On Tue, Dec 10, 2013 at 2:36 PM, Alan Modra <amo...@gmail.com> wrote: > On Mon, Dec 09, 2013 at 07:10:23PM -0800, H.J. Lu wrote: >> Linker sets e_type in ELF header to ET_DYN for -pie -Ttext-segment=0xXXX. >> When I added -Ttext-segment=0xXXX, one goal was to load >> small model executable above 4GB on Linux/x86-64, which >> was done with -pie -Ttext-segment=0xXXX. But -pie sets >> e_type in ELF header to ET_DYN and kernel may ignore >> p_vaddr in ELF header to load ET_DYN binary at a random >> address. This patch changes ld to set e_type in ELF header >> to ET_EXEC if the first PT_LOAD segment has non-zero >> p_vaddr. If this is unacceptable as generic ELF change, >> I can make it specific to x86. > > Well, I suppose it's a hack to use ET_DYN for executables in the first > place, so one more hack in the linker hardly matters. Why not just > patch the kernel though? The kernel can look at the first PT_LOAD > header just as easily as the linker, and it's the kernel that is doing > the loading after all. >
Kernel should have some freedom on where to load ET_DYN object. But when -Ttext-segment= is used, programmer expects the executable will be loaded at the specified address. Setting ET_EXEC will guarantee that it will be loaded at that address. -- H.J. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
