.org/ml/gdb/2014-04/msg00095.html
>
> Please don't break this use case ( and fix the one reported in
> that thread :-) ).
BTW, there was a follow up v2 patch
On 06/18/2016 11:21 AM, Andy Lutomirski wrote:
> A 32-bit tracer can set a tracee's TS_COMPAT flag by poking orig_ax.
>
> - If the tracee is stopped in a 32-bit syscall, this has no effect
> as TS_COMPAT will already be set.
>
> - If the tracee is stopped on entry to a 64-bit syscall, this coul
A 32-bit tracer can set a tracee's TS_COMPAT flag by poking orig_ax.
- If the tracee is stopped in a 32-bit syscall, this has no effect
as TS_COMPAT will already be set.
- If the tracee is stopped on entry to a 64-bit syscall, this could
cause problems: in_compat_syscall() etc will be out of
17 matches
Mail list logo
