Le lun. 27 janv. 2025 à 17:41, Arnd Bergmann <a...@arndb.de> a écrit :
> On Mon, Jan 27, 2025, at 15:19, Jérémy Lal wrote: > > Hi, > > > > as discussed in > > https://github.com/libuv/libuv/issues/4678 > > > > and associated build failures > > https://buildd.debian.org/status/package.php?p=libuv1&suite=experimental > > > > It seems that gcc is doing something wrong with the offset parameter of > > preadv, pwritev. > > The same problem happens with optimization levels 0, 1, 2. > > > > The call is made at > > > https://salsa.debian.org/debian/libuv1/-/blob/debian/sid/src/unix/fs.c?ref_type=heads#L494 > > > > To reproduce, just dpkg-buildpackage from > > dget -xu > https://deb.debian.org/debian/pool/main/libu/libuv1/libuv1_1.49.2-1.dsc > > > > I'd be surprised if it concerns only libuv ! > > Please have a look, because the libuv maintainers already tried their > best. > > My strong guess is that this is caused by the implied 64-bit > off_t after the time64 conversion. On i386, the file is > likely still built with a 32-bit off_t. > > In the source line > > p = dlsym(RTLD_DEFAULT, is_pread ? "preadv" : "pwritev"); > > the uv__preadv_or_pwritev() function looks up the preadv() or > pwritev() symbols in glibc, but those expect a 32-bit ("long") > off_t, unlike preadv64() and pwritev64(). > > It appears that https://github.com/libuv/libuv/issues/4532 > attempted to address the issue, but completely misunderstood > the problem, as this was a bug in libuv, not in gcc. > > Ideally the library should avoid using dlsym() here, since > that makes it unportable. If it can't be avoided, it could > try to do something like > > if ((sizeof(long)< sizeof(off_t)) > p = dlsym(RTLD_DEFAULT, is_pread ? "preadv64" : "pwritev64"); > else > p = dlsym(RTLD_DEFAULT, is_pread ? "preadv" : "pwritev"); > Thank you, it works with that. I linked your reply in the upstream issue. This in turn makes it less portable to non-glibc > implementations like musl. > I suppose that unless upstream rewrites some parts, we will just add a patch in the Debian package for now.
