Re: [PATCH] um: use POSIX ucontext_t instead of struct ucontext

From: Krzysztof Mazur
Date: Wed Nov 15 2017 - 06:22:27 EST


On Wed, Nov 15, 2017 at 12:15:00PM +0100, Richard Weinberger wrote:
> Am Mittwoch, 15. November 2017, 12:04:16 CET schrieb Krzysztof Mazur:
> > On Wed, Nov 15, 2017 at 11:19:41AM +0100, Richard Weinberger wrote:
> > > Am Mittwoch, 15. November 2017, 11:12:39 CET schrieb Krzysztof Mazur:
> > > > glibc 2.26 removed the 'struct ucontext' to "improve" POSIX compliance
> > > > and break programs, including User Mode Linux. Fix User Mode Linux
> > > > by using POSIX ucontext_t.
> > > >
> > > > This fixes:
> > > >
> > > > arch/um/os-Linux/signal.c: In function 'hard_handler':
> > > > arch/um/os-Linux/signal.c:163:22: error: dereferencing pointer to
> > > > incomplete type 'struct ucontext' mcontext_t *mc = &uc->uc_mcontext;
> > > > arch/x86/um/stub_segv.c: In function 'stub_segv_handler':
> > > > arch/x86/um/stub_segv.c:16:13: error: dereferencing pointer to
> > > > incomplete
> > > > type 'struct ucontext' &uc->uc_mcontext);
> > >
> > > Do all older glibcs have ucontext_t?
> > > Otherwise this patch will break other stuff.
> >
> > Yes, ucontext_t typedef was always available. They changed:
> >
> > typedef struct ucontext { ... } ucontex_t;
> >
> > to
> >
> > typedef struct ucontext_t { ... } ucontex_t;
> >
> > https://sourceware.org/glibc/wiki/Release/2.26#Removal_of_.27struct_ucontext
> > .27
>
> Okay, then we can mark your patch as stable and hope for the best. ;-)

Thanks

Krzysiek