1. A method for intercepting a system call in a process executing in user space and for executing processing in relation with the intercepted system call in user space, said method being executed on a computer wherein an operating system kernel supports ptrace system calls including a system trace, said method further comprising: setting up in the executing process a signal handler comprising code for executing operations in relation to the system call to be intercepted; performing in the executing process, before execution of the system call to be intercepted, a self ptrace request which sets a system trace flag and a self trace flag in the kernel; upon execution of the system call, the kernel verifying that the system trace and the self trace flags are set; the kernel saving system call information and sending a signal corresponding to the signal handler conveying system call information; upon reception of the signal by the executing process, starting execution of the signal handler; at the end of signal handler execution, restarting execution in the executing process at the next instruction following the intercepted system call while providing a system call return information.