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Commit 8b7b80b9 authored by Ananth N Mavinakayanahalli's avatar Ananth N Mavinakayanahalli Committed by Benjamin Herrenschmidt
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powerpc: Uprobes port to powerpc 



This is the port of uprobes to powerpc. Usage is similar to x86.

[root@xxxx ~]# ./bin/perf probe -x /lib64/libc.so.6 malloc
Added new event:
  probe_libc:malloc    (on 0xb4860)

You can now use it in all perf tools, such as:

	perf record -e probe_libc:malloc -aR sleep 1

[root@xxxx ~]# ./bin/perf record -e probe_libc:malloc -aR sleep 20
[ perf record: Woken up 22 times to write data ]
[ perf record: Captured and wrote 5.843 MB perf.data (~255302 samples) ]
[root@xxxx ~]# ./bin/perf report --stdio
...

    69.05%           tar  libc-2.12.so   [.] malloc
    28.57%            rm  libc-2.12.so   [.] malloc
     1.32%  avahi-daemon  libc-2.12.so   [.] malloc
     0.58%          bash  libc-2.12.so   [.] malloc
     0.28%          sshd  libc-2.12.so   [.] malloc
     0.08%    irqbalance  libc-2.12.so   [.] malloc
     0.05%         bzip2  libc-2.12.so   [.] malloc
     0.04%         sleep  libc-2.12.so   [.] malloc
     0.03%    multipathd  libc-2.12.so   [.] malloc
     0.01%      sendmail  libc-2.12.so   [.] malloc
     0.01%     automount  libc-2.12.so   [.] malloc

The trap_nr addition patch is a prereq.

Signed-off-by: default avatarAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 41ab5266

arch/powerpc/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -239,6 +239,9 @@ config PPC_OF_PLATFORM_PCI 
config ARCH_SUPPORTS_DEBUG_PAGEALLOC

	def_bool y



config ARCH_SUPPORTS_UPROBES

	def_bool y



config PPC_ADV_DEBUG_REGS

	bool

	depends on 40x || BOOKE

arch/powerpc/include/asm/thread_info.h

+3 −1
Original line number Diff line number Diff line
@@ -102,6 +102,7 @@ static inline struct thread_info *current_thread_info(void) 
#define TIF_RESTOREALL		11	/* Restore all regs (implies NOERROR) */

#define TIF_NOERROR		12	/* Force successful syscall return */

#define TIF_NOTIFY_RESUME	13	/* callback before returning to user */

#define TIF_UPROBE		14	/* breakpointed or single-stepping */

#define TIF_SYSCALL_TRACEPOINT	15	/* syscall tracepoint instrumentation */



/* as above, but as bit values */
@@ -118,12 +119,13 @@ static inline struct thread_info *current_thread_info(void) 
#define _TIF_RESTOREALL		(1<<TIF_RESTOREALL)

#define _TIF_NOERROR		(1<<TIF_NOERROR)

#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)

#define _TIF_UPROBE		(1<<TIF_UPROBE)

#define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)

#define _TIF_SYSCALL_T_OR_A	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \

				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT)



#define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \

				 _TIF_NOTIFY_RESUME)

				 _TIF_NOTIFY_RESUME | _TIF_UPROBE)

#define _TIF_PERSYSCALL_MASK	(_TIF_RESTOREALL|_TIF_NOERROR)



/* Bits in local_flags */

arch/powerpc/include/asm/uprobes.h

0 → 100644
+54 −0
Original line number Diff line number Diff line 
#ifndef _ASM_UPROBES_H

#define _ASM_UPROBES_H

/*

 * User-space Probes (UProbes) for powerpc

 *

 * 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 IBM Corporation, 2007-2012

 *

 * Adapted from the x86 port by Ananth N Mavinakayanahalli <ananth@in.ibm.com>

 */



#include <linux/notifier.h>

#include <asm/probes.h>



typedef opcode_t uprobe_opcode_t;



#define MAX_UINSN_BYTES		4

#define UPROBE_XOL_SLOT_BYTES	(MAX_UINSN_BYTES)



/* The following alias is needed for reference from arch-agnostic code */

#define UPROBE_SWBP_INSN	BREAKPOINT_INSTRUCTION

#define UPROBE_SWBP_INSN_SIZE	4 /* swbp insn size in bytes */



struct arch_uprobe {

	union {

		u8	insn[MAX_UINSN_BYTES];

		u32	ainsn;

	};

};



struct arch_uprobe_task {

	unsigned long	saved_trap_nr;

};



extern int  arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long addr);

extern int  arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs);

extern int  arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);

extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);

extern int  arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data);

extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs);

#endif	/* _ASM_UPROBES_H */

arch/powerpc/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ obj-$(CONFIG_MODULES) += ppc_ksyms.o 
obj-$(CONFIG_BOOTX_TEXT)	+= btext.o

obj-$(CONFIG_SMP)		+= smp.o

obj-$(CONFIG_KPROBES)		+= kprobes.o

obj-$(CONFIG_UPROBES)		+= uprobes.o

obj-$(CONFIG_PPC_UDBG_16550)	+= legacy_serial.o udbg_16550.o

obj-$(CONFIG_STACKTRACE)	+= stacktrace.o

obj-$(CONFIG_SWIOTLB)		+= dma-swiotlb.o

arch/powerpc/kernel/signal.c

+6 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 


#include <linux/tracehook.h>

#include <linux/signal.h>

#include <linux/uprobes.h>

#include <linux/key.h>

#include <asm/hw_breakpoint.h>

#include <asm/uaccess.h>
@@ -157,6 +158,11 @@ static int do_signal(struct pt_regs *regs) 


void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)

{

	if (thread_info_flags & _TIF_UPROBE) {

		clear_thread_flag(TIF_UPROBE);

		uprobe_notify_resume(regs);

	}



	if (thread_info_flags & _TIF_SIGPENDING)

		do_signal(regs);