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