xref: /openbmc/linux/arch/um/kernel/skas/syscall.c (revision 87c2ce3b)
1 /*
2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include "linux/sys.h"
7 #include "linux/ptrace.h"
8 #include "asm/errno.h"
9 #include "asm/unistd.h"
10 #include "asm/ptrace.h"
11 #include "asm/current.h"
12 #include "sysdep/syscalls.h"
13 #include "kern_util.h"
14 #include "syscall.h"
15 
16 void handle_syscall(union uml_pt_regs *r)
17 {
18 	struct pt_regs *regs = container_of(r, struct pt_regs, regs);
19 	long result;
20 	int syscall;
21 #ifdef UML_CONFIG_SYSCALL_DEBUG
22   	int index;
23 
24   	index = record_syscall_start(UPT_SYSCALL_NR(r));
25 #endif
26 	syscall_trace(r, 0);
27 
28 	current->thread.nsyscalls++;
29 	nsyscalls++;
30 
31 	/* This should go in the declaration of syscall, but when I do that,
32 	 * strace -f -c bash -c 'ls ; ls' breaks, sometimes not tracing
33 	 * children at all, sometimes hanging when bash doesn't see the first
34 	 * ls exit.
35 	 * The assembly looks functionally the same to me.  This is
36 	 *     gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)
37 	 * in case it's a compiler bug.
38 	 */
39 	syscall = UPT_SYSCALL_NR(r);
40 	if((syscall >= NR_syscalls) || (syscall < 0))
41 		result = -ENOSYS;
42 	else result = EXECUTE_SYSCALL(syscall, regs);
43 
44 	REGS_SET_SYSCALL_RETURN(r->skas.regs, result);
45 
46 	syscall_trace(r, 1);
47 #ifdef UML_CONFIG_SYSCALL_DEBUG
48   	record_syscall_end(index, result);
49 #endif
50 }
51