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Comment · 4 months ago
Comment · 6 months ago
It's a bit ridiculous to imply Tokuyama gets better shinkansen service than Hamamatsu, because it has Nozomi service.

Looking at the schedule towards Tokyo for Monday, April 27th: Tokuyama has: 4 16 car Nozomi trains to Tokyo 19 8 car Kodoma/Sakura trains to Shin-Osaka 9 8 car Kodoma/Sakura to Okayama

Hamamatsu has: 31 16 car Kodoma to Tokyo 19 16 car Hikari to Tokyo

Keep in mind the fastest Kodoma seems to only take around 1 hr 40 mins to Tokyo, and the fastest Hikaru is only 1 hr 20 mins.

I'm sure it's nice getting a 1 seat ride to Tokyo from Tokuyama if you can get on one of the 4 Nozomis, and unfortunate you can't get a one seat ride past Shin-Osaka from Hanamatsu, but the service levels seem pretty proportionate to me.

Comment · 3 years ago
Comment · 3 years ago
For those interested, the key takeaway from this IMO is that by issuing many sequential reads, the memory controller will hold a target row open for an extended amount of time to service the consecutive accesses.

This is in contrast to the original rowhammer attack, which issues accesses such that target rows are repeatedly opened and closed to trigger bitflips in neighboring rows.

By stretching out the row open time to 30ms (!), the authors claim they are able to reliably trigger bitflips with a single row opening in 13% of tested rows at 50°C[1]. Some rows in certain chips can be flipped with access times of under 10ms[2].

At more realistic row open times of 7.8 - 70us, there seems to be a 1/x relationship between row open time and number of activations required, they cumulative amount of time the row needs to be held open for to trigger a flip seems to remain fairly constant (around 50ms total from my very approximate estimations). Note that the attack needs to be executed in under 64 ms total, otherwise the automatic DRAM refresh will reset any progress made.

The authors demonstrate this attack with a userspace program that maps a 1 GB hugepage to be able to directly manipulate the lower 30 physical address bits[3], although they don't seem to provide the row open times they end up being able to achieve in practice.

The attack code itself: https://github.com/CMU-SAFARI/RowPress/blob/main/demonstrati...

https://arxiv.org/pdf/2306.17061.pdf [1] pg 5. obsv. 2 [2] pg 6. obsv. 6 [3] pg 11. sec 6.1

Comment · 3 years ago
Comment · 4 years ago
Comment · 5 years ago
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Comment · 6 years ago
Comment · 6 years ago
Could you expand on this a bit more? That's certainly the impression I have of semver.
Comment · 6 years ago
I'd highly encourage anyone interested in this case to hear the oral arguments for themselves, you can listen to them here: https://www.c-span.org/video/?469263-1/google-v-oracle-ameri...

While I believe that it would be better for society if the court sides with Google, I personally think that APIs can be a creative work, and thus would have copyright protection under the law. However one of Google's arguments is that Oracle is trying to use copyright to acquire a patent-like right, referencing the case of Baker v. Selden[0]. Despite being from 1879(!) I found this case to be especially relevant and I'm quite interested to see how the court will consider it into their opinion.

In his arguments, Oracle's lawyer argues that declaring code is not distinguishable from implementing code and thus deserves all the same copyright protections. As a programmer I find this argument quite unconvincing, as there is clearly a technical distinction in many systems, see: .h files, dynamic linking, etc.

[0] https://en.wikipedia.org/wiki/Baker_v._Selden

Comment · 6 years ago
Comment · 6 years ago
Nope, no support needed. SSLH will proxy SSL traffic to whatever other SSL service you have running (nginx, openvpn, etc.), and send the SSH traffic to openssh. It look like it even supports recognizing plain HTTP traffic as well and proxying it accordingly.

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