| Message ID | 1377639509-22778-15-git-send-email-ben.dooks@codethink.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Aug 27, 2013 at 10:38:24PM +0100, Ben Dooks wrote: > To avoid having to make every text section swap the instruction order > of all instructions, make sure modules are built also built with --be8 > (as is the current kernel final link). > > If we do not do this, we would end up having to swap all instructions > when loading a module, instead of just the instructions that we are > applying ELF relocations to. Someone on one of the previous threads asked about whether we need module vermagic for BE8. I'm a bit hazy on whether this is needed. The interesting scenario would be if someone tried to load a BE32 module into a BE8 kernel or vice versa. Currently the kernel does not seem to check ELF endianness at all either for modules or userspace binaries -- they load get loaded/ fixed up/executed just is if they were native endianness. So BE8 doesn't add any new brokenness here. Fixing all that stuff falls outside the scope of this series. Any thoughts? For this patch though: Reviewed-by: Dave Martin <Dave.Martin@arm.com> Cheers ---Dave > Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> > --- > arch/arm/Makefile | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/Makefile b/arch/arm/Makefile > index 6fd2cea..2c659f9 100644 > --- a/arch/arm/Makefile > +++ b/arch/arm/Makefile > @@ -16,6 +16,7 @@ LDFLAGS := > LDFLAGS_vmlinux :=-p --no-undefined -X > ifeq ($(CONFIG_CPU_ENDIAN_BE8),y) > LDFLAGS_vmlinux += --be8 > +LDFLAGS_MODULE += --be8 > endif > > OBJCOPYFLAGS :=-O binary -R .comment -S > -- > 1.7.10.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 28/08/13 17:38, Dave Martin wrote: > On Tue, Aug 27, 2013 at 10:38:24PM +0100, Ben Dooks wrote: >> To avoid having to make every text section swap the instruction order >> of all instructions, make sure modules are built also built with --be8 >> (as is the current kernel final link). >> >> If we do not do this, we would end up having to swap all instructions >> when loading a module, instead of just the instructions that we are >> applying ELF relocations to. > > Someone on one of the previous threads asked about whether we need > module vermagic for BE8. Don't think so, although we could do this if needed. I would like to get this series merged and then think about updates. > I'm a bit hazy on whether this is needed. The interesting scenario > would be if someone tried to load a BE32 module into a BE8 kernel > or vice versa. > > Currently the kernel does not seem to check ELF endianness at all > either for modules or userspace binaries -- they load get loaded/ > fixed up/executed just is if they were native endianness. I've not tried BE32 binaries on BE8 kernels, although it would probably produce an undefined instruction quite quickly. > So BE8 doesn't add any new brokenness here. Fixing all that stuff > falls outside the scope of this series. think so. > Any thoughts? > > > For this patch though: > > Reviewed-by: Dave Martin<Dave.Martin@arm.com> > > Cheers > ---Dave > >> Signed-off-by: Ben Dooks<ben.dooks@codethink.co.uk> >> --- >> arch/arm/Makefile | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/arch/arm/Makefile b/arch/arm/Makefile >> index 6fd2cea..2c659f9 100644 >> --- a/arch/arm/Makefile >> +++ b/arch/arm/Makefile >> @@ -16,6 +16,7 @@ LDFLAGS := >> LDFLAGS_vmlinux :=-p --no-undefined -X >> ifeq ($(CONFIG_CPU_ENDIAN_BE8),y) >> LDFLAGS_vmlinux += --be8 >> +LDFLAGS_MODULE += --be8 >> endif >> >> OBJCOPYFLAGS :=-O binary -R .comment -S >> -- >> 1.7.10.4 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 6fd2cea..2c659f9 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -16,6 +16,7 @@ LDFLAGS := LDFLAGS_vmlinux :=-p --no-undefined -X ifeq ($(CONFIG_CPU_ENDIAN_BE8),y) LDFLAGS_vmlinux += --be8 +LDFLAGS_MODULE += --be8 endif OBJCOPYFLAGS :=-O binary -R .comment -S
To avoid having to make every text section swap the instruction order of all instructions, make sure modules are built also built with --be8 (as is the current kernel final link). If we do not do this, we would end up having to swap all instructions when loading a module, instead of just the instructions that we are applying ELF relocations to. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> --- arch/arm/Makefile | 1 + 1 file changed, 1 insertion(+)