Messages in this thread | | | Subject | Re: [PATCH RFC 2/8] blackfin: implement syscall restart generically | From | Jonas Bonn <> | Date | Wed, 26 Oct 2011 08:16:41 +0200 |
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On Tue, 2011-10-25 at 20:01 -0400, Mike Frysinger wrote: > On Sun, Oct 23, 2011 at 06:19, Jonas Bonn <jonas@southpole.se> wrote: > > --- a/arch/blackfin/include/asm/syscall.h > > +++ b/arch/blackfin/include/asm/syscall.h > > > > static inline long > > syscall_get_nr(struct task_struct *task, struct pt_regs *regs) > > { > > - return regs->p0; > > + return regs->orig_p0; > > } > > i'm not sure this is correct. we set the orig_p0 to -1 when forcing > the syscall to go to restart. shouldn't syscall_get_nr() still return > the right value ?
No, syscall_get_nr is only valid while processing a syscall (should return -1 otherwise) and the syscall processing is effectively finished once you've handled the restart requirements so returning -1 at that point makes sense... patch 1/8 relies on that fact.
> > > syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, > > int error, long val) > > { > > - regs->r0 = error ? -error : val; > > + regs->r0 = error ? error : val; > > } > > this fix is unrelated (and unmentioned in the changelog). i also see > a bunch of other arches doing this. so we should pull this change out > into a dedicated patchset, and fix all the arches at the same time.
Agreed, this should go into a separate patch. It's true that some arches do the negation as above, but those arch's return positive error numbers and indicate syscall error by setting a separate flag. I'll prepare a separate patch for this.
/Jonas
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