From 8b7b80b9ebb46dd88fbb94e918297295cf312b59 Mon Sep 17 00:00:00 2001
From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Date: Thu, 23 Aug 2012 21:31:32 +0000
Subject: 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: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/include/asm/thread_info.h |  4 ++-
 arch/powerpc/include/asm/uprobes.h     | 54 ++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/include/asm/uprobes.h

(limited to 'arch/powerpc/include')

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index faf93529cbf..e942203cd4a 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -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 */
diff --git a/arch/powerpc/include/asm/uprobes.h b/arch/powerpc/include/asm/uprobes.h
new file mode 100644
index 00000000000..13ba5077b59
--- /dev/null
+++ b/arch/powerpc/include/asm/uprobes.h
@@ -0,0 +1,54 @@
+#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 */
-- 
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