/* * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com) * Licensed under the GPL */ #include <stddef.h> #include <signal.h> #include <asm/unistd.h> #include "uml-config.h" #include "sysdep/sigcontext.h" #include "sysdep/faultinfo.h" #include "sysdep/stub.h" /* Copied from sys-x86_64/signal.c - Can't find an equivalent definition * in the libc headers anywhere. */ struct rt_sigframe { char *pretcode; struct ucontext uc; struct siginfo info; }; /* Copied here from <linux/kernel.h> - we're userspace. */ #define container_of(ptr, type, member) ({ \ const typeof( ((type *)0)->member ) *__mptr = (ptr); \ (type *)( (char *)__mptr - offsetof(type,member) );}) void __attribute__ ((__section__ (".__syscall_stub"))) stub_segv_handler(int sig) { struct ucontext *uc; int pid; __asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :); GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA), &uc->uc_mcontext); pid = stub_syscall0(__NR_getpid); stub_syscall2(__NR_kill, pid, SIGUSR1); /* sys_sigreturn expects that the stack pointer will be 8 bytes into * the signal frame. So, we use the ucontext pointer, which we know * already, to get the signal frame pointer, and add 8 to that. */ __asm__ __volatile__("movq %0, %%rsp; movq %1, %%rax ; syscall": : "g" ((unsigned long) container_of(uc, struct rt_sigframe, uc) + 8), "g" (__NR_rt_sigreturn)); }