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443Entrepreneur at Siltakatu Solutions Oy
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Jarkko Sakkinen
jarkko
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Jann Horn
jann@infosec.exchangefun Linux fact: because MAP_SHARED|MAP_ANONYMOUS is actually a file-backed mapping under the hood, unmapping part of such a mapping does not discard the data stored in that part:
$ cat mremap.c
#define _GNU_SOURCE
#include <err.h>
#include <stdio.h>
#include <sys/mman.h>
int main(void) {
char *p = mmap(NULL, 0x2000, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
if (p == MAP_FAILED) err(1, "mmap");
p[0x1000] = 'X';
if (munmap(p+0x1000, 0x1000)) err(1, "munmap");
// that 'X' we just wrote... is it gone?
// nope, let's bring it back!
p = mremap(p, 0x1000, 0x2000, MREMAP_MAYMOVE);
if (p == MAP_FAILED) err(1, "mremap");
printf("p[0x1000]='%c'\n", p[0x1000]);
}
$ gcc -o mremap mremap.c
$ ./mremap
p[0x1000]='X'
$
Jarkko Sakkinen
jarkko
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OSNews
osnews@mstdn.socialUS government’s attack on free speech, science, and research is causing a brain drain
How do you create a brain drain and lose your status as eminent destination for scientists and researchers?
The United States seems to be sending out questionnaires to researchers at universities and research institutes outside of the United States, asking them about their political leanings. Dutch universities are strongly advising Dutch researches not to respond to the questionnaire
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Jarkko Sakkinen
jarkkohttps://www.youtube.com/watch?v=ioXT82QwgAo
Vapriikki (https://www.vapriikki.fi/en/) has e.g.,
1. Most extensive video game museum in Finland.
2. Some other tech stuff like the first ever IRC Server in a glass case ;-)
Great place to visit if around here.
#c64 #chiptune
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Jarkko Sakkinen
jarkko
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Jon Seager
jnsgruk@hachyderm.ioThis week Michael Hudson-Doyle of the #Ubuntu Foundations team published a write-up of our experimentation with the `-O3` GCC flag by default in the distribution.
The tl;dr is that we don't yet believe that the change makes sense globally, but there are certainly come packages that would benefit from using the increased optimisation level.
See the post here: https://discourse.ubuntu.com/t/benchmarking-a-distribution-and-some-o3-results/58027
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Jarkko Sakkinen
jarkkoCheap means here something like less than 1000 euros.
E.g., in Intel SGX the latest and greatest are NUC7's from 2018 and for VM based confidential computing there's nothing appropriate.
Shame on you CPU companies!
#arm #intel #amd #cpu
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Mark Dominus
mjd@mathstodon.xyzI'm looking for a job. I have 30 years of experience doing complex systems programming in many languages, most recently Typescript, Haskell, and Python. I learn quickly. I can do advanced mathematics.
In 2024 I helped a company migrate 15,000 customers from another company into their own systems.
In 2023 I helped develop a differential privacy database product written in Haskell.
Before that I helped develop a laboratory information management system that tracked up to 40,000 Covid-19 tests per day.
I live in Philadelphia, Pennsylvania, USA, but I have years of success working remotely, and I am also willing to consider relocation.
Please check out my CV.
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