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[PATCH] uml: S390 preparation, abstract host page fault data 

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>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Bodo Stroesser 2005-05-05 16:15:31 -07:00 committed by Linus Torvalds
parent ea66e8a3b6
commit c578455a3e
24 changed files with 279 additions and 115 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/um/include/kern_util.h
View File

@ -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 int current_pid(void);
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 timer_irq(union uml_pt_regs *regs);
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);

29
arch/um/include/sysdep-i386/faultinfo.h Normal file
View File

@ -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

23
arch/um/include/sysdep-i386/ptrace.h
View File

@ -31,6 +31,7 @@ extern int sysemu_supported;
#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 @@ extern int sysemu_supported;
#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 @@ union uml_pt_regs {
struct tt_regs {
long syscall;
void *sc;
struct faultinfo faultinfo;
} tt;
#endif
#ifdef UML_CONFIG_MODE_SKAS
@ -78,9 +74,7 @@ union uml_pt_regs {
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 @@ struct syscall_args {
#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

19
arch/um/include/sysdep-i386/sigcontext.h
View File

@ -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);

22
arch/um/include/sysdep-i386/skas_ptrace.h Normal file
View File

@ -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

22
arch/um/include/sysdep-ia64/skas_ptrace.h Normal file
View File

@ -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

22
arch/um/include/sysdep-ppc/skas_ptrace.h Normal file
View File

@ -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

29
arch/um/include/sysdep-x86_64/faultinfo.h Normal file
View File

@ -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

16
arch/um/include/sysdep-x86_64/ptrace.h
View File

@ -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 @@ union uml_pt_regs {
long syscall;
unsigned long orig_rax;
void *sc;
struct faultinfo faultinfo;
} tt;
#endif
#ifdef UML_CONFIG_MODE_SKAS
@ -90,9 +92,7 @@ union uml_pt_regs {
/* 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 @@ struct syscall_args {
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

15
arch/um/include/sysdep-x86_64/sigcontext.h
View File

@ -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);

22
arch/um/include/sysdep-x86_64/skas_ptrace.h Normal file
View File

@ -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

16
arch/um/kernel/ptrace.c
View File

@ -252,13 +252,13 @@ long sys_ptrace(long request, long pid, long addr, long data)
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;
@ -269,6 +269,7 @@ long sys_ptrace(long request, long pid, long addr, long data)
sizeof(child->pending.signal));
break;
#ifdef PTRACE_LDT
case PTRACE_LDT: {
struct ptrace_ldt ldt;
@ -284,6 +285,7 @@ long sys_ptrace(long request, long pid, long addr, long data)
ret = -EIO;
break;
}
#endif
#ifdef CONFIG_PROC_MM
case PTRACE_SWITCH_MM: {
struct mm_struct *old = child->mm;

3
arch/um/kernel/skas/include/skas.h
View File

@ -27,9 +27,10 @@ extern void map(int fd, unsigned long virt, unsigned long len, int r, int w,
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

26
arch/um/kernel/skas/process.c
View File

@ -4,6 +4,7 @@
*/
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
@ -37,17 +38,26 @@ int is_skas_winch(int pid, int fd, void *data)
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);
segv(fault.addr, 0, FAULT_WRITE(fault.is_write), 1, NULL);
/* 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));
}
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 @@ void userspace(union uml_pt_regs *regs)
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 @@ void userspace(union uml_pt_regs *regs)
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 "

24
arch/um/kernel/skas/trap_user.c
View File

@ -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 @@ void sig_handler_common_skas(int sig, void *sc_ptr)
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 @@ void sig_handler_common_skas(int sig, void *sc_ptr)
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);

25
arch/um/kernel/trap_kern.c
View File

@ -133,12 +133,19 @@ static int check_remapped_addr(unsigned long address, int is_write)
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 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write,
}
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 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write,
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 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write,
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 @@ void relay_signal(int sig, union uml_pt_regs *regs)
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);
}

13
arch/um/kernel/trap_user.c
View File

@ -54,23 +54,22 @@ struct {
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)

4
arch/um/kernel/tt/tracer.c
View File

@ -89,8 +89,10 @@ void tracer_panic(char *format, ...)
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();
}

6
arch/um/kernel/tt/trap_user.c
View File

@ -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 @@ void sig_handler_common_tt(int sig, void *sc_ptr)
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;

17
arch/um/sys-i386/signal.c
View File

@ -47,9 +47,6 @@ static int copy_sc_from_user_skas(struct pt_regs *regs,
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 @@ static int copy_sc_from_user_skas(struct pt_regs *regs,
}
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 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp,
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 @@ static int copy_sc_to_user(struct sigcontext *to, struct _fpstate *fp,
{
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,

10
arch/um/sys-x86_64/signal.c
View File

@ -57,7 +57,7 @@ static int copy_sc_from_user_skas(struct pt_regs *regs,
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 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp,
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);
}

5
include/asm-um/processor-generic.h
View File

@ -24,9 +24,6 @@ struct thread_struct {
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 @@ struct thread_struct {
.forking = 0, \
.nsyscalls = 0, \
.regs = EMPTY_REGS, \
.cr2 = 0, \
.err = 0, \
.fault_addr = NULL, \
.prev_sched = NULL, \
.temp_stack = 0, \

7
include/asm-um/processor-i386.h
View File

@ -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"

12
include/asm-um/processor-x86_64.h
View File

@ -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 @@ extern inline void rep_nop(void)
#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; })