Hi Ralf,
On Tue, 4 Mar 2003 21:36:05 +0100
Ralf Baechle <ralf@linux-mips.org> wrote:
> On Mon, Mar 03, 2003 at 07:21:37PM +0900, Yoichi Yuasa wrote:
>
> > I found a bug in simulate_ll and simulate_sc.
> > The board that uses ll/sc emulation is not started.
> >
> > When send_sig in these, in order not to operate the value of EPC correctly,
> > simulate_* happens continuously.
> >
> > The previous patches were not perfect, I changed more.
> > Please apply these patches to CVS tree.
>
> As previously mentioned there were some problems with your fix, so I
> wrote an alternative fix which is attached below. It's untested because
> I don't have any ll/sc-less test platform.
I tested ll/sc simulate.
Furthermore, the following patch is also needed.
Thanks,
Yoichi
diff -aruN --exclude=CVS --exclude=.cvsignore linux.orig/arch/mips/kernel/traps.c linux/arch/mips/kernel/traps.c
--- linux.orig/arch/mips/kernel/traps.c Wed Mar 5 12:05:00 2003
+++ linux/arch/mips/kernel/traps.c Thu Mar 6 16:37:40 2003
@@ -173,6 +173,7 @@
}
if (ll_bit == 0 || ll_task != current) {
regs->regs[reg] = 0;
+ compute_return_epc(regs);
return;
}
>
> Ralf
>
> Index: arch/mips/kernel/traps.c
> ===================================================================
> RCS file: /home/cvs/linux/arch/mips/kernel/traps.c,v
> retrieving revision 1.99.2.41
> diff -u -r1.99.2.41 traps.c
> --- arch/mips/kernel/traps.c 10 Feb 2003 22:50:48 -0000 1.99.2.41
> +++ arch/mips/kernel/traps.c 4 Mar 2003 20:32:10 -0000
> @@ -134,13 +134,14 @@
> ll_bit = 0;
> }
> ll_task = current;
> +
> regs->regs[(opcode & RT) >> 16] = value;
>
> compute_return_epc(regs);
> return;
>
> sig:
> - send_sig(signal, current, 1);
> + force_sig(signal, current);
> }
>
> static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
> @@ -172,19 +173,21 @@
> }
> if (ll_bit == 0 || ll_task != current) {
> regs->regs[reg] = 0;
> - goto sig;
> + return;
> }
>
> - if (put_user(regs->regs[reg], vaddr))
> + if (put_user(regs->regs[reg], vaddr)) {
> signal = SIGSEGV;
> - else
> - regs->regs[reg] = 1;
> + goto sig;
> + }
> +
> + regs->regs[reg] = 1;
>
> compute_return_epc(regs);
> return;
>
> sig:
> - send_sig(signal, current, 1);
> + force_sig(signal, current);
> }
>
> /*
>
>
--
Yoichi Yuasa
Montavista Software Japan, Inc.
e-mail: yoichi_yuasa@montavista.co.jp
http://www.montavista.co.jp
PHONE: 03-5469-8840 FAX: 03-5469-8841
