SKAS4 - Guest support for using PTRACE_GETSIGINFO

new file mode 100644
index 0000000..c000267
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2002- 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SIGINFO_SIGSEGV_H_
+#define __SIGINFO_SIGSEGV_H_
+
+/*
+ * Provide signal.h, except for replacing siginfo_t with one that has
+ * the CPU trap number and error code in the SIGSEGV case.
+ */
+
+#include <time.h>
+
+/* Rename the signal.h siginfo and siginfo_t out of the way */
+#define siginfo old_siginfo
+#define siginfo_t old_siginfo_t
+
+#include <signal.h>
+
+#undef siginfo
+#undef siginfo_t
+
+#define __ARCH_SI_TRAPNO
+#define __ARCH_SI_ERROR
+
+/* The new siginfo_t, plus associated definitions */
+
+/*
+ * This is the size (including padding) of the part of the
+ * struct siginfo that is before the union.
+ */
+#ifndef __ARCH_SI_PREAMBLE_SIZE
+#define __ARCH_SI_PREAMBLE_SIZE	(3 * sizeof(int))
+#endif
+
+#define SI_MAX_SIZE	128
+#ifndef SI_PAD_SIZE
+#define SI_PAD_SIZE	((SI_MAX_SIZE - __ARCH_SI_PREAMBLE_SIZE) / sizeof(int))
+#endif
+
+#ifndef __ARCH_SI_UID_T
+#define __ARCH_SI_UID_T	uid_t
+#endif
+
+/*
+ * The default "si_band" type is "long", as specified by POSIX.
+ * However, some architectures want to override this to "int"
+ * for historical compatibility reasons, so we allow that.
+ */
+#ifndef __ARCH_SI_BAND_T
+#define __ARCH_SI_BAND_T long
+#endif
+
+#define __user
+
+typedef struct siginfo {
+	int si_signo;
+	int si_errno;
+	int si_code;
+
+	union {
+		int _pad[SI_PAD_SIZE];
+
+		/* kill() */
+		struct {
+			pid_t _pid;		/* sender's pid */
+			__ARCH_SI_UID_T _uid;	/* sender's uid */
+		} _kill;
+
+		/* POSIX.1b timers */
+		struct {
+			timer_t _tid;		/* timer id */
+			int _overrun;		/* overrun count */
+			char _pad[sizeof( __ARCH_SI_UID_T) - sizeof(int)];
+			sigval_t _sigval;	/* same as below */
+			int _sys_private;       /* not to be passed to user */
+		} _timer;
+
+		/* POSIX.1b signals */
+		struct {
+			pid_t _pid;		/* sender's pid */
+			__ARCH_SI_UID_T _uid;	/* sender's uid */
+			sigval_t _sigval;
+		} _rt;
+
+		/* SIGCHLD */
+		struct {
+			pid_t _pid;		/* which child */
+			__ARCH_SI_UID_T _uid;	/* sender's uid */
+			int _status;		/* exit code */
+			clock_t _utime;
+			clock_t _stime;
+		} _sigchld;
+
+		/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
+		struct {
+			void __user *_addr; /* faulting insn/memory ref. */
+#ifdef __ARCH_SI_TRAPNO
+			int _trapno;	/* TRAP # which caused the signal */
+#endif
+#ifdef __ARCH_SI_ERROR
+			int _error;	/* CPU error code */
+#endif
+		} _sigfault;
+
+		/* SIGPOLL */
+		struct {
+			__ARCH_SI_BAND_T _band;	/* POLL_IN, POLL_OUT, POLL_MSG */
+			int _fd;
+		} _sigpoll;
+	} _sifields;
+} siginfo_t;
+
+#ifdef __ARCH_SI_TRAPNO
+#define si_trapno	_sifields._sigfault._trapno
+#endif
+#ifdef __ARCH_SI_ERROR
+#define si_error	_sifields._sigfault._error
+#endif
+
+#undef si_addr
+#define si_addr	_sifields._sigfault._addr
+
+#define GET_FAULTINFO_FROM_SI(fi, si) \
+	{ \
+		(fi).cr2 = (unsigned long) (si).si_addr; \
+		(fi).error_code = (si).si_error; \
+		(fi).trap_no = (si).si_trapno; \
+	}
+
+#endif

index b073f8a..d6cbb4f 100644
@@ -8,6 +8,8 @@
 
 #include "sysdep/ptrace.h"
 
+extern int have_siginfo_segv;
+
 extern int userspace_pid[];
 extern int proc_mm, ptrace_faultinfo, ptrace_ldt;
 extern int skas_needs_stub;

index e8b7a97..82a0780 100644
@@ -3,6 +3,9 @@
  * Licensed under the GPL
  */
 
+/* Include this first, before anything else includes <signal.h> */
+#include "siginfo_segv.h"
+
 #include <stdlib.h>
 #include <unistd.h>
 #include <sched.h>

@@ -91,11 +94,23 @@ bad_wait:
 
 extern unsigned long current_stub_stack(void);
 
+#ifndef PTRACE_GETSIGINFO
+#define PTRACE_GETSIGINFO	0x4202
+#endif
+
 void get_skas_faultinfo(int pid, struct faultinfo * fi)
 {
+	siginfo_t si;
 	int err;
 
-	if (ptrace_faultinfo) {
+	if(have_siginfo_segv){
+		err = ptrace(PTRACE_GETSIGINFO, pid, 0, &si);
+		if(err)
+			printk("PTRACE_GETSIGINFO failed, err = %d\n", errno);
+
+		GET_FAULTINFO_FROM_SI(*fi, si);
+	}
+	else if (ptrace_faultinfo) {
 		err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
 		if (err)
 			panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "

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