1USER_REGSET_WRITEBAC(9)          Machine State         USER_REGSET_WRITEBAC(9)
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NAME

6       user_regset_writeback_fn - type of writeback function in struct
7       user_regset
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SYNOPSIS

10       typedef int user_regset_writeback_fn(struct task_struct * target,
11                                            const struct user_regset * regset,
12                                            int immediate);
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ARGUMENTS

15       target
16           thread being examined
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18       regset
19           regset being examined
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21       immediate
22           zero if writeback at completion of next context switch is OK
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DESCRIPTION

25       This call is optional; usually the pointer is NULL. When provided,
26       there is some user memory associated with this regset´s hardware, such
27       as memory backing cached register data on register window machines; the
28       regset´s data controls what user memory is used (e.g. via the stack
29       pointer value).
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31       Write register data back to user memory. If the immediate flag is
32       nonzero, it must be written to the user memory so uaccess or
33       access_process_vm can see it when this call returns; if zero, then it
34       must be written back by the time the task completes a context switch
35       (as synchronized with wait_task_inactive). Return 0 on success or if
36       there was nothing to do, -EFAULT for a memory problem (bad stack
37       pointer or whatever), or -EIO for a hardware problem.
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41Kernel Hackers Manual 2.6.         June 2019           USER_REGSET_WRITEBAC(9)