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Subject[PATCH 11/22] UML - S390 preparation, abstract host page fault data
Date
From

From: Bodo Stroesser <bstroesser@fujitsu-siemens.com>

This patch removes the arch-specific fault/trap-infos
from thread and skas-regs.
It adds a new struct faultinfo, that is arch-specific
defined in sysdep/faultinfo.h.
The structure is inserted in thread.arch and
thread.regs.skas and thread.regs.tt
Now, segv and other trap-handlers can copy the contents
from regs.X.faultinfo to thread.arch.faultinfo
with one simple assignment.
Also, the number of macros necessary is reduced to

FAULT_ADDRESS(struct faultinfo)
extracts the faulting address from faultinfo

FAULT_WRITE(struct faultinfo)
extracts the "is_write" flag

SEGV_IS_FIXABLE(struct faultinfo)
is true for the fixable segvs, i.e. (TRAP == 14)
on i386

UPT_FAULTINFO(regs)
result is (struct faultinfo *) to the faultinfo
in regs->skas.faultinfo

GET_FAULTINFO_FROM_SC(struct faultinfo, struct sigcontext *)
copies the relevant parts of the sigcontext to
struct faultinfo.
On SIGSEGV, call user_signal() instead of handle_segv(), if the
architecture provides the information needed in PTRACE_FAULTINFO,
or if PTRACE_FAULTINFO is missing, because segv-stub will provide
the info.
The benefit of the change is, that in case of a non-fixable SIGSEGV,
we can give user processes a SIGSEGV, instead of possibly looping
on pagefault handling.
Since handle_segv() sikked arch_fixup() implicitly by passing ip==0
to segv(), I changed segv() to call arch_fixup() only, if !is_user.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>

Index: linux-2.6.11-mm/arch/um/include/kern_util.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/kern_util.h 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/kern_util.h 2005-04-30 13:08:02.000000000 -0400
@@ -8,6 +8,7 @@

#include "linux/threads.h"
#include "sysdep/ptrace.h"
+#include "sysdep/faultinfo.h"

extern int ncpus;
extern char *linux_prog;
@@ -31,8 +32,8 @@
extern unsigned long alloc_stack(int order, int atomic);
extern int do_signal(void);
extern int is_stack_fault(unsigned long sp);
-extern unsigned long segv(unsigned long address, unsigned long ip,
- int is_write, int is_user, void *sc);
+extern unsigned long segv(struct faultinfo fi, unsigned long ip,
+ int is_user, void *sc);
extern int handle_page_fault(unsigned long address, unsigned long ip,
int is_write, int is_user, int *code_out);
extern void syscall_ready(void);
@@ -82,7 +83,7 @@
extern void unprotect_stack(unsigned long stack);
extern void do_uml_exitcalls(void);
extern int attach_debugger(int idle_pid, int pid, int stop);
-extern void bad_segv(unsigned long address, unsigned long ip, int is_write);
+extern void bad_segv(struct faultinfo fi, unsigned long ip);
extern int config_gdb(char *str);
extern int remove_gdb(void);
extern char *uml_strdup(char *string);
Index: linux-2.6.11-mm/arch/um/include/sysdep-i386/faultinfo.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-i386/faultinfo.h 2003-09-15 09:40:47.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-i386/faultinfo.h 2005-04-30 13:08:02.000000000 -0400
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
+ * Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
+ * Licensed under the GPL
+ */
+
+#ifndef __FAULTINFO_I386_H
+#define __FAULTINFO_I386_H
+
+/* this structure contains the full arch-specific faultinfo
+ * from the traps.
+ * On i386, ptrace_faultinfo unfortunately doesn't provide
+ * all the info, since trap_no is missing.
+ * All common elements are defined at the same position in
+ * both structures, thus making it easy to copy the
+ * contents without knowledge about the structure elements.
+ */
+struct faultinfo {
+ int error_code; /* in ptrace_faultinfo misleadingly called is_write */
+ unsigned long cr2; /* in ptrace_faultinfo called addr */
+ int trap_no; /* missing in ptrace_faultinfo */
+};
+
+#define FAULT_WRITE(fi) ((fi).error_code & 2)
+#define FAULT_ADDRESS(fi) ((fi).cr2)
+
+#define PTRACE_FULL_FAULTINFO 0
+
+#endif
Index: linux-2.6.11-mm/arch/um/include/sysdep-i386/ptrace.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-i386/ptrace.h 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-i386/ptrace.h 2005-04-30 13:08:02.000000000 -0400
@@ -31,6 +31,7 @@
#ifdef UML_CONFIG_MODE_SKAS

#include "skas_ptregs.h"
+#include "sysdep/faultinfo.h"

#define REGS_IP(r) ((r)[HOST_IP])
#define REGS_SP(r) ((r)[HOST_SP])
@@ -53,12 +54,6 @@

#define REGS_RESTART_SYSCALL(r) IP_RESTART_SYSCALL(REGS_IP(r))

-#define REGS_SEGV_IS_FIXABLE(r) SEGV_IS_FIXABLE((r)->trap_type)
-
-#define REGS_FAULT_ADDR(r) ((r)->fault_addr)
-
-#define REGS_FAULT_WRITE(r) FAULT_WRITE((r)->fault_type)
-
#endif
#ifndef PTRACE_SYSEMU_SINGLESTEP
#define PTRACE_SYSEMU_SINGLESTEP 32
@@ -71,6 +66,7 @@
struct tt_regs {
long syscall;
void *sc;
+ struct faultinfo faultinfo;
} tt;
#endif
#ifdef UML_CONFIG_MODE_SKAS
@@ -78,9 +74,7 @@
unsigned long regs[HOST_FRAME_SIZE];
unsigned long fp[HOST_FP_SIZE];
unsigned long xfp[HOST_XFP_SIZE];
- unsigned long fault_addr;
- unsigned long fault_type;
- unsigned long trap_type;
+ struct faultinfo faultinfo;
long syscall;
int is_user;
} skas;
@@ -217,15 +211,8 @@
#define UPT_SYSCALL_NR(r) UPT_ORIG_EAX(r)
#define UPT_SYSCALL_RET(r) UPT_EAX(r)

-#define UPT_SEGV_IS_FIXABLE(r) \
- CHOOSE_MODE(SC_SEGV_IS_FIXABLE(UPT_SC(r)), \
- REGS_SEGV_IS_FIXABLE(&r->skas))
-
-#define UPT_FAULT_ADDR(r) \
- __CHOOSE_MODE(SC_FAULT_ADDR(UPT_SC(r)), REGS_FAULT_ADDR(&r->skas))
-
-#define UPT_FAULT_WRITE(r) \
- CHOOSE_MODE(SC_FAULT_WRITE(UPT_SC(r)), REGS_FAULT_WRITE(&r->skas))
+#define UPT_FAULTINFO(r) \
+ CHOOSE_MODE((&(r)->tt.faultinfo), (&(r)->skas.faultinfo))

#endif

Index: linux-2.6.11-mm/arch/um/include/sysdep-i386/sigcontext.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-i386/sigcontext.h 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-i386/sigcontext.h 2005-04-30 13:08:02.000000000 -0400
@@ -13,15 +13,12 @@
#define SC_RESTART_SYSCALL(sc) IP_RESTART_SYSCALL(SC_IP(sc))
#define SC_SET_SYSCALL_RETURN(sc, result) SC_EAX(sc) = (result)

-#define SC_FAULT_ADDR(sc) SC_CR2(sc)
-#define SC_FAULT_TYPE(sc) SC_ERR(sc)
-
-#define FAULT_WRITE(err) (err & 2)
-#define TO_SC_ERR(is_write) ((is_write) ? 2 : 0)
-
-#define SC_FAULT_WRITE(sc) (FAULT_WRITE(SC_ERR(sc)))
-
-#define SC_TRAP_TYPE(sc) SC_TRAPNO(sc)
+#define GET_FAULTINFO_FROM_SC(fi,sc) \
+ { \
+ (fi).cr2 = SC_CR2(sc); \
+ (fi).error_code = SC_ERR(sc); \
+ (fi).trap_no = SC_TRAPNO(sc); \
+ }

/* ptrace expects that, at the start of a system call, %eax contains
* -ENOSYS, so this makes it so.
@@ -29,9 +26,7 @@
#define SC_START_SYSCALL(sc) do SC_EAX(sc) = -ENOSYS; while(0)

/* This is Page Fault */
-#define SEGV_IS_FIXABLE(trap) (trap == 14)
-
-#define SC_SEGV_IS_FIXABLE(sc) (SEGV_IS_FIXABLE(SC_TRAPNO(sc)))
+#define SEGV_IS_FIXABLE(fi) ((fi)->trap_no == 14)

extern unsigned long *sc_sigmask(void *sc_ptr);
extern int sc_get_fpregs(unsigned long buf, void *sc_ptr);
Index: linux-2.6.11-mm/arch/um/include/sysdep-i386/skas_ptrace.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-i386/skas_ptrace.h 2003-09-15 09:40:47.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-i386/skas_ptrace.h 2005-04-30 13:08:02.000000000 -0400
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSDEP_I386_SKAS_PTRACE_H
+#define __SYSDEP_I386_SKAS_PTRACE_H
+
+struct ptrace_faultinfo {
+ int is_write;
+ unsigned long addr;
+};
+
+struct ptrace_ldt {
+ int func;
+ void *ptr;
+ unsigned long bytecount;
+};
+
+#define PTRACE_LDT 54
+
+#endif
Index: linux-2.6.11-mm/arch/um/include/sysdep-ia64/skas_ptrace.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-ia64/skas_ptrace.h 2003-09-15 09:40:47.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-ia64/skas_ptrace.h 2005-04-30 13:08:02.000000000 -0400
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSDEP_IA64_SKAS_PTRACE_H
+#define __SYSDEP_IA64_SKAS_PTRACE_H
+
+struct ptrace_faultinfo {
+ int is_write;
+ unsigned long addr;
+};
+
+struct ptrace_ldt {
+ int func;
+ void *ptr;
+ unsigned long bytecount;
+};
+
+#define PTRACE_LDT 54
+
+#endif
Index: linux-2.6.11-mm/arch/um/include/sysdep-ppc/skas_ptrace.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-ppc/skas_ptrace.h 2003-09-15 09:40:47.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-ppc/skas_ptrace.h 2005-04-30 13:08:02.000000000 -0400
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSDEP_PPC_SKAS_PTRACE_H
+#define __SYSDEP_PPC_SKAS_PTRACE_H
+
+struct ptrace_faultinfo {
+ int is_write;
+ unsigned long addr;
+};
+
+struct ptrace_ldt {
+ int func;
+ void *ptr;
+ unsigned long bytecount;
+};
+
+#define PTRACE_LDT 54
+
+#endif
Index: linux-2.6.11-mm/arch/um/include/sysdep-x86_64/faultinfo.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-x86_64/faultinfo.h 2003-09-15 09:40:47.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-x86_64/faultinfo.h 2005-04-30 13:08:02.000000000 -0400
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
+ * Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
+ * Licensed under the GPL
+ */
+
+#ifndef __FAULTINFO_X86_64_H
+#define __FAULTINFO_X86_64_H
+
+/* this structure contains the full arch-specific faultinfo
+ * from the traps.
+ * On i386, ptrace_faultinfo unfortunately doesn't provide
+ * all the info, since trap_no is missing.
+ * All common elements are defined at the same position in
+ * both structures, thus making it easy to copy the
+ * contents without knowledge about the structure elements.
+ */
+struct faultinfo {
+ int error_code; /* in ptrace_faultinfo misleadingly called is_write */
+ unsigned long cr2; /* in ptrace_faultinfo called addr */
+ int trap_no; /* missing in ptrace_faultinfo */
+};
+
+#define FAULT_WRITE(fi) ((fi).error_code & 2)
+#define FAULT_ADDRESS(fi) ((fi).cr2)
+
+#define PTRACE_FULL_FAULTINFO 1
+
+#endif
Index: linux-2.6.11-mm/arch/um/include/sysdep-x86_64/ptrace.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-x86_64/ptrace.h 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-x86_64/ptrace.h 2005-04-30 13:08:02.000000000 -0400
@@ -9,6 +9,7 @@

#include "uml-config.h"
#include "user_constants.h"
+#include "sysdep/faultinfo.h"

#define MAX_REG_OFFSET (UM_FRAME_SIZE)
#define MAX_REG_NR ((MAX_REG_OFFSET) / sizeof(unsigned long))
@@ -83,6 +84,7 @@
long syscall;
unsigned long orig_rax;
void *sc;
+ struct faultinfo faultinfo;
} tt;
#endif
#ifdef UML_CONFIG_MODE_SKAS
@@ -90,9 +92,7 @@
/* XXX */
unsigned long regs[27];
unsigned long fp[65];
- unsigned long fault_addr;
- unsigned long fault_type;
- unsigned long trap_type;
+ struct faultinfo faultinfo;
long syscall;
int is_user;
} skas;
@@ -241,14 +241,8 @@
CHOOSE_MODE(SC_SEGV_IS_FIXABLE(UPT_SC(r)), \
REGS_SEGV_IS_FIXABLE(&r->skas))

-#define UPT_FAULT_ADDR(r) \
- __CHOOSE_MODE(SC_FAULT_ADDR(UPT_SC(r)), REGS_FAULT_ADDR(&r->skas))
-
-#define UPT_FAULT_WRITE(r) \
- CHOOSE_MODE(SC_FAULT_WRITE(UPT_SC(r)), REGS_FAULT_WRITE(&r->skas))
-
-#define UPT_TRAP(r) __CHOOSE_MODE(SC_TRAP_TYPE(UPT_SC(r)), REGS_TRAP(&r->skas))
-#define UPT_ERR(r) __CHOOSE_MODE(SC_FAULT_TYPE(UPT_SC(r)), REGS_ERR(&r->skas))
+#define UPT_FAULTINFO(r) \
+ CHOOSE_MODE((&(r)->tt.faultinfo), (&(r)->skas.faultinfo))

#endif

Index: linux-2.6.11-mm/arch/um/include/sysdep-x86_64/sigcontext.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-x86_64/sigcontext.h 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-x86_64/sigcontext.h 2005-04-30 13:08:02.000000000 -0400
@@ -17,11 +17,12 @@
#define SC_FAULT_ADDR(sc) SC_CR2(sc)
#define SC_FAULT_TYPE(sc) SC_ERR(sc)

-#define FAULT_WRITE(err) ((err) & 2)
-
-#define SC_FAULT_WRITE(sc) FAULT_WRITE(SC_FAULT_TYPE(sc))
-
-#define SC_TRAP_TYPE(sc) SC_TRAPNO(sc)
+#define GET_FAULTINFO_FROM_SC(fi,sc) \
+ { \
+ (fi).cr2 = SC_CR2(sc); \
+ (fi).error_code = SC_ERR(sc); \
+ (fi).trap_no = SC_TRAPNO(sc); \
+ }

/* ptrace expects that, at the start of a system call, %eax contains
* -ENOSYS, so this makes it so.
@@ -29,8 +30,8 @@

#define SC_START_SYSCALL(sc) do SC_RAX(sc) = -ENOSYS; while(0)

-#define SEGV_IS_FIXABLE(trap) ((trap) == 14)
-#define SC_SEGV_IS_FIXABLE(sc) SEGV_IS_FIXABLE(SC_TRAP_TYPE(sc))
+/* This is Page Fault */
+#define SEGV_IS_FIXABLE(fi) ((fi)->trap_no == 14)

extern unsigned long *sc_sigmask(void *sc_ptr);

Index: linux-2.6.11-mm/arch/um/include/sysdep-x86_64/skas_ptrace.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/include/sysdep-x86_64/skas_ptrace.h 2003-09-15 09:40:47.000000000 -0400
+++ linux-2.6.11-mm/arch/um/include/sysdep-x86_64/skas_ptrace.h 2005-04-30 13:08:02.000000000 -0400
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSDEP_X86_64_SKAS_PTRACE_H
+#define __SYSDEP_X86_64_SKAS_PTRACE_H
+
+struct ptrace_faultinfo {
+ int is_write;
+ unsigned long addr;
+};
+
+struct ptrace_ldt {
+ int func;
+ void *ptr;
+ unsigned long bytecount;
+};
+
+#define PTRACE_LDT 54
+
+#endif
Index: linux-2.6.11-mm/arch/um/kernel/ptrace.c
===================================================================
--- linux-2.6.11-mm.orig/arch/um/kernel/ptrace.c 2005-04-30 12:57:43.000000000 -0400
+++ linux-2.6.11-mm/arch/um/kernel/ptrace.c 2005-04-30 13:08:02.000000000 -0400
@@ -250,13 +250,13 @@
break;
#endif
case PTRACE_FAULTINFO: {
- struct ptrace_faultinfo fault;
-
- fault = ((struct ptrace_faultinfo)
- { .is_write = child->thread.err,
- .addr = child->thread.cr2 });
- ret = copy_to_user((unsigned long __user *) data, &fault,
- sizeof(fault));
+ /* Take the info from thread->arch->faultinfo,
+ * but transfer max. sizeof(struct ptrace_faultinfo).
+ * On i386, ptrace_faultinfo is smaller!
+ */
+ ret = copy_to_user((unsigned long __user *) data,
+ &child->thread.arch.faultinfo,
+ sizeof(struct ptrace_faultinfo));
if(ret)
break;
break;
@@ -267,6 +267,7 @@
sizeof(child->pending.signal));
break;

+#ifdef PTRACE_LDT
case PTRACE_LDT: {
struct ptrace_ldt ldt;

@@ -282,6 +283,7 @@
ret = -EIO;
break;
}
+#endif
#ifdef CONFIG_PROC_MM
case PTRACE_SWITCH_MM: {
struct mm_struct *old = child->mm;
Index: linux-2.6.11-mm/arch/um/kernel/skas/include/skas.h
===================================================================
--- linux-2.6.11-mm.orig/arch/um/kernel/skas/include/skas.h 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/kernel/skas/include/skas.h 2005-04-30 13:08:02.000000000 -0400
@@ -27,9 +27,10 @@
extern int unmap(int fd, void *addr, unsigned long len);
extern int protect(int fd, unsigned long addr, unsigned long len,
int r, int w, int x);
-extern void user_signal(int sig, union uml_pt_regs *regs);
+extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
extern int new_mm(int from);
extern void start_userspace(int cpu);
+extern void get_skas_faultinfo(int pid, struct faultinfo * fi);
extern long execute_syscall_skas(void *r);

#endif
Index: linux-2.6.11-mm/arch/um/kernel/skas/process.c
===================================================================
--- linux-2.6.11-mm.orig/arch/um/kernel/skas/process.c 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/kernel/skas/process.c 2005-04-30 13:08:02.000000000 -0400
@@ -4,6 +4,7 @@
*/

#include <stdlib.h>
+#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
@@ -37,17 +38,26 @@
return(1);
}

-static void handle_segv(int pid)
+void get_skas_faultinfo(int pid, struct faultinfo * fi)
{
- struct ptrace_faultinfo fault;
int err;

- err = ptrace(PTRACE_FAULTINFO, pid, 0, &fault);
+ err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
if(err)
- panic("handle_segv - PTRACE_FAULTINFO failed, errno = %d\n",
- errno);
+ panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
+ "errno = %d\n", errno);
+
+ /* Special handling for i386, which has different structs */
+ if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
+ memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
+ sizeof(struct faultinfo) -
+ sizeof(struct ptrace_faultinfo));
+}

- segv(fault.addr, 0, FAULT_WRITE(fault.is_write), 1, NULL);
+static void handle_segv(int pid, union uml_pt_regs * regs)
+{
+ get_skas_faultinfo(pid, &regs->skas.faultinfo);
+ segv(regs->skas.faultinfo, 0, 1, NULL);
}

/*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/
@@ -163,7 +173,7 @@
if(WIFSTOPPED(status)){
switch(WSTOPSIG(status)){
case SIGSEGV:
- handle_segv(pid);
+ handle_segv(pid, regs);
break;
case SIGTRAP + 0x80:
handle_trap(pid, regs, local_using_sysemu);
@@ -177,7 +187,7 @@
case SIGBUS:
case SIGFPE:
case SIGWINCH:
- user_signal(WSTOPSIG(status), regs);
+ user_signal(WSTOPSIG(status), regs, pid);
break;
default:
printk("userspace - child stopped with signal "
Index: linux-2.6.11-mm/arch/um/kernel/skas/trap_user.c
===================================================================
--- linux-2.6.11-mm.orig/arch/um/kernel/skas/trap_user.c 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/kernel/skas/trap_user.c 2005-04-30 13:08:02.000000000 -0400
@@ -5,12 +5,15 @@

#include <signal.h>
#include <errno.h>
-#include "sysdep/ptrace.h"
#include "signal_user.h"
#include "user_util.h"
#include "kern_util.h"
#include "task.h"
#include "sigcontext.h"
+#include "skas.h"
+#include "ptrace_user.h"
+#include "sysdep/ptrace.h"
+#include "sysdep/ptrace_user.h"

void sig_handler_common_skas(int sig, void *sc_ptr)
{
@@ -31,9 +34,11 @@
r = &TASK_REGS(get_current())->skas;
save_user = r->is_user;
r->is_user = 0;
- r->fault_addr = SC_FAULT_ADDR(sc);
- r->fault_type = SC_FAULT_TYPE(sc);
- r->trap_type = SC_TRAP_TYPE(sc);
+ if ( sig == SIGFPE || sig == SIGSEGV ||
+ sig == SIGBUS || sig == SIGILL ||
+ sig == SIGTRAP ) {
+ GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
+ }

change_sig(SIGUSR1, 1);
info = &sig_info[sig];
@@ -45,14 +50,17 @@
r->is_user = save_user;
}

-void user_signal(int sig, union uml_pt_regs *regs)
+extern int ptrace_faultinfo;
+
+void user_signal(int sig, union uml_pt_regs *regs, int pid)
{
struct signal_info *info;
+ int segv = ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) ||
+ (sig == SIGILL) || (sig == SIGTRAP));

regs->skas.is_user = 1;
- regs->skas.fault_addr = 0;
- regs->skas.fault_type = 0;
- regs->skas.trap_type = 0;
+ if (segv)
+ get_skas_faultinfo(pid, &regs->skas.faultinfo);
info = &sig_info[sig];
(*info->handler)(sig, regs);

Index: linux-2.6.11-mm/arch/um/kernel/trap_kern.c
===================================================================
--- linux-2.6.11-mm.orig/arch/um/kernel/trap_kern.c 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/kernel/trap_kern.c 2005-04-30 13:08:02.000000000 -0400
@@ -133,12 +133,19 @@
return(0);
}

-unsigned long segv(unsigned long address, unsigned long ip, int is_write,
- int is_user, void *sc)
+/*
+ * We give a *copy* of the faultinfo in the regs to segv.
+ * This must be done, since nesting SEGVs could overwrite
+ * the info in the regs. A pointer to the info then would
+ * give us bad data!
+ */
+unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
{
struct siginfo si;
void *catcher;
int err;
+ int is_write = FAULT_WRITE(fi);
+ unsigned long address = FAULT_ADDRESS(fi);

if(!is_user && (address >= start_vm) && (address < end_vm)){
flush_tlb_kernel_vm();
@@ -159,7 +166,7 @@
}
else if(current->thread.fault_addr != NULL)
panic("fault_addr set but no fault catcher");
- else if(arch_fixup(ip, sc))
+ else if(!is_user && arch_fixup(ip, sc))
return(0);

if(!is_user)
@@ -171,6 +178,7 @@
si.si_errno = 0;
si.si_code = BUS_ADRERR;
si.si_addr = (void *)address;
+ current->thread.arch.faultinfo = fi;
force_sig_info(SIGBUS, &si, current);
}
else if(err == -ENOMEM){
@@ -180,22 +188,20 @@
else {
si.si_signo = SIGSEGV;
si.si_addr = (void *) address;
- current->thread.cr2 = address;
- current->thread.err = is_write;
+ current->thread.arch.faultinfo = fi;
force_sig_info(SIGSEGV, &si, current);
}
return(0);
}

-void bad_segv(unsigned long address, unsigned long ip, int is_write)
+void bad_segv(struct faultinfo fi, unsigned long ip)
{
struct siginfo si;

si.si_signo = SIGSEGV;
si.si_code = SEGV_ACCERR;
- si.si_addr = (void *) address;
- current->thread.cr2 = address;
- current->thread.err = is_write;
+ si.si_addr = (void *) FAULT_ADDRESS(fi);
+ current->thread.arch.faultinfo = fi;
force_sig_info(SIGSEGV, &si, current);
}

@@ -204,6 +210,7 @@
if(arch_handle_signal(sig, regs)) return;
if(!UPT_IS_USER(regs))
panic("Kernel mode signal %d", sig);
+ current->thread.arch.faultinfo = *UPT_FAULTINFO(regs);
force_sig(sig, current);
}

Index: linux-2.6.11-mm/arch/um/kernel/trap_user.c
===================================================================
--- linux-2.6.11-mm.orig/arch/um/kernel/trap_user.c 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/kernel/trap_user.c 2005-04-30 13:08:02.000000000 -0400
@@ -54,23 +54,22 @@
void segv_handler(int sig, union uml_pt_regs *regs)
{
int index, max;
+ struct faultinfo * fi = UPT_FAULTINFO(regs);

- if(UPT_IS_USER(regs) && !UPT_SEGV_IS_FIXABLE(regs)){
- bad_segv(UPT_FAULT_ADDR(regs), UPT_IP(regs),
- UPT_FAULT_WRITE(regs));
+ if(UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)){
+ bad_segv(*fi, UPT_IP(regs));
return;
}
max = sizeof(segfault_record)/sizeof(segfault_record[0]);
index = next_trap_index(max);

nsegfaults++;
- segfault_record[index].address = UPT_FAULT_ADDR(regs);
+ segfault_record[index].address = FAULT_ADDRESS(*fi);
segfault_record[index].pid = os_getpid();
- segfault_record[index].is_write = UPT_FAULT_WRITE(regs);
+ segfault_record[index].is_write = FAULT_WRITE(*fi);
segfault_record[index].sp = UPT_SP(regs);
segfault_record[index].is_user = UPT_IS_USER(regs);
- segv(UPT_FAULT_ADDR(regs), UPT_IP(regs), UPT_FAULT_WRITE(regs),
- UPT_IS_USER(regs), regs);
+ segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);
}

void usr2_handler(int sig, union uml_pt_regs *regs)
Index: linux-2.6.11-mm/arch/um/kernel/tt/tracer.c
===================================================================
--- linux-2.6.11-mm.orig/arch/um/kernel/tt/tracer.c 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/kernel/tt/tracer.c 2005-04-30 13:08:02.000000000 -0400
@@ -89,8 +89,10 @@

static void tracer_segv(int sig, struct sigcontext sc)
{
+ struct faultinfo fi;
+ GET_FAULTINFO_FROM_SC(fi, &sc);
printf("Tracing thread segfault at address 0x%lx, ip 0x%lx\n",
- SC_FAULT_ADDR(&sc), SC_IP(&sc));
+ FAULT_ADDRESS(fi), SC_IP(&sc));
while(1)
pause();
}
Index: linux-2.6.11-mm/arch/um/kernel/tt/trap_user.c
===================================================================
--- linux-2.6.11-mm.orig/arch/um/kernel/tt/trap_user.c 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/kernel/tt/trap_user.c 2005-04-30 13:08:02.000000000 -0400
@@ -7,6 +7,7 @@
#include <errno.h>
#include <signal.h>
#include "sysdep/ptrace.h"
+#include "sysdep/sigcontext.h"
#include "signal_user.h"
#include "user_util.h"
#include "kern_util.h"
@@ -28,6 +29,11 @@
change_sig(SIGSEGV, 1);

r = &TASK_REGS(get_current())->tt;
+ if ( sig == SIGFPE || sig == SIGSEGV ||
+ sig == SIGBUS || sig == SIGILL ||
+ sig == SIGTRAP ) {
+ GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
+ }
save_regs = *r;
is_user = user_context(SC_SP(sc));
r->sc = sc;
Index: linux-2.6.11-mm/arch/um/sys-i386/signal.c
===================================================================
--- linux-2.6.11-mm.orig/arch/um/sys-i386/signal.c 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/sys-i386/signal.c 2005-04-30 13:08:02.000000000 -0400
@@ -47,9 +47,6 @@
REGS_CS(regs->regs.skas.regs) = sc.cs;
REGS_EFLAGS(regs->regs.skas.regs) = sc.eflags;
REGS_SS(regs->regs.skas.regs) = sc.ss;
- regs->regs.skas.fault_addr = sc.cr2;
- regs->regs.skas.fault_type = FAULT_WRITE(sc.err);
- regs->regs.skas.trap_type = sc.trapno;

err = restore_fp_registers(userspace_pid[0], fpregs);
if(err < 0){
@@ -62,11 +59,11 @@
}

int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp,
- struct pt_regs *regs, unsigned long fault_addr,
- int fault_type)
+ struct pt_regs *regs)
{
struct sigcontext sc;
unsigned long fpregs[HOST_FP_SIZE];
+ struct faultinfo * fi = &current->thread.arch.faultinfo;
int err;

sc.gs = REGS_GS(regs->regs.skas.regs);
@@ -86,9 +83,9 @@
sc.eflags = REGS_EFLAGS(regs->regs.skas.regs);
sc.esp_at_signal = regs->regs.skas.regs[UESP];
sc.ss = regs->regs.skas.regs[SS];
- sc.cr2 = fault_addr;
- sc.err = TO_SC_ERR(fault_type);
- sc.trapno = regs->regs.skas.trap_type;
+ sc.cr2 = fi->cr2;
+ sc.err = fi->error_code;
+ sc.trapno = fi->trap_no;

err = save_fp_registers(userspace_pid[0], fpregs);
if(err < 0){
@@ -167,9 +164,7 @@
{
return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
sizeof(*fp)),
- copy_sc_to_user_skas(to, fp, from,
- current->thread.cr2,
- current->thread.err)));
+ copy_sc_to_user_skas(to, fp, from)));
}

static int copy_ucontext_to_user(struct ucontext *uc, struct _fpstate *fp,
Index: linux-2.6.11-mm/arch/um/sys-x86_64/signal.c
===================================================================
--- linux-2.6.11-mm.orig/arch/um/sys-x86_64/signal.c 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/arch/um/sys-x86_64/signal.c 2005-04-30 13:08:02.000000000 -0400
@@ -57,7 +57,7 @@
int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp,
struct pt_regs *regs, unsigned long mask)
{
- unsigned long eflags;
+ struct faultinfo * fi = &current->thread.arch.faultinfo;
int err = 0;

err |= __put_user(0, &to->gs);
@@ -84,14 +84,16 @@
err |= PUTREG(regs, R14, to, r14);
err |= PUTREG(regs, R15, to, r15);
err |= PUTREG(regs, CS, to, cs); /* XXX x86_64 doesn't do this */
- err |= __put_user(current->thread.err, &to->err);
- err |= __put_user(current->thread.trap_no, &to->trapno);
+
+ err |= __put_user(fi->cr2, &to->cr2);
+ err |= __put_user(fi->error_code, &to->err);
+ err |= __put_user(fi->trap_no, &to->trapno);
+
err |= PUTREG(regs, RIP, to, rip);
err |= PUTREG(regs, EFLAGS, to, eflags);
#undef PUTREG

err |= __put_user(mask, &to->oldmask);
- err |= __put_user(current->thread.cr2, &to->cr2);

return(err);
}
Index: linux-2.6.11-mm/include/asm-um/processor-generic.h
===================================================================
--- linux-2.6.11-mm.orig/include/asm-um/processor-generic.h 2005-04-30 12:57:45.000000000 -0400
+++ linux-2.6.11-mm/include/asm-um/processor-generic.h 2005-04-30 13:08:02.000000000 -0400
@@ -24,9 +24,6 @@
int forking;
int nsyscalls;
struct pt_regs regs;
- unsigned long cr2;
- int err;
- unsigned long trap_no;
int singlestep_syscall;
void *fault_addr;
void *fault_catcher;
@@ -74,8 +71,6 @@
.forking = 0, \
.nsyscalls = 0, \
.regs = EMPTY_REGS, \
- .cr2 = 0, \
- .err = 0, \
.fault_addr = NULL, \
.prev_sched = NULL, \
.temp_stack = 0, \
Index: linux-2.6.11-mm/include/asm-um/processor-i386.h
===================================================================
--- linux-2.6.11-mm.orig/include/asm-um/processor-i386.h 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/include/asm-um/processor-i386.h 2005-04-30 13:08:02.000000000 -0400
@@ -9,13 +9,18 @@
extern int host_has_xmm;
extern int host_has_cmov;

+/* include faultinfo structure */
+#include "sysdep/faultinfo.h"
+
struct arch_thread {
unsigned long debugregs[8];
int debugregs_seq;
+ struct faultinfo faultinfo;
};

#define INIT_ARCH_THREAD { .debugregs = { [ 0 ... 7 ] = 0 }, \
- .debugregs_seq = 0 }
+ .debugregs_seq = 0, \
+ .faultinfo = { 0, 0, 0 } }

#include "asm/arch/user.h"

Index: linux-2.6.11-mm/include/asm-um/processor-x86_64.h
===================================================================
--- linux-2.6.11-mm.orig/include/asm-um/processor-x86_64.h 2005-04-30 12:56:25.000000000 -0400
+++ linux-2.6.11-mm/include/asm-um/processor-x86_64.h 2005-04-30 13:08:02.000000000 -0400
@@ -7,9 +7,13 @@
#ifndef __UM_PROCESSOR_X86_64_H
#define __UM_PROCESSOR_X86_64_H

-#include "asm/arch/user.h"
+/* include faultinfo structure */
+#include "sysdep/faultinfo.h"

struct arch_thread {
+ unsigned long debugregs[8];
+ int debugregs_seq;
+ struct faultinfo faultinfo;
};

/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
@@ -20,7 +24,11 @@

#define cpu_relax() rep_nop()

-#define INIT_ARCH_THREAD { }
+#define INIT_ARCH_THREAD { .debugregs = { [ 0 ... 7 ] = 0 }, \
+ .debugregs_seq = 0, \
+ .faultinfo = { 0, 0, 0 } }
+
+#include "asm/arch/user.h"

#define current_text_addr() \
({ void *pc; __asm__("movq $1f,%0\n1:":"=g" (pc)); pc; })
-
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