Messages in this thread | | | From | Måns Rullgård <> | Subject | Re: [PATCH 1/2] alpha: Remove "strange" OSF/1 fork semantics | Date | Wed, 30 Jul 2014 23:04:20 +0100 |
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Richard Henderson <rth@twiddle.net> writes:
> The assignment to regs->r20 kills the original tls_val input > to the clone syscall, which means that clone can no longer be > restarted with the original inputs. > > We could, perhaps, retain this result for true fork, but OSF/1 > compatibility is no longer important. Note that glibc has never > used the r20 result value, instead always testing r0 vs 0 to > determine the child/parent status.
What effect does this have on OSF/1 compat?
> This failure can be seen in the glibc nptl/tst-eintr* tests. > > Reported-by: Michael Cree <mcree@orcon.net.nz> > Signed-off-by: Richard Henderson <rth@twiddle.net> > --- > arch/alpha/kernel/process.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c > index 1941a07..77028d7 100644 > --- a/arch/alpha/kernel/process.c > +++ b/arch/alpha/kernel/process.c > @@ -278,8 +278,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp, > *childregs = *regs; > childregs->r0 = 0; > childregs->r19 = 0; > - childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */ > - regs->r20 = 0; > stack = ((struct switch_stack *) regs) - 1; > *childstack = *stack; > childstack->r26 = (unsigned long) ret_from_fork; > -- > 1.9.3 >
-- Måns Rullgård mans@mansr.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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