Messages in this thread | | | Subject | Re: [PATCH] signal: Unexport sigsuspend() | From | Richard Weinberger <> | Date | Wed, 18 Nov 2015 21:47:22 +0100 |
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Am 18.11.2015 um 21:44 schrieb Andrew Morton: > On Mon, 16 Nov 2015 19:18:21 +0100 Richard Weinberger <richard@nod.at> wrote: > >> sigsuspend() is nowhere used except in signal.c itself, >> so we can mark it static do not pollute the global namespace. >> >> But this patch is more than a boring cleanup patch, >> it fixes a real issue on UserModeLinux. >> UML has a special console driver to display ttys using xterm, >> or other terminal emulators, on the host side. >> Vegard reported that sometimes UML is unable to spawn a xterm >> and he's facing the following warning: >> WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0() >> It turned out that this warning makes absolutely no sense as >> the UML xterm code calls sigsuspend() on the host side, at least it tries. >> But as the kernel itself offers a sigsuspend() symbol the linker choose >> this one instead of the glibc wrapper. Interestingly this code used to >> work since ever but always blocked signals on the wrong side. >> Some recent kernel change made the WARN_ON() trigger and uncovered the bug. >> > > So we don't know what caused this or when it started happening. hrm. > I guess I'll stick a cc:stable in there as it's likely to affect 4.3 > and perhaps earlier, OK?
I fear it has been this way for ever. CC'ing stable is a good idea!
Thanks, //richard
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