Re: [RFC PATCH] set TASK_TRACED before arch_ptrace code to fix a race

[Roland McGrath]

>  [<a00000010000a9f0>] skip_rbs_switch+0xe0/0x110
>                                 sp=e000000141c9fe30 bsp=e000000141c90cf8
>  [<a000000000010740>] __kernel_syscall_via_break+0x0/0x20
>                                 sp=e000000141ca0000 bsp=e000000141c90cf8
>  [<a0000001000971c0>] ptrace_stop+0xa0/0x3e0
>                                 sp=e00000014716fdb0 bsp=e000000147160ca8
>  [<a000000100097650>] ptrace_notify+0x150/0x1c0
>                                 sp=e00000014716fdb0 bsp=e000000147160c88

If this is a backtrace of a single thread on the same kernel stack, it has
a stack depth of over 84MB.  You still need to follow the path inside
ia64_ptrace_stop() to see how any of this is possible.


Thanks,
Roland
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