• Jeff Dike's avatar
    uml: floating point signal delivery fixes · a5f6096c
    Jeff Dike authored
    Handle floating point state in across signals correctly.  UML/i386 needs to
    know whether the host does PTRACE_[GS]ETFPXREGS, so an arch_init_registers
    hook is added, which on x86_64 does nothing.
    
    UML doesn't save and restore floating point registers on kernel entry and
    exit, so they need to be copied between the host process and the sigcontext.
    save_fpx_registers and restore_fpx_registers are added for this purpose.
    save_fp_registers and restore_fp_registers already exist.
    
    There was a bunch of floating point state conversion code in
    arch/um/sys-i386/ptrace.c which isn't needed there, but is needed in signal.c,
    so it is moved over.
    
    The i386 code now distinguishes between fp and fpx state and handles them
    correctly.  The x86_64 code just needs to copy state as-is between the host
    process and the stack.  There are also some fixes there to pass the correct
    address of the floating point state around.
    Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    a5f6096c
ptrace.h 7.46 KB