1 /* 2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Licensed under the GPL 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/ptrace.h> 8 #include <linux/seccomp.h> 9 #include <kern_util.h> 10 #include <sysdep/ptrace.h> 11 #include <sysdep/ptrace_user.h> 12 #include <sysdep/syscalls.h> 13 14 void handle_syscall(struct uml_pt_regs *r) 15 { 16 struct pt_regs *regs = container_of(r, struct pt_regs, regs); 17 int syscall; 18 19 /* Initialize the syscall number and default return value. */ 20 UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp); 21 PT_REGS_SET_SYSCALL_RETURN(regs, -ENOSYS); 22 23 if (syscall_trace_enter(regs)) 24 return; 25 26 /* Do the seccomp check after ptrace; failures should be fast. */ 27 if (secure_computing(NULL) == -1) 28 return; 29 30 /* Update the syscall number after orig_ax has potentially been updated 31 * with ptrace. 32 */ 33 UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp); 34 syscall = UPT_SYSCALL_NR(r); 35 36 if (syscall >= 0 && syscall <= __NR_syscall_max) 37 PT_REGS_SET_SYSCALL_RETURN(regs, 38 EXECUTE_SYSCALL(syscall, regs)); 39 40 syscall_trace_leave(regs); 41 } 42