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Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

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Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#111

Post by blibble »

cyphar wrote: post #100
gnulinux wrote: post #51

Earlier quoted context omitted.

Did you read his mail though? He literally answers this criticism. ZFS is not userland so kernel developers are free to break it, just like they can break ext4 and do, and then they fix them. The problem with ZFS is that they can't fix it because it's not part of linux. It's a 3rd party kernel module. So your entire comment reads like a misunderstanding of the situation.

The breakage of ZoL wasn't a side-effect of some big technical change. They literally just made the SIMD enable/disable barriers no longer usable from non-GPL modules (the changed an EXPORT_SYMBOL to EXPORT_SYMBOL_GPL). This means you can't use SIMD-accelerated hashing functions from ZoL -- and there is no way to fix it without hurting performance other than reverting the "license change". And the entire justificatio…

ZoL already worked around it months ago

Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#112

Post by [deleted] »

blibble wrote: post #111
cyphar wrote: post #100

Earlier quoted context omitted.

The breakage of ZoL wasn't a side-effect of some big technical change. They literally just made the SIMD enable/disable barriers no longer usable from non-GPL modules (the changed an EXPORT_SYMBOL to EXPORT_SYMBOL_GPL). This means you can't use SIMD-accelerated hashing functions from ZoL -- and there is no way to fix it without hurting performance other than reverting the "license change". And the entire justificatio…

ZoL already worked around it months ago

[deleted]

Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#113

Post by bane »

tialaramex wrote: post #95
Phemist wrote: post #76

Earlier quoted context omitted.

Off-topic: I can't help but be nosy and check the https version of your page. You seem to be serving a cert with CN=albertstreetantiquescentre.co.uk. Might want to get this looked at :) Edit: Interesting, https://jdebp.uk has the correct cert configured, whereas https://jdebp.uk . serves the cert as mentioned above.

So, firstly don't put a dot at the end. Whatever you might feel about it, the decision in practice was that the host part of the URL is an FQDN but doesn't need a dot at the end. So don't write one there. The browser should probably trim it out when you type in or follow such a link. The Apache web server that the bulk host is using for that site has a fairly poor implementation of HTTPS. It's unsatisfactory in vario…

I wonder how much trouble this causes for censys.io as I believe they pull certs based off of ip address requests.

Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#114

Post by loeg »

inshadows wrote: post #110
loeg wrote: post #40

Earlier quoted context omitted.

For a scary few days he was considering completely breaking the ABI of getrandom(2). If he decides to break interfaces, I don't know that anyone can stop him. It is a downside to the BDFL model. Edit: Breaking ZFS is not a great example — as sibling comment points out, that is a kernel module using kernel-internal APIs, not userspace syscall ABI. The Linux kernel notoriously considers all kernel interfaces unstable.…

I think that it is a upside of BDFL model, unless it's someone incompetent. If you dig deep in the threads you'll find that so far his judgement on what to break or not has always been stellar. As long as you have someone as competent as Linus making the call, BDFL model is perfect. RE getrandom(2): As Linus said several times, we don't break userspace rule does not apply to security bugs. If there's no other way to…

> unless it's someone incompetent.

Unfortunately, Linus is dangerously incompetent at cryptography. As was the case with getrandom(2).

> RE getrandom(2): As Linus said several times, we don't break userspace rule does not apply to security bugs.

I don't think you understand or correctly recall the scenario in which Linus nearly broke getrandom(2). The bug Linus was attempting to fix by breaking getrandom(2) was not a security bug. It was an availability bug, in userspace, caused by broken userspace code deadlocking itself.

Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#115

Post by tylerl »

cyphar wrote: post #100
gnulinux wrote: post #51

Earlier quoted context omitted.

Did you read his mail though? He literally answers this criticism. ZFS is not userland so kernel developers are free to break it, just like they can break ext4 and do, and then they fix them. The problem with ZFS is that they can't fix it because it's not part of linux. It's a 3rd party kernel module. So your entire comment reads like a misunderstanding of the situation.

The breakage of ZoL wasn't a side-effect of some big technical change. They literally just made the SIMD enable/disable barriers no longer usable from non-GPL modules (the changed an EXPORT_SYMBOL to EXPORT_SYMBOL_GPL). This means you can't use SIMD-accelerated hashing functions from ZoL -- and there is no way to fix it without hurting performance other than reverting the "license change". And the entire justificatio…

> ...disliked ZFS because they feel it was designed to be incompatible with Linux...

Ya... That may have just a bit to do with the fact that ZFS is released under a licence that was explicitly designed to be incompatible with Linux.

"Mozilla was selected partially because it is GPL incompatible. That was part of the design when they released OpenSolaris. ... the engineers who wrote Solaris ... had some biases about how it should be released, and you have to respect that."

I can see how that might suggest to Linux maintainers that they are not welcome to use this code. Maybe sorta.

Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#116

Post by tylerl »

michaelmrose wrote: post #54
sheepdestroyer wrote: post #32

Earlier quoted context omitted.

ZFS is not user land. It's kernel code but without being in the kernel. So it has to be built separately and may not even be compliant with GPL (still has to be tested in court AFAIK). Linux's promise to not break userspace is just that, It can not be held responsible for code that should be in the kernel but does not play fair with the license.

It's not that it doesn't play fair. Sun published under a license that made inclusion in the kernel impossible thus the current developers are bound by the same decisions regardless of their opinion on the matter. Furthermore it is profoundly curious to claim that a cross platform filesystem that began life on Solaris and existed for years as a stable complete work before being ported to several OS including Linux be…

Magical indeed. Except that public opinion counts for nothing in copyright law; you have to fight it out in court. Luckily, Sun isn't the kind of company that would file questionable lawsuits against Linux users just to... wait.. wasn't Sun bought by another company?

Well, whoever owns the copyright now, you're probably reasonably safe unless they're a hyper-litigious corporation with deep pockets and an army of lawyers, who see lawsuits about software licensing as a potential source of income....

I mean, what are the chances?

Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#117

Post by michaelmrose »

inshadows wrote: post #109
michaelmrose wrote: post #54

Earlier quoted context omitted.

It's not that it doesn't play fair. Sun published under a license that made inclusion in the kernel impossible thus the current developers are bound by the same decisions regardless of their opinion on the matter. Furthermore it is profoundly curious to claim that a cross platform filesystem that began life on Solaris and existed for years as a stable complete work before being ported to several OS including Linux be…

> The extra work is 10 seconds of work. How childish and unprofessional. While Oracle keeping the code under incompatible license for more than 10 years is totally OK.

What does it have to do with the zfs developers who no longer work for oracle?

Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#118

Post by nailer »

hpcjoe wrote: post #22
nailer wrote: post #6

Here's an example from a decade ago (ifconfig was deprecated then too): - bonded interfaces - with vlans - with multiple IPs If this sounds unrealistic, it was the standard config for index arbitrage at an investment bank. The interfaces, added with distro scripts, will use `ip` and all the interfaces will show up in `ip addr` and work perfectly. ifconfig won't show about half of them - they won't be up, or down, the…

I set up systems in 2009+ that had multiple IPs per phy, bonded, vlan, etc. on linux. I used the config files within the distro (mostly CentOS/RH then) to do this. Worked fine. I developed somewhat better inspection scripting to augment this. My users never had problems with this. I think the distro tooling used ip under the covers. I didn't care one way or the other. Nor did the users.

Yes, that's correct, all distros use ip and have for about 15 years.

Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#119

Post by wtallis »

saagarjha wrote: post #101
wtallis wrote: post #67

Earlier quoted context omitted.

> I already did: socketcall Got anything that applies to modern platforms or recent kernel versions? Also, does socketcall actually have higher overhead than doing a similar dispatch in userspace, or does it just mean you get a cache miss slightly later in the process? (You could try elucidating an actual argument rather than just naming a syscall and assuming that the rest of your argument is obvious.) > And NT does…

Doing things in userspace prevents a context switch, presumably.

Not when it's just prep work before doing an unavoidable syscall.

Re: Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)

#120

Post by p_l »

tylerl wrote: post #115
cyphar wrote: post #100

Earlier quoted context omitted.

The breakage of ZoL wasn't a side-effect of some big technical change. They literally just made the SIMD enable/disable barriers no longer usable from non-GPL modules (the changed an EXPORT_SYMBOL to EXPORT_SYMBOL_GPL). This means you can't use SIMD-accelerated hashing functions from ZoL -- and there is no way to fix it without hurting performance other than reverting the "license change". And the entire justificatio…

> ...disliked ZFS because they feel it was designed to be incompatible with Linux... Ya... That may have just a bit to do with the fact that ZFS is released under a licence that was explicitly designed to be incompatible with Linux. "Mozilla was selected partially because it is GPL incompatible. That was part of the design when they released OpenSolaris. ... the engineers who wrote Solaris ... had some biases about h…

The incompatibility comes from GPL side terms. As for it being intentional, there are only anecdotes, and conflicting ones. When first CDDL sources dropped (DTrace) management expected to see it incorporated into Linux within month
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