[PATCH v4] perf: Split out arch specific code & improve PowerPC perf probe support

[PATCH v4] perf: Split out arch specific code & improve PowerPC perf probe support

[Ian Munsie]

Here's the 4th version of the perf probe PowerPC support and perf arch specific
infrastructure patches rebased on top of tip/perf/core.


Changelog V4:
* Rebased on top of tip/perf/core (with powerpc/next merged) and resolved merge
  conflicts.
* Move the check for DWARF support prior to the inclusion of the arch
  specific Makefile so that the arch specific Makefile can include the relevant
  files in the build only if DWARF support is available.
* Fix NO_DWARF build on x86 and PowerPC

Changelog V3:
  From Masami Hiramatsu's feedback DWARF support is disabled altogether if the
  architecture specific Makefile does not define PERF_HAVE_DWARF_REGS - ie,
  DWARF register mappings are missing for the architecture. A message
  indicating this is printed out during compilation.

Changelog V2:
  From Masami Hiramatsu's suggestion, I added a check in the Makefile for if
  the arch specific Makefile defines PERF_HAVE_DWARF_REGS, printing a message
  during build if it has not. This simplifies the code removing the odd macro
  from the previous version and the need for an arch specific
  arch_dwarf-regs.h.  I have not entirely disabled DWARF support for
  architectures that don't implement the register mappings, so that they can
  still add a probe based on a line number (they will be missing the ability to
  capture the value of a variable from a register).

These patches add the required mappings to use perf probe on PowerPC.

Part 1 of the patch series moves the arch dependent x86 32 and 64 bit DWARF
register number mappings out into a separate arch directory and adds the
necessary Makefile foo to use it.

Part 2 of the patch series adds the PowerPC mappings -
Functionality wise it requires the patch titled "powerpc: Add kprobe-based
event tracer" from the powerpc-next tree to provide the
HAVE_REGS_AND_STACK_ACCESS_API required for CONFIG_KPROBE_EVENT. The code will
still compile cleanly without it and will fail gracefully at runtime on the
missing CONFIG_KPROBE_EVENT support as before as well as printing a warning
message during compilation.

[PATCH v4] perf: Split out arch specific code & improve PowerPC perf probe support

[Ian Munsie]

Here's the 4th version of the perf probe PowerPC support and perf arch specific
infrastructure patches rebased on top of tip/perf/core.


Changelog V4:
* Rebased on top of tip/perf/core (with powerpc/next merged) and resolved merge
  conflicts.
* Move the check for DWARF support prior to the inclusion of the arch
  specific Makefile so that the arch specific Makefile can include the relevant
  files in the build only if DWARF support is available.
* Fix NO_DWARF build on x86 and PowerPC

Changelog V3:
  From Masami Hiramatsu's feedback DWARF support is disabled altogether if the
  architecture specific Makefile does not define PERF_HAVE_DWARF_REGS - ie,
  DWARF register mappings are missing for the architecture. A message
  indicating this is printed out during compilation.

Changelog V2:
  From Masami Hiramatsu's suggestion, I added a check in the Makefile for if
  the arch specific Makefile defines PERF_HAVE_DWARF_REGS, printing a message
  during build if it has not. This simplifies the code removing the odd macro
  from the previous version and the need for an arch specific
  arch_dwarf-regs.h.  I have not entirely disabled DWARF support for
  architectures that don't implement the register mappings, so that they can
  still add a probe based on a line number (they will be missing the ability to
  capture the value of a variable from a register).

These patches add the required mappings to use perf probe on PowerPC.

Part 1 of the patch series moves the arch dependent x86 32 and 64 bit DWARF
register number mappings out into a separate arch directory and adds the
necessary Makefile foo to use it.

Part 2 of the patch series adds the PowerPC mappings -
Functionality wise it requires the patch titled "powerpc: Add kprobe-based
event tracer" from the powerpc-next tree to provide the
HAVE_REGS_AND_STACK_ACCESS_API required for CONFIG_KPROBE_EVENT. The code will
still compile cleanly without it and will fail gracefully at runtime on the
missing CONFIG_KPROBE_EVENT support as before as well as printing a warning
message during compilation.

[PATCH v4 1/2] perf: Move arch specific code into separate arch directory

[Ian Munsie]

From: Ian Munsie <imunsie@au.ibm.com>

The perf userspace tool included some architecture specific code to map
registers from the DWARF register number into the names used by the regs
and stack access API.

This patch moves the architecture specific code out into a separate
arch/x86 directory along with the infrastructure required to use it.

Signed-off-by: Ian Munsie <imunsie@au.ibm.com>
---
Changes since v3:
* Move the check for DWARF support prior to the inclusion of the arch specific
  Makefile so that the arch specific Makefile can include the relevant files in
  the build only if DWARF support is available.
* Fix NO_DWARF build

 tools/perf/Makefile                   |   36 +++++++++++++---
 tools/perf/arch/x86/Makefile          |    4 ++
 tools/perf/arch/x86/util/dwarf-regs.c |   75 +++++++++++++++++++++++++++++++++
 tools/perf/util/include/dwarf-regs.h  |    8 ++++
 tools/perf/util/probe-finder.c        |   55 +-----------------------
 5 files changed, 119 insertions(+), 59 deletions(-)
 create mode 100644 tools/perf/arch/x86/Makefile
 create mode 100644 tools/perf/arch/x86/util/dwarf-regs.c
 create mode 100644 tools/perf/util/include/dwarf-regs.h

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 3cb3449..e8bf2e1 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -173,6 +173,20 @@ uname_R := $(shell sh -c 'uname -r 2>/dev/null || echo not')
 uname_P := $(shell sh -c 'uname -p 2>/dev/null || echo not')
 uname_V := $(shell sh -c 'uname -v 2>/dev/null || echo not')
 
+ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
+				  -e s/arm.*/arm/ -e s/sa110/arm/ \
+				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
+				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
+				  -e s/sh[234].*/sh/ )
+
+# Additional ARCH settings for x86
+ifeq ($(ARCH),i386)
+        ARCH := x86
+endif
+ifeq ($(ARCH),x86_64)
+        ARCH := x86
+endif
+
 # CFLAGS and LDFLAGS are for the users to override from the command line.
 
 #
@@ -285,7 +299,7 @@ endif
 # Those must not be GNU-specific; they are shared with perl/ which may
 # be built by a different compiler. (Note that this is an artifact now
 # but it still might be nice to keep that distinction.)
-BASIC_CFLAGS = -Iutil/include
+BASIC_CFLAGS = -Iutil/include -Iarch/$(ARCH)/include
 BASIC_LDFLAGS =
 
 # Guard against environment variables
@@ -367,6 +381,7 @@ LIB_H += util/include/asm/byteorder.h
 LIB_H += util/include/asm/swab.h
 LIB_H += util/include/asm/system.h
 LIB_H += util/include/asm/uaccess.h
+LIB_H += util/include/dwarf-regs.h
 LIB_H += perf.h
 LIB_H += util/cache.h
 LIB_H += util/callchain.h
@@ -487,6 +502,15 @@ PERFLIBS = $(LIB_FILE)
 -include config.mak.autogen
 -include config.mak
 
+ifndef NO_DWARF
+ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
+	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/elfutils-dev);
+	NO_DWARF := 1
+endif # Dwarf support
+endif # NO_DWARF
+
+-include arch/$(ARCH)/Makefile
+
 ifeq ($(uname_S),Darwin)
 	ifndef NO_FINK
 		ifeq ($(shell test -d /sw/lib && echo y),y)
@@ -519,15 +543,15 @@ else
 	msg := $(error No libelf.h/libelf found, please install libelf-dev/elfutils-libelf-devel and glibc-dev[el]);
 endif
 
-ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
-	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/elfutils-dev);
-else
 ifndef NO_DWARF
+ifeq ($(origin PERF_HAVE_DWARF_REGS), undefined)
+	msg := $(warning DWARF register mappings have not been defined for architecture $(ARCH), DWARF support disabled);
+else
 	BASIC_CFLAGS += -I/usr/include/elfutils -DDWARF_SUPPORT
 	EXTLIBS += -lelf -ldw
 	LIB_OBJS += $(OUTPUT)util/probe-finder.o
-endif
-endif
+endif # PERF_HAVE_DWARF_REGS
+endif # NO_DWARF
 
 ifneq ($(shell sh -c "(echo '\#include <newt.h>'; echo 'int main(void) { newtInit(); newtCls(); return newtFinished(); }') | $(CC) -x c - $(ALL_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -lnewt -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
 	msg := $(warning newt not found, disables TUI support. Please install newt-devel or libnewt-dev);
diff --git a/tools/perf/arch/x86/Makefile b/tools/perf/arch/x86/Makefile
new file mode 100644
index 0000000..15130b5
--- /dev/null
+++ b/tools/perf/arch/x86/Makefile
@@ -0,0 +1,4 @@
+ifndef NO_DWARF
+PERF_HAVE_DWARF_REGS := 1
+LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
+endif
diff --git a/tools/perf/arch/x86/util/dwarf-regs.c b/tools/perf/arch/x86/util/dwarf-regs.c
new file mode 100644
index 0000000..a794d30
--- /dev/null
+++ b/tools/perf/arch/x86/util/dwarf-regs.c
@@ -0,0 +1,75 @@
+/*
+ * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
+ * Extracted from probe-finder.c
+ *
+ * Written by Masami Hiramatsu <mhiramat@redhat.com>
+ *
+ * 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.
+ *
+ */
+
+#include <libio.h>
+#include <dwarf-regs.h>
+
+/*
+ * Generic dwarf analysis helpers
+ */
+
+#define X86_32_MAX_REGS 8
+const char *x86_32_regs_table[X86_32_MAX_REGS] = {
+	"%ax",
+	"%cx",
+	"%dx",
+	"%bx",
+	"$stack",	/* Stack address instead of %sp */
+	"%bp",
+	"%si",
+	"%di",
+};
+
+#define X86_64_MAX_REGS 16
+const char *x86_64_regs_table[X86_64_MAX_REGS] = {
+	"%ax",
+	"%dx",
+	"%cx",
+	"%bx",
+	"%si",
+	"%di",
+	"%bp",
+	"%sp",
+	"%r8",
+	"%r9",
+	"%r10",
+	"%r11",
+	"%r12",
+	"%r13",
+	"%r14",
+	"%r15",
+};
+
+/* TODO: switching by dwarf address size */
+#ifdef __x86_64__
+#define ARCH_MAX_REGS X86_64_MAX_REGS
+#define arch_regs_table x86_64_regs_table
+#else
+#define ARCH_MAX_REGS X86_32_MAX_REGS
+#define arch_regs_table x86_32_regs_table
+#endif
+
+/* Return architecture dependent register string (for kprobe-tracer) */
+const char *get_arch_regstr(unsigned int n)
+{
+	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
+}
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
new file mode 100644
index 0000000..cf6727e
--- /dev/null
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -0,0 +1,8 @@
+#ifndef _PERF_DWARF_REGS_H_
+#define _PERF_DWARF_REGS_H_
+
+#ifdef DWARF_SUPPORT
+const char *get_arch_regstr(unsigned int n);
+#endif
+
+#endif
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 3e79775..e7ee52f 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -31,6 +31,7 @@
 #include <string.h>
 #include <stdarg.h>
 #include <ctype.h>
+#include <dwarf-regs.h>
 
 #include "string.h"
 #include "event.h"
@@ -38,61 +39,9 @@
 #include "util.h"
 #include "probe-finder.h"
 
-
-/*
- * Generic dwarf analysis helpers
- */
-
-#define X86_32_MAX_REGS 8
-const char *x86_32_regs_table[X86_32_MAX_REGS] = {
-	"%ax",
-	"%cx",
-	"%dx",
-	"%bx",
-	"$stack",	/* Stack address instead of %sp */
-	"%bp",
-	"%si",
-	"%di",
-};
-
-#define X86_64_MAX_REGS 16
-const char *x86_64_regs_table[X86_64_MAX_REGS] = {
-	"%ax",
-	"%dx",
-	"%cx",
-	"%bx",
-	"%si",
-	"%di",
-	"%bp",
-	"%sp",
-	"%r8",
-	"%r9",
-	"%r10",
-	"%r11",
-	"%r12",
-	"%r13",
-	"%r14",
-	"%r15",
-};
-
-/* TODO: switching by dwarf address size */
-#ifdef __x86_64__
-#define ARCH_MAX_REGS X86_64_MAX_REGS
-#define arch_regs_table x86_64_regs_table
-#else
-#define ARCH_MAX_REGS X86_32_MAX_REGS
-#define arch_regs_table x86_32_regs_table
-#endif
-
 /* Kprobe tracer basic type is up to u64 */
 #define MAX_BASIC_TYPE_BITS	64
 
-/* Return architecture dependent register string (for kprobe-tracer) */
-static const char *get_arch_regstr(unsigned int n)
-{
-	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
-}
-
 /*
  * Compare the tail of two strings.
  * Return 0 if whole of either string is same as another's tail part.
@@ -447,7 +396,7 @@ static int convert_location(Dwarf_Op *op, struct probe_finder *pf)
 
 	regs = get_arch_regstr(regn);
 	if (!regs) {
-		pr_warning("%u exceeds max register number.\n", regn);
+		pr_warning("Mapping for DWARF register number %u missing on this architecture.", regn);
 		return -ERANGE;
 	}
 
-- 
1.7.0

[PATCH v4 1/2] perf: Move arch specific code into separate arch directory

[Ian Munsie]

From: Ian Munsie <imunsie@au.ibm.com>

The perf userspace tool included some architecture specific code to map
registers from the DWARF register number into the names used by the regs
and stack access API.

This patch moves the architecture specific code out into a separate
arch/x86 directory along with the infrastructure required to use it.

Signed-off-by: Ian Munsie <imunsie@au.ibm.com>
---
Changes since v3:
* Move the check for DWARF support prior to the inclusion of the arch specific
  Makefile so that the arch specific Makefile can include the relevant files in
  the build only if DWARF support is available.
* Fix NO_DWARF build

 tools/perf/Makefile                   |   36 +++++++++++++---
 tools/perf/arch/x86/Makefile          |    4 ++
 tools/perf/arch/x86/util/dwarf-regs.c |   75 +++++++++++++++++++++++++++++++++
 tools/perf/util/include/dwarf-regs.h  |    8 ++++
 tools/perf/util/probe-finder.c        |   55 +-----------------------
 5 files changed, 119 insertions(+), 59 deletions(-)
 create mode 100644 tools/perf/arch/x86/Makefile
 create mode 100644 tools/perf/arch/x86/util/dwarf-regs.c
 create mode 100644 tools/perf/util/include/dwarf-regs.h

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 3cb3449..e8bf2e1 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -173,6 +173,20 @@ uname_R := $(shell sh -c 'uname -r 2>/dev/null || echo not')
 uname_P := $(shell sh -c 'uname -p 2>/dev/null || echo not')
 uname_V := $(shell sh -c 'uname -v 2>/dev/null || echo not')
 
+ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
+				  -e s/arm.*/arm/ -e s/sa110/arm/ \
+				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
+				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
+				  -e s/sh[234].*/sh/ )
+
+# Additional ARCH settings for x86
+ifeq ($(ARCH),i386)
+        ARCH := x86
+endif
+ifeq ($(ARCH),x86_64)
+        ARCH := x86
+endif
+
 # CFLAGS and LDFLAGS are for the users to override from the command line.
 
 #
@@ -285,7 +299,7 @@ endif
 # Those must not be GNU-specific; they are shared with perl/ which may
 # be built by a different compiler. (Note that this is an artifact now
 # but it still might be nice to keep that distinction.)
-BASIC_CFLAGS = -Iutil/include
+BASIC_CFLAGS = -Iutil/include -Iarch/$(ARCH)/include
 BASIC_LDFLAGS =
 
 # Guard against environment variables
@@ -367,6 +381,7 @@ LIB_H += util/include/asm/byteorder.h
 LIB_H += util/include/asm/swab.h
 LIB_H += util/include/asm/system.h
 LIB_H += util/include/asm/uaccess.h
+LIB_H += util/include/dwarf-regs.h
 LIB_H += perf.h
 LIB_H += util/cache.h
 LIB_H += util/callchain.h
@@ -487,6 +502,15 @@ PERFLIBS = $(LIB_FILE)
 -include config.mak.autogen
 -include config.mak
 
+ifndef NO_DWARF
+ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
+	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/elfutils-dev);
+	NO_DWARF := 1
+endif # Dwarf support
+endif # NO_DWARF
+
+-include arch/$(ARCH)/Makefile
+
 ifeq ($(uname_S),Darwin)
 	ifndef NO_FINK
 		ifeq ($(shell test -d /sw/lib && echo y),y)
@@ -519,15 +543,15 @@ else
 	msg := $(error No libelf.h/libelf found, please install libelf-dev/elfutils-libelf-devel and glibc-dev[el]);
 endif
 
-ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
-	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/elfutils-dev);
-else
 ifndef NO_DWARF
+ifeq ($(origin PERF_HAVE_DWARF_REGS), undefined)
+	msg := $(warning DWARF register mappings have not been defined for architecture $(ARCH), DWARF support disabled);
+else
 	BASIC_CFLAGS += -I/usr/include/elfutils -DDWARF_SUPPORT
 	EXTLIBS += -lelf -ldw
 	LIB_OBJS += $(OUTPUT)util/probe-finder.o
-endif
-endif
+endif # PERF_HAVE_DWARF_REGS
+endif # NO_DWARF
 
 ifneq ($(shell sh -c "(echo '\#include <newt.h>'; echo 'int main(void) { newtInit(); newtCls(); return newtFinished(); }') | $(CC) -x c - $(ALL_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -lnewt -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
 	msg := $(warning newt not found, disables TUI support. Please install newt-devel or libnewt-dev);
diff --git a/tools/perf/arch/x86/Makefile b/tools/perf/arch/x86/Makefile
new file mode 100644
index 0000000..15130b5
--- /dev/null
+++ b/tools/perf/arch/x86/Makefile
@@ -0,0 +1,4 @@
+ifndef NO_DWARF
+PERF_HAVE_DWARF_REGS := 1
+LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
+endif
diff --git a/tools/perf/arch/x86/util/dwarf-regs.c b/tools/perf/arch/x86/util/dwarf-regs.c
new file mode 100644
index 0000000..a794d30
--- /dev/null
+++ b/tools/perf/arch/x86/util/dwarf-regs.c
@@ -0,0 +1,75 @@
+/*
+ * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
+ * Extracted from probe-finder.c
+ *
+ * Written by Masami Hiramatsu <mhiramat@redhat.com>
+ *
+ * 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.
+ *
+ */
+
+#include <libio.h>
+#include <dwarf-regs.h>
+
+/*
+ * Generic dwarf analysis helpers
+ */
+
+#define X86_32_MAX_REGS 8
+const char *x86_32_regs_table[X86_32_MAX_REGS] = {
+	"%ax",
+	"%cx",
+	"%dx",
+	"%bx",
+	"$stack",	/* Stack address instead of %sp */
+	"%bp",
+	"%si",
+	"%di",
+};
+
+#define X86_64_MAX_REGS 16
+const char *x86_64_regs_table[X86_64_MAX_REGS] = {
+	"%ax",
+	"%dx",
+	"%cx",
+	"%bx",
+	"%si",
+	"%di",
+	"%bp",
+	"%sp",
+	"%r8",
+	"%r9",
+	"%r10",
+	"%r11",
+	"%r12",
+	"%r13",
+	"%r14",
+	"%r15",
+};
+
+/* TODO: switching by dwarf address size */
+#ifdef __x86_64__
+#define ARCH_MAX_REGS X86_64_MAX_REGS
+#define arch_regs_table x86_64_regs_table
+#else
+#define ARCH_MAX_REGS X86_32_MAX_REGS
+#define arch_regs_table x86_32_regs_table
+#endif
+
+/* Return architecture dependent register string (for kprobe-tracer) */
+const char *get_arch_regstr(unsigned int n)
+{
+	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
+}
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
new file mode 100644
index 0000000..cf6727e
--- /dev/null
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -0,0 +1,8 @@
+#ifndef _PERF_DWARF_REGS_H_
+#define _PERF_DWARF_REGS_H_
+
+#ifdef DWARF_SUPPORT
+const char *get_arch_regstr(unsigned int n);
+#endif
+
+#endif
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 3e79775..e7ee52f 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -31,6 +31,7 @@
 #include <string.h>
 #include <stdarg.h>
 #include <ctype.h>
+#include <dwarf-regs.h>
 
 #include "string.h"
 #include "event.h"
@@ -38,61 +39,9 @@
 #include "util.h"
 #include "probe-finder.h"
 
-
-/*
- * Generic dwarf analysis helpers
- */
-
-#define X86_32_MAX_REGS 8
-const char *x86_32_regs_table[X86_32_MAX_REGS] = {
-	"%ax",
-	"%cx",
-	"%dx",
-	"%bx",
-	"$stack",	/* Stack address instead of %sp */
-	"%bp",
-	"%si",
-	"%di",
-};
-
-#define X86_64_MAX_REGS 16
-const char *x86_64_regs_table[X86_64_MAX_REGS] = {
-	"%ax",
-	"%dx",
-	"%cx",
-	"%bx",
-	"%si",
-	"%di",
-	"%bp",
-	"%sp",
-	"%r8",
-	"%r9",
-	"%r10",
-	"%r11",
-	"%r12",
-	"%r13",
-	"%r14",
-	"%r15",
-};
-
-/* TODO: switching by dwarf address size */
-#ifdef __x86_64__
-#define ARCH_MAX_REGS X86_64_MAX_REGS
-#define arch_regs_table x86_64_regs_table
-#else
-#define ARCH_MAX_REGS X86_32_MAX_REGS
-#define arch_regs_table x86_32_regs_table
-#endif
-
 /* Kprobe tracer basic type is up to u64 */
 #define MAX_BASIC_TYPE_BITS	64
 
-/* Return architecture dependent register string (for kprobe-tracer) */
-static const char *get_arch_regstr(unsigned int n)
-{
-	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
-}
-
 /*
  * Compare the tail of two strings.
  * Return 0 if whole of either string is same as another's tail part.
@@ -447,7 +396,7 @@ static int convert_location(Dwarf_Op *op, struct probe_finder *pf)
 
 	regs = get_arch_regstr(regn);
 	if (!regs) {
-		pr_warning("%u exceeds max register number.\n", regn);
+		pr_warning("Mapping for DWARF register number %u missing on this architecture.", regn);
 		return -ERANGE;
 	}
 
-- 
1.7.0

[PATCH v4 2/2] perf probe: Add PowerPC DWARF register number mappings

[Ian Munsie]

From: Ian Munsie <imunsie@au.ibm.com>

This patch adds mappings from the register numbers from DWARF to the
register names used in the PowerPC Regs and Stack Access API. This
allows perf probe to be used to record variable contents on PowerPC.

This patch depends on functionality in the powerpc/next tree, though it
will compile fine without it. Specifically this patch depends on commit
"powerpc: Add kprobe-based event tracer"

Signed-off-by: Ian Munsie <imunsie@au.ibm.com>
---
Changes since v3:
* Fix NO_DWARF build

 tools/perf/arch/powerpc/Makefile          |    4 +
 tools/perf/arch/powerpc/util/dwarf-regs.c |   88 +++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+), 0 deletions(-)
 create mode 100644 tools/perf/arch/powerpc/Makefile
 create mode 100644 tools/perf/arch/powerpc/util/dwarf-regs.c

diff --git a/tools/perf/arch/powerpc/Makefile b/tools/perf/arch/powerpc/Makefile
new file mode 100644
index 0000000..15130b5
--- /dev/null
+++ b/tools/perf/arch/powerpc/Makefile
@@ -0,0 +1,4 @@
+ifndef NO_DWARF
+PERF_HAVE_DWARF_REGS := 1
+LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
+endif
diff --git a/tools/perf/arch/powerpc/util/dwarf-regs.c b/tools/perf/arch/powerpc/util/dwarf-regs.c
new file mode 100644
index 0000000..48ae0c5
--- /dev/null
+++ b/tools/perf/arch/powerpc/util/dwarf-regs.c
@@ -0,0 +1,88 @@
+/*
+ * Mapping of DWARF debug register numbers into register names.
+ *
+ * Copyright (C) 2010 Ian Munsie, IBM Corporation.
+ *
+ * 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.
+ */
+
+#include <libio.h>
+#include <dwarf-regs.h>
+
+
+struct pt_regs_dwarfnum {
+	const char *name;
+	unsigned int dwarfnum;
+};
+
+#define STR(s) #s
+#define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
+#define GPR_DWARFNUM_NAME(num)	\
+	{.name = STR(%gpr##num), .dwarfnum = num}
+#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
+
+/*
+ * Reference:
+ * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
+ */
+static const struct pt_regs_dwarfnum regdwarfnum_table[] = {
+	GPR_DWARFNUM_NAME(0),
+	GPR_DWARFNUM_NAME(1),
+	GPR_DWARFNUM_NAME(2),
+	GPR_DWARFNUM_NAME(3),
+	GPR_DWARFNUM_NAME(4),
+	GPR_DWARFNUM_NAME(5),
+	GPR_DWARFNUM_NAME(6),
+	GPR_DWARFNUM_NAME(7),
+	GPR_DWARFNUM_NAME(8),
+	GPR_DWARFNUM_NAME(9),
+	GPR_DWARFNUM_NAME(10),
+	GPR_DWARFNUM_NAME(11),
+	GPR_DWARFNUM_NAME(12),
+	GPR_DWARFNUM_NAME(13),
+	GPR_DWARFNUM_NAME(14),
+	GPR_DWARFNUM_NAME(15),
+	GPR_DWARFNUM_NAME(16),
+	GPR_DWARFNUM_NAME(17),
+	GPR_DWARFNUM_NAME(18),
+	GPR_DWARFNUM_NAME(19),
+	GPR_DWARFNUM_NAME(20),
+	GPR_DWARFNUM_NAME(21),
+	GPR_DWARFNUM_NAME(22),
+	GPR_DWARFNUM_NAME(23),
+	GPR_DWARFNUM_NAME(24),
+	GPR_DWARFNUM_NAME(25),
+	GPR_DWARFNUM_NAME(26),
+	GPR_DWARFNUM_NAME(27),
+	GPR_DWARFNUM_NAME(28),
+	GPR_DWARFNUM_NAME(29),
+	GPR_DWARFNUM_NAME(30),
+	GPR_DWARFNUM_NAME(31),
+	REG_DWARFNUM_NAME("%msr",   66),
+	REG_DWARFNUM_NAME("%ctr",   109),
+	REG_DWARFNUM_NAME("%link",  108),
+	REG_DWARFNUM_NAME("%xer",   101),
+	REG_DWARFNUM_NAME("%dar",   119),
+	REG_DWARFNUM_NAME("%dsisr", 118),
+	REG_DWARFNUM_END,
+};
+
+/**
+ * get_arch_regstr() - lookup register name from it's DWARF register number
+ * @n:	the DWARF register number
+ *
+ * get_arch_regstr() returns the name of the register in struct
+ * regdwarfnum_table from it's DWARF register number. If the register is not
+ * found in the table, this returns NULL;
+ */
+const char *get_arch_regstr(unsigned int n)
+{
+	const struct pt_regs_dwarfnum *roff;
+	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
+		if (roff->dwarfnum == n)
+			return roff->name;
+	return NULL;
+}
-- 
1.7.0

[PATCH v4 2/2] perf probe: Add PowerPC DWARF register number mappings

[Ian Munsie]

From: Ian Munsie <imunsie@au.ibm.com>

This patch adds mappings from the register numbers from DWARF to the
register names used in the PowerPC Regs and Stack Access API. This
allows perf probe to be used to record variable contents on PowerPC.

This patch depends on functionality in the powerpc/next tree, though it
will compile fine without it. Specifically this patch depends on commit
"powerpc: Add kprobe-based event tracer"

Signed-off-by: Ian Munsie <imunsie@au.ibm.com>
---
Changes since v3:
* Fix NO_DWARF build

 tools/perf/arch/powerpc/Makefile          |    4 +
 tools/perf/arch/powerpc/util/dwarf-regs.c |   88 +++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+), 0 deletions(-)
 create mode 100644 tools/perf/arch/powerpc/Makefile
 create mode 100644 tools/perf/arch/powerpc/util/dwarf-regs.c

diff --git a/tools/perf/arch/powerpc/Makefile b/tools/perf/arch/powerpc/Makefile
new file mode 100644
index 0000000..15130b5
--- /dev/null
+++ b/tools/perf/arch/powerpc/Makefile
@@ -0,0 +1,4 @@
+ifndef NO_DWARF
+PERF_HAVE_DWARF_REGS := 1
+LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
+endif
diff --git a/tools/perf/arch/powerpc/util/dwarf-regs.c b/tools/perf/arch/powerpc/util/dwarf-regs.c
new file mode 100644
index 0000000..48ae0c5
--- /dev/null
+++ b/tools/perf/arch/powerpc/util/dwarf-regs.c
@@ -0,0 +1,88 @@
+/*
+ * Mapping of DWARF debug register numbers into register names.
+ *
+ * Copyright (C) 2010 Ian Munsie, IBM Corporation.
+ *
+ * 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.
+ */
+
+#include <libio.h>
+#include <dwarf-regs.h>
+
+
+struct pt_regs_dwarfnum {
+	const char *name;
+	unsigned int dwarfnum;
+};
+
+#define STR(s) #s
+#define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
+#define GPR_DWARFNUM_NAME(num)	\
+	{.name = STR(%gpr##num), .dwarfnum = num}
+#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
+
+/*
+ * Reference:
+ * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
+ */
+static const struct pt_regs_dwarfnum regdwarfnum_table[] = {
+	GPR_DWARFNUM_NAME(0),
+	GPR_DWARFNUM_NAME(1),
+	GPR_DWARFNUM_NAME(2),
+	GPR_DWARFNUM_NAME(3),
+	GPR_DWARFNUM_NAME(4),
+	GPR_DWARFNUM_NAME(5),
+	GPR_DWARFNUM_NAME(6),
+	GPR_DWARFNUM_NAME(7),
+	GPR_DWARFNUM_NAME(8),
+	GPR_DWARFNUM_NAME(9),
+	GPR_DWARFNUM_NAME(10),
+	GPR_DWARFNUM_NAME(11),
+	GPR_DWARFNUM_NAME(12),
+	GPR_DWARFNUM_NAME(13),
+	GPR_DWARFNUM_NAME(14),
+	GPR_DWARFNUM_NAME(15),
+	GPR_DWARFNUM_NAME(16),
+	GPR_DWARFNUM_NAME(17),
+	GPR_DWARFNUM_NAME(18),
+	GPR_DWARFNUM_NAME(19),
+	GPR_DWARFNUM_NAME(20),
+	GPR_DWARFNUM_NAME(21),
+	GPR_DWARFNUM_NAME(22),
+	GPR_DWARFNUM_NAME(23),
+	GPR_DWARFNUM_NAME(24),
+	GPR_DWARFNUM_NAME(25),
+	GPR_DWARFNUM_NAME(26),
+	GPR_DWARFNUM_NAME(27),
+	GPR_DWARFNUM_NAME(28),
+	GPR_DWARFNUM_NAME(29),
+	GPR_DWARFNUM_NAME(30),
+	GPR_DWARFNUM_NAME(31),
+	REG_DWARFNUM_NAME("%msr",   66),
+	REG_DWARFNUM_NAME("%ctr",   109),
+	REG_DWARFNUM_NAME("%link",  108),
+	REG_DWARFNUM_NAME("%xer",   101),
+	REG_DWARFNUM_NAME("%dar",   119),
+	REG_DWARFNUM_NAME("%dsisr", 118),
+	REG_DWARFNUM_END,
+};
+
+/**
+ * get_arch_regstr() - lookup register name from it's DWARF register number
+ * @n:	the DWARF register number
+ *
+ * get_arch_regstr() returns the name of the register in struct
+ * regdwarfnum_table from it's DWARF register number. If the register is not
+ * found in the table, this returns NULL;
+ */
+const char *get_arch_regstr(unsigned int n)
+{
+	const struct pt_regs_dwarfnum *roff;
+	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
+		if (roff->dwarfnum == n)
+			return roff->name;
+	return NULL;
+}
-- 
1.7.0

Re: [PATCH v4] perf: Split out arch specific code & improve PowerPC perf probe support

[Ian Munsie]

Excerpts from Ian Munsie's message of Tue Apr 20 16:58:31 +1000 2010:
> Here's the 4th version of the perf probe PowerPC support and perf arch specific
> infrastructure patches rebased on top of tip/perf/core.

That should read "rebased on top of tip/master".

Cheers,
-Ian

Re: [PATCH v4] perf: Split out arch specific code & improve PowerPC perf probe support

[Ian Munsie]

Excerpts from Ian Munsie's message of Tue Apr 20 16:58:31 +1000 2010:
> Here's the 4th version of the perf probe PowerPC support and perf arch specific
> infrastructure patches rebased on top of tip/perf/core.

That should read "rebased on top of tip/master".

Cheers,
-Ian

Re: [PATCH v4 1/2] perf: Move arch specific code into separate arch directory

[Masami Hiramatsu]

Hi Ian,

Please feel free to add my ack. :)

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>

Ingo, I think this one is important enhancement for perf
to port it on other archs.

Thank you,

Ian Munsie wrote:
> From: Ian Munsie <imunsie@au.ibm.com>
> 
> The perf userspace tool included some architecture specific code to map
> registers from the DWARF register number into the names used by the regs
> and stack access API.
> 
> This patch moves the architecture specific code out into a separate
> arch/x86 directory along with the infrastructure required to use it.
> 
> Signed-off-by: Ian Munsie <imunsie@au.ibm.com>
> ---
> Changes since v3:
> * Move the check for DWARF support prior to the inclusion of the arch specific
>   Makefile so that the arch specific Makefile can include the relevant files in
>   the build only if DWARF support is available.
> * Fix NO_DWARF build
> 
>  tools/perf/Makefile                   |   36 +++++++++++++---
>  tools/perf/arch/x86/Makefile          |    4 ++
>  tools/perf/arch/x86/util/dwarf-regs.c |   75 +++++++++++++++++++++++++++++++++
>  tools/perf/util/include/dwarf-regs.h  |    8 ++++
>  tools/perf/util/probe-finder.c        |   55 +-----------------------
>  5 files changed, 119 insertions(+), 59 deletions(-)
>  create mode 100644 tools/perf/arch/x86/Makefile
>  create mode 100644 tools/perf/arch/x86/util/dwarf-regs.c
>  create mode 100644 tools/perf/util/include/dwarf-regs.h
> 
> diff --git a/tools/perf/Makefile b/tools/perf/Makefile
> index 3cb3449..e8bf2e1 100644
> --- a/tools/perf/Makefile
> +++ b/tools/perf/Makefile
> @@ -173,6 +173,20 @@ uname_R := $(shell sh -c 'uname -r 2>/dev/null || echo not')
>  uname_P := $(shell sh -c 'uname -p 2>/dev/null || echo not')
>  uname_V := $(shell sh -c 'uname -v 2>/dev/null || echo not')
>  
> +ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
> +				  -e s/arm.*/arm/ -e s/sa110/arm/ \
> +				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
> +				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
> +				  -e s/sh[234].*/sh/ )
> +
> +# Additional ARCH settings for x86
> +ifeq ($(ARCH),i386)
> +        ARCH := x86
> +endif
> +ifeq ($(ARCH),x86_64)
> +        ARCH := x86
> +endif
> +
>  # CFLAGS and LDFLAGS are for the users to override from the command line.
>  
>  #
> @@ -285,7 +299,7 @@ endif
>  # Those must not be GNU-specific; they are shared with perl/ which may
>  # be built by a different compiler. (Note that this is an artifact now
>  # but it still might be nice to keep that distinction.)
> -BASIC_CFLAGS = -Iutil/include
> +BASIC_CFLAGS = -Iutil/include -Iarch/$(ARCH)/include
>  BASIC_LDFLAGS =
>  
>  # Guard against environment variables
> @@ -367,6 +381,7 @@ LIB_H += util/include/asm/byteorder.h
>  LIB_H += util/include/asm/swab.h
>  LIB_H += util/include/asm/system.h
>  LIB_H += util/include/asm/uaccess.h
> +LIB_H += util/include/dwarf-regs.h
>  LIB_H += perf.h
>  LIB_H += util/cache.h
>  LIB_H += util/callchain.h
> @@ -487,6 +502,15 @@ PERFLIBS = $(LIB_FILE)
>  -include config.mak.autogen
>  -include config.mak
>  
> +ifndef NO_DWARF
> +ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
> +	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/elfutils-dev);
> +	NO_DWARF := 1
> +endif # Dwarf support
> +endif # NO_DWARF
> +
> +-include arch/$(ARCH)/Makefile
> +
>  ifeq ($(uname_S),Darwin)
>  	ifndef NO_FINK
>  		ifeq ($(shell test -d /sw/lib && echo y),y)
> @@ -519,15 +543,15 @@ else
>  	msg := $(error No libelf.h/libelf found, please install libelf-dev/elfutils-libelf-devel and glibc-dev[el]);
>  endif
>  
> -ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
> -	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/elfutils-dev);
> -else
>  ifndef NO_DWARF
> +ifeq ($(origin PERF_HAVE_DWARF_REGS), undefined)
> +	msg := $(warning DWARF register mappings have not been defined for architecture $(ARCH), DWARF support disabled);
> +else
>  	BASIC_CFLAGS += -I/usr/include/elfutils -DDWARF_SUPPORT
>  	EXTLIBS += -lelf -ldw
>  	LIB_OBJS += $(OUTPUT)util/probe-finder.o
> -endif
> -endif
> +endif # PERF_HAVE_DWARF_REGS
> +endif # NO_DWARF
>  
>  ifneq ($(shell sh -c "(echo '\#include <newt.h>'; echo 'int main(void) { newtInit(); newtCls(); return newtFinished(); }') | $(CC) -x c - $(ALL_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -lnewt -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
>  	msg := $(warning newt not found, disables TUI support. Please install newt-devel or libnewt-dev);
> diff --git a/tools/perf/arch/x86/Makefile b/tools/perf/arch/x86/Makefile
> new file mode 100644
> index 0000000..15130b5
> --- /dev/null
> +++ b/tools/perf/arch/x86/Makefile
> @@ -0,0 +1,4 @@
> +ifndef NO_DWARF
> +PERF_HAVE_DWARF_REGS := 1
> +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
> +endif
> diff --git a/tools/perf/arch/x86/util/dwarf-regs.c b/tools/perf/arch/x86/util/dwarf-regs.c
> new file mode 100644
> index 0000000..a794d30
> --- /dev/null
> +++ b/tools/perf/arch/x86/util/dwarf-regs.c
> @@ -0,0 +1,75 @@
> +/*
> + * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
> + * Extracted from probe-finder.c
> + *
> + * Written by Masami Hiramatsu <mhiramat@redhat.com>
> + *
> + * 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.
> + *
> + */
> +
> +#include <libio.h>
> +#include <dwarf-regs.h>
> +
> +/*
> + * Generic dwarf analysis helpers
> + */
> +
> +#define X86_32_MAX_REGS 8
> +const char *x86_32_regs_table[X86_32_MAX_REGS] = {
> +	"%ax",
> +	"%cx",
> +	"%dx",
> +	"%bx",
> +	"$stack",	/* Stack address instead of %sp */
> +	"%bp",
> +	"%si",
> +	"%di",
> +};
> +
> +#define X86_64_MAX_REGS 16
> +const char *x86_64_regs_table[X86_64_MAX_REGS] = {
> +	"%ax",
> +	"%dx",
> +	"%cx",
> +	"%bx",
> +	"%si",
> +	"%di",
> +	"%bp",
> +	"%sp",
> +	"%r8",
> +	"%r9",
> +	"%r10",
> +	"%r11",
> +	"%r12",
> +	"%r13",
> +	"%r14",
> +	"%r15",
> +};
> +
> +/* TODO: switching by dwarf address size */
> +#ifdef __x86_64__
> +#define ARCH_MAX_REGS X86_64_MAX_REGS
> +#define arch_regs_table x86_64_regs_table
> +#else
> +#define ARCH_MAX_REGS X86_32_MAX_REGS
> +#define arch_regs_table x86_32_regs_table
> +#endif
> +
> +/* Return architecture dependent register string (for kprobe-tracer) */
> +const char *get_arch_regstr(unsigned int n)
> +{
> +	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
> +}
> diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
> new file mode 100644
> index 0000000..cf6727e
> --- /dev/null
> +++ b/tools/perf/util/include/dwarf-regs.h
> @@ -0,0 +1,8 @@
> +#ifndef _PERF_DWARF_REGS_H_
> +#define _PERF_DWARF_REGS_H_
> +
> +#ifdef DWARF_SUPPORT
> +const char *get_arch_regstr(unsigned int n);
> +#endif
> +
> +#endif
> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> index 3e79775..e7ee52f 100644
> --- a/tools/perf/util/probe-finder.c
> +++ b/tools/perf/util/probe-finder.c
> @@ -31,6 +31,7 @@
>  #include <string.h>
>  #include <stdarg.h>
>  #include <ctype.h>
> +#include <dwarf-regs.h>
>  
>  #include "string.h"
>  #include "event.h"
> @@ -38,61 +39,9 @@
>  #include "util.h"
>  #include "probe-finder.h"
>  
> -
> -/*
> - * Generic dwarf analysis helpers
> - */
> -
> -#define X86_32_MAX_REGS 8
> -const char *x86_32_regs_table[X86_32_MAX_REGS] = {
> -	"%ax",
> -	"%cx",
> -	"%dx",
> -	"%bx",
> -	"$stack",	/* Stack address instead of %sp */
> -	"%bp",
> -	"%si",
> -	"%di",
> -};
> -
> -#define X86_64_MAX_REGS 16
> -const char *x86_64_regs_table[X86_64_MAX_REGS] = {
> -	"%ax",
> -	"%dx",
> -	"%cx",
> -	"%bx",
> -	"%si",
> -	"%di",
> -	"%bp",
> -	"%sp",
> -	"%r8",
> -	"%r9",
> -	"%r10",
> -	"%r11",
> -	"%r12",
> -	"%r13",
> -	"%r14",
> -	"%r15",
> -};
> -
> -/* TODO: switching by dwarf address size */
> -#ifdef __x86_64__
> -#define ARCH_MAX_REGS X86_64_MAX_REGS
> -#define arch_regs_table x86_64_regs_table
> -#else
> -#define ARCH_MAX_REGS X86_32_MAX_REGS
> -#define arch_regs_table x86_32_regs_table
> -#endif
> -
>  /* Kprobe tracer basic type is up to u64 */
>  #define MAX_BASIC_TYPE_BITS	64
>  
> -/* Return architecture dependent register string (for kprobe-tracer) */
> -static const char *get_arch_regstr(unsigned int n)
> -{
> -	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
> -}
> -
>  /*
>   * Compare the tail of two strings.
>   * Return 0 if whole of either string is same as another's tail part.
> @@ -447,7 +396,7 @@ static int convert_location(Dwarf_Op *op, struct probe_finder *pf)
>  
>  	regs = get_arch_regstr(regn);
>  	if (!regs) {
> -		pr_warning("%u exceeds max register number.\n", regn);
> +		pr_warning("Mapping for DWARF register number %u missing on this architecture.", regn);
>  		return -ERANGE;
>  	}
>  

-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

Re: [PATCH v4 1/2] perf: Move arch specific code into separate arch directory

[Masami Hiramatsu]

Hi Ian,

Please feel free to add my ack. :)

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>

Ingo, I think this one is important enhancement for perf
to port it on other archs.

Thank you,

Ian Munsie wrote:
> From: Ian Munsie <imunsie@au.ibm.com>
> 
> The perf userspace tool included some architecture specific code to map
> registers from the DWARF register number into the names used by the regs
> and stack access API.
> 
> This patch moves the architecture specific code out into a separate
> arch/x86 directory along with the infrastructure required to use it.
> 
> Signed-off-by: Ian Munsie <imunsie@au.ibm.com>
> ---
> Changes since v3:
> * Move the check for DWARF support prior to the inclusion of the arch specific
>   Makefile so that the arch specific Makefile can include the relevant files in
>   the build only if DWARF support is available.
> * Fix NO_DWARF build
> 
>  tools/perf/Makefile                   |   36 +++++++++++++---
>  tools/perf/arch/x86/Makefile          |    4 ++
>  tools/perf/arch/x86/util/dwarf-regs.c |   75 +++++++++++++++++++++++++++++++++
>  tools/perf/util/include/dwarf-regs.h  |    8 ++++
>  tools/perf/util/probe-finder.c        |   55 +-----------------------
>  5 files changed, 119 insertions(+), 59 deletions(-)
>  create mode 100644 tools/perf/arch/x86/Makefile
>  create mode 100644 tools/perf/arch/x86/util/dwarf-regs.c
>  create mode 100644 tools/perf/util/include/dwarf-regs.h
> 
> diff --git a/tools/perf/Makefile b/tools/perf/Makefile
> index 3cb3449..e8bf2e1 100644
> --- a/tools/perf/Makefile
> +++ b/tools/perf/Makefile
> @@ -173,6 +173,20 @@ uname_R := $(shell sh -c 'uname -r 2>/dev/null || echo not')
>  uname_P := $(shell sh -c 'uname -p 2>/dev/null || echo not')
>  uname_V := $(shell sh -c 'uname -v 2>/dev/null || echo not')
>  
> +ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
> +				  -e s/arm.*/arm/ -e s/sa110/arm/ \
> +				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
> +				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
> +				  -e s/sh[234].*/sh/ )
> +
> +# Additional ARCH settings for x86
> +ifeq ($(ARCH),i386)
> +        ARCH := x86
> +endif
> +ifeq ($(ARCH),x86_64)
> +        ARCH := x86
> +endif
> +
>  # CFLAGS and LDFLAGS are for the users to override from the command line.
>  
>  #
> @@ -285,7 +299,7 @@ endif
>  # Those must not be GNU-specific; they are shared with perl/ which may
>  # be built by a different compiler. (Note that this is an artifact now
>  # but it still might be nice to keep that distinction.)
> -BASIC_CFLAGS = -Iutil/include
> +BASIC_CFLAGS = -Iutil/include -Iarch/$(ARCH)/include
>  BASIC_LDFLAGS =
>  
>  # Guard against environment variables
> @@ -367,6 +381,7 @@ LIB_H += util/include/asm/byteorder.h
>  LIB_H += util/include/asm/swab.h
>  LIB_H += util/include/asm/system.h
>  LIB_H += util/include/asm/uaccess.h
> +LIB_H += util/include/dwarf-regs.h
>  LIB_H += perf.h
>  LIB_H += util/cache.h
>  LIB_H += util/callchain.h
> @@ -487,6 +502,15 @@ PERFLIBS = $(LIB_FILE)
>  -include config.mak.autogen
>  -include config.mak
>  
> +ifndef NO_DWARF
> +ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
> +	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/elfutils-dev);
> +	NO_DWARF := 1
> +endif # Dwarf support
> +endif # NO_DWARF
> +
> +-include arch/$(ARCH)/Makefile
> +
>  ifeq ($(uname_S),Darwin)
>  	ifndef NO_FINK
>  		ifeq ($(shell test -d /sw/lib && echo y),y)
> @@ -519,15 +543,15 @@ else
>  	msg := $(error No libelf.h/libelf found, please install libelf-dev/elfutils-libelf-devel and glibc-dev[el]);
>  endif
>  
> -ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
> -	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/elfutils-dev);
> -else
>  ifndef NO_DWARF
> +ifeq ($(origin PERF_HAVE_DWARF_REGS), undefined)
> +	msg := $(warning DWARF register mappings have not been defined for architecture $(ARCH), DWARF support disabled);
> +else
>  	BASIC_CFLAGS += -I/usr/include/elfutils -DDWARF_SUPPORT
>  	EXTLIBS += -lelf -ldw
>  	LIB_OBJS += $(OUTPUT)util/probe-finder.o
> -endif
> -endif
> +endif # PERF_HAVE_DWARF_REGS
> +endif # NO_DWARF
>  
>  ifneq ($(shell sh -c "(echo '\#include <newt.h>'; echo 'int main(void) { newtInit(); newtCls(); return newtFinished(); }') | $(CC) -x c - $(ALL_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -lnewt -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
>  	msg := $(warning newt not found, disables TUI support. Please install newt-devel or libnewt-dev);
> diff --git a/tools/perf/arch/x86/Makefile b/tools/perf/arch/x86/Makefile
> new file mode 100644
> index 0000000..15130b5
> --- /dev/null
> +++ b/tools/perf/arch/x86/Makefile
> @@ -0,0 +1,4 @@
> +ifndef NO_DWARF
> +PERF_HAVE_DWARF_REGS := 1
> +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
> +endif
> diff --git a/tools/perf/arch/x86/util/dwarf-regs.c b/tools/perf/arch/x86/util/dwarf-regs.c
> new file mode 100644
> index 0000000..a794d30
> --- /dev/null
> +++ b/tools/perf/arch/x86/util/dwarf-regs.c
> @@ -0,0 +1,75 @@
> +/*
> + * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
> + * Extracted from probe-finder.c
> + *
> + * Written by Masami Hiramatsu <mhiramat@redhat.com>
> + *
> + * 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.
> + *
> + */
> +
> +#include <libio.h>
> +#include <dwarf-regs.h>
> +
> +/*
> + * Generic dwarf analysis helpers
> + */
> +
> +#define X86_32_MAX_REGS 8
> +const char *x86_32_regs_table[X86_32_MAX_REGS] = {
> +	"%ax",
> +	"%cx",
> +	"%dx",
> +	"%bx",
> +	"$stack",	/* Stack address instead of %sp */
> +	"%bp",
> +	"%si",
> +	"%di",
> +};
> +
> +#define X86_64_MAX_REGS 16
> +const char *x86_64_regs_table[X86_64_MAX_REGS] = {
> +	"%ax",
> +	"%dx",
> +	"%cx",
> +	"%bx",
> +	"%si",
> +	"%di",
> +	"%bp",
> +	"%sp",
> +	"%r8",
> +	"%r9",
> +	"%r10",
> +	"%r11",
> +	"%r12",
> +	"%r13",
> +	"%r14",
> +	"%r15",
> +};
> +
> +/* TODO: switching by dwarf address size */
> +#ifdef __x86_64__
> +#define ARCH_MAX_REGS X86_64_MAX_REGS
> +#define arch_regs_table x86_64_regs_table
> +#else
> +#define ARCH_MAX_REGS X86_32_MAX_REGS
> +#define arch_regs_table x86_32_regs_table
> +#endif
> +
> +/* Return architecture dependent register string (for kprobe-tracer) */
> +const char *get_arch_regstr(unsigned int n)
> +{
> +	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
> +}
> diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
> new file mode 100644
> index 0000000..cf6727e
> --- /dev/null
> +++ b/tools/perf/util/include/dwarf-regs.h
> @@ -0,0 +1,8 @@
> +#ifndef _PERF_DWARF_REGS_H_
> +#define _PERF_DWARF_REGS_H_
> +
> +#ifdef DWARF_SUPPORT
> +const char *get_arch_regstr(unsigned int n);
> +#endif
> +
> +#endif
> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> index 3e79775..e7ee52f 100644
> --- a/tools/perf/util/probe-finder.c
> +++ b/tools/perf/util/probe-finder.c
> @@ -31,6 +31,7 @@
>  #include <string.h>
>  #include <stdarg.h>
>  #include <ctype.h>
> +#include <dwarf-regs.h>
>  
>  #include "string.h"
>  #include "event.h"
> @@ -38,61 +39,9 @@
>  #include "util.h"
>  #include "probe-finder.h"
>  
> -
> -/*
> - * Generic dwarf analysis helpers
> - */
> -
> -#define X86_32_MAX_REGS 8
> -const char *x86_32_regs_table[X86_32_MAX_REGS] = {
> -	"%ax",
> -	"%cx",
> -	"%dx",
> -	"%bx",
> -	"$stack",	/* Stack address instead of %sp */
> -	"%bp",
> -	"%si",
> -	"%di",
> -};
> -
> -#define X86_64_MAX_REGS 16
> -const char *x86_64_regs_table[X86_64_MAX_REGS] = {
> -	"%ax",
> -	"%dx",
> -	"%cx",
> -	"%bx",
> -	"%si",
> -	"%di",
> -	"%bp",
> -	"%sp",
> -	"%r8",
> -	"%r9",
> -	"%r10",
> -	"%r11",
> -	"%r12",
> -	"%r13",
> -	"%r14",
> -	"%r15",
> -};
> -
> -/* TODO: switching by dwarf address size */
> -#ifdef __x86_64__
> -#define ARCH_MAX_REGS X86_64_MAX_REGS
> -#define arch_regs_table x86_64_regs_table
> -#else
> -#define ARCH_MAX_REGS X86_32_MAX_REGS
> -#define arch_regs_table x86_32_regs_table
> -#endif
> -
>  /* Kprobe tracer basic type is up to u64 */
>  #define MAX_BASIC_TYPE_BITS	64
>  
> -/* Return architecture dependent register string (for kprobe-tracer) */
> -static const char *get_arch_regstr(unsigned int n)
> -{
> -	return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
> -}
> -
>  /*
>   * Compare the tail of two strings.
>   * Return 0 if whole of either string is same as another's tail part.
> @@ -447,7 +396,7 @@ static int convert_location(Dwarf_Op *op, struct probe_finder *pf)
>  
>  	regs = get_arch_regstr(regn);
>  	if (!regs) {
> -		pr_warning("%u exceeds max register number.\n", regn);
> +		pr_warning("Mapping for DWARF register number %u missing on this architecture.", regn);
>  		return -ERANGE;
>  	}
>  

-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

Re: [PATCH v4 2/2] perf probe: Add PowerPC DWARF register number mappings

[Masami Hiramatsu]

Ian Munsie wrote:
> From: Ian Munsie <imunsie@au.ibm.com>
> 
> This patch adds mappings from the register numbers from DWARF to the
> register names used in the PowerPC Regs and Stack Access API. This
> allows perf probe to be used to record variable contents on PowerPC.
> 
> This patch depends on functionality in the powerpc/next tree, though it
> will compile fine without it. Specifically this patch depends on commit
> "powerpc: Add kprobe-based event tracer"
> 
> Signed-off-by: Ian Munsie <imunsie@au.ibm.com>


Acked-by: Masami Hiramatsu <mhiramat@redhat.com>

> ---
> Changes since v3:
> * Fix NO_DWARF build

Nice catch!

> 
>  tools/perf/arch/powerpc/Makefile          |    4 +
>  tools/perf/arch/powerpc/util/dwarf-regs.c |   88 +++++++++++++++++++++++++++++
>  2 files changed, 92 insertions(+), 0 deletions(-)
>  create mode 100644 tools/perf/arch/powerpc/Makefile
>  create mode 100644 tools/perf/arch/powerpc/util/dwarf-regs.c
> 
> diff --git a/tools/perf/arch/powerpc/Makefile b/tools/perf/arch/powerpc/Makefile
> new file mode 100644
> index 0000000..15130b5
> --- /dev/null
> +++ b/tools/perf/arch/powerpc/Makefile
> @@ -0,0 +1,4 @@
> +ifndef NO_DWARF
> +PERF_HAVE_DWARF_REGS := 1
> +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
> +endif
> diff --git a/tools/perf/arch/powerpc/util/dwarf-regs.c b/tools/perf/arch/powerpc/util/dwarf-regs.c
> new file mode 100644
> index 0000000..48ae0c5
> --- /dev/null
> +++ b/tools/perf/arch/powerpc/util/dwarf-regs.c
> @@ -0,0 +1,88 @@
> +/*
> + * Mapping of DWARF debug register numbers into register names.
> + *
> + * Copyright (C) 2010 Ian Munsie, IBM Corporation.
> + *
> + * 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.
> + */
> +
> +#include <libio.h>
> +#include <dwarf-regs.h>
> +
> +
> +struct pt_regs_dwarfnum {
> +	const char *name;
> +	unsigned int dwarfnum;
> +};
> +
> +#define STR(s) #s
> +#define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
> +#define GPR_DWARFNUM_NAME(num)	\
> +	{.name = STR(%gpr##num), .dwarfnum = num}
> +#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
> +
> +/*
> + * Reference:
> + * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
> + */
> +static const struct pt_regs_dwarfnum regdwarfnum_table[] = {
> +	GPR_DWARFNUM_NAME(0),
> +	GPR_DWARFNUM_NAME(1),
> +	GPR_DWARFNUM_NAME(2),
> +	GPR_DWARFNUM_NAME(3),
> +	GPR_DWARFNUM_NAME(4),
> +	GPR_DWARFNUM_NAME(5),
> +	GPR_DWARFNUM_NAME(6),
> +	GPR_DWARFNUM_NAME(7),
> +	GPR_DWARFNUM_NAME(8),
> +	GPR_DWARFNUM_NAME(9),
> +	GPR_DWARFNUM_NAME(10),
> +	GPR_DWARFNUM_NAME(11),
> +	GPR_DWARFNUM_NAME(12),
> +	GPR_DWARFNUM_NAME(13),
> +	GPR_DWARFNUM_NAME(14),
> +	GPR_DWARFNUM_NAME(15),
> +	GPR_DWARFNUM_NAME(16),
> +	GPR_DWARFNUM_NAME(17),
> +	GPR_DWARFNUM_NAME(18),
> +	GPR_DWARFNUM_NAME(19),
> +	GPR_DWARFNUM_NAME(20),
> +	GPR_DWARFNUM_NAME(21),
> +	GPR_DWARFNUM_NAME(22),
> +	GPR_DWARFNUM_NAME(23),
> +	GPR_DWARFNUM_NAME(24),
> +	GPR_DWARFNUM_NAME(25),
> +	GPR_DWARFNUM_NAME(26),
> +	GPR_DWARFNUM_NAME(27),
> +	GPR_DWARFNUM_NAME(28),
> +	GPR_DWARFNUM_NAME(29),
> +	GPR_DWARFNUM_NAME(30),
> +	GPR_DWARFNUM_NAME(31),
> +	REG_DWARFNUM_NAME("%msr",   66),
> +	REG_DWARFNUM_NAME("%ctr",   109),
> +	REG_DWARFNUM_NAME("%link",  108),
> +	REG_DWARFNUM_NAME("%xer",   101),
> +	REG_DWARFNUM_NAME("%dar",   119),
> +	REG_DWARFNUM_NAME("%dsisr", 118),
> +	REG_DWARFNUM_END,
> +};
> +
> +/**
> + * get_arch_regstr() - lookup register name from it's DWARF register number
> + * @n:	the DWARF register number
> + *
> + * get_arch_regstr() returns the name of the register in struct
> + * regdwarfnum_table from it's DWARF register number. If the register is not
> + * found in the table, this returns NULL;
> + */
> +const char *get_arch_regstr(unsigned int n)
> +{
> +	const struct pt_regs_dwarfnum *roff;
> +	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
> +		if (roff->dwarfnum == n)
> +			return roff->name;
> +	return NULL;
> +}

-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

Re: [PATCH v4 2/2] perf probe: Add PowerPC DWARF register number mappings

[Masami Hiramatsu]

Ian Munsie wrote:
> From: Ian Munsie <imunsie@au.ibm.com>
> 
> This patch adds mappings from the register numbers from DWARF to the
> register names used in the PowerPC Regs and Stack Access API. This
> allows perf probe to be used to record variable contents on PowerPC.
> 
> This patch depends on functionality in the powerpc/next tree, though it
> will compile fine without it. Specifically this patch depends on commit
> "powerpc: Add kprobe-based event tracer"
> 
> Signed-off-by: Ian Munsie <imunsie@au.ibm.com>


Acked-by: Masami Hiramatsu <mhiramat@redhat.com>

> ---
> Changes since v3:
> * Fix NO_DWARF build

Nice catch!

> 
>  tools/perf/arch/powerpc/Makefile          |    4 +
>  tools/perf/arch/powerpc/util/dwarf-regs.c |   88 +++++++++++++++++++++++++++++
>  2 files changed, 92 insertions(+), 0 deletions(-)
>  create mode 100644 tools/perf/arch/powerpc/Makefile
>  create mode 100644 tools/perf/arch/powerpc/util/dwarf-regs.c
> 
> diff --git a/tools/perf/arch/powerpc/Makefile b/tools/perf/arch/powerpc/Makefile
> new file mode 100644
> index 0000000..15130b5
> --- /dev/null
> +++ b/tools/perf/arch/powerpc/Makefile
> @@ -0,0 +1,4 @@
> +ifndef NO_DWARF
> +PERF_HAVE_DWARF_REGS := 1
> +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
> +endif
> diff --git a/tools/perf/arch/powerpc/util/dwarf-regs.c b/tools/perf/arch/powerpc/util/dwarf-regs.c
> new file mode 100644
> index 0000000..48ae0c5
> --- /dev/null
> +++ b/tools/perf/arch/powerpc/util/dwarf-regs.c
> @@ -0,0 +1,88 @@
> +/*
> + * Mapping of DWARF debug register numbers into register names.
> + *
> + * Copyright (C) 2010 Ian Munsie, IBM Corporation.
> + *
> + * 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.
> + */
> +
> +#include <libio.h>
> +#include <dwarf-regs.h>
> +
> +
> +struct pt_regs_dwarfnum {
> +	const char *name;
> +	unsigned int dwarfnum;
> +};
> +
> +#define STR(s) #s
> +#define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
> +#define GPR_DWARFNUM_NAME(num)	\
> +	{.name = STR(%gpr##num), .dwarfnum = num}
> +#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
> +
> +/*
> + * Reference:
> + * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
> + */
> +static const struct pt_regs_dwarfnum regdwarfnum_table[] = {
> +	GPR_DWARFNUM_NAME(0),
> +	GPR_DWARFNUM_NAME(1),
> +	GPR_DWARFNUM_NAME(2),
> +	GPR_DWARFNUM_NAME(3),
> +	GPR_DWARFNUM_NAME(4),
> +	GPR_DWARFNUM_NAME(5),
> +	GPR_DWARFNUM_NAME(6),
> +	GPR_DWARFNUM_NAME(7),
> +	GPR_DWARFNUM_NAME(8),
> +	GPR_DWARFNUM_NAME(9),
> +	GPR_DWARFNUM_NAME(10),
> +	GPR_DWARFNUM_NAME(11),
> +	GPR_DWARFNUM_NAME(12),
> +	GPR_DWARFNUM_NAME(13),
> +	GPR_DWARFNUM_NAME(14),
> +	GPR_DWARFNUM_NAME(15),
> +	GPR_DWARFNUM_NAME(16),
> +	GPR_DWARFNUM_NAME(17),
> +	GPR_DWARFNUM_NAME(18),
> +	GPR_DWARFNUM_NAME(19),
> +	GPR_DWARFNUM_NAME(20),
> +	GPR_DWARFNUM_NAME(21),
> +	GPR_DWARFNUM_NAME(22),
> +	GPR_DWARFNUM_NAME(23),
> +	GPR_DWARFNUM_NAME(24),
> +	GPR_DWARFNUM_NAME(25),
> +	GPR_DWARFNUM_NAME(26),
> +	GPR_DWARFNUM_NAME(27),
> +	GPR_DWARFNUM_NAME(28),
> +	GPR_DWARFNUM_NAME(29),
> +	GPR_DWARFNUM_NAME(30),
> +	GPR_DWARFNUM_NAME(31),
> +	REG_DWARFNUM_NAME("%msr",   66),
> +	REG_DWARFNUM_NAME("%ctr",   109),
> +	REG_DWARFNUM_NAME("%link",  108),
> +	REG_DWARFNUM_NAME("%xer",   101),
> +	REG_DWARFNUM_NAME("%dar",   119),
> +	REG_DWARFNUM_NAME("%dsisr", 118),
> +	REG_DWARFNUM_END,
> +};
> +
> +/**
> + * get_arch_regstr() - lookup register name from it's DWARF register number
> + * @n:	the DWARF register number
> + *
> + * get_arch_regstr() returns the name of the register in struct
> + * regdwarfnum_table from it's DWARF register number. If the register is not
> + * found in the table, this returns NULL;
> + */
> +const char *get_arch_regstr(unsigned int n)
> +{
> +	const struct pt_regs_dwarfnum *roff;
> +	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
> +		if (roff->dwarfnum == n)
> +			return roff->name;
> +	return NULL;
> +}

-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com