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Commit c1bf207d authored by David Daney's avatar David Daney Committed by Ralf Baechle
Browse files

MIPS: kprobe: Add support. 



This patch is based on previous work by Sony and Himanshu Chauhan.

I have done some cleanup and implemented JProbes and KRETPROBES.  The
KRETPROBES part is pretty much copied verbatim from powerpc.  A possible
future enhance might be to factor out the common code.

Signed-off-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
Cc: Himanshu Chauhan <hschauhan@nulltrace.org>
To: linux-mips@linux-mips.org
To: ananth@in.ibm.com,
To: anil.s.keshavamurthy@intel.com
To: davem@davemloft.net
To: masami.hiramatsu.pt@hitachi.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1525/
Patchwork: https://patchwork.linux-mips.org/patch/1530/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 2ea6399f

arch/mips/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -10,6 +10,8 @@ config MIPS 
	select HAVE_DYNAMIC_FTRACE

	select HAVE_FTRACE_MCOUNT_RECORD

	select HAVE_FUNCTION_GRAPH_TRACER

	select HAVE_KPROBES

	select HAVE_KRETPROBES

	select RTC_LIB if !MACH_LOONGSON



mainmenu "Linux/MIPS Kernel Configuration"

arch/mips/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -259,6 +259,9 @@ endif 
vmlinux.32: vmlinux

	$(OBJCOPY) -O $(32bit-bfd) $(OBJCOPYFLAGS) $< $@





#obj-$(CONFIG_KPROBES)		+= kprobes.o



#

# The 64-bit ELF tools are pretty broken so at this time we generate 64-bit

# ELF files from 32-bit files by conversion.

arch/mips/include/asm/break.h

+2 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ 
#define BRK_BUG		512	/* Used by BUG() */

#define BRK_KDB		513	/* Used in KDB_ENTER() */

#define BRK_MEMU	514	/* Used by FPU emulator */

#define BRK_KPROBE_BP	515	/* Kprobe break */

#define BRK_KPROBE_SSTEPBP 516	/* Kprobe single step software implementation */

#define BRK_MULOVF	1023	/* Multiply overflow */



#endif /* __ASM_BREAK_H */

arch/mips/include/asm/kdebug.h

+3 −0
Original line number Diff line number Diff line
@@ -8,6 +8,9 @@ enum die_val { 
	DIE_FP,

	DIE_TRAP,

	DIE_RI,

	DIE_PAGE_FAULT,

	DIE_BREAK,

	DIE_SSTEPBP

};



#endif /* _ASM_MIPS_KDEBUG_H */

arch/mips/include/asm/kprobes.h

0 → 100644
+92 −0
Original line number Diff line number Diff line 
/*

 *  Kernel Probes (KProbes)

 *  include/asm-mips/kprobes.h

 *

 *  Copyright 2006 Sony Corp.

 *  Copyright 2010 Cavium Networks

 *

 *  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; version 2 of the License.

 *

 *  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

 */



#ifndef _ASM_KPROBES_H

#define _ASM_KPROBES_H



#include <linux/ptrace.h>

#include <linux/types.h>



#include <asm/cacheflush.h>

#include <asm/kdebug.h>

#include <asm/inst.h>



#define  __ARCH_WANT_KPROBES_INSN_SLOT



struct kprobe;

struct pt_regs;



typedef union mips_instruction kprobe_opcode_t;



#define MAX_INSN_SIZE 2



#define flush_insn_slot(p)						\

do {									\

	flush_icache_range((unsigned long)p->addr,			\

			   (unsigned long)p->addr +			\

			   (MAX_INSN_SIZE * sizeof(kprobe_opcode_t)));	\

} while (0)





#define kretprobe_blacklist_size 0



void arch_remove_kprobe(struct kprobe *p);



/* Architecture specific copy of original instruction*/

struct arch_specific_insn {

	/* copy of the original instruction */

	kprobe_opcode_t *insn;

};



struct prev_kprobe {

	struct kprobe *kp;

	unsigned long status;

	unsigned long old_SR;

	unsigned long saved_SR;

	unsigned long saved_epc;

};



#define MAX_JPROBES_STACK_SIZE 128

#define MAX_JPROBES_STACK_ADDR \

	(((unsigned long)current_thread_info()) + THREAD_SIZE - 32 - sizeof(struct pt_regs))



#define MIN_JPROBES_STACK_SIZE(ADDR)					\

	((((ADDR) + MAX_JPROBES_STACK_SIZE) > MAX_JPROBES_STACK_ADDR)	\

		? MAX_JPROBES_STACK_ADDR - (ADDR)			\

		: MAX_JPROBES_STACK_SIZE)





/* per-cpu kprobe control block */

struct kprobe_ctlblk {

	unsigned long kprobe_status;

	unsigned long kprobe_old_SR;

	unsigned long kprobe_saved_SR;

	unsigned long kprobe_saved_epc;

	unsigned long jprobe_saved_sp;

	struct pt_regs jprobe_saved_regs;

	u8 jprobes_stack[MAX_JPROBES_STACK_SIZE];

	struct prev_kprobe prev_kprobe;

};



extern int kprobe_exceptions_notify(struct notifier_block *self,

				    unsigned long val, void *data);



#endif				/* _ASM_KPROBES_H */