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An obscure kernel feature to get more info about dying processes

timetobleed.com

21–30 of 39 posts

Re: An obscure kernel feature to get more info about dying processes

#22
post #5

[deleted]

I don't feel like this is a particularly fair criticism of this post. First, this guy is rooting around in the kernel code for fun. Why are we criticizing this? Second, I've done a fair amount of C programming and mucking about at the OS level, and I wasn't aware of this feature. Maybe that's because most of my production deployment has been on BSD and Solaris, not Linux, but I found the post useful. Third, I didn't…

[deleted]

Re: An obscure kernel feature to get more info about dying processes

#23
post #5

[deleted]

Did you even read some of the other articles on his website?

GCC Optimisations that fail: http://timetobleed.com/gcc-optimization-flag-makes-your-64bi...

Symbol tables on Linux and Mac OS X and how to hook them: http://timetobleed.com/dynamic-linking-elf-vs-mach-o/ http://timetobleed.com/dynamic-symbol-table-duel-elf-vs-mach...

Building a Ruby memory profiler: http://timetobleed.com/string-together-global-offset-tables-... http://timetobleed.com/rewrite-your-ruby-vm-at-runtime-to-ho...

Hooking inlined functions: http://timetobleed.com/hot-patching-inlined-functions-with-x...

He even spoke at DefCon 18: http://vimeo.com/14951625

What have you accomplished? What knowledge have you posted out there for the rest of the world to use?

Re: An obscure kernel feature to get more info about dying processes

#24
post #19

Earlier quoted context omitted.

Sounds like you're annoyed with these folks for discovering something new (to them) and being excited about it in public. What exactly bothers you about that?

[deleted]

If common lisp were obscure and not something that was very common knowledge you would have a point. I had never heard of this ability that he brought out in the open, because of having this posted on HN I now learned something new today, something I can take with me and teach others or use in my daily job.

That in and of itself is fantastic and exactly why I like posts such as the one he made.

Re: An obscure kernel feature to get more info about dying processes

#25
post #23
post #5

[deleted]

Did you even read some of the other articles on his website? GCC Optimisations that fail: http://timetobleed.com/gcc-optimization-flag-makes-your-64bi... Symbol tables on Linux and Mac OS X and how to hook them: http://timetobleed.com/dynamic-linking-elf-vs-mach-o/ http://timetobleed.com/dynamic-symbol-table-duel-elf-vs-mach... Building a Ruby memory profiler: http://timetobleed.com/string-together-global-offset-tabl…

[deleted]

Re: An obscure kernel feature to get more info about dying processes

#26
post #5

[deleted]

Let's go through some of your "points".

The comparison with Torvalds is bizarre. Linus has done an enormous amount of self-promotion (warranted as it is), and even admits to having an ego the size of Joe's biceps. So I don't know what point you're trying to make there.

Next and most importantly. While you (a bastard love-child of Kernighan perhaps) may find this feature banal, a decent number of C programmers aren't familiar with this method; and if they are, they haven't done shit with it. So hating on someone for actually writing free code that makes a bunch of dev's lives easier is, well, just kinda jealous.

Lastly. If a comment like your comment, does, in fact, generate a large number of 'U Mad' replies -- well, that is strong evidence that you are, in fact, mad.

(btw, Joe is not 20 years old. "20" actually refers to the number of women Joe sleeps with in a typical night.)

Re: An obscure kernel feature to get more info about dying processes

#27
post #19

Earlier quoted context omitted.

Sounds like you're annoyed with these folks for discovering something new (to them) and being excited about it in public. What exactly bothers you about that?

[deleted]

Let me make sure I'm understanding you correctly: You're saying that the Linux kernel's ability to easily run arbitrary code when a core dump occurs is fundamental knowledge that all reasonably experienced C programmers (and most HN readers) possess?

Re: An obscure kernel feature to get more info about dying processes

#28
post #25
post #23

Earlier quoted context omitted.

Did you even read some of the other articles on his website? GCC Optimisations that fail: http://timetobleed.com/gcc-optimization-flag-makes-your-64bi... Symbol tables on Linux and Mac OS X and how to hook them: http://timetobleed.com/dynamic-linking-elf-vs-mach-o/ http://timetobleed.com/dynamic-symbol-table-duel-elf-vs-mach... Building a Ruby memory profiler: http://timetobleed.com/string-together-global-offset-tabl…

[deleted]

don't let the door hit you on the way out.

the original author wasn't writing his blog post for you, and he didn't submit it here. the post is at the top of the front page because 26 other HN users found it interesting. i learned something new, and i'm grateful.

Re: An obscure kernel feature to get more info about dying processes

#29
post #8

Earlier quoted context omitted.

If you have the ability to modify or create files in /proc you almost certainly already control the system.

on the other hand, it makes for an interesting rootkit hook.

Which is more dangerous than all the others things you can do as root - like inserting an arbitrary kernel module - how?

Re: An obscure kernel feature to get more info about dying processes

#30
post #8

Earlier quoted context omitted.

on the other hand, it makes for an interesting rootkit hook.

Which is more dangerous than all the others things you can do as root - like inserting an arbitrary kernel module - how?

it's not (yet) an obvious place to look.
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