OpenBSD on Zenbleed
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OpenBSD on Zenbleed
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Re: OpenBSD on Zenbleed
#2> On Linux, glibc has AVX-based optimizations for simple functions (string
and memory copies) which will store secrets into the register file which
can be extracted trivially, so the impact on glibc-based systems is
HUGE.
Interesting. I would have expected it to be some amount of worse performance not using AVX. Though perhaps the past throttling effects from AVX-512 and friends made it so it was too complex to manage which instructions to select in BSD.
Re: OpenBSD on Zenbleed
#3> On Linux, glibc has AVX-based optimizations for simple functions (string and memory copies) which will store secrets into the register file which can be extracted trivially, so the impact on glibc-based systems is HUGE. Interesting. I would have expected it to be some amount of worse performance not using AVX. Though perhaps the past throttling effects from AVX-512 and friends made it so it was too complex to manag…
OpenBSD is not a fast system.
Re: OpenBSD on Zenbleed
#4> On Linux, glibc has AVX-based optimizations for simple functions (string and memory copies) which will store secrets into the register file which can be extracted trivially, so the impact on glibc-based systems is HUGE. Interesting. I would have expected it to be some amount of worse performance not using AVX. Though perhaps the past throttling effects from AVX-512 and friends made it so it was too complex to manag…
OpenBSD is not a fast system.
Nor does it needs to. Safety is better than performance anyway
Re: OpenBSD on Zenbleed
#5Worth re-posting Theo's 2007 note about CPU security bugs again:
https://marc.info/?l=openbsd-misc&m=118296441702631&w=2
My hunch is that as they suspected these types of issues is what guided them away from things like AVX and other optimizations.
Re: OpenBSD on Zenbleed
#6Re: OpenBSD on Zenbleed
#7> On Linux, glibc has AVX-based optimizations for simple functions (string and memory copies) which will store secrets into the register file which can be extracted trivially, so the impact on glibc-based systems is HUGE. Interesting. I would have expected it to be some amount of worse performance not using AVX. Though perhaps the past throttling effects from AVX-512 and friends made it so it was too complex to manag…
Full pipe string copies are not a frequent task for any OS.
Re: OpenBSD on Zenbleed
#8> On Linux, glibc has AVX-based optimizations for simple functions (string and memory copies) which will store secrets into the register file which can be extracted trivially, so the impact on glibc-based systems is HUGE. Interesting. I would have expected it to be some amount of worse performance not using AVX. Though perhaps the past throttling effects from AVX-512 and friends made it so it was too complex to manag…
Full pipe string copies are not a frequent task for any OS.
String comparisons are, though.
Re: OpenBSD on Zenbleed
#9> On Linux, glibc has AVX-based optimizations for simple functions (string and memory copies) which will store secrets into the register file which can be extracted trivially, so the impact on glibc-based systems is HUGE. Interesting. I would have expected it to be some amount of worse performance not using AVX. Though perhaps the past throttling effects from AVX-512 and friends made it so it was too complex to manag…
OpenBSD is not a fast system.
configure comes to mind as a great example of this.