oss-sec mailing list archives
Re: Intel hyper-threading security issues
From: Seth Arnold <seth.arnold () canonical com>
Date: Fri, 22 Jun 2018 12:26:07 -0700
On Fri, Jun 22, 2018 at 02:08:03PM +1000, Michael Ellerman wrote:
See the script below for example, which shows CPUs grouped by core.
#!/usr/bin/python3 import os import glob by_core = {} for path in glob.iglob('/sys/devices/system/cpu/cpu*/topology/core_id'): num = int(path.split('/')[5].replace('cpu', '')) core_id = int(open(path).read(), 10) by_core.setdefault(core_id, []).append(num) for core in sorted(by_core.keys()): print('%d: %s' % (core, ', '.join([str(s) for s in sorted(by_core[core])])))
Note that this gives misleading results on multi-socket systems: 0: 0, 8, 16, 24 1: 1, 9, 17, 25 2: 2, 10, 18, 26 3: 3, 11, 19, 27 4: 4, 12, 20, 28 5: 5, 13, 21, 29 6: 6, 14, 22, 30 7: 7, 15, 23, 31 This system has two sockets, eight cores per socket, two threads per core. Solar's cpuinfo reports; $ ./cpuinfo Found 32 logical processors across 16 physical cores Thanks
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- Intel hyper-threading security issues Loganaden Velvindron (Jun 19)
- Re: Intel hyper-threading security issues Georgi Guninski (Jun 20)
- Re: Intel hyper-threading security issues Stuart Henderson (Jun 21)
- Re: Intel hyper-threading security issues Lukas Odzioba (Jun 21)
- Re: Intel hyper-threading security issues Lukas Odzioba (Jun 21)
- Re: Intel hyper-threading security issues Sven Schwedas (Jun 21)
- Re: Intel hyper-threading security issues Solar Designer (Jun 21)
- Re: Intel hyper-threading security issues Michael Ellerman (Jun 22)
- Re: Intel hyper-threading security issues Solar Designer (Jun 22)
- Re: Intel hyper-threading security issues Seth Arnold (Jun 22)
- Re: Intel hyper-threading security issues Peter Kjellström (Jun 23)
- Re: Intel hyper-threading security issues Stuart Henderson (Jun 21)
- Re: Intel hyper-threading security issues Lukas Odzioba (Jun 21)
- Re: Intel hyper-threading security issues Georgi Guninski (Jun 20)
- Re: Intel hyper-threading security issues Gordon Tetlow (Jun 21)