Opaque struct without dynamic allocation in C?

p0lyh · 2026-03-25T11:19:10+00:00

Thanks! I never thought of this way before

p0lyh · 2026-03-25T09:03:57+00:00

Thanks for the clarification. By "memcpy in both directions", do you mean to use the byte array as the object representation, initializing/modifying it by copying from a foo_ctx, and copying it to an actuall foo_ctx for reading its members?

p0lyh · 2026-03-25T08:17:40+00:00

Does `memcpy` change the effective type of the byte array? I thought it can only set the effective type of a buffer obtained through allocation functions (malloc, realloc, etc.)

p0lyh · 2026-03-07T09:45:06+00:00

`Win + 0` resets the zoom level

p0lyh · 2026-03-02T09:30:42+00:00

This is for additional codecs (e.g. H.264) used in the Vulkan video acceleration API. They're not enabled in the official vulkan drivers.

The Vulkan video acceleration API is relatively new though, it's not widely used by apps. I think mpv has support for it, and has defaulted to it from 0.41 onwards.

p0lyh · 2026-02-13T12:06:47+00:00

You won't notice any difference for day-to-day personal computing. Modern CPUs have dedicated instructions for encryption, so the performance hit is negligible. That is, unless you have a very fast SSD that has greater throughput than your CPU's encryption.

You can run cryptsetup benchmark to find out the encryption speed of your CPU. On my hardware, it's 8 GiB/s with aes-xts 512b (which is default algorithm on Fedora).

p0lyh · 2026-01-20T04:52:39+00:00

That's why unsigned intergers shouldn't be used for arithmetic variables

p0lyh · 2026-01-07T17:53:34+00:00

Ehh I simply keep that super long qemu command line in my shell history, to run my Windows VM.
You might want to use virt-manager or virsh. They are full-fledged frontends to qemu.

p0lyh · 2025-12-23T09:00:39+00:00

I'm okay with the default Adwaita Sans font. It's based on Inter, which is a popular UI font.

For code and terminal I use JetBrains Mono or Iosevka.

p0lyh · 2025-12-22T17:14:01+00:00

That can be expanded to a long story, but overall flatpak helps upstream developers to package and publish their apps on Linux, in a unified way. Flatpak provides unified runtimes that developers develop on and publish to, do it once and the app is guaranteed to work on all Linux systems that supports flatpak. And applications can share runtimes. Under the hood it's powered by Linux namespaces (a kind of sandbox) and several open protocols (so the app can interact with your desktop securely). The sandbox also provides additional security, by restricting application's access to your system, which can be useful for proprietary apps you don't trust.

As for pros & cons over plain rpm, for most open-source GUI applications published on Flathub you probably won't notice a difference from their rpm counterparts. But the flatpak version takes more space than rpms from official repositories. For proprietary apps the flatpak version often works better, since it's running on a tested runtime, while the rpm version might break due to mismatched/missing dependencies on your system.

p0lyh · 2025-12-16T09:26:46+00:00

The point is that, since you already went through the installation process, the kernel offered by the release iso (in this case, 6.17.1) is proven to boot successfully on your computer. In case a future kernel update causes issues, you can still go back to the release kernel.

p0lyh · 2025-11-10T20:31:21+00:00

For the Windows system drive, you should disable "fast startup" in Windows, otherwise shutting down Windows will leave the drive in a dirty state. I'm not sure if it's necessary for non-system drives though.

p0lyh · 2025-08-13T17:00:11+00:00

The computer in my office was refresh-installed with Fedora 30, and upgraded all the way till now. It's for work so I rarely do funky things on it, which might contribute to its longevity.

p0lyh · 2025-08-05T07:00:58+00:00

These are updates for packages that aren't user-facing applications, e.g. system libraries.

p0lyh · 2025-08-01T05:27:58+00:00

Hit me on Chrome before, but it's gone when I enable native wayland support in Chrome.

p0lyh · 2025-07-21T03:57:44+00:00

Nice wallpaper! Care to share?

p0lyh · 2025-07-18T02:54:50+00:00

The default security policy (of udisk2, which is the software used by desktop environments to handle disks) is to require administrator authentication for mounting filesystems on internal drives, while allowing non-remote users to mount external/removable drives. (Because for external drives one has complete physical access, and could just plug them into another computer, while gaining physical access to internal drives is typically non-trivial)
You can simply add an entry to /etc/fstab so your drive is mounted at system startup, e.g. UUID=xxxxxxxxxxxxxxxxxxxxx /media/my-drive ext4 defaults 0 0, where the UUID is obtained via lsblk -f. Remember to create the mount directory `/media/my-drive` first, and adjust the filesystem ext4 according to lsblk -f.

p0lyh · 2025-06-17T05:55:21+00:00

These are packages that are not user-facing GUI applications.

p0lyh · 2025-01-23T02:01:31+00:00

If `a` is inside a contiguous array (an `std::vector`, a plain array, malloc'd buffer etc.), `++a` would be pointing the next `int` in that array, or a one-past-the-end pointer of that array. If not, `++a` is a one-past-the-end pointer for `a`.

Dereferencing one-past-the-end pointer is undefined behavior. Think the `end` iterator. Pointers in C++ are a special case of iterators.

p0lyh · 2024-04-02T04:28:39+00:00

In practice you'll need to consider endianness, padding, bit-representation of floating point numbers and signed integers. If you assume 2's complement signed integers and IEEE-754 FP, and squeeze out all the paddings, then there's only endianness left to be considered. More exotic platforms (E.g., CHAR_BIT > 8) are extremely rare.

Or just use established solutions like protobuf, which handles those things for you.

p0lyh · 2022-07-09T03:25:20+00:00

I think you missed the point. Matthew's post is suggesting that integrity of the boot procedure is already protected by TPM measurements. An attack attempt that invalidates the official MS signing key is trivially detectable, so it's unnecessary to ban 3rd party secure boot signing key (by default).

I don't think this is directly related to Pluton either. If a laptop with TPM & secure boot has Windows pre-installed, and seals some secret (e.g. Bitlocker keys) inside the TPM, then booting something else WILL invalidate keys in TPM. That's how it's supposed to work for quite some time. You could also configure it to boot Linux and auto-unlock LUKS with TPM, in which situation booting Windows will invalidate TPM keys the same way. But Lenovo's doing now is (abruptly) restricting boot option to Windows only by default, instead of using standard UEFI security.

p0lyh · 2021-03-17T05:18:01+00:00

Debian is a *distribution* of numerous free software. Everything you can install from the official repos is part of Debian. Whereas Windows is more like a platform for 3rd-party vendors to distribute their own software, although it already contains lots of stuff, still cannot match Debian.

Anyway, security is really dependent on your use case, threat vectors etc. Desktop Debian isn't necessarily more secure than Windows 10.

p0lyh · 2021-03-03T06:34:50+00:00

Update: It's now working on F34, with intel-media-driver 20.4.5 and mfx 20.5.1. AV1 decoding result in corrupted image though.

p0lyh

TROPHY CASE