3 ms·
You're right that it is an example of a case that matches the "basic" description of the conditions to hit the bug, but it probably won't satisfy any of the thr
by DougBTX 9y ago
You're right that it is an example of a case that matches the "basic" description of the conditions to hit the bug, but it probably won't satisfy any of the three conditions when they are considered in detail:
* The files being written probably won't be using memory mapped IO (I'd expect them to use the equivalent of fwrite instead) as the installer won't need to make complex changes to the binaries in the same way that a compiler/linker would
* There will likely be a significant delay between writing the file and running it compared with a build process that uses its own build output as part of the build (even in the build process case, the bug went away for a year, possibly due to an additional delay between the write and execute steps)
* Once the installer has run, the system will probably not be under heavy load (the author was running a highly parallel build on a 24-core machine, and this bug was still only hit in 3% of builds)
Really the earlier post was just misleading, as it implies the bug is much easier to hit than it really is.
- kuschku 9y agoThere are other use cases where this might occur, though – JITs that store JITed binaries on disk. That’s rare (usually there you’d read it back in and execute in your process space), but it’d be at least a second realistic scenario.