suse man page for syscall_rollback

SYSCALL_ROLLBACK(9)						   Machine State					       SYSCALL_ROLLBACK(9)

NAME
       syscall_rollback - roll back registers after an aborted system call

SYNOPSIS
       void syscall_rollback(struct task_struct * task, struct pt_regs * regs);

ARGUMENTS
       task
	   task of interest, must be in system call exit tracing

       regs

	   task_pt_regs of task

DESCRIPTION
       It's only valid to call this when task is stopped for system call exit tracing (due to TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT), after
       tracehook_report_syscall_entry returned nonzero to prevent the system call from taking place.

       This rolls back the register state in regs so it's as if the system call instruction was a no-op. The registers containing the system call
       number and arguments are as they were before the system call instruction. This may not be the same as what the register state looked like
       at system call entry tracing.

Kernel Hackers Manual 2.6.					     July 2010						       SYSCALL_ROLLBACK(9)