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-rw-r--r--arch/um/sys-x86_64/stub_segv.c39
1 files changed, 5 insertions, 34 deletions
diff --git a/arch/um/sys-x86_64/stub_segv.c b/arch/um/sys-x86_64/stub_segv.c
index 3afb590f0072..ced051afc705 100644
--- a/arch/um/sys-x86_64/stub_segv.c
+++ b/arch/um/sys-x86_64/stub_segv.c
@@ -1,51 +1,22 @@
1/* 1/*
2 * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com) 2 * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL 3 * Licensed under the GPL
4 */ 4 */
5 5
6#include <stddef.h>
7#include <signal.h> 6#include <signal.h>
8#include <asm/unistd.h>
9#include "as-layout.h" 7#include "as-layout.h"
10#include "uml-config.h"
11#include "sysdep/sigcontext.h"
12#include "sysdep/faultinfo.h"
13#include "sysdep/stub.h" 8#include "sysdep/stub.h"
14 9#include "sysdep/faultinfo.h"
15/* Copied from sys-x86_64/signal.c - Can't find an equivalent definition 10#include "sysdep/sigcontext.h"
16 * in the libc headers anywhere.
17 */
18struct rt_sigframe
19{
20 char *pretcode;
21 struct ucontext uc;
22 struct siginfo info;
23};
24
25/* Copied here from <linux/kernel.h> - we're userspace. */
26#define container_of(ptr, type, member) ({ \
27 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
28 (type *)( (char *)__mptr - offsetof(type,member) );})
29 11
30void __attribute__ ((__section__ (".__syscall_stub"))) 12void __attribute__ ((__section__ (".__syscall_stub")))
31stub_segv_handler(int sig) 13stub_segv_handler(int sig)
32{ 14{
33 struct ucontext *uc; 15 struct ucontext *uc;
34 int pid;
35 16
36 __asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :); 17 __asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :);
37 GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA), 18 GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA),
38 &uc->uc_mcontext); 19 &uc->uc_mcontext);
39 20 trap_myself();
40 pid = stub_syscall0(__NR_getpid);
41 stub_syscall2(__NR_kill, pid, SIGUSR1);
42
43 /* sys_sigreturn expects that the stack pointer will be 8 bytes into
44 * the signal frame. So, we use the ucontext pointer, which we know
45 * already, to get the signal frame pointer, and add 8 to that.
46 */
47 __asm__ __volatile__("movq %0, %%rsp; movq %1, %%rax ; syscall": :
48 "g" ((unsigned long)
49 container_of(uc, struct rt_sigframe, uc) + 8),
50 "g" (__NR_rt_sigreturn));
51} 21}
22