Hi, When I tried the test case (ptrace-syscall-ret) on 2.6.26-rc1 kernel, found it always fails, but could pass on previous ones. Here is the result (both in x86 and x86_64 box): [wjhuang@10-182-121-27 single-test]$ ./ptrace-syscall-ret ./ptrace-syscall-ret: PTRACE_CONT, pid 17315, retvalue -1: No such process In the case, a child is created and kept in syscall loop. The parent will trace the syscall and kill the child at last. It seems the child is early exited, but should stay in infinite loop. Is this my misunderstanding or actual regression of kernel? The test case is attached to the mail. Thanks, Wenji