1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
/*
* Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
#include <stddef.h>
#include <signal.h>
#include <linux/compiler.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));
}
|
