On Tue, Oct 6, 2020 at 8:57 PM Aurélien Aptel <aaptel@xxxxxxxx> wrote: > > Hi Ronnie, > > Ronnie Sahlberg <lsahlber@xxxxxxxxxx> writes: > > Some calls that set attributes, like utimensat(), are not supposed to return > > -EINTR and thus do not have handlers for this in glibc which causes us > > to leak -EINTR to the applications which are also unprepared to handle it. > > EINTR happens when the task receives a signal right? > > https://www.gnu.org/software/libc/manual/html_node/Interrupted-Primitives.html > > Given what you said and what the glibc doc reads it seems like the fix > should go in glibc. Otherwise we need to care about every single syscall. glibc have handling for EINTR in most places, but not in for example utimensat() because this function is not supposed to be able to return this error. Similarly we have functions like chmod and chown that also come into cifs.ko via the same entrypoint: cifs_setattr() I think all of these "update inode data" are never supposed to be interruptible since they were classically just updating the in-memory inode and the thread would never hit d-state. Anyway, for these functions EINTR is not a valid return code so I think we should take care to not return it. Even if we change glibc adn the very very thin wrapper for this functions there are applications that might call the systemcall directly or via a different c-library. > > Cheers, > -- > Aurélien Aptel / SUSE Labs Samba Team > GPG: 1839 CB5F 9F5B FB9B AA97 8C99 03C8 A49B 521B D5D3 > SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg, DE > GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 247165 (AG München)
