Source: ispell Version: 3.3.02-6 Severity: wishlist User: [email protected] Usertags: randomness toolchain
Hi! While working on Debian's “reproducible builds” effort [1], we have noticed that buildhash from ispell produces unreproducible .hash files (example [2]). After some investigation, I found out that those undeterministic lines come when "sflaglist" (which is a list of "flagent" structs) is written [3]. The problem is that "sizeof(struct flagent)" is 800 bytes, while the summed up size of the individual members is only 794 bytes [4]. So after those 794 bytes are written, the remaining 6 bytes are read from uninitialized memory (which is undeterministic). Packing the struct (__attribute__ ((__packed__))) would probably help, but is no solution as this would change the size of the .hash files and other tools reading them will probably have problems. The best solution is probably to initialize the whole sflaglist (or each flagent) with zero when it is allocated. Regards, Reiner [1]: https://wiki.debian.org/ReproducibleBuilds [2]: https://packages.debian.org/jessie/lava-server [3]: https://sources.debian.net/src/ispell/3.3.02-6/buildhash.c/#L398 [4]: https://sources.debian.net/src/ispell/3.3.02-6/ispell.h/#L332
signature.asc
Description: OpenPGP digital signature
