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task_current_syscall(9) [suse man page]

TASK_CURRENT_SYSCALL(9) 					   Machine State					   TASK_CURRENT_SYSCALL(9)

NAME

       task_current_syscall - Discover what a blocked task is doing.

SYNOPSIS

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

ARGUMENTS

       target
	   thread to examine

       callno
	   filled with system call number or -1

       args[6]
	   filled with maxargs system call arguments

       maxargs
	   number of elements in args to fill

       sp
	   filled with user stack pointer

       pc
	   filled with user PC

DESCRIPTION

       If target is blocked in a system call, returns zero with *callno set to the the call's number and args filled in with its arguments.
       Registers not used for system call arguments may not be available and it is not kosher to use struct user_regset calls while the system
       call is still in progress. Note we may get this result if target has finished its system call but not yet returned to user mode, such as
       when it's stopped for signal handling or syscall exit tracing.

       If target is blocked in the kernel during a fault or exception, returns zero with *callno set to -1 and does not fill in args. If so, it's
       now safe to examine target using struct user_regset get calls as long as we're sure target won't return to user mode.

       Returns -EAGAIN if target does not remain blocked.

       Returns -EINVAL if maxargs is too large (maximum is six).

Kernel Hackers Manual 2.6.					     July 2010						   TASK_CURRENT_SYSCALL(9)

Check Out this Related Man Page

UTRACE_ATTACH_TASK(9)						  utrace core API					     UTRACE_ATTACH_TASK(9)

NAME

       utrace_attach_task - attach new engine, or look up an attached engine

SYNOPSIS

       struct utrace_engine * utrace_attach_task(struct task_struct * target, int flags, const struct utrace_engine_ops * ops, void * data);

ARGUMENTS

       target
	   thread to attach to

       flags
	   flag bits combined with OR, see below

       ops
	   callback table for new engine

       data
	   engine private data pointer

DESCRIPTION

       The caller must ensure that the target thread does not get freed, i.e. hold a ref or be its parent. It is always safe to call this on
       current, or on the child pointer in a report_clone callback. For most other cases, it's easier to use utrace_attach_pid instead.

UTRACE_ATTACH_CREATE
       Create a new engine. If UTRACE_ATTACH_CREATE is not specified, you only look up an existing engine already attached to the thread.

UTRACE_ATTACH_EXCLUSIVE
       Attempting to attach a second (matching) engine fails with -EEXIST.

UTRACE_ATTACH_MATCH_OPS
       Only consider engines matching ops.

UTRACE_ATTACH_MATCH_DATA
       Only consider engines matching data.

       Calls with neither UTRACE_ATTACH_MATCH_OPS nor UTRACE_ATTACH_MATCH_DATA match the first among any engines attached to target. That means
       that UTRACE_ATTACH_EXCLUSIVE in such a call fails with -EEXIST if there are any engines on target at all.

Kernel Hackers Manual 2.6.					     July 2010						     UTRACE_ATTACH_TASK(9)
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