Re: [PATCH 07/12] perf_events: add LBR software filter support for Intel X86

From: Andi Kleen
Date: Fri Oct 07 2011 - 11:09:20 EST

> if (kernel_ip(addr) || !test_tsk_thread_flag(current, TIF_IA32))

That's not good, a 64bit process can do 32bit syscalls.

The only fully working way is to check the code segment, unfortunately
that requires checking the LDT to be fully correct :-(

In 2.4 we had some code for that if you want to copy, but it disappeared

ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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