From mboxrd@z Thu Jan 1 00:00:00 1970 From: nico@fluxnic.net (Nicolas Pitre) Date: Mon, 22 Jul 2013 14:53:23 -0400 (EDT) Subject: [PATCH 4/4] ARM: set --be8 when linking modules In-Reply-To: <51ED69CA.3030501@codethink.co.uk> References: <1374510833-25716-1-git-send-email-ben.dooks@codethink.co.uk> <1374510833-25716-5-git-send-email-ben.dooks@codethink.co.uk> <20130722170500.GC19639@codeaurora.org> <51ED69CA.3030501@codethink.co.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, 22 Jul 2013, Ben Dooks wrote: > On 22/07/13 18:05, Stephen Boyd wrote: > > On 07/22, 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. > > > > > > > If someone tries to load a be8 module on a non-be8 kernel will it > > still work? Or should we add an extra version magic string in > > asm/module.h to prevent that? > > The ELF header changes the EI_DATA field in the ei_ident from > ELFDATA2LSB to ELFDATA2MSB when compiling so we should be able > to detect these when loading. > > I have not checked to see if the kernel correctly checks for this. > > I do not think it currently checks the ei_flags field for the > EF_ARM_BE8 in ABI 4 and 5. I am not sure if this is really important? If the information is already there and easily accessible, then it should be used. Nicolas