dfox

22 ms·

271.
by dfox 3y ago
If you are targeting Linux you should probably prefer POSIX IPC to all the funky SysV weirdness involving ftok(3). The same holds for any OS that implements POSIX IPC correctly. Unfortunately, BSD derivates usually have POSIX IPC implemente
272.
by dfox 3y ago
Even the significantly smaller capacitance of some kind of CMOS input will appear as short for some amount of time. In combination with the series termination this will low-pass filter the signal, which is (maybe somewhat counterintuitively
273.
by dfox 3y ago
It is trivial and intentional bug in the presented hackme.c. The strcpy() to stack allocated buffer there serves no useful purpose (one can just call the printf() with argv[1] directly), but is an obvious thing to exploit. Also, W^X would n
274.
by dfox 3y ago
The diagnostic tools are apparently mostly written in Perl, so they come with source code in the ISO. So, there is at least some source code.
275.
by dfox 3y ago
Which is the case for vast majority of RFCs.
276.
by dfox 3y ago
You can probably trigger the behavior of random interleaving even with GIL if you use something other than list or tuple as an argument to list.extend(). CPython special cases list and tuples and copies the contents directly (list_extend_fa
277.
by dfox 3y ago
Code that assumes that something is going to be atomic because of the GIL (or any other implementation detail) is simply broken. If you need something to be atomic you should be explicit about that and use mutex or something.
278.
by dfox 3y ago
NASM has a logical and sane syntax that is both readable and maps directly to the generated instructions, in other words it is designed to be written by hand, not as an convenient intermediate format for the compiler to generate. Contrast t
279.
by dfox 3y ago
MISRA C is total nonsense. If you need that then you should not be using C. Either you can just write the thing in straight assembler while observing the same set of rules and the result will be more readable (or well, COBOL which is more o
280.
by dfox 3y ago
clang produces explicit warning for that exact statement, while gcc do not. But well in embedded space there is the another question of how things like IAR behave, which I'm too lazy to test now.
281.
by dfox 3y ago
On linux the stable API and ABI that you are supposed to use is also just libc. But due to various reasons people think that the libc ABI is less stable than how stable it really is. Edit: NT with its split OS API dll and separate libc is i
282.
by dfox 3y ago
Another stable ABI boundary is anything produced by glibc that can be conceivably placed into memory shared by different unrelated processes (ie. Posix IPC primitives). The requirement for backwards compatibility and architecture variant co
283.
by dfox 3y ago
I would say that for any modern unix implementation mmaped pages are quite significant, as all the read-only copies of libc code, other shared libraries and various mmaped data files (iconv tables, locales, terminfo, gettext catalogs…) are
284.
by dfox 3y ago
In general, no and it will happen when there is something actually written to the page (which will cause a page fault and the kernel will have to somehow materialize the page). This works the same way regardless of how /proc/sys&#
285.
by dfox 3y ago
The whole point of the procedure as designed is to make how the constant was selected irrelevant to the security of the resulting curve. Also you have to consider the historical context. The procedure was originally designed to generate par
286.
by dfox 3y ago
The procedures in Annex A.3.3.1 and A.3.3.2 do not really specify how you are supposed to come up with the SEED value used in the first step ("Choose an arbitrary bit string SEED"). Note that this value is part of the output that
287.
by dfox 3y ago
I'm not entirely convinced that the ninth case is necessarily an miscompilation. My understanding of the standard is that C99 6.7.3 p6 and C11 6.7.3 p7 allows for exactly this behavior. One can argue (as the author does in the linked p
288.
by dfox 3y ago
The issue with the NIST curves is that they were generated from a PRNG with some kind of completely random seed. The conspiracy theory there is that the seed was selected such as to make the curve exploitable for NSA and NSA only. Choosing
289.
by dfox 3y ago
Another issue with luxury watch crowd is that they have truly skewed definition of what is meant by “works”. The primary function of a watch is to keep time with reasonable precision, not to be an overengineered piece of mechanical complexi
290.
by dfox 3y ago
Well, it is certainly a prototype. In the early consumer CD players the whole CD decoding datapath was split into chip with the analog part (servo amplifier, which also produces an error signal that contains the read data) and digital chip
291.
by dfox 3y ago
I meant “standard USB charger” from your pile of random chargers, not the one that RPi Foundation sells. Such a thing hopefully provides the 500mA, that the USB2 port is supposed to deliver.
292.
by dfox 3y ago
In digital circuits the “frequency” when the lumped model breaks down is determined by the slew-rate (ie. spectral content of the edges), not the bitrate/clock frequency. In the electronics hobbyist community there are many cases when
293.
by dfox 3y ago
> I honestly don't know that I'd be able to debug "When all but one wire in a group of wires switch, that one will switch also." in my binary counter's inputs or outputs. The intention of the maxim is to design t
294.
by dfox 3y ago
The standard charger is 2.5W, not 5W, and RPi3 will happily run from that, for RPi4 2.5W is somewhat marginal, but it will still work. I suspect that RPi5 is going to be somewhere around 3W (non-PD USB3). The official RPi specs intentionall
295.
by dfox 3y ago
One pretty popular home alarm brand uses I2C as “the bus” with somewhat ridiculously large cable lengths for what was designed as a board/enclosure level cheap serial bus. It is in no way a sane design, but it seems to work.
296.
by dfox 3y ago
Smalltalk uses ^ for return and _ for assignment (aliased to := in esentially all implementations for obvious practical reasons) because in draft version of ASCII these two characters were ↑ and ←.
297.
by dfox 3y ago
I'm somewhat disturbed by the fact that the list of possible behaviors does not contain equivalent of -xkboption ctrl:swapcaps, ie. swap caps lock and left control.
298.
by dfox 3y ago
And if you care so much about getting your code into the kernel you should consider replying to this: https://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/m... On a related note Christophe Leroy should be applaud
299.
by dfox 3y ago
The fact that this kind of kernel patch is in any way relevant to one's resume is exactly the thing that is getting out of hand. And the author links to his linkedin profile in the footer, and well, the reference to this patch/con
300.
by dfox 3y ago
Except nobody said “I like my code better”. Or even pointed to another issue for OP to fix. See https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-June/24...

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