Hi all- I've spent a bunch of time cleaning up the x86 vdso implementation. In linux-next (via tip/x86/vdso), there is a build-time helper vdso2c that takes a .so.dbg file and generates a .c file that describes the vdso image. That helper can extract symbols, find the alternative patching instructions, check for undefined symbols, fully strip the image, and set up a nice data structure that contains pretty much all of the information needed to map the vdso. The helper and the linker script know how to set up any number of pages immediately after the vdso mapping that can be referenced (in a pc-relative manner) from the vdso to do useful things like timing. I'm currently working on further improvements to remove the need for arch_vma_name and such. Would there be interest in trying to unify this stuff across architectures? AFAICT a lot of architectures contain copies of pretty much the same code. Note that I'm talking about real vdsos, not magic pages that are mapped in kernel address space. The latter is awful and should be eliminated whenever possible. I still don't understand why ARM has one of these. --Andy -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
