From: dave.martin@linaro.org (Dave Martin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 2/8] ARM: kexec: ensure new kernel is entered in ARM state
Date: Wed, 24 Aug 2011 11:17:27 +0100 [thread overview]
Message-ID: <20110824101727.GD2078@arm.com> (raw)
In-Reply-To: <alpine.LFD.2.00.1108232126550.20358@xanadu.home>
On Tue, Aug 23, 2011 at 09:28:12PM -0400, Nicolas Pitre wrote:
> On Tue, 23 Aug 2011, Will Deacon wrote:
>
> > Commit 540b5738 ("ARM: 6999/1: head, zImage: Always Enter the kernel in
> > ARM state") mandates that the kernel should be entered in ARM state.
> >
> > If a Thumb-2 kernel kexecs a new kernel image, we need to ensure that
> > we change state when branching to the new code. This patch replaces a
> > mov pc, lr with a bx lr so that we transition to ARM state if need be.
>
> This will break kexec support on ARMv4 targets. No idea if any ARMv4
> target uses kexec though.
Huh, good point -- I was too hasty.
We should use ARM() THUMB() here.
Cheers
---Dave
>
> > Signed-off-by: Will Deacon <will.deacon@arm.com>
> > ---
> > arch/arm/kernel/relocate_kernel.S | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S
> > index 9cf4cbf..0908633 100644
> > --- a/arch/arm/kernel/relocate_kernel.S
> > +++ b/arch/arm/kernel/relocate_kernel.S
> > @@ -57,7 +57,7 @@ relocate_new_kernel:
> > mov r0,#0
> > ldr r1,kexec_mach_type
> > ldr r2,kexec_boot_atags
> > - mov pc,lr
> > + bx lr
> >
> > .align
> >
> > --
> > 1.7.0.4
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2011-08-24 10:17 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-23 21:46 [PATCH v4 0/8] MMU disabling code and kexec fixes Will Deacon
2011-08-23 21:46 ` [PATCH v4 1/8] ARM: proc-v7: disable SCTLR.TE when disabling MMU Will Deacon
2011-08-24 10:15 ` Dave Martin
2011-08-24 11:01 ` Will Deacon
2011-08-25 11:19 ` Dave Martin
2011-08-23 21:46 ` [PATCH v4 2/8] ARM: kexec: ensure new kernel is entered in ARM state Will Deacon
2011-08-24 1:28 ` Nicolas Pitre
2011-08-24 10:17 ` Dave Martin [this message]
2011-08-24 11:13 ` Will Deacon
2011-08-24 10:16 ` Dave Martin
2011-08-23 21:46 ` [PATCH v4 3/8] ARM: lib: add switch_stack function for safely changing stack Will Deacon
2011-08-24 1:07 ` Nicolas Pitre
2011-08-24 10:19 ` Dave Martin
2011-08-24 11:14 ` Will Deacon
2011-08-23 21:46 ` [PATCH v4 4/8] ARM: idmap: add header file for identity mapping functions Will Deacon
2011-08-23 21:46 ` [PATCH v4 5/8] ARM: reset: allow kernelspace mappings to be flat mapped during reset Will Deacon
2011-08-23 21:46 ` [PATCH v4 6/8] ARM: reset: add reset functionality for jumping to a physical address Will Deacon
2011-08-23 21:46 ` [PATCH v4 7/8] ARM: kexec: use arm_machine_reset for branching to the reboot buffer Will Deacon
2011-08-23 21:46 ` [PATCH v4 8/8] ARM: stop: execute platform callback from cpu_stop code Will Deacon
2011-08-24 1:25 ` [PATCH v4 0/8] MMU disabling code and kexec fixes Nicolas Pitre
2011-08-24 10:58 ` Will Deacon
2011-08-24 14:53 ` Nicolas Pitre
2011-08-24 16:59 ` Will Deacon
2011-08-24 17:30 ` Nicolas Pitre
2011-08-24 17:45 ` Will Deacon
2011-08-25 13:16 ` Will Deacon
2011-08-24 12:34 ` Jamie Iles
2011-08-24 12:42 ` Will Deacon
2011-08-24 12:54 ` Jamie Iles
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