kernel-ark/include/asm-ppc64/kprobes.h
Rusty Lynch 97f7943d70 [PATCH] Return probe redesign: ppc64 specific implementation
The following is a patch provided by Ananth Mavinakayanahalli that implements
the new PPC64 specific parts of the new function return probe design.

NOTE: Since getting Ananth's patch, I changed trampoline_probe_handler()
      to consume each of the outstanding return probem instances (feedback
      on my original RFC after Ananth cut a patch), and also added the
      arch_init() function (adding arch specific initialization.) I have
      cross compiled but have not testing this on a PPC64 machine.

Changes include:
 * Addition of kretprobe_trampoline to act as a dummy function for instrumented
   functions to return to, and for the return probe infrastructure to place
   a kprobe on on, gaining control so that the return probe handler
   can be called, and so that the instruction pointer can be moved back
   to the original return address.
 * Addition of arch_init(), allowing a kprobe to be registered on
   kretprobe_trampoline
 * Addition of trampoline_probe_handler() which is used as the pre_handler
   for the kprobe inserted on kretprobe_implementation.  This is the function
   that handles the details for calling the return probe handler function
   and returning control back at the original return address
 * Addition of arch_prepare_kretprobe() which is setup as the pre_handler
   for a kprobe registered at the beginning of the target function by
   kernel/kprobes.c so that a return probe instance can be setup when
   a caller enters the target function.  (A return probe instance contains
   all the needed information for trampoline_probe_handler to do it's job.)
 * Hooks added to the exit path of a task so that we can cleanup any left-over
   return probe instances (i.e. if a task dies while inside a targeted function
   then the return probe instance was reserved at the beginning of the function
   but the function never returns so we need to mark the instance as unused.)

Signed-off-by: Rusty Lynch <rusty.lynch@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27 15:23:53 -07:00

65 lines
2.1 KiB
C

#ifndef _ASM_KPROBES_H
#define _ASM_KPROBES_H
/*
* Kernel Probes (KProbes)
* include/asm-ppc64/kprobes.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) IBM Corporation, 2002, 2004
*
* 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
* Probes initial implementation ( includes suggestions from
* Rusty Russell).
* 2004-Nov Modified for PPC64 by Ananth N Mavinakayanahalli
* <ananth@in.ibm.com>
*/
#include <linux/types.h>
#include <linux/ptrace.h>
struct pt_regs;
typedef unsigned int kprobe_opcode_t;
#define BREAKPOINT_INSTRUCTION 0x7fe00008 /* trap */
#define MAX_INSN_SIZE 1
#define IS_TW(instr) (((instr) & 0xfc0007fe) == 0x7c000008)
#define IS_TD(instr) (((instr) & 0xfc0007fe) == 0x7c000088)
#define IS_TDI(instr) (((instr) & 0xfc000000) == 0x08000000)
#define IS_TWI(instr) (((instr) & 0xfc000000) == 0x0c000000)
#define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)((func_descr_t *)pentry)
#define ARCH_SUPPORTS_KRETPROBES
void kretprobe_trampoline(void);
/* Architecture specific copy of original instruction */
struct arch_specific_insn {
/* copy of original instruction */
kprobe_opcode_t *insn;
};
#ifdef CONFIG_KPROBES
extern int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data);
#else /* !CONFIG_KPROBES */
static inline int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data)
{
return 0;
}
#endif
#endif /* _ASM_KPROBES_H */