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Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

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Are there any things in Linux that need to be started over from scratch? (lemmy.ca)

submitted 7 months ago by [email protected] to c/[email protected]

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I'm curious how software can be created and evolve over time. I'm afraid that at some point, we'll realize there are issues with the software we're using that can only be remedied by massive changes or a complete rewrite.

Are there any instances of this happening? Where something is designed with a flaw that doesn't get realized until much later, necessitating scrapping the whole thing and starting from scratch?

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[–] [email protected] 1 points 7 months ago (1 children)

Assembly doesn't have concept of objects.

[–] [email protected] 1 points 7 months ago (1 children)

It does very much have the concept of objects as in subject, verb, object of operations implemented in assembly.

As in who (user foo) tried to do what (open/read/write/delete/...) to which object (e.g. which socket, which file, which Linux namespace, which memory mapping,...).

[–] [email protected] 1 points 7 months ago* (last edited 7 months ago) (1 children)

implemented in assembly.

Indeed. Assembly is(can be) used to implement them.

As in who (user foo) tried to do what (open/read/write/delete/...) to which object (e.g. which socket, which file, which Linux namespace, which memory mapping,...).

Kernel implements it in software(except memory mappings, it is implemented in MMU). There are no sockets, files and namespaces in ISA.

[–] [email protected] 1 points 7 months ago (1 children)

You were the one who brought up assembly.

And stop acting like you don't know what I am talking about. Syscalls implement operations that are called by someone who has certain permissions and operate on various kinds of objects. Nobody who wants to debug why that call returned "Permission denied" or "File does not exist" without any detail cares that there is hardware several layers of abstraction deeper down that doesn't know anything about those concepts. Nothing in the hardware forces people to make APIs with bad error reporting.

[–] [email protected] 1 points 7 months ago (1 children)

And why "Permission denied" is bad reporting?

[–] [email protected] 1 points 7 months ago (1 children)

Because if a program dies and just prints strerror(errno) it just gives me "Permission denied" without any detail on which operation had permissions denied to do what. So basically I have not enough information to fix the issue or in many cases even to reproduce it.

[–] [email protected] 0 points 7 months ago* (last edited 7 months ago)

It may just not print anything at all. This is logging issue, not "C based assumption". I wouldn't be surprised if you will call "403 Forbidden" a "C based assumtion" too.

But since we are talking about local program, competent sysadmin can strace program. It will print arguments and error codes.