> > The *real* fix for this is almost certainly to just get rid of the 64-bit > code entirely, and use the 32-bit code as the base for one single unified > setup.
That would likely break the ABI. x86-64 ABI is completely different here -- no ibcs, just pure x86 ISA. I always thought direct FXSAVE from/to user space to be a cute trick, but yes the exception Suresh noticed makes it lose some of its beauty. > The 32-bit code should be largely a superset of the 64-bit code > anyway, since it has to handle more cases, and does it more cleanly. If you consider compat code 64bit handles as many cases as 32bit. > which isn't exactly pretty, but the memory address generation works fine > in 32-bit code too, and the rex override is easily done with > > #ifdef CONFIG_X86_64 > #define REX64 "rex64/" > #else > #define REX64 "" > #endif > > and then you just use > > REX64 "fxsave" That didn't work on older assemblers. > But maybe I'm missing some reason why it doesn't matter. The 32-bit code > was fixed back in 2003 (commit 5bff44fc272b948a85e893a007d01b9dfb3ad04f 64bit FPU semantics are somewhat different. I don't remember if this particular issue was addressed or not, but I fixed a few shared bugs in a quite different way on 64bit vs 32bit. If anybody wants to change something here don't assume they are the same. >From a cursory look it's probably broken though. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
