Messages in this thread |  | | Date | Thu, 19 Mar 2015 16:10:21 -0700 | | From | David Daney <> | | Subject | Re: [PATCH 3.13.y-ckt 71/80] MIPS: Fix C0_Pagegrain[IEC] support. |
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On 03/19/2015 03:35 PM, Kamal Mostafa wrote: > 3.13.11-ckt17 -stable review patch. If anyone has any objections, please let me know. >
Read the patch commentary. It should only be applied to 3.17 and later.
So: NACK.
> ------------------ > > From: David Daney <david.daney@cavium.com> > > commit 9ead8632bbf454cfc709b6205dc9cd8582fb0d64 upstream. > > The following commits: > > 5890f70f15c52d (MIPS: Use dedicated exception handler if CPU supports RI/XI exceptions) > 6575b1d4173eae (MIPS: kernel: cpu-probe: Detect unique RI/XI exceptions) > > break the kernel for *all* existing MIPS CPUs that implement the > CP0_PageGrain[IEC] bit. They cause the TLB exception handlers to be > generated without the legacy execute-inhibit handling, but never set > the CP0_PageGrain[IEC] bit to activate the use of dedicated exception > vectors for execute-inhibit exceptions. The result is that upon > detection of an execute-inhibit violation, we loop forever in the TLB > exception handlers instead of sending SIGSEGV to the task. > > If we are generating TLB exception handlers expecting separate > vectors, we must also enable the CP0_PageGrain[IEC] feature. > > The bug was introduced in kernel version 3.17. > > Signed-off-by: David Daney <david.daney@cavium.com> > Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> > Cc: linux-mips@linux-mips.org > Patchwork: http://patchwork.linux-mips.org/patch/8880/ > Signed-off-by: Ralf Baechle <ralf@linux-mips.org> > Signed-off-by: Kamal Mostafa <kamal@canonical.com> > --- > arch/mips/mm/tlb-r4k.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c > index da3b0b9..d04fe4e 100644 > --- a/arch/mips/mm/tlb-r4k.c > +++ b/arch/mips/mm/tlb-r4k.c > @@ -429,6 +429,8 @@ void tlb_init(void) > #ifdef CONFIG_64BIT > pg |= PG_ELPA; > #endif > + if (cpu_has_rixiex) > + pg |= PG_IEC; > write_c0_pagegrain(pg); > } > >
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