1TASK_CURRENT_SYSCALL(9)          Machine State         TASK_CURRENT_SYSCALL(9)
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NAME

6       task_current_syscall - Discover what a blocked task is doing.
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SYNOPSIS

9       int task_current_syscall(struct task_struct * target, long * callno,
10                                unsigned long args[6], unsigned int maxargs,
11                                unsigned long * sp, unsigned long * pc);
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ARGUMENTS

14       target
15           thread to examine
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17       callno
18           filled with system call number or -1
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20       args[6]
21           filled with maxargs system call arguments
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23       maxargs
24           number of elements in args to fill
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26       sp
27           filled with user stack pointer
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29       pc
30           filled with user PC
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DESCRIPTION

33       If target is blocked in a system call, returns zero with *callno set to
34       the the call's number and args filled in with its arguments. Registers
35       not used for system call arguments may not be available and it is not
36       kosher to use struct user_regset calls while the system call is still
37       in progress. Note we may get this result if target has finished its
38       system call but not yet returned to user mode, such as when it's
39       stopped for signal handling or syscall exit tracing.
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41       If target is blocked in the kernel during a fault or exception, returns
42       zero with *callno set to -1 and does not fill in args. If so, it's now
43       safe to examine target using struct user_regset get calls as long as
44       we're sure target won't return to user mode.
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46       Returns -EAGAIN if target does not remain blocked.
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48       Returns -EINVAL if maxargs is too large (maximum is six).
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52Kernel Hackers Manual 2.6.       November 2011         TASK_CURRENT_SYSCALL(9)
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