97f7943d70
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>
65 lines
2.1 KiB
C
65 lines
2.1 KiB
C
#ifndef _ASM_KPROBES_H
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#define _ASM_KPROBES_H
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/*
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* Kernel Probes (KProbes)
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* include/asm-ppc64/kprobes.h
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright (C) IBM Corporation, 2002, 2004
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*
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* 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
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* Probes initial implementation ( includes suggestions from
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* Rusty Russell).
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* 2004-Nov Modified for PPC64 by Ananth N Mavinakayanahalli
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* <ananth@in.ibm.com>
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*/
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#include <linux/types.h>
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#include <linux/ptrace.h>
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struct pt_regs;
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typedef unsigned int kprobe_opcode_t;
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#define BREAKPOINT_INSTRUCTION 0x7fe00008 /* trap */
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#define MAX_INSN_SIZE 1
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#define IS_TW(instr) (((instr) & 0xfc0007fe) == 0x7c000008)
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#define IS_TD(instr) (((instr) & 0xfc0007fe) == 0x7c000088)
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#define IS_TDI(instr) (((instr) & 0xfc000000) == 0x08000000)
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#define IS_TWI(instr) (((instr) & 0xfc000000) == 0x0c000000)
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#define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)((func_descr_t *)pentry)
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#define ARCH_SUPPORTS_KRETPROBES
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void kretprobe_trampoline(void);
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/* Architecture specific copy of original instruction */
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struct arch_specific_insn {
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/* copy of original instruction */
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kprobe_opcode_t *insn;
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};
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#ifdef CONFIG_KPROBES
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extern int kprobe_exceptions_notify(struct notifier_block *self,
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unsigned long val, void *data);
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#else /* !CONFIG_KPROBES */
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static inline int kprobe_exceptions_notify(struct notifier_block *self,
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unsigned long val, void *data)
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{
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return 0;
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}
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#endif
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#endif /* _ASM_KPROBES_H */
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