1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 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#include <linux/time-internal.h>
14#include <asm/unistd.h>
15#include <asm/delay.h>
16
17void handle_syscall(struct uml_pt_regs *r)
18{
19	struct pt_regs *regs = container_of(r, struct pt_regs, regs);
20	int syscall;
21
 
 
 
 
 
 
 
 
 
 
 
22	/* Initialize the syscall number and default return value. */
23	UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp);
24	PT_REGS_SET_SYSCALL_RETURN(regs, -ENOSYS);
25
26	if (syscall_trace_enter(regs))
27		goto out;
28
29	/* Do the seccomp check after ptrace; failures should be fast. */
30	if (secure_computing() == -1)
31		goto out;
32
33	syscall = UPT_SYSCALL_NR(r);
34	if (syscall >= 0 && syscall < __NR_syscalls) {
35		unsigned long ret = EXECUTE_SYSCALL(syscall, regs);
36
37		PT_REGS_SET_SYSCALL_RETURN(regs, ret);
38
39		/*
40		 * An error value here can be some form of -ERESTARTSYS
41		 * and then we'd just loop. Make any error syscalls take
42		 * some time, so that it won't just loop if something is
43		 * not ready, and hopefully other things will make some
44		 * progress.
45		 */
46		if (IS_ERR_VALUE(ret) &&
47		    (time_travel_mode == TT_MODE_INFCPU ||
48		     time_travel_mode == TT_MODE_EXTERNAL)) {
49			um_udelay(1);
50			schedule();
51		}
52	}
53
54out:
55	syscall_trace_leave(regs);
56}

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 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#include <linux/time-internal.h>
14#include <asm/unistd.h>
 
15
16void handle_syscall(struct uml_pt_regs *r)
17{
18	struct pt_regs *regs = container_of(r, struct pt_regs, regs);
19	int syscall;
20
21	/*
22	 * If we have infinite CPU resources, then make every syscall also a
23	 * preemption point, since we don't have any other preemption in this
24	 * case, and kernel threads would basically never run until userspace
25	 * went to sleep, even if said userspace interacts with the kernel in
26	 * various ways.
27	 */
28	if (time_travel_mode == TT_MODE_INFCPU ||
29	    time_travel_mode == TT_MODE_EXTERNAL)
30		schedule();
31
32	/* Initialize the syscall number and default return value. */
33	UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp);
34	PT_REGS_SET_SYSCALL_RETURN(regs, -ENOSYS);
35
36	if (syscall_trace_enter(regs))
37		goto out;
38
39	/* Do the seccomp check after ptrace; failures should be fast. */
40	if (secure_computing() == -1)
41		goto out;
42
43	syscall = UPT_SYSCALL_NR(r);
44	if (syscall >= 0 && syscall < __NR_syscalls)
45		PT_REGS_SET_SYSCALL_RETURN(regs,
46				EXECUTE_SYSCALL(syscall, regs));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
47
48out:
49	syscall_trace_leave(regs);
50}