Re: [PATCH v3 2/3] x86/signal: Rewire the restart_block() syscall to have a constant nr

Pedro Alves
2016-06-21T12:41:47Z

Hi Andy,

On 06/21/2016 12:39 AM, Andy Lutomirski wrote:
> Suppose a 64-bit task A traces a 32-bit task B.

I gave your x86/ptrace branch a try:

https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/log/?h=x86/ptrace

(this looks to be the same patch set.)

Unfortunately, with gdb git master, I still get the
64-bit ptracer x 32-bit ptracee problem:

(gdb) r
Starting program: interrupt.32
talk to me baby
^C

Program received signal SIGINT, Interrupt.
0xf7fd9d09 in __kernel_vsyscall ()
(gdb) p func1 ()
$1 = 4
(gdb) c
Continuing.
Unknown error 512
[Inferior 1 (process 2198) exited with code 01]
(gdb) q

Is this expected?

This is the same testcase as before:

https://sourceware.org/ml/gdb/2014-05/msg00004.html

Thanks,
Pedro Alves