Re: [Qemu-devel] [ARM/FDPIC 1/4] linux-user: ARM-FDPIC: Add configure option to support loading of FDPIC binaries
On 16 April 2018 at 08:57, Christophe Lyon wrote: > On 13/04/2018 17:04, Peter Maydell wrote: >> I think we should just have support for these binaries enabled >> always. Otherwise it will bitrot because nobody compiles it. >> > We are relying on a pre-existing CONFIG_USE_FDPIC, which is currently > never defined. This was introduced by commit 1af02e83 back in 2011, > and indeed if you try to build QEMU with CONFIG_USE_FDPIC, the build fails > because elf_is_fdpic() is not defined. This looks like an excellent demonstration of why we shouldn't hide this feature behind a defaults-to-off #define :-) > Do you suggest removing CONFIG_USE_FDPIC? Yes. Given how old the existing disabled FDPIC code is, I would also suggest you carefully review any of it that you're using... thanks -- PMM
Re: [Qemu-devel] [ARM/FDPIC 1/4] linux-user: ARM-FDPIC: Add configure option to support loading of FDPIC binaries
On 13/04/2018 17:04, Peter Maydell wrote: On 6 April 2018 at 16:17, Christophe Lyon wrote: Adds --enable-fdpic and --disable-fdpic configure options. This feature is disabled by default, that's why it is not described in the "Optional features" help section (which are enabled by default if possible). FDPIC ELF objects are identified with e_ident[EI_OSABI] == ELFOSABI_ARM_FDPIC. If we can identify these ELF objects by looking in the ELF header, why would we want to make this all a configure option that's disabled by default? I think we should just have support for these binaries enabled always. Otherwise it will bitrot because nobody compiles it. We are relying on a pre-existing CONFIG_USE_FDPIC, which is currently never defined. This was introduced by commit 1af02e83 back in 2011, and indeed if you try to build QEMU with CONFIG_USE_FDPIC, the build fails because elf_is_fdpic() is not defined. We tried to conform to this existing support, but maybe it's already bit-rotten? Do you suggest removing CONFIG_USE_FDPIC? Thanks thanks -- PMM .
Re: [Qemu-devel] [ARM/FDPIC 1/4] linux-user: ARM-FDPIC: Add configure option to support loading of FDPIC binaries
On 6 April 2018 at 16:17, Christophe Lyon wrote: > Adds --enable-fdpic and --disable-fdpic configure options. This > feature is disabled by default, that's why it is not described in the > "Optional features" help section (which are enabled by default if > possible). > > FDPIC ELF objects are identified with e_ident[EI_OSABI] == > ELFOSABI_ARM_FDPIC. If we can identify these ELF objects by looking in the ELF header, why would we want to make this all a configure option that's disabled by default? I think we should just have support for these binaries enabled always. Otherwise it will bitrot because nobody compiles it. thanks -- PMM
