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[PATCH] Kprobes/IA64: kdebug die notification mechanism 

As many of you know that kprobes exist in the main line kernel for various
architecture including i386, x86_64, ppc64 and sparc64.  Attached patches
following this mail are a port of Kprobes and Jprobes for IA64.

I have tesed this patches for kprobes and Jprobes and this seems to work fine.
 I have tested this patch by inserting kprobes on various slots and various
templates including various types of branch instructions.

I have also tested this patch using the tool
http://marc.theaimsgroup.com/?l=linux-kernel&m=111657358022586&w=2 and the
kprobes for IA64 works great.

Here is list of TODO things and pathes for the same will appear soon.

1) Support kprobes on "mov r1=ip" type of instruction
2) Support Kprobes and Jprobes to exist on the same address
3) Support Return probes
3) Architecture independent cleanup of kprobes

This patch adds the kdebug die notification mechanism needed by Kprobes.

For break instruction on Branch type slot, imm21 is ignored and value
zero is placed in IIM register, hence we need to handle kprobes
for switch case zero.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Rusty Lynch <Rusty.lynch@intel.com>

From: Rusty Lynch <rusty.lynch@intel.com>

At the point in traps.c where we recieve a break with a zero value, we can
not say if the break was a result of a kprobe or some other debug facility.

This simple patch changes the informational string to a more correct "break
0" value, and applies to the 2.6.12-rc2-mm2 tree with all the kprobes
patches that were just recently included for the next mm cut.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Anil S Keshavamurthy 2005-06-23 00:09:27 -07:00 committed by Linus Torvalds
parent 0aa55e4d7d
commit 7213b25218
4 changed files with 103 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
arch/ia64/kernel/traps.c
View File

@ -21,12 +21,26 @@
#include <asm/intrinsics.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/kdebug.h>
extern spinlock_t timerlist_lock;
fpswa_interface_t *fpswa_interface;
EXPORT_SYMBOL(fpswa_interface);
struct notifier_block *ia64die_chain;
static DEFINE_SPINLOCK(die_notifier_lock);
int register_die_notifier(struct notifier_block *nb)
{
int err = 0;
unsigned long flags;
spin_lock_irqsave(&die_notifier_lock, flags);
err = notifier_chain_register(&ia64die_chain, nb);
spin_unlock_irqrestore(&die_notifier_lock, flags);
return err;
}
void __init
trap_init (void)
{
@ -137,6 +151,10 @@ ia64_bad_break (unsigned long break_num, struct pt_regs *regs)
switch (break_num) {
case 0: /* unknown error (used by GCC for __builtin_abort()) */
if (notify_die(DIE_BREAK, "break 0", regs, break_num, TRAP_BRKPT, SIGTRAP)
== NOTIFY_STOP) {
return;
}
die_if_kernel("bugcheck!", regs, break_num);
sig = SIGILL; code = ILL_ILLOPC;
break;
@ -189,6 +207,15 @@ ia64_bad_break (unsigned long break_num, struct pt_regs *regs)
sig = SIGILL; code = __ILL_BNDMOD;
break;
case 0x80200:
case 0x80300:
if (notify_die(DIE_BREAK, "kprobe", regs, break_num, TRAP_BRKPT, SIGTRAP)
== NOTIFY_STOP) {
return;
}
sig = SIGTRAP; code = TRAP_BRKPT;
break;
default:
if (break_num < 0x40000 || break_num > 0x100000)
die_if_kernel("Bad break", regs, break_num);
@ -548,7 +575,11 @@ ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
#endif
break;
case 35: siginfo.si_code = TRAP_BRANCH; ifa = 0; break;
case 36: siginfo.si_code = TRAP_TRACE; ifa = 0; break;
case 36:
if (notify_die(DIE_SS, "ss", &regs, vector,
vector, SIGTRAP) == NOTIFY_STOP)
return;
siginfo.si_code = TRAP_TRACE; ifa = 0; break;
}
siginfo.si_signo = SIGTRAP;
siginfo.si_errno = 0;

8
arch/ia64/mm/fault.c
View File

@ -14,6 +14,7 @@
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/kdebug.h>
extern void die (char *, struct pt_regs *, long);
@ -102,6 +103,13 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
goto bad_area_no_up;
#endif
/*
* This is to handle the kprobes on user space access instructions
*/
if (notify_die(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT,
SIGSEGV) == NOTIFY_STOP)
return;
down_read(&mm->mmap_sem);
vma = find_vma_prev(mm, address, &prev_vma);

2
include/asm-ia64/break.h
View File

@ -12,6 +12,8 @@
* OS-specific debug break numbers:
*/
#define __IA64_BREAK_KDB 0x80100
#define __IA64_BREAK_KPROBE 0x80200
#define __IA64_BREAK_JPROBE 0x80300
/*
* OS-specific break numbers:

61
include/asm-ia64/kdebug.h Normal file
View File

@ -0,0 +1,61 @@
#ifndef _IA64_KDEBUG_H
#define _IA64_KDEBUG_H 1
/*
* include/asm-ia64/kdebug.h
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) Intel Corporation, 2005
*
* 2005-Apr Rusty Lynch <rusty.lynch@intel.com> and Anil S Keshavamurthy
* <anil.s.keshavamurthy@intel.com> adopted from
* include/asm-x86_64/kdebug.h
*/
#include <linux/notifier.h>
struct pt_regs;
struct die_args {
struct pt_regs *regs;
const char *str;
long err;
int trapnr;
int signr;
};
int register_die_notifier(struct notifier_block *nb);
extern struct notifier_block *ia64die_chain;
enum die_val {
DIE_BREAK = 1,
DIE_SS,
DIE_PAGE_FAULT,
};
static inline int notify_die(enum die_val val, char *str, struct pt_regs *regs,
long err, int trap, int sig)
{
struct die_args args = {
.regs = regs,
.str = str,
.err = err,
.trapnr = trap,
.signr = sig
};
return notifier_call_chain(&ia64die_chain, val, &args);
}
#endif