1/*
2 * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
3 * Licensed under the GPL
4 */
5
6#include <stddef.h>
7#include <signal.h>
8#include <asm/unistd.h>
9#include "uml-config.h"
10#include "sysdep/sigcontext.h"
11#include "sysdep/faultinfo.h"
12#include "sysdep/stub.h"
13
14/* Copied from sys-x86_64/signal.c - Can't find an equivalent definition
15 * in the libc headers anywhere.
16 */
17struct rt_sigframe
18{
19	char *pretcode;
20	struct ucontext uc;
21	struct siginfo info;
22};
23
24/* Copied here from <linux/kernel.h> - we're userspace. */
25#define container_of(ptr, type, member) ({                   \
26	const typeof( ((type *)0)->member ) *__mptr = (ptr); \
27	(type *)( (char *)__mptr - offsetof(type,member) );})
28
29void __attribute__ ((__section__ (".__syscall_stub")))
30stub_segv_handler(int sig)
31{
32	struct ucontext *uc;
33        int pid;
34
35	__asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :);
36	GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
37			      &uc->uc_mcontext);
38
39	pid = stub_syscall0(__NR_getpid);
40	stub_syscall2(__NR_kill, pid, SIGUSR1);
41
42	/* sys_sigreturn expects that the stack pointer will be 8 bytes into
43	 * the signal frame.  So, we use the ucontext pointer, which we know
44	 * already, to get the signal frame pointer, and add 8 to that.
45	 */
46	__asm__ __volatile__("movq %0, %%rsp; movq %1, %%rax ; syscall": :
47                             "g" ((unsigned long)
48                                  container_of(uc, struct rt_sigframe, uc) + 8),
49                             "g" (__NR_rt_sigreturn));
50}
51