From: Anshuman Khandual <khandual@linux•vnet.ibm.com>
To: Mahesh J Salgaonkar <mahesh@linux•vnet.ibm.com>
Cc: linuxppc-dev <linuxppc-dev@ozlabs•org>,
Paul Mackerras <paulus@samba•org>,
Anton Blanchard <anton@samba•org>
Subject: Re: [PATCH] powerpc: Fix the corrupt r3 error during MCE handling.
Date: Thu, 11 Jul 2013 11:24:15 +0530 [thread overview]
Message-ID: <51DE4887.6050206@linux.vnet.ibm.com> (raw)
In-Reply-To: <20130710130155.4993.61577.stgit@mars>
On 07/10/2013 06:32 PM, Mahesh J Salgaonkar wrote:
> From: Mahesh Salgaonkar <mahesh@linux•vnet.ibm.com>
>
> During Machine Check interrupt on pseries platform, R3 generally points to
> memory region inside RTAS (FWNMI) area. We see r3 corruption because when RTAS
> delivers the machine check exception it passes the address inside FWNMI area
> with the top most bit set. This patch fixes this issue by masking top two bit
> in machine check exception handler.
>
> Signed-off-by: Mahesh Salgaonkar <mahesh@linux•vnet.ibm.com>
> ---
> arch/powerpc/platforms/pseries/ras.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
> index 7b3cbde..721c058 100644
> --- a/arch/powerpc/platforms/pseries/ras.c
> +++ b/arch/powerpc/platforms/pseries/ras.c
> @@ -287,6 +287,9 @@ static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
> unsigned long *savep;
> struct rtas_error_log *h, *errhdr = NULL;
>
> + /* Mask top two bits */
> + regs->gpr[3] &= ~(0x3UL << 62);
We need to replace this "62" with a shift macro specifying the significance
of these top two address bits in the real mode.
next prev parent reply other threads:[~2013-07-11 5:54 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-10 13:02 [PATCH] powerpc: Fix the corrupt r3 error during MCE handling Mahesh J Salgaonkar
2013-07-10 14:11 ` Aneesh Kumar K.V
2013-07-11 4:34 ` Mahesh Jagannath Salgaonkar
2013-07-11 4:42 ` Benjamin Herrenschmidt
2013-07-11 5:54 ` Anshuman Khandual [this message]
2013-07-15 6:06 ` Aneesh Kumar K.V
2013-07-15 6:18 ` Anshuman Khandual
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