Re: Strange Linux behaviour with blocking syscalls and stop signals+SIGCONT

From: Manfred Spraul
Date: Tue Jul 04 2006 - 15:01:52 EST


Michael Kerrisk wrote:

c) The Linux baehviour has been arbitrary across kernel versions and system calls. In particular, the following system calls showed this behaviour in earlier kernel versions, but then the behaviour was changed without forewarning and (AFAIK) without subsequent complaint:

[snip]

* msgsnd() and msgrcv() in kernels before 2.6.9.

That was my change - and I even forgot to mention it in the changelog (hiding in shame):
I replaced -EINTR with -ERESTARTNOHAND.
That hides signals that are handled in the kernel from user space - probably what we want.

Michael: Could you replace the EINTR in inotify.c with ERESTARTNOHAND? That should prevent the kernel from showing the signal to user space.
I'd guess that most instances of EINTR are wrong, except in device drivers: It means we return from the syscall, even if the signal handler wants to restart the system call.

--
Manfred
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