static int vsyscall_seccomp(struct task_struct *tsk, int syscall_nr)
{
if (!seccomp_mode(&tsk->seccomp))
return 0;
task_pt_regs(tsk)->orig_ax = syscall_nr;
task_pt_regs(tsk)->ax = syscall_nr;
return __secure_computing(syscall_nr);
}
/*
* Notification of system call entry/exit
* - triggered by current->work.syscall_trace
*/
asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
{
user_exit();
current_thread_info()->syscall = syscall;
if (test_thread_flag(TIF_SYSCALL_TRACE)) {
if (tracehook_report_syscall_entry(regs))
return -1;
syscall = current_thread_info()->syscall;
}
#ifdef CONFIG_SECCOMP
if (unlikely(test_thread_flag(TIF_SECCOMP))) {
int ret, i;
struct seccomp_data sd;
unsigned long args[6];
sd.nr = syscall;
sd.arch = syscall_get_arch();
syscall_get_arguments(current, regs, 0, 6, args);
for (i = 0; i < 6; i++)
sd.args[i] = args[i];
sd.instruction_pointer = KSTK_EIP(current);
ret = __secure_computing(&sd);
if (ret == -1)
return ret;
syscall = current_thread_info()->syscall;
}
#endif
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_enter(regs, regs->regs[2]);
audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
regs->regs[6], regs->regs[7]);
/*
* Negative syscall numbers are mistaken for rejected syscalls, but
* won't have had the return value set appropriately, so we do so now.
*/
if (syscall < 0)
syscall_set_return_value(current, regs, -ENOSYS, 0);
return syscall;
}
/*
* Returns the syscall nr to run (which should match regs->orig_ax) or -1
* to skip the syscall.
*/
static long syscall_trace_enter(struct pt_regs *regs)
{
u32 arch = in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
struct thread_info *ti = current_thread_info();
unsigned long ret = 0;
bool emulated = false;
u32 work;
if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
BUG_ON(regs != task_pt_regs(current));
work = ACCESS_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY;
if (unlikely(work & _TIF_SYSCALL_EMU))
emulated = true;
if ((emulated || (work & _TIF_SYSCALL_TRACE)) &&
tracehook_report_syscall_entry(regs))
return -1L;
if (emulated)
return -1L;
#ifdef CONFIG_SECCOMP
/*
* Do seccomp after ptrace, to catch any tracer changes.
*/
if (work & _TIF_SECCOMP) {
struct seccomp_data sd;
sd.arch = arch;
sd.nr = regs->orig_ax;
sd.instruction_pointer = regs->ip;
#ifdef CONFIG_X86_64
if (arch == AUDIT_ARCH_X86_64) {
sd.args[0] = regs->di;
sd.args[1] = regs->si;
sd.args[2] = regs->dx;
sd.args[3] = regs->r10;
sd.args[4] = regs->r8;
sd.args[5] = regs->r9;
} else
#endif
{
sd.args[0] = regs->bx;
sd.args[1] = regs->cx;
sd.args[2] = regs->dx;
sd.args[3] = regs->si;
sd.args[4] = regs->di;
sd.args[5] = regs->bp;
}
ret = __secure_computing(&sd);
if (ret == -1)
return ret;
}
#endif
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_enter(regs, regs->orig_ax);
do_audit_syscall_entry(regs, arch);
return ret ?: regs->orig_ax;
}
