Posts by ezhes_@mastodon.online
(DIR) Post #ARek1Kxu39BPJGbWka by ezhes_@mastodon.online
2023-01-15T02:07:53Z
0 likes, 0 repeats
@zhuowei @Muirey03 hmm, I suppose you could use it when the kernel maps its objects into your space as RO by taking a COW remap of it yourself? There are some (app sandbox reachable) kernel facilities and drivers that intend to only provide user space RO access to kernel data and being able to blast it would give you some fun effects, though not sure if it's code-execution-fun. No need to chain other nasty techniques either and it's just this one race to win.
(DIR) Post #AWsR8l3wdbBSnjGcJU by ezhes_@mastodon.online
2023-06-20T04:20:24Z
0 likes, 0 repeats
@dougall Predictors are very cool :) Most any conditional predictor more advanced than simple saturating counters requires tagging (i.e. TAGE), which gives a strong signal for unknown branches. If you never enter NT branches into the table and you guess every predictor miss is NT, you can predict all NT branches 100% correctly for no extra cost! This also dovetails very well with next line predictors and trace caches since they only predict what they've seen, so never taken is never predicted!
(DIR) Post #AWsR8nsi9oyrXl2Bii by ezhes_@mastodon.online
2023-06-20T05:54:22Z
0 likes, 0 repeats
@dougall @madcoder ah, that's true, you'll definitely pollute your GHR with a bunch of NTs. Not quite free but still better than what we're doing today.There's always csel abuse :) Corrupt lr with xzr or a special flag (if you don't care too much about code size) and then you'll trap on the next return. Considerably worse but extremely cheap!
(DIR) Post #AnG30KemhiYgzmzmka by ezhes_@mastodon.online
2024-10-22T05:53:51Z
3 likes, 6 repeats
i'm so glad the RISC-V vendor ecosystem has embraced reasonable and easy to remember extension names
(DIR) Post #AnyBNtgnS3m3w7QTxY by ezhes_@mastodon.online
2024-11-12T05:15:08Z
0 likes, 1 repeats
appreciation post for __builtin_dump_struct, beloved by all those who live without functional debuggers https://clang.llvm.org/docs/LanguageExtensions.html#builtin-dump-struct(the builtin takes a C/C++ struct and, through compiler magic, pretty prints it using a function of your choice)
(DIR) Post #AtMkuJy1SmVh1JYIYy by ezhes_@mastodon.online
2025-04-21T17:56:48Z
0 likes, 0 repeats
genuinely baffling that signal completely excludes itself from iCloud backups.Like, if someone restores a full iCloud backup with my keychain, they’ll be able to steal my literal car and rob me blind, but thankfully they won’t be able to…see my signal contacts list?bah. Guess there are some acquaintances I will never message again because I didn’t save off their numbers.
(DIR) Post #AtMkuKZFEOHgsky1a4 by ezhes_@mastodon.online
2025-04-22T22:05:35Z
0 likes, 2 repeats
after much research, I have discovered the only way to backup your messages on Signal for iOS is to add an editor from The Atlantic to all your conversations.