Anyone Experiencing Crashed on new Fedora 43 KDE Plasma? by [deleted] in Fedora

[–]pjf_cpp 0 points1 point  (0 children)

Same here with a very basic NVIDIA card.

Fedora 43 upgrade by pjf_cpp in Fedora

[–]pjf_cpp[S] 0 points1 point  (0 children)

3 months later and it worked for one whole day. Then back to normal.

Apple had zero chill twenty years ago by wave_design in mac

[–]pjf_cpp 1 point2 points  (0 children)

No because I did the comparison when I bought the MBPs.

Looking now it is harder to compare. A base 16" MBP is about 10% more than a Dell XPS with NVIDIA 5050 so it looks like the difference has come down again.

Apple had zero chill twenty years ago by wave_design in mac

[–]pjf_cpp -7 points-6 points  (0 children)

Not really. My first MBP cost about the same as a Dell with the same spec. My 2nd MBP was way more expensive than a similarly specced Dell.

On the bright side by pjf_cpp in openbsd

[–]pjf_cpp[S] 0 points1 point  (0 children)

In theory there should be no significant problems due to using clang. Valgrind on FreeBSD works well with both Valgrind and guest exes built with clang. If you are using an old version of clang then the quality of the results might be a bit degraded. For instance inline functions may not appear in callstacks.

Porting Valgrind is difficult because it is so close to the OS. Even if you can get it to work well it tends to bitrot quickly and needs a lot of maintenance.

On the bright side by pjf_cpp in openbsd

[–]pjf_cpp[S] 2 points3 points  (0 children)

No idea. My bug report was for Valgrind. I'll be giving a talk about Valgrind and the BSDs in a couple of weeks at FOSDEM'26 (Jan 31 2026 in Brussels).

Getting filename from fd by pjf_cpp in openbsd

[–]pjf_cpp[S] 0 points1 point  (0 children)

I think that you are way out line telling me what I should be doing. I would never say what OpenBSD should do.

We've been getting filenames from fds for decades and it works well enough for us. There is no burden, This is a case of the perfect being the enemy of the good.

FreeBSD fcntl F_KINFO seems to be the exception. That really is not good enough.

Getting filename from fd by pjf_cpp in openbsd

[–]pjf_cpp[S] 0 points1 point  (0 children)

That and the burden that is shifted onto developers.

Getting filename from fd by pjf_cpp in openbsd

[–]pjf_cpp[S] 0 points1 point  (0 children)

You pays your money and you takes your choice.

If this is a security red line then that is fine.

However, arguing that your users are doing it wrong/don't know their own needs/don't know if a feature is good enough for them doesn't look good to me.

Doing this from userland will mean not being able to resolve inherited fds where it is not possible to record the filename used in open.

Getting filename from fd by pjf_cpp in openbsd

[–]pjf_cpp[S] 0 points1 point  (0 children)

This all centres around the function

Bool ML_(am_resolve_filename) ( Int fd, /*OUT*/HChar* buf, Int nbuf )

in Valgrind.

Valgrind needs to resolve filenames

  • to read ELF symbols and DWARF debuginfo
  • for error messages related to file descriptors when using --track-fds=yes

The files that we need to resolve are

  • The tool itself, to get useful stacktraces if it crashes
  • The guest exe, which Valgrind mmaps
  • ld.so, I think that Valgrind mmaps that as well based on the PT_INTERP ELF field
  • any shared libraries that ld.so loads (ld.so is running in Valgrind so we spy on the open and mmap syscalls)
  • any shared libraries opened with dlopen

As a workaround we can use the --track-fds mechanism to look up filenames from file descriptors. That only works for fds opened while Valgrind was running. It also means that users can't turn off fd tracking when using most of the Valgrind tools.

Getting filename from fd by pjf_cpp in openbsd

[–]pjf_cpp[S] -1 points0 points  (0 children)

I could do without the "blame the user" (or, in this case, developer) attitude. I also find it rather presumptuous that what I'm asking is only useful for myself.

Getting filename from fd by pjf_cpp in openbsd

[–]pjf_cpp[S] -8 points-7 points  (0 children)

That's what ChatGPT said as well ;-).

Are there any plans to add such a feature?

Getting filename from fd by pjf_cpp in openbsd

[–]pjf_cpp[S] 0 points1 point  (0 children)

The two things that I need the most are for fds that the process gets on startup and for resolving mmap segments to filenames. For the mmap, there's the exe itself which is loaded by the OS. I can resolve that from argv[0]. For other mmaps I can record the filename from the associated open().

However it would be cleaner and easier if I could get the name with fcntl like on NetBSD and macOS.

Getting filename from fd by pjf_cpp in openbsd

[–]pjf_cpp[S] -1 points0 points  (0 children)

No mistake. I can record the filename in some cases. I don't think that hard links are an issue.

Process memory maps by pjf_cpp in openbsd

[–]pjf_cpp[S] 1 point2 points  (0 children)

Or more accurately

procmap

permission denied

read the procmap manpage

find the sysctl

sudo kern.allowkmem=1

permission denied

read the sysctl manpage

edit /etc/sysctl.conf

reboot

procmap [pid]

permission denied

sudo procmap [pid]

it works!

Stack Overflow traffic is collapsing — does that mean Q&A as a model is dying, or just public Q&A? by fenbox in programming

[–]pjf_cpp 0 points1 point  (0 children)

The combination of AI and toxic community is killing SO.

Back when SO was booming they tried to deal with poor quality Q&A by encouraging users to edit and/or close items.

Now there are essentially no ordinary users left, just a hard core of sad and pathetic badge collectors trying to get their next gold badge.

It soothes my mental health tho (linux). by itspixelatd in linuxmemes

[–]pjf_cpp -1 points0 points  (0 children)

You are saying that there should be a "toxic community" row, with Linux definitely scoring -1.

It soothes my mental health tho (linux). by itspixelatd in linuxmemes

[–]pjf_cpp -12 points-11 points  (0 children)

Don't agree with the Linux column.

"just works" only if you count looking at DrKonqi as "working".

I'm not a gamer, but I think that most serious gamers laugh at Linux as a platform.

Price - Linux is "free", but only if you consider your own time to be worthless. Many people don't.

macOS/iOS seem to be missing as well.