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    uml: stop saving process FP state · 42daba31
    Jeff Dike 提交于
    Throw out a lot of code dealing with saving and restoring floating-point
    state.  In skas mode, where processes run in a restoring floating-point state
    on kernel entry and exit is pointless.
    
    This eliminates most of arch/um/os-Linux/sys-{i386,x86_64}/registers.c.  Most
    of what remained is now arch-indpendent, and can be moved up to
    arch/um/os-Linux/registers.c.  Both arches need the jmp_buf accessor
    get_thread_reg, and i386 needs {save,restore}_fp_regs because it cheats during
    sigreturn by getting the fp state using ptrace rather than copying it out of
    the process sigcontext.
    
    After this, it turns out that arch/um/include/skas/mode-skas.h is almost
    completely unneeded.  The declarations in it are variables which either don't
    exist or which don't have global scope.  The one exception is
    kill_off_processes_skas.  If that's removed, this header can be deleted.
    
    This uncovered a bug in user.h, which wasn't correctly making sure that a
    size_t definition was available to both userspace and kernelspace files.
    Signed-off-by: NJeff Dike <jdike@linux.intel.com>
    Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
    42daba31
user.h 906 字节