Recent content on sneela
Foreword This blog post is a summarized and introductory write up of our paper recently accepted at ESORICS 2026 to be presented in Rome, Italy between September 14-16, 2026: “A Systematic Look at Quality-of-Service Feature Effects on Side Channels in AMD SEV-SNP”. Not all the scientific details are mentioned in this blog post. If you’re interested, there’s a full paper…
There’s something charming about owning a physical thing that’s yours . Maybe it’s the hoarder in me that’s talking, but I really like having things that I physically can hold and appreciate. I really like postcards, stamps, coins, and tiny trinkets from various trips and events - it’s an insignia of the memories associated with that moment. Yeah, it’s a stamp.…
I wanted to have a place on the interwebs to synchronize my KeePass2 database across devices without relying on Dropbox or Google Drive. Previously, I used the KeePass Sftp Sync plugin on Linux, a horribly outdated plugin which was last updated in 2017. I had a VPS somewhere in Singapore - the place all my devices synchronized the KDBX file with. Recently, the latest KeePass 2.61 update seems to…
<et cetera> I recently bought a film camera (Minolta X-700) and I’ve been having a lot of fun with it ! I’ve mostly been on Program Select till now, where the camera automagically decides the shutter speed and aperture, which is really nice since one doesn’t get immediate feedback after taking a photo. However, I decided to be more daring and changed from Program Select to…
Got chatgpt to make this command for me: stress-ex: run stress-ng on every logical cpu except the ones listed: so stress-ex 0 2 3 , will run stress-ng -c 1 on every cpu except 0,2,3 #!/bin/sh # stress-ex: run one stress-ng on every logical CPU except listed # usage: stress-ex 0 2 3 command -v taskset >/dev/null 2>& 1 || { echo "taskset required" >&2; exit 1; } command -v stress-ng >/dev/null 2>& 1…
<rant> I had issues with my internet at home where, every once in a while, I noticed really bad ping spikes on all my devices. Sometimes, the entire apartment’s internet just froze for 2-5 seconds and I could not explain why. All of my wireless devices (phone, laptops) would experience this simultaneous freeze. When I started investigating, I noticed that I had really, really bad ping spikes…
Foreword This blog post is a summarized and introductory write up of our paper recently accepted at NDSS 2026 , “Eviction Notice: Reviving and Advancing Page Cache Attacks”. Read the full paper here . Authors: Sudheendra Raghav Neela , Jonas Juffinger , Lukas Maar , Daniel Gruss Artifacts: Github Repository , Zenodo Record (Available, Functional, and Reproducible) CVE-2025-21691:…
Backstory My left wrist & forearm has been hurting quite a bit. Alarmingly so. I haven’t visited the doctor to determine the exact issue, but it’s a pretty obvious sign that the pain starts after some typing — something something correlation and causation. My office’s 100% Cherry Stream keyboard doesn’t cause me much pain; although by the end of the day, it leaves me…
Are you freaking sick of having to calculate the TSC frequency on Intel systems? Me too! Here’s a script that can spit the value out for you: #!/bin/bash cpuid_output = $( cpuid -1 -l 0x15 --raw ) ecx = $( echo " $cpuid_output " | grep -oP 'ecx=0x\K[0-9A-Fa-f]+' ) ebx = $( echo " $cpuid_output " | grep -oP 'ebx=0x\K[0-9A-Fa-f]+' ) eax = $( echo " $cpuid_output " | grep -oP…
Finally! I’ve finished my Master’s degree by finally finishing my Master’s thesis, which I successfully defended on December 12th, 2024. Work done in the thesis systematically analyzes SecureTSC, a feature in AMD’s latest evolution of their confidential computing suite called SEV-SNP . With SecureTSC, SEV-SNP Virtual Machines can securely read the CPU’s Time-Stamp…
Today morning, I was building an AMD SEV virtual machine from source . It requires TianoCore/edk2 , “ the reference implementation of UEFI by Intel ”. While the build script cloned SubhookLib/subhook , I was asked for a Github username and password: This set off alarm bells. After a quick search through the issues in AMD SEV’s repository leading to no result, I decided to go…
Hack available from: https://sourcefoundry.org/hack/ VSCode General Settings: { "editor.fontFamily" : "'Hack', 'IBM Plex Mono', 'Droid Sans Mono', 'monospace', monospace" , "editor.fontSize" : 16 , "editor.rulers" : [ 80 , 120 ], "workbench.colorCustomizations" : { "editorRuler.foreground" : "#333333" }, "editor.minimap.renderCharacters" : false , "editor.guides.bracketPairs" : true ,…
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Are you freaking sick of having to calculate the TSC frequency on AMD systems? Me too! Here’s a one-liner that can spit the value out for you: #!/bin/bash CPUID_OUTPUT = $( cpuid -1 -l 0x1 --raw ) EAX = $( echo " $CPUID_OUTPUT " | grep -oP 'eax=0x\K[0-9A-Fa-f]+' ) FAMILY = $( echo " ${ EAX } " | python3 -c " import sys eax = int(sys.stdin.read().strip(), 16) result = ((eax & 0xFF00000) >>…
A covert channel’s true capacity is calculated as: T = C · (1 + (1 − p)·log 2 (1 − p) + p·log 2 (p)) Raw Capacity [C]: Bit Error Rate [P] (0 - 100): Compute True Capacity [T] = —
Shell script used for multithreaded pngcrush and removing EXIF data, in one fell swoop. Needs: pngcrush & exiftool (can apt install these two), multicrush (no apt, download py file and tweak). Multicrush was made for python2, so it needs some tweaks. I pretty much changed it in a hacky way, ymmv. Biggest tweak is to modify get_brute_range() to the values returned by the -m flag returned by…
<praise> Recently, I found out about the Search and Run a Command function in GIMP , a hidden gem that makes GIMP 10x faster to use because you don’t have to know the location of the specific tool that you’re looking for. Some people around the office apparently didn’t know it as well, so here’s the P.S.A. about the function. Activate this shortcut with the ‘/’…
Download file: bibtex-zotero-minimal.csl To add this: Download the file Zotero > Edit > Preferences > Cite Press the “+” button, and add the downloaded file. Optionally to enable quick copy (Ctrl + Shift + C to copy bib entry): Zotero > Edit > Export Item format: “BibTeX [sneela]’s minimal citation style” You can press Ctrl + Shift + C when a paper is open to copy the…
<et cetera> I DIDN’T KNOW MARKDOWN SUPPORTED FOOTNOTES 1 . Previously, I used to do all this stuff manually. See How System Requests Work and How to Add Your Own SysReq . My markdown looks like: In line 1210, we have `device_initcall`< sup id = "return-footnote-1" >< a href = "#footnote-1" >1</ a ></ sup >. Initcalls are used by the kernel to call functions when the kernel boots. The…
<et cetera> I always wondered how discord launches its desktop application when you click on an invite link from the browser. I’m no full-stack / front-end developer, and my knowledge is very limited when it comes to anything of this sort, so this was a bit of messing around. For example, I tried joining The Programmer’s Hangout , a public discord server about programming. Upon…
<praise> During the past few months, I’ve had many, many conversations about why I use PowerPoint . I’m usually an anti-BigTech kind of person and my dislike of Windows is relatively well known. Thus, my vehement support for a mere presentation software bewilders many I converse with. Why do I still have Windows when I’m very against Microsoft and MANY of their practices ? What…
I needed to add a custom System Request (Sys Req or SysRq) to a linux kernel some time ago. While doing so, I dug deep into how it works and I thought I’d make a quick post about it. Here is a good SuperUser answer about what a SysRq is. You may also know about SysRq via REISUB . This post has three parts: how to raise a SysRq, how SysRq works (looking into kernel code), and how to add your…
<rant> When I’m in a cranky mood sometimes (perhaps due to the lack of food), I find the smallest nuisance EXCEEDINGLY annoying. Unfortunately, yesterday was one of those days where an incredibly infinitesimal inconvenience irrationally irritated I 1 — thick, “chonky” navbars. I’m talking about websites that have fixed navbars that are taller than Doug Dimmadome…
I had to set up multiple machines with slightly varying configs repeatedly. After having to SSH into the machines once in a while and deal with default bash, I realized that I’m seriously not used to the lack of features, aliases 1 , and theme(s) that zsh + oh-my-zsh provide. In fact, I feel slightly less efficient when forced to use just plain bash. Many years ago, I read multiple comments…
<et cetera> As mentioned in I had a brain hiccup with __builtin_parity : Two things: I work with bits often on a daily basis. I’m pretty stupid and my brain occasionally has a hiccup… like it did today. Only the second point is relevant in today’s hella face-palmy ramble. I was working on some sockets code and I needed to log some stuff where nanoseconds mattered. Although I…
<et cetera> I attempted to install something on my Virtual Private Server (VPS) this morning. While cleaning things up (removing old software), I noticed my VPS was becoming exponentially sluggish by the second — I could not type anything or send any signals. This ‘sluggishness’ had happened to me once before on another VPS when the memory became totally occupied. Back then, the…
<et cetera> I needed a tmux script that launched 2 windows, each with 8 panes. I hacked this together very quickly, and I know I’ll need it again in the future or a variation thereof. The image below shows how one of the two windows is numbered: #!/bin/bash # Note to self: You get what you deserve for not writing better code tmux new-session \; \ split-window -h \; \ select -pane -t 1 \; \…
<et cetera> Two things: I work with bits often on a daily basis. I’m pretty stupid and my brain occasionally has a hiccup… like it did today. While looking through one of gcc’s built-in functions, __builtin_parity : Built-in Function: int __builtin_parity (unsigned int x) Returns the parity of x, i.e. the number of 1-bits in x modulo 2. For a brief moment, I forgot what parity…
Foreword If you’ve read my Oct ‘23 ramble, I Made A Game , I partook in a course called Game Design & Development 1 . We had to make two games — one individually and another one in a group. The output of the individual effort is in the aforementioned ramble; the output of the group work is this page. We made Blob: https://roehrichamapparat.itch.io/blob . Music found below at: The…
<rant> I use Zotero , a “free, easy-to-use tool to help you collect, organize, annotate, cite, and share research” (from their website). Zotero is based on Firefox and users can install addons from XPI files. I looking to install a DOM-Inspector to Zotero and I subsequently found zotero-inspector on Github. Upon going to the releases page, I clicked on the xpi file only to see an alert…
<et cetera> I wanted a pastel color palette with 7 colors, one for each day of the week, for LibreOffice Calc around a year ago. After coming across many palettes with 5 colors, I decided to bring together a few colors I saw floating online with inspirations from this pintrest post . Here is the palette in action (looks good with black text): above contains the classes used below -->…
Foreword: This ramble is largely conjecture. I’m writing this based on one (N=1) observation and 0 further testing, i.e. there could be bias in my observation. Read this ramble with this disclaiming foreword in mind. <rant> I used to use Google Keyboard ( Wikipedia: Gboard ) for a long time because that was the default keyboard that came with my Android phone. Around a year or so ago, I…
<et cetera> Caddy ( https://caddyserver.com/ ) is one of the nicest web servers to work with and I’ve been using it since early 2020. </et cetera>
SearXNG For many, many years, I’ve been using DuckDuckGo and I’ve largely been satisfied with it. It’s better than the more famous alternatives and generally respects privacy by not tracking you . That being said, DDG has had some controversy in the past which, to their credit, they resolved in three months. Around some time ago, I started noticing that results were being…
<et cetera> Recently, I came across this now-removed meme and it was so stupid-funny that I could NOT stop laughing. “You’re just a cat, Fluffy. Give up” is now my motto in life.
<et cetera> I don’t really like LinkedIn as a social media. However, I find it cute that the company ID of LinkedIn (the company) on LinkedIn (the website) is 1337 ( leetspeak ) as shown below. Check it out yourself at: https://www.linkedin.com/company/1337/ . Note that the URL automatically redirects to /company/linkedin when you visit it.
If you want to skip the floof and see the settings to tweak on Firefox, go to Settings to Tweak below. <rant> Don’t you love how tiny scroll bars have become??? I sure do! A bunch of other people on lemmy totally love it too! Just search for scrollbars on lemmy and you’ll see the amount of love there is in the tiny-scrollbar-loving community:
<praise> Many moons ago, I found out about one of India’s (digital) gems: the Telecom Service Provider’s (TSP) “Do Not Disturb” registry. Copied directly from Airtel’s DND website : “To avoid unwanted telemarketing calls or SMS, please register your telephone number in Airtel’s Do Not Disturb registry.” And they (Airtel, in my case) make it…
<praise> Back in 2017, my parents got me a One Plus 5 and the one feature that made it truly incredible was ⚡ dash charging ⚡ (20 Watts). Compared to charging over night, I could charge my phone for 20-30 minutes and get nearly 40-60% of electricity juice — this was a game changer. It truly felt fast and was a great quality of life update. Now, I have Warp Charging (65 watts) which gives me 40-70%…
<et cetera> For my Game Design & Development 1 course, I made a (pretty dumb) game in Unity: Blobby’s Adventure - https://sneela.itch.io/blobbys-adventure . There’s nothing really great about the game 1 . Although there is a little bit of a learning curve to using Unity, the Unity Docs are surprisingly good once you get the idea. Most of the assets were made by me on pixilart.com and I…
Introduction This semester I’m taking Futurology , a course taught by Christian Dayé and Roman Prunc , whose “aim is to enable students to understand and critically reflect on different approaches to futurology as well as the methods and techniques that this field of research applies” (from the course description). In this course, we (as the students) play a nearly-semester long…
<rant> Why does the Intel® 64 and IA-32 Architectures Software Developer’s Manual [1] use different fonts 1 at different places and why is it so hard to read being technical documentation? Figure 1: Table 8-1 (Page 8-5, Volume 1, Intel SDM) In figure 1, notice (in some cases, try to notice) the four highlighted differences between:
<et cetera> I needed a magic number recently and stumbled across this website while looking for all possible words made from the hex characters (abcdef): https://www.litscape.com/word_tools/words_made_from.php . Because I know that I will be using it in the future, here is the list for other magic-number seekers: AA AB ACCEDE ACCEDED ACE ACED AD ADD ADDED BAA BAAED BABE BAD BADE BE BEAD BEADED BED…
<et cetera> I recently deleted my swap partition (Debian 12, KDE Plasma) and created a bigger one which led to a change in the UUID of what the swap partition should be. I modified /etc/fstab and restarted the system. Much to my surprise, my boot did not take its usual one second but nearly thirty seconds without any indication of what was making it wait. Guessing that it was something to do with…
<et cetera> I bought my Desktop back in 2019 and I’ve made it a point to clean it roughly every six months. After moving continents, the Desktop stayed put in a not-so-great cardboard box which itself was sat in a pretty dusty environment. The last time I cleaned it was around 1.5 years ago. I recently attempted to clean it and because the before-and-after ‘glow-up’ photos show a…
<et cetera> Recently, I bought a pair of funky indoor flip flops as shown in Figure 1. While on a video call with a friend, they asked me why the flip flops had different designs. After a few seconds of thinking, I replied saying that it was to help differentiate between the left one and the right one. Cue a few seconds of ellipses.
<et cetera> While doing a bit of ISO flashing recently, I was reminded of November 2019 - a dark moment in history (for me). Someone had come over to my room to ask for help installing Ubuntu and being the perpetual IT support person that I am, I begrudgingly said yes. I took my USB stick, plugged it into my desktop to flash Ubuntu 18, and started thinking that the next two hours of my life would…
<rant> Every once in a while, I need to open Windows. Every single time, I find something new to hate more about that Operating System. While I was on a bus sans internet, I needed to take a real quick note of something. I opened sticky notes to find:
<praise> I love Flask ’s documentation, their User’s Guide , and their API Reference . It is, from my personal experience, some of the best newbie-friendly documentation to exist. Many other projects / software / frameworks fall into the hole of making topics overly overwhelming quite quickly. Not Flask. Flask - you get a 10/10 in my books for having really good documentation.…
Foreword This webpage contains 19 MP4 videos that sum up to 6.5 Mb in total. I tried to compress these videos down as much as possible, but that didn’t work too well. This post is an overkill, waste of time, and really has zero reason to be this unnecessarily elaborate. However, considering the amount of effort sunk in (see Sunk Cost Fallacy ), this page has to exist. To go the extra mile,…