xref: /openbmc/linux/arch/um/kernel/skas/syscall.c (revision 82e6fdd6)
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 		goto out;
25 
26 	/* Do the seccomp check after ptrace; failures should be fast. */
27 	if (secure_computing(NULL) == -1)
28 		goto out;
29 
30 	syscall = UPT_SYSCALL_NR(r);
31 	if (syscall >= 0 && syscall <= __NR_syscall_max)
32 		PT_REGS_SET_SYSCALL_RETURN(regs,
33 				EXECUTE_SYSCALL(syscall, regs));
34 
35 out:
36 	syscall_trace_leave(regs);
37 }
38