From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Vignesh Raghavendra <vigneshr@ti.com>,
Tudor Ambarus <Tudor.Ambarus@microchip.com>,
Richard Weinberger <richard@nod.at>,
stable@vger.kernel.org, Marek Vasut <marek.vasut@gmail.com>,
Boris Brezillon <boris.brezillon@collabora.com>,
linux-mtd@lists.infradead.org,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
Brian Norris <computersforpeace@gmail.com>,
David Woodhouse <dwmw2@infradead.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] mtd: spear_smi: Fix nonalignment not handled in memcpy_toio
Date: Tue, 22 Oct 2019 11:47:35 +0200 [thread overview]
Message-ID: <20191022114735.0321864e@xps13> (raw)
In-Reply-To: <20191022092619.GQ25745@shell.armlinux.org.uk>
Hi Russell,
Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote on Tue, 22
Oct 2019 10:26:19 +0100:
> On Tue, Oct 22, 2019 at 11:17:07AM +0200, Miquel Raynal wrote:
> > Hi Russell,
> >
> > Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote on Tue, 22
> > Oct 2019 09:26:43 +0100:
> >
> > > On Fri, Oct 18, 2019 at 04:36:43PM +0200, Miquel Raynal wrote:
> > > > Any write with either dd or flashcp to a device driven by the
> > > > spear_smi.c driver will pass through the spear_smi_cpy_toio()
> > > > function. This function will get called for chunks of up to 256 bytes.
> > > > If the amount of data is smaller, we may have a problem if the data
> > > > length is not 4-byte aligned. In this situation, the kernel panics
> > > > during the memcpy:
> > > >
> > > > # dd if=/dev/urandom bs=1001 count=1 of=/dev/mtd6
> > > > spear_smi_cpy_toio [620] dest c9070000, src c7be8800, len 256
> > > > spear_smi_cpy_toio [620] dest c9070100, src c7be8900, len 256
> > > > spear_smi_cpy_toio [620] dest c9070200, src c7be8a00, len 256
> > > > spear_smi_cpy_toio [620] dest c9070300, src c7be8b00, len 233
> > > > Unhandled fault: external abort on non-linefetch (0x808) at 0xc90703e8
> > > > [...]
> > > > PC is at memcpy+0xcc/0x330
> > >
> > > I need the full oops if you want me to comment on this.
> >
> > FYI, I ran the dd command within a for loop, incrementing the block size
> > (bs) by one byte, if failed with bs=6.
> >
> > Disabling WB_MODE (burst mode) does not change anything.
> >
> > Adding a wmb() right after the memcpy_toio() prevents the fault.
>
> Thanks. Can you check what the result of the write buffer test earlier
> in the kernel boot is?
>
> CPU: Testing write buffer coherency: ...
>
> ?
CPU: Testing write buffer coherency: ok
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/
WARNING: multiple messages have this Message-ID (diff)
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Vignesh Raghavendra <vigneshr@ti.com>,
Tudor Ambarus <Tudor.Ambarus@microchip.com>,
Richard Weinberger <richard@nod.at>,
stable@vger.kernel.org, Marek Vasut <marek.vasut@gmail.com>,
Boris Brezillon <boris.brezillon@collabora.com>,
linux-mtd@lists.infradead.org,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
Brian Norris <computersforpeace@gmail.com>,
David Woodhouse <dwmw2@infradead.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] mtd: spear_smi: Fix nonalignment not handled in memcpy_toio
Date: Tue, 22 Oct 2019 11:47:35 +0200 [thread overview]
Message-ID: <20191022114735.0321864e@xps13> (raw)
In-Reply-To: <20191022092619.GQ25745@shell.armlinux.org.uk>
Hi Russell,
Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote on Tue, 22
Oct 2019 10:26:19 +0100:
> On Tue, Oct 22, 2019 at 11:17:07AM +0200, Miquel Raynal wrote:
> > Hi Russell,
> >
> > Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote on Tue, 22
> > Oct 2019 09:26:43 +0100:
> >
> > > On Fri, Oct 18, 2019 at 04:36:43PM +0200, Miquel Raynal wrote:
> > > > Any write with either dd or flashcp to a device driven by the
> > > > spear_smi.c driver will pass through the spear_smi_cpy_toio()
> > > > function. This function will get called for chunks of up to 256 bytes.
> > > > If the amount of data is smaller, we may have a problem if the data
> > > > length is not 4-byte aligned. In this situation, the kernel panics
> > > > during the memcpy:
> > > >
> > > > # dd if=/dev/urandom bs=1001 count=1 of=/dev/mtd6
> > > > spear_smi_cpy_toio [620] dest c9070000, src c7be8800, len 256
> > > > spear_smi_cpy_toio [620] dest c9070100, src c7be8900, len 256
> > > > spear_smi_cpy_toio [620] dest c9070200, src c7be8a00, len 256
> > > > spear_smi_cpy_toio [620] dest c9070300, src c7be8b00, len 233
> > > > Unhandled fault: external abort on non-linefetch (0x808) at 0xc90703e8
> > > > [...]
> > > > PC is at memcpy+0xcc/0x330
> > >
> > > I need the full oops if you want me to comment on this.
> >
> > FYI, I ran the dd command within a for loop, incrementing the block size
> > (bs) by one byte, if failed with bs=6.
> >
> > Disabling WB_MODE (burst mode) does not change anything.
> >
> > Adding a wmb() right after the memcpy_toio() prevents the fault.
>
> Thanks. Can you check what the result of the write buffer test earlier
> in the kernel boot is?
>
> CPU: Testing write buffer coherency: ...
>
> ?
CPU: Testing write buffer coherency: ok
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Richard Weinberger <richard@nod.at>,
David Woodhouse <dwmw2@infradead.org>,
Brian Norris <computersforpeace@gmail.com>,
Marek Vasut <marek.vasut@gmail.com>,
Tudor Ambarus <Tudor.Ambarus@microchip.com>,
Vignesh Raghavendra <vigneshr@ti.com>,
stable@vger.kernel.org,
Boris Brezillon <boris.brezillon@collabora.com>,
linux-mtd@lists.infradead.org,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] mtd: spear_smi: Fix nonalignment not handled in memcpy_toio
Date: Tue, 22 Oct 2019 11:47:35 +0200 [thread overview]
Message-ID: <20191022114735.0321864e@xps13> (raw)
In-Reply-To: <20191022092619.GQ25745@shell.armlinux.org.uk>
Hi Russell,
Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote on Tue, 22
Oct 2019 10:26:19 +0100:
> On Tue, Oct 22, 2019 at 11:17:07AM +0200, Miquel Raynal wrote:
> > Hi Russell,
> >
> > Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote on Tue, 22
> > Oct 2019 09:26:43 +0100:
> >
> > > On Fri, Oct 18, 2019 at 04:36:43PM +0200, Miquel Raynal wrote:
> > > > Any write with either dd or flashcp to a device driven by the
> > > > spear_smi.c driver will pass through the spear_smi_cpy_toio()
> > > > function. This function will get called for chunks of up to 256 bytes.
> > > > If the amount of data is smaller, we may have a problem if the data
> > > > length is not 4-byte aligned. In this situation, the kernel panics
> > > > during the memcpy:
> > > >
> > > > # dd if=/dev/urandom bs=1001 count=1 of=/dev/mtd6
> > > > spear_smi_cpy_toio [620] dest c9070000, src c7be8800, len 256
> > > > spear_smi_cpy_toio [620] dest c9070100, src c7be8900, len 256
> > > > spear_smi_cpy_toio [620] dest c9070200, src c7be8a00, len 256
> > > > spear_smi_cpy_toio [620] dest c9070300, src c7be8b00, len 233
> > > > Unhandled fault: external abort on non-linefetch (0x808) at 0xc90703e8
> > > > [...]
> > > > PC is at memcpy+0xcc/0x330
> > >
> > > I need the full oops if you want me to comment on this.
> >
> > FYI, I ran the dd command within a for loop, incrementing the block size
> > (bs) by one byte, if failed with bs=6.
> >
> > Disabling WB_MODE (burst mode) does not change anything.
> >
> > Adding a wmb() right after the memcpy_toio() prevents the fault.
>
> Thanks. Can you check what the result of the write buffer test earlier
> in the kernel boot is?
>
> CPU: Testing write buffer coherency: ...
>
> ?
CPU: Testing write buffer coherency: ok
next prev parent reply other threads:[~2019-10-22 9:48 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-18 14:36 [PATCH] mtd: spear_smi: Fix nonalignment not handled in memcpy_toio Miquel Raynal
2019-10-18 14:36 ` Miquel Raynal
2019-10-18 14:36 ` Miquel Raynal
2019-10-18 14:49 ` Miquel Raynal
2019-10-18 14:49 ` Miquel Raynal
2019-10-18 14:49 ` Miquel Raynal
2019-10-21 8:01 ` Boris Brezillon
2019-10-21 8:01 ` Boris Brezillon
2019-10-21 8:01 ` Boris Brezillon
2019-10-22 7:44 ` Miquel Raynal
2019-10-22 7:44 ` Miquel Raynal
2019-10-22 7:44 ` Miquel Raynal
2019-10-22 7:51 ` Miquel Raynal
2019-10-22 7:51 ` Miquel Raynal
2019-10-22 7:51 ` Miquel Raynal
2019-10-22 7:52 ` Thomas Petazzoni
2019-10-22 7:52 ` Thomas Petazzoni
2019-10-22 7:52 ` Thomas Petazzoni
2019-10-22 8:26 ` Russell King - ARM Linux admin
2019-10-22 8:26 ` Russell King - ARM Linux admin
2019-10-22 8:26 ` Russell King - ARM Linux admin
2019-10-22 9:17 ` Miquel Raynal
2019-10-22 9:17 ` Miquel Raynal
2019-10-22 9:17 ` Miquel Raynal
2019-10-22 9:26 ` Russell King - ARM Linux admin
2019-10-22 9:26 ` Russell King - ARM Linux admin
2019-10-22 9:26 ` Russell King - ARM Linux admin
2019-10-22 9:47 ` Miquel Raynal [this message]
2019-10-22 9:47 ` Miquel Raynal
2019-10-22 9:47 ` Miquel Raynal
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