From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave.Martin@arm.com (Dave Martin) Date: Thu, 25 Jul 2013 18:11:30 +0100 Subject: [PATCH] ARM: kdgb: use .inst for data to be assembled as intruction In-Reply-To: <1374763778-5305-2-git-send-email-ben.dooks@codethink.co.uk> References: <1374763778-5305-1-git-send-email-ben.dooks@codethink.co.uk> <1374763778-5305-2-git-send-email-ben.dooks@codethink.co.uk> Message-ID: <20130725171130.GE2546@localhost.localdomain> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jul 25, 2013 at 03:49:38PM +0100, Ben Dooks wrote: > The arch_kgdb_breakpoint() function uses an inline assembly directive > to assemble a specific instruction using .word. This means the linker > will not treat is as an instruction, and therefore incorrectly swap > the endian-ness if running BE8. > > Note, not tested, please comment if this is wrong. > > Signed-off-by: Ben Dooks > --- > arch/arm/include/asm/kgdb.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/include/asm/kgdb.h b/arch/arm/include/asm/kgdb.h > index 48066ce..76227c8 100644 > --- a/arch/arm/include/asm/kgdb.h > +++ b/arch/arm/include/asm/kgdb.h > @@ -41,7 +41,7 @@ > > static inline void arch_kgdb_breakpoint(void) > { > - asm(".word 0xe7ffdeff"); > + asm(".inst 0xe7ffdeff"); Yikes, this isn't going to work in a Thumb kernel. We should make HAVE_ARCH_KGDB depend on !THUMB2_KERNEL until/unless that gets fixed... It looks like the incompatibilities may be more extensive than just this one instruction. For the ARM case, similarly to the other patches, please use the __inst macros from instead of emitting the opcode explicitly. Cheers ---Dave