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Groups > linux.kernel > #1470262 > unrolled thread

[PATCH v2 0/3] perf probe: Introduce remote cross-arch probes

Started byMasami Hiramatsu <mhiramat@kernel.org>
First post2016-08-25 18:30 +0200
Last post2016-08-31 03:10 +0200
Articles 10 — 3 participants

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Contents

  [PATCH v2 0/3] perf probe: Introduce remote cross-arch probes Masami Hiramatsu <mhiramat@kernel.org> - 2016-08-25 18:30 +0200
    [PATCH v2 3/3] perf-probe: Support probing on offline cross-arch binary Masami Hiramatsu <mhiramat@kernel.org> - 2016-08-25 18:30 +0200
      Re: [PATCH v2 3/3] perf-probe: Support probing on offline cross-arch  binary Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-08-31 23:00 +0200
        Re: [PATCH v2 3/3] perf-probe: Support probing on offline  cross-arch binary Masami Hiramatsu <mhiramat@kernel.org> - 2016-09-01 01:30 +0200
      [tip:perf/core] perf probe: Support probing on offline cross-arch  binary tip-bot for Masami Hiramatsu <tipbot@zytor.com> - 2016-09-05 15:30 +0200
    [PATCH v2 1/3] perf-probe: Show trace event definition Masami Hiramatsu <mhiramat@kernel.org> - 2016-08-25 18:30 +0200
      [tip:perf/core] perf probe: Show trace event definition tip-bot for Masami Hiramatsu <tipbot@zytor.com> - 2016-09-05 15:30 +0200
    [PATCH v2 4/4] perf-probe: Ignore vmlinux Build-id when offline vmlinux given Masami Hiramatsu <mhiramat@kernel.org> - 2016-08-26 17:00 +0200
      [tip:perf/core] perf probe: Ignore vmlinux Build-id when offline  vmlinux given tip-bot for Masami Hiramatsu <tipbot@zytor.com> - 2016-09-05 15:30 +0200
    Re: [PATCH v2 0/3] perf probe: Introduce remote cross-arch probes Masami Hiramatsu <mhiramat@kernel.org> - 2016-08-31 03:10 +0200

#1470262 — [PATCH v2 0/3] perf probe: Introduce remote cross-arch probes

FromMasami Hiramatsu <mhiramat@kernel.org>
Date2016-08-25 18:30 +0200
Subject[PATCH v2 0/3] perf probe: Introduce remote cross-arch probes
Message-ID<sa5Hr-3mY-11@gated-at.bofh.it>
Hi,

Here is the 2nd version of remote cross-arch probe support on perf-probe.
V1 is here:
  https://lkml.org/lkml/2016/8/24/29

Currently perf-probe doesn't supoort cross/remote target. This means
we have to cross-build the perf-tools including libraries (elfutils,
libelf etc.), and to prepare vmlinux with debuginfo which can be 
accessed from the target machine.
This requires too much resource for a small embededd device.

If we can analyze the debuginfo by perf-probe on host machine,
we do not need to cross-build perf-tools, nor copy vmlinux on the
device. :)

For that purpose, this series adds --definition(-D) command for
perf-probe, which shows trace event definition instead of adding
it in running kernel, according to Arnaldo's comment.
Using -D with --vmlinux(or -k)=OFFLINE-VMLINUX, perf-probe reads
the vmlinux architecture and show definition with correct
dwarf-registers.

  perf probe -k <cross-vmlinux> -D <probe-point> <arguments>

Here is an example:
  -----
  $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
  p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
  -----
Here, we can get probe/do_sys_open event by "copy & paste" the
definition to target-machine's debugfs/tracing/kprobe_events.

Note that it shows definition with direct symbol name instead of
_text+offset. It is treated as an offline module.

Thanks,
---

Masami Hiramatsu (3):
      perf-probe: Show trace event definition
      perf-probe: Ignore vmlinux buildid if offline kernel is given
      perf-probe: Support probing on offline cross-arch binary


 tools/perf/Documentation/perf-probe.txt            |    9 +++
 tools/perf/arch/arm/include/dwarf-regs-table.h     |    9 +++
 tools/perf/arch/arm64/include/dwarf-regs-table.h   |   13 +++++
 tools/perf/arch/powerpc/include/dwarf-regs-table.h |   27 ++++++++++
 tools/perf/arch/s390/include/dwarf-regs-table.h    |    8 +++
 tools/perf/arch/sh/include/dwarf-regs-table.h      |   25 +++++++++
 tools/perf/arch/sparc/include/dwarf-regs-table.h   |   18 +++++++
 tools/perf/arch/x86/include/dwarf-regs-table.h     |   14 +++++
 tools/perf/arch/xtensa/include/dwarf-regs-table.h  |    8 +++
 tools/perf/builtin-probe.c                         |   34 ++++++++++--
 tools/perf/util/Build                              |    1 
 tools/perf/util/dwarf-regs.c                       |   55 ++++++++++++++++++++
 tools/perf/util/include/dwarf-regs.h               |    6 ++
 tools/perf/util/probe-event.c                      |   50 ++++++++++++++++++
 tools/perf/util/probe-event.h                      |    1 
 tools/perf/util/probe-finder.c                     |   27 ++++++----
 tools/perf/util/probe-finder.h                     |    1 
 tools/perf/util/symbol-elf.c                       |    2 -
 18 files changed, 289 insertions(+), 19 deletions(-)
 create mode 100644 tools/perf/arch/arm/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/arm64/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/powerpc/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/s390/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/sh/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/sparc/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/x86/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/xtensa/include/dwarf-regs-table.h
 create mode 100644 tools/perf/util/dwarf-regs.c

--
Masami Hiramatsu (Linaro Ltd.) <mhiramat@kernel.org>

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#1470263 — [PATCH v2 3/3] perf-probe: Support probing on offline cross-arch binary

FromMasami Hiramatsu <mhiramat@kernel.org>
Date2016-08-25 18:30 +0200
Subject[PATCH v2 3/3] perf-probe: Support probing on offline cross-arch binary
Message-ID<sa5Hs-3mY-21@gated-at.bofh.it>
In reply to#1470262
Support probing on offline cross-architecture binary by
adding getting the target machine arch from ELF and
choose correct register string for the machine.

Here is an example:
  -----
  $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
  p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
  -----
Here, we can get probe/do_sys_open event by "copy & paste" from
./tracing/kprobe_events to target-machine's debugfs/tracing/kprobe_events

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
  Changes from v1:
   - Change the example.
---
 tools/perf/arch/arm/include/dwarf-regs-table.h     |    9 +++
 tools/perf/arch/arm64/include/dwarf-regs-table.h   |   13 +++++
 tools/perf/arch/powerpc/include/dwarf-regs-table.h |   27 ++++++++++
 tools/perf/arch/s390/include/dwarf-regs-table.h    |    8 +++
 tools/perf/arch/sh/include/dwarf-regs-table.h      |   25 +++++++++
 tools/perf/arch/sparc/include/dwarf-regs-table.h   |   18 +++++++
 tools/perf/arch/x86/include/dwarf-regs-table.h     |   14 +++++
 tools/perf/arch/xtensa/include/dwarf-regs-table.h  |    8 +++
 tools/perf/util/Build                              |    1 
 tools/perf/util/dwarf-regs.c                       |   55 ++++++++++++++++++++
 tools/perf/util/include/dwarf-regs.h               |    6 ++
 tools/perf/util/probe-finder.c                     |   27 ++++++----
 tools/perf/util/probe-finder.h                     |    1 
 13 files changed, 201 insertions(+), 11 deletions(-)
 create mode 100644 tools/perf/arch/arm/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/arm64/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/powerpc/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/s390/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/sh/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/sparc/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/x86/include/dwarf-regs-table.h
 create mode 100644 tools/perf/arch/xtensa/include/dwarf-regs-table.h
 create mode 100644 tools/perf/util/dwarf-regs.c

diff --git a/tools/perf/arch/arm/include/dwarf-regs-table.h b/tools/perf/arch/arm/include/dwarf-regs-table.h
new file mode 100644
index 0000000..f298d03
--- /dev/null
+++ b/tools/perf/arch/arm/include/dwarf-regs-table.h
@@ -0,0 +1,9 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const arm_regstr_tbl[] = {
+	"%r0", "%r1", "%r2", "%r3", "%r4",
+	"%r5", "%r6", "%r7", "%r8", "%r9", "%r10",
+	"%fp", "%ip", "%sp", "%lr", "%pc",
+};
+#endif
diff --git a/tools/perf/arch/arm64/include/dwarf-regs-table.h b/tools/perf/arch/arm64/include/dwarf-regs-table.h
new file mode 100644
index 0000000..2675936
--- /dev/null
+++ b/tools/perf/arch/arm64/include/dwarf-regs-table.h
@@ -0,0 +1,13 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const aarch64_regstr_tbl[] = {
+	"%r0", "%r1", "%r2", "%r3", "%r4",
+	"%r5", "%r6", "%r7", "%r8", "%r9",
+	"%r10", "%r11", "%r12", "%r13", "%r14",
+	"%r15", "%r16", "%r17", "%r18", "%r19",
+	"%r20", "%r21", "%r22", "%r23", "%r24",
+	"%r25", "%r26", "%r27", "%r28", "%r29",
+	"%lr", "%sp",
+};
+#endif
diff --git a/tools/perf/arch/powerpc/include/dwarf-regs-table.h b/tools/perf/arch/powerpc/include/dwarf-regs-table.h
new file mode 100644
index 0000000..db4730f
--- /dev/null
+++ b/tools/perf/arch/powerpc/include/dwarf-regs-table.h
@@ -0,0 +1,27 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+/*
+ * Reference:
+ * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
+ * http://refspecs.linux-foundation.org/elf/elfspec_ppc.pdf
+ */
+#define REG_DWARFNUM_NAME(reg, idx)	[idx] = "%" #reg
+
+static const char * const powerpc_regstr_tbl[] = {
+	"%gpr0", "%gpr1", "%gpr2", "%gpr3", "%gpr4",
+	"%gpr5", "%gpr6", "%gpr7", "%gpr8", "%gpr9",
+	"%gpr10", "%gpr11", "%gpr12", "%gpr13", "%gpr14",
+	"%gpr15", "%gpr16", "%gpr17", "%gpr18", "%gpr19",
+	"%gpr20", "%gpr21", "%gpr22", "%gpr23", "%gpr24",
+	"%gpr25", "%gpr26", "%gpr27", "%gpr28", "%gpr29",
+	"%gpr30", "%gpr31",
+	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),
+};
+
+#endif
diff --git a/tools/perf/arch/s390/include/dwarf-regs-table.h b/tools/perf/arch/s390/include/dwarf-regs-table.h
new file mode 100644
index 0000000..9da74a9
--- /dev/null
+++ b/tools/perf/arch/s390/include/dwarf-regs-table.h
@@ -0,0 +1,8 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const s390_regstr_tbl[] = {
+	"%r0", "%r1",  "%r2",  "%r3",  "%r4",  "%r5",  "%r6",  "%r7",
+	"%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15",
+};
+#endif
diff --git a/tools/perf/arch/sh/include/dwarf-regs-table.h b/tools/perf/arch/sh/include/dwarf-regs-table.h
new file mode 100644
index 0000000..3a2deaf
--- /dev/null
+++ b/tools/perf/arch/sh/include/dwarf-regs-table.h
@@ -0,0 +1,25 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+const char * const sh_regstr_tbl[] = {
+	"r0",
+	"r1",
+	"r2",
+	"r3",
+	"r4",
+	"r5",
+	"r6",
+	"r7",
+	"r8",
+	"r9",
+	"r10",
+	"r11",
+	"r12",
+	"r13",
+	"r14",
+	"r15",
+	"pc",
+	"pr",
+};
+
+#endif
diff --git a/tools/perf/arch/sparc/include/dwarf-regs-table.h b/tools/perf/arch/sparc/include/dwarf-regs-table.h
new file mode 100644
index 0000000..12c0761
--- /dev/null
+++ b/tools/perf/arch/sparc/include/dwarf-regs-table.h
@@ -0,0 +1,18 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const sparc_regstr_tbl[] = {
+	"%g0", "%g1", "%g2", "%g3", "%g4", "%g5", "%g6", "%g7",
+	"%o0", "%o1", "%o2", "%o3", "%o4", "%o5", "%sp", "%o7",
+	"%l0", "%l1", "%l2", "%l3", "%l4", "%l5", "%l6", "%l7",
+	"%i0", "%i1", "%i2", "%i3", "%i4", "%i5", "%fp", "%i7",
+	"%f0", "%f1", "%f2", "%f3", "%f4", "%f5", "%f6", "%f7",
+	"%f8", "%f9", "%f10", "%f11", "%f12", "%f13", "%f14", "%f15",
+	"%f16", "%f17", "%f18", "%f19", "%f20", "%f21", "%f22", "%f23",
+	"%f24", "%f25", "%f26", "%f27", "%f28", "%f29", "%f30", "%f31",
+	"%f32", "%f33", "%f34", "%f35", "%f36", "%f37", "%f38", "%f39",
+	"%f40", "%f41", "%f42", "%f43", "%f44", "%f45", "%f46", "%f47",
+	"%f48", "%f49", "%f50", "%f51", "%f52", "%f53", "%f54", "%f55",
+	"%f56", "%f57", "%f58", "%f59", "%f60", "%f61", "%f62", "%f63",
+};
+#endif
diff --git a/tools/perf/arch/x86/include/dwarf-regs-table.h b/tools/perf/arch/x86/include/dwarf-regs-table.h
new file mode 100644
index 0000000..39ac7cb
--- /dev/null
+++ b/tools/perf/arch/x86/include/dwarf-regs-table.h
@@ -0,0 +1,14 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const x86_32_regstr_tbl[] = {
+	"%ax", "%cx", "%dx", "%bx", "$stack",/* Stack address instead of %sp */
+	"%bp", "%si", "%di",
+};
+
+static const char * const x86_64_regstr_tbl[] = {
+	"%ax", "dx", "%cx", "%bx", "%si", "%di",
+	"%bp", "%sp", "%r8", "%r9", "%r10", "%r11",
+	"%r12", "%r13", "%r14", "%r15",
+};
+#endif
diff --git a/tools/perf/arch/xtensa/include/dwarf-regs-table.h b/tools/perf/arch/xtensa/include/dwarf-regs-table.h
new file mode 100644
index 0000000..aa0444a
--- /dev/null
+++ b/tools/perf/arch/xtensa/include/dwarf-regs-table.h
@@ -0,0 +1,8 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const xtensa_regstr_tbl[] = {
+	"a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
+	"a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15",
+};
+#endif
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 91c5f6e..f1a6d17 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -98,6 +98,7 @@ endif
 
 libperf-$(CONFIG_DWARF) += probe-finder.o
 libperf-$(CONFIG_DWARF) += dwarf-aux.o
+libperf-$(CONFIG_DWARF) += dwarf-regs.o
 
 libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
 libperf-$(CONFIG_LOCAL_LIBUNWIND)    += unwind-libunwind-local.o
diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
new file mode 100644
index 0000000..ce15816
--- /dev/null
+++ b/tools/perf/util/dwarf-regs.c
@@ -0,0 +1,55 @@
+/*
+ * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
+ *
+ * Written by: Masami Hiramatsu <mhiramat@kernel.org>
+ */
+
+#include <util.h>
+#include <debug.h>
+#include <dwarf-regs.h>
+#include <elf.h>
+
+/* Define const char * {arch}_register_tbl[] */
+#define DEFINE_DWARF_REGSTR_TABLE
+#include "../arch/x86/include/dwarf-regs-table.h"
+#include "../arch/arm/include/dwarf-regs-table.h"
+#include "../arch/arm64/include/dwarf-regs-table.h"
+#include "../arch/sh/include/dwarf-regs-table.h"
+#include "../arch/powerpc/include/dwarf-regs-table.h"
+#include "../arch/s390/include/dwarf-regs-table.h"
+#include "../arch/sparc/include/dwarf-regs-table.h"
+#include "../arch/xtensa/include/dwarf-regs-table.h"
+
+#define __get_dwarf_regstr(tbl, n) (((n) < ARRAY_SIZE(tbl)) ? (tbl)[(n)] : NULL)
+
+/* Return architecture dependent register string (for kprobe-tracer) */
+const char *get_dwarf_regstr(unsigned int n, unsigned int machine)
+{
+	switch (machine) {
+	case EM_NONE:	/* Generic arch - use host arch */
+		return get_arch_regstr(n);
+	case EM_386:
+		return __get_dwarf_regstr(x86_32_regstr_tbl, n);
+	case EM_X86_64:
+		return __get_dwarf_regstr(x86_64_regstr_tbl, n);
+	case EM_ARM:
+		return __get_dwarf_regstr(arm_regstr_tbl, n);
+	case EM_AARCH64:
+		return __get_dwarf_regstr(aarch64_regstr_tbl, n);
+	case EM_SH:
+		return __get_dwarf_regstr(sh_regstr_tbl, n);
+	case EM_S390:
+		return __get_dwarf_regstr(s390_regstr_tbl, n);
+	case EM_PPC:
+	case EM_PPC64:
+		return __get_dwarf_regstr(powerpc_regstr_tbl, n);
+	case EM_SPARC:
+	case EM_SPARCV9:
+		return __get_dwarf_regstr(sparc_regstr_tbl, n);
+	case EM_XTENSA:
+		return __get_dwarf_regstr(xtensa_regstr_tbl, n);
+	default:
+		pr_err("ELF MACHINE %x is not supported.\n", machine);
+	}
+	return NULL;
+}
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
index 07c644e..43bfd8d 100644
--- a/tools/perf/util/include/dwarf-regs.h
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -3,6 +3,12 @@
 
 #ifdef HAVE_DWARF_SUPPORT
 const char *get_arch_regstr(unsigned int n);
+/*
+ * get_dwarf_regstr - Returns ftrace register string from DWARF regnum
+ * n: DWARF register number
+ * machine: ELF machine signature (EM_*)
+ */
+const char *get_dwarf_regstr(unsigned int n, unsigned int machine);
 #endif
 
 #ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index ac4740f..508b61c 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -171,6 +171,7 @@ static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
  */
 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
 				     Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
+				     unsigned int machine,
 				     struct probe_trace_arg *tvar)
 {
 	Dwarf_Attribute attr;
@@ -266,7 +267,7 @@ static_var:
 	if (!tvar)
 		return ret2;
 
-	regs = get_arch_regstr(regn);
+	regs = get_dwarf_regstr(regn, machine);
 	if (!regs) {
 		/* This should be a bug in DWARF or this tool */
 		pr_warning("Mapping for the register number %u "
@@ -543,7 +544,7 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 		 dwarf_diename(vr_die));
 
 	ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
-					&pf->sp_die, pf->tvar);
+					&pf->sp_die, pf->machine, pf->tvar);
 	if (ret == -ENOENT || ret == -EINVAL) {
 		pr_err("Failed to find the location of the '%s' variable at this address.\n"
 		       " Perhaps it has been optimized out.\n"
@@ -1106,11 +1107,8 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
 				  struct probe_finder *pf)
 {
 	int ret = 0;
-
-#if _ELFUTILS_PREREQ(0, 142)
 	Elf *elf;
 	GElf_Ehdr ehdr;
-	GElf_Shdr shdr;
 
 	if (pf->cfi_eh || pf->cfi_dbg)
 		return debuginfo__find_probe_location(dbg, pf);
@@ -1123,11 +1121,18 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
 	if (gelf_getehdr(elf, &ehdr) == NULL)
 		return -EINVAL;
 
-	if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
-	    shdr.sh_type == SHT_PROGBITS)
-		pf->cfi_eh = dwarf_getcfi_elf(elf);
+	pf->machine = ehdr.e_machine;
+
+#if _ELFUTILS_PREREQ(0, 142)
+	do {
+		GElf_Shdr shdr;
+
+		if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
+		    shdr.sh_type == SHT_PROGBITS)
+			pf->cfi_eh = dwarf_getcfi_elf(elf);
 
-	pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
+		pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
+	} while (0);
 #endif
 
 	ret = debuginfo__find_probe_location(dbg, pf);
@@ -1155,7 +1160,7 @@ static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
 	    (tag == DW_TAG_variable && vf->vars)) {
 		if (convert_variable_location(die_mem, vf->pf->addr,
 					      vf->pf->fb_ops, &pf->sp_die,
-					      NULL) == 0) {
+					      pf->machine, NULL) == 0) {
 			vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
 			if (vf->args[vf->nargs].var == NULL) {
 				vf->ret = -ENOMEM;
@@ -1318,7 +1323,7 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
 	    tag == DW_TAG_variable) {
 		ret = convert_variable_location(die_mem, af->pf.addr,
 						af->pf.fb_ops, &af->pf.sp_die,
-						NULL);
+						af->pf.machine, NULL);
 		if (ret == 0 || ret == -ERANGE) {
 			int ret2;
 			bool externs = !af->child;
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index 51137fc..f1d8558 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -80,6 +80,7 @@ struct probe_finder {
 	Dwarf_CFI		*cfi_dbg;
 #endif
 	Dwarf_Op		*fb_ops;	/* Frame base attribute */
+	unsigned int		machine;	/* Target machine arch */
 	struct perf_probe_arg	*pvar;		/* Current target variable */
 	struct probe_trace_arg	*tvar;		/* Current result variable */
 };

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#1473856 — Re: [PATCH v2 3/3] perf-probe: Support probing on offline cross-arch binary

FromArnaldo Carvalho de Melo <acme@kernel.org>
Date2016-08-31 23:00 +0200
SubjectRe: [PATCH v2 3/3] perf-probe: Support probing on offline cross-arch binary
Message-ID<sckM2-7eb-39@gated-at.bofh.it>
In reply to#1470263
Em Fri, Aug 26, 2016 at 01:24:57AM +0900, Masami Hiramatsu escreveu:
> Support probing on offline cross-architecture binary by
> adding getting the target machine arch from ELF and
> choose correct register string for the machine.
> 
> Here is an example:
>   -----
>   $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
>   p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
>   -----
> Here, we can get probe/do_sys_open event by "copy & paste" from
> ./tracing/kprobe_events to target-machine's debugfs/tracing/kprobe_events

Fixing the example not to refer to "tracing/kprobe_events", as it is not
there anymore, instead append what '--definition' produced to the target
machine <tracefs mountpoint>/tracing/kprobe_events file.

- Arnaldo
 
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> ---
>   Changes from v1:
>    - Change the example.
> ---
>  tools/perf/arch/arm/include/dwarf-regs-table.h     |    9 +++
>  tools/perf/arch/arm64/include/dwarf-regs-table.h   |   13 +++++
>  tools/perf/arch/powerpc/include/dwarf-regs-table.h |   27 ++++++++++
>  tools/perf/arch/s390/include/dwarf-regs-table.h    |    8 +++
>  tools/perf/arch/sh/include/dwarf-regs-table.h      |   25 +++++++++
>  tools/perf/arch/sparc/include/dwarf-regs-table.h   |   18 +++++++
>  tools/perf/arch/x86/include/dwarf-regs-table.h     |   14 +++++
>  tools/perf/arch/xtensa/include/dwarf-regs-table.h  |    8 +++
>  tools/perf/util/Build                              |    1 
>  tools/perf/util/dwarf-regs.c                       |   55 ++++++++++++++++++++
>  tools/perf/util/include/dwarf-regs.h               |    6 ++
>  tools/perf/util/probe-finder.c                     |   27 ++++++----
>  tools/perf/util/probe-finder.h                     |    1 
>  13 files changed, 201 insertions(+), 11 deletions(-)
>  create mode 100644 tools/perf/arch/arm/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/arm64/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/powerpc/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/s390/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/sh/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/sparc/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/x86/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/xtensa/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/util/dwarf-regs.c
> 
> diff --git a/tools/perf/arch/arm/include/dwarf-regs-table.h b/tools/perf/arch/arm/include/dwarf-regs-table.h
> new file mode 100644
> index 0000000..f298d03
> --- /dev/null
> +++ b/tools/perf/arch/arm/include/dwarf-regs-table.h
> @@ -0,0 +1,9 @@
> +#ifdef DEFINE_DWARF_REGSTR_TABLE
> +/* This is included in perf/util/dwarf-regs.c */
> +
> +static const char * const arm_regstr_tbl[] = {
> +	"%r0", "%r1", "%r2", "%r3", "%r4",
> +	"%r5", "%r6", "%r7", "%r8", "%r9", "%r10",
> +	"%fp", "%ip", "%sp", "%lr", "%pc",
> +};
> +#endif
> diff --git a/tools/perf/arch/arm64/include/dwarf-regs-table.h b/tools/perf/arch/arm64/include/dwarf-regs-table.h
> new file mode 100644
> index 0000000..2675936
> --- /dev/null
> +++ b/tools/perf/arch/arm64/include/dwarf-regs-table.h
> @@ -0,0 +1,13 @@
> +#ifdef DEFINE_DWARF_REGSTR_TABLE
> +/* This is included in perf/util/dwarf-regs.c */
> +
> +static const char * const aarch64_regstr_tbl[] = {
> +	"%r0", "%r1", "%r2", "%r3", "%r4",
> +	"%r5", "%r6", "%r7", "%r8", "%r9",
> +	"%r10", "%r11", "%r12", "%r13", "%r14",
> +	"%r15", "%r16", "%r17", "%r18", "%r19",
> +	"%r20", "%r21", "%r22", "%r23", "%r24",
> +	"%r25", "%r26", "%r27", "%r28", "%r29",
> +	"%lr", "%sp",
> +};
> +#endif
> diff --git a/tools/perf/arch/powerpc/include/dwarf-regs-table.h b/tools/perf/arch/powerpc/include/dwarf-regs-table.h
> new file mode 100644
> index 0000000..db4730f
> --- /dev/null
> +++ b/tools/perf/arch/powerpc/include/dwarf-regs-table.h
> @@ -0,0 +1,27 @@
> +#ifdef DEFINE_DWARF_REGSTR_TABLE
> +/* This is included in perf/util/dwarf-regs.c */
> +
> +/*
> + * Reference:
> + * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
> + * http://refspecs.linux-foundation.org/elf/elfspec_ppc.pdf
> + */
> +#define REG_DWARFNUM_NAME(reg, idx)	[idx] = "%" #reg
> +
> +static const char * const powerpc_regstr_tbl[] = {
> +	"%gpr0", "%gpr1", "%gpr2", "%gpr3", "%gpr4",
> +	"%gpr5", "%gpr6", "%gpr7", "%gpr8", "%gpr9",
> +	"%gpr10", "%gpr11", "%gpr12", "%gpr13", "%gpr14",
> +	"%gpr15", "%gpr16", "%gpr17", "%gpr18", "%gpr19",
> +	"%gpr20", "%gpr21", "%gpr22", "%gpr23", "%gpr24",
> +	"%gpr25", "%gpr26", "%gpr27", "%gpr28", "%gpr29",
> +	"%gpr30", "%gpr31",
> +	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),
> +};
> +
> +#endif
> diff --git a/tools/perf/arch/s390/include/dwarf-regs-table.h b/tools/perf/arch/s390/include/dwarf-regs-table.h
> new file mode 100644
> index 0000000..9da74a9
> --- /dev/null
> +++ b/tools/perf/arch/s390/include/dwarf-regs-table.h
> @@ -0,0 +1,8 @@
> +#ifdef DEFINE_DWARF_REGSTR_TABLE
> +/* This is included in perf/util/dwarf-regs.c */
> +
> +static const char * const s390_regstr_tbl[] = {
> +	"%r0", "%r1",  "%r2",  "%r3",  "%r4",  "%r5",  "%r6",  "%r7",
> +	"%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15",
> +};
> +#endif
> diff --git a/tools/perf/arch/sh/include/dwarf-regs-table.h b/tools/perf/arch/sh/include/dwarf-regs-table.h
> new file mode 100644
> index 0000000..3a2deaf
> --- /dev/null
> +++ b/tools/perf/arch/sh/include/dwarf-regs-table.h
> @@ -0,0 +1,25 @@
> +#ifdef DEFINE_DWARF_REGSTR_TABLE
> +/* This is included in perf/util/dwarf-regs.c */
> +
> +const char * const sh_regstr_tbl[] = {
> +	"r0",
> +	"r1",
> +	"r2",
> +	"r3",
> +	"r4",
> +	"r5",
> +	"r6",
> +	"r7",
> +	"r8",
> +	"r9",
> +	"r10",
> +	"r11",
> +	"r12",
> +	"r13",
> +	"r14",
> +	"r15",
> +	"pc",
> +	"pr",
> +};
> +
> +#endif
> diff --git a/tools/perf/arch/sparc/include/dwarf-regs-table.h b/tools/perf/arch/sparc/include/dwarf-regs-table.h
> new file mode 100644
> index 0000000..12c0761
> --- /dev/null
> +++ b/tools/perf/arch/sparc/include/dwarf-regs-table.h
> @@ -0,0 +1,18 @@
> +#ifdef DEFINE_DWARF_REGSTR_TABLE
> +/* This is included in perf/util/dwarf-regs.c */
> +
> +static const char * const sparc_regstr_tbl[] = {
> +	"%g0", "%g1", "%g2", "%g3", "%g4", "%g5", "%g6", "%g7",
> +	"%o0", "%o1", "%o2", "%o3", "%o4", "%o5", "%sp", "%o7",
> +	"%l0", "%l1", "%l2", "%l3", "%l4", "%l5", "%l6", "%l7",
> +	"%i0", "%i1", "%i2", "%i3", "%i4", "%i5", "%fp", "%i7",
> +	"%f0", "%f1", "%f2", "%f3", "%f4", "%f5", "%f6", "%f7",
> +	"%f8", "%f9", "%f10", "%f11", "%f12", "%f13", "%f14", "%f15",
> +	"%f16", "%f17", "%f18", "%f19", "%f20", "%f21", "%f22", "%f23",
> +	"%f24", "%f25", "%f26", "%f27", "%f28", "%f29", "%f30", "%f31",
> +	"%f32", "%f33", "%f34", "%f35", "%f36", "%f37", "%f38", "%f39",
> +	"%f40", "%f41", "%f42", "%f43", "%f44", "%f45", "%f46", "%f47",
> +	"%f48", "%f49", "%f50", "%f51", "%f52", "%f53", "%f54", "%f55",
> +	"%f56", "%f57", "%f58", "%f59", "%f60", "%f61", "%f62", "%f63",
> +};
> +#endif
> diff --git a/tools/perf/arch/x86/include/dwarf-regs-table.h b/tools/perf/arch/x86/include/dwarf-regs-table.h
> new file mode 100644
> index 0000000..39ac7cb
> --- /dev/null
> +++ b/tools/perf/arch/x86/include/dwarf-regs-table.h
> @@ -0,0 +1,14 @@
> +#ifdef DEFINE_DWARF_REGSTR_TABLE
> +/* This is included in perf/util/dwarf-regs.c */
> +
> +static const char * const x86_32_regstr_tbl[] = {
> +	"%ax", "%cx", "%dx", "%bx", "$stack",/* Stack address instead of %sp */
> +	"%bp", "%si", "%di",
> +};
> +
> +static const char * const x86_64_regstr_tbl[] = {
> +	"%ax", "dx", "%cx", "%bx", "%si", "%di",
> +	"%bp", "%sp", "%r8", "%r9", "%r10", "%r11",
> +	"%r12", "%r13", "%r14", "%r15",
> +};
> +#endif
> diff --git a/tools/perf/arch/xtensa/include/dwarf-regs-table.h b/tools/perf/arch/xtensa/include/dwarf-regs-table.h
> new file mode 100644
> index 0000000..aa0444a
> --- /dev/null
> +++ b/tools/perf/arch/xtensa/include/dwarf-regs-table.h
> @@ -0,0 +1,8 @@
> +#ifdef DEFINE_DWARF_REGSTR_TABLE
> +/* This is included in perf/util/dwarf-regs.c */
> +
> +static const char * const xtensa_regstr_tbl[] = {
> +	"a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
> +	"a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15",
> +};
> +#endif
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 91c5f6e..f1a6d17 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -98,6 +98,7 @@ endif
>  
>  libperf-$(CONFIG_DWARF) += probe-finder.o
>  libperf-$(CONFIG_DWARF) += dwarf-aux.o
> +libperf-$(CONFIG_DWARF) += dwarf-regs.o
>  
>  libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
>  libperf-$(CONFIG_LOCAL_LIBUNWIND)    += unwind-libunwind-local.o
> diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
> new file mode 100644
> index 0000000..ce15816
> --- /dev/null
> +++ b/tools/perf/util/dwarf-regs.c
> @@ -0,0 +1,55 @@
> +/*
> + * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
> + *
> + * Written by: Masami Hiramatsu <mhiramat@kernel.org>
> + */
> +
> +#include <util.h>
> +#include <debug.h>
> +#include <dwarf-regs.h>
> +#include <elf.h>
> +
> +/* Define const char * {arch}_register_tbl[] */
> +#define DEFINE_DWARF_REGSTR_TABLE
> +#include "../arch/x86/include/dwarf-regs-table.h"
> +#include "../arch/arm/include/dwarf-regs-table.h"
> +#include "../arch/arm64/include/dwarf-regs-table.h"
> +#include "../arch/sh/include/dwarf-regs-table.h"
> +#include "../arch/powerpc/include/dwarf-regs-table.h"
> +#include "../arch/s390/include/dwarf-regs-table.h"
> +#include "../arch/sparc/include/dwarf-regs-table.h"
> +#include "../arch/xtensa/include/dwarf-regs-table.h"
> +
> +#define __get_dwarf_regstr(tbl, n) (((n) < ARRAY_SIZE(tbl)) ? (tbl)[(n)] : NULL)
> +
> +/* Return architecture dependent register string (for kprobe-tracer) */
> +const char *get_dwarf_regstr(unsigned int n, unsigned int machine)
> +{
> +	switch (machine) {
> +	case EM_NONE:	/* Generic arch - use host arch */
> +		return get_arch_regstr(n);
> +	case EM_386:
> +		return __get_dwarf_regstr(x86_32_regstr_tbl, n);
> +	case EM_X86_64:
> +		return __get_dwarf_regstr(x86_64_regstr_tbl, n);
> +	case EM_ARM:
> +		return __get_dwarf_regstr(arm_regstr_tbl, n);
> +	case EM_AARCH64:
> +		return __get_dwarf_regstr(aarch64_regstr_tbl, n);
> +	case EM_SH:
> +		return __get_dwarf_regstr(sh_regstr_tbl, n);
> +	case EM_S390:
> +		return __get_dwarf_regstr(s390_regstr_tbl, n);
> +	case EM_PPC:
> +	case EM_PPC64:
> +		return __get_dwarf_regstr(powerpc_regstr_tbl, n);
> +	case EM_SPARC:
> +	case EM_SPARCV9:
> +		return __get_dwarf_regstr(sparc_regstr_tbl, n);
> +	case EM_XTENSA:
> +		return __get_dwarf_regstr(xtensa_regstr_tbl, n);
> +	default:
> +		pr_err("ELF MACHINE %x is not supported.\n", machine);
> +	}
> +	return NULL;
> +}
> diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
> index 07c644e..43bfd8d 100644
> --- a/tools/perf/util/include/dwarf-regs.h
> +++ b/tools/perf/util/include/dwarf-regs.h
> @@ -3,6 +3,12 @@
>  
>  #ifdef HAVE_DWARF_SUPPORT
>  const char *get_arch_regstr(unsigned int n);
> +/*
> + * get_dwarf_regstr - Returns ftrace register string from DWARF regnum
> + * n: DWARF register number
> + * machine: ELF machine signature (EM_*)
> + */
> +const char *get_dwarf_regstr(unsigned int n, unsigned int machine);
>  #endif
>  
>  #ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> index ac4740f..508b61c 100644
> --- a/tools/perf/util/probe-finder.c
> +++ b/tools/perf/util/probe-finder.c
> @@ -171,6 +171,7 @@ static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
>   */
>  static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
>  				     Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
> +				     unsigned int machine,
>  				     struct probe_trace_arg *tvar)
>  {
>  	Dwarf_Attribute attr;
> @@ -266,7 +267,7 @@ static_var:
>  	if (!tvar)
>  		return ret2;
>  
> -	regs = get_arch_regstr(regn);
> +	regs = get_dwarf_regstr(regn, machine);
>  	if (!regs) {
>  		/* This should be a bug in DWARF or this tool */
>  		pr_warning("Mapping for the register number %u "
> @@ -543,7 +544,7 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
>  		 dwarf_diename(vr_die));
>  
>  	ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
> -					&pf->sp_die, pf->tvar);
> +					&pf->sp_die, pf->machine, pf->tvar);
>  	if (ret == -ENOENT || ret == -EINVAL) {
>  		pr_err("Failed to find the location of the '%s' variable at this address.\n"
>  		       " Perhaps it has been optimized out.\n"
> @@ -1106,11 +1107,8 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
>  				  struct probe_finder *pf)
>  {
>  	int ret = 0;
> -
> -#if _ELFUTILS_PREREQ(0, 142)
>  	Elf *elf;
>  	GElf_Ehdr ehdr;
> -	GElf_Shdr shdr;
>  
>  	if (pf->cfi_eh || pf->cfi_dbg)
>  		return debuginfo__find_probe_location(dbg, pf);
> @@ -1123,11 +1121,18 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
>  	if (gelf_getehdr(elf, &ehdr) == NULL)
>  		return -EINVAL;
>  
> -	if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
> -	    shdr.sh_type == SHT_PROGBITS)
> -		pf->cfi_eh = dwarf_getcfi_elf(elf);
> +	pf->machine = ehdr.e_machine;
> +
> +#if _ELFUTILS_PREREQ(0, 142)
> +	do {
> +		GElf_Shdr shdr;
> +
> +		if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
> +		    shdr.sh_type == SHT_PROGBITS)
> +			pf->cfi_eh = dwarf_getcfi_elf(elf);
>  
> -	pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
> +		pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
> +	} while (0);
>  #endif
>  
>  	ret = debuginfo__find_probe_location(dbg, pf);
> @@ -1155,7 +1160,7 @@ static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
>  	    (tag == DW_TAG_variable && vf->vars)) {
>  		if (convert_variable_location(die_mem, vf->pf->addr,
>  					      vf->pf->fb_ops, &pf->sp_die,
> -					      NULL) == 0) {
> +					      pf->machine, NULL) == 0) {
>  			vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
>  			if (vf->args[vf->nargs].var == NULL) {
>  				vf->ret = -ENOMEM;
> @@ -1318,7 +1323,7 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
>  	    tag == DW_TAG_variable) {
>  		ret = convert_variable_location(die_mem, af->pf.addr,
>  						af->pf.fb_ops, &af->pf.sp_die,
> -						NULL);
> +						af->pf.machine, NULL);
>  		if (ret == 0 || ret == -ERANGE) {
>  			int ret2;
>  			bool externs = !af->child;
> diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
> index 51137fc..f1d8558 100644
> --- a/tools/perf/util/probe-finder.h
> +++ b/tools/perf/util/probe-finder.h
> @@ -80,6 +80,7 @@ struct probe_finder {
>  	Dwarf_CFI		*cfi_dbg;
>  #endif
>  	Dwarf_Op		*fb_ops;	/* Frame base attribute */
> +	unsigned int		machine;	/* Target machine arch */
>  	struct perf_probe_arg	*pvar;		/* Current target variable */
>  	struct probe_trace_arg	*tvar;		/* Current result variable */
>  };

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#1473964 — Re: [PATCH v2 3/3] perf-probe: Support probing on offline cross-arch binary

FromMasami Hiramatsu <mhiramat@kernel.org>
Date2016-09-01 01:30 +0200
SubjectRe: [PATCH v2 3/3] perf-probe: Support probing on offline cross-arch binary
Message-ID<scn7c-pj-5@gated-at.bofh.it>
In reply to#1473856
On Wed, 31 Aug 2016 17:54:11 -0300
Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> Em Fri, Aug 26, 2016 at 01:24:57AM +0900, Masami Hiramatsu escreveu:
> > Support probing on offline cross-architecture binary by
> > adding getting the target machine arch from ELF and
> > choose correct register string for the machine.
> > 
> > Here is an example:
> >   -----
> >   $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
> >   p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
> >   -----
> > Here, we can get probe/do_sys_open event by "copy & paste" from
> > ./tracing/kprobe_events to target-machine's debugfs/tracing/kprobe_events
> 
> Fixing the example not to refer to "tracing/kprobe_events", as it is not
> there anymore, instead append what '--definition' produced to the target
> machine <tracefs mountpoint>/tracing/kprobe_events file.

Oops, right, it's my mistake...

Thank you,

> 
> - Arnaldo
>  
> > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> > ---
> >   Changes from v1:
> >    - Change the example.
> > ---
> >  tools/perf/arch/arm/include/dwarf-regs-table.h     |    9 +++
> >  tools/perf/arch/arm64/include/dwarf-regs-table.h   |   13 +++++
> >  tools/perf/arch/powerpc/include/dwarf-regs-table.h |   27 ++++++++++
> >  tools/perf/arch/s390/include/dwarf-regs-table.h    |    8 +++
> >  tools/perf/arch/sh/include/dwarf-regs-table.h      |   25 +++++++++
> >  tools/perf/arch/sparc/include/dwarf-regs-table.h   |   18 +++++++
> >  tools/perf/arch/x86/include/dwarf-regs-table.h     |   14 +++++
> >  tools/perf/arch/xtensa/include/dwarf-regs-table.h  |    8 +++
> >  tools/perf/util/Build                              |    1 
> >  tools/perf/util/dwarf-regs.c                       |   55 ++++++++++++++++++++
> >  tools/perf/util/include/dwarf-regs.h               |    6 ++
> >  tools/perf/util/probe-finder.c                     |   27 ++++++----
> >  tools/perf/util/probe-finder.h                     |    1 
> >  13 files changed, 201 insertions(+), 11 deletions(-)
> >  create mode 100644 tools/perf/arch/arm/include/dwarf-regs-table.h
> >  create mode 100644 tools/perf/arch/arm64/include/dwarf-regs-table.h
> >  create mode 100644 tools/perf/arch/powerpc/include/dwarf-regs-table.h
> >  create mode 100644 tools/perf/arch/s390/include/dwarf-regs-table.h
> >  create mode 100644 tools/perf/arch/sh/include/dwarf-regs-table.h
> >  create mode 100644 tools/perf/arch/sparc/include/dwarf-regs-table.h
> >  create mode 100644 tools/perf/arch/x86/include/dwarf-regs-table.h
> >  create mode 100644 tools/perf/arch/xtensa/include/dwarf-regs-table.h
> >  create mode 100644 tools/perf/util/dwarf-regs.c
> > 
> > diff --git a/tools/perf/arch/arm/include/dwarf-regs-table.h b/tools/perf/arch/arm/include/dwarf-regs-table.h
> > new file mode 100644
> > index 0000000..f298d03
> > --- /dev/null
> > +++ b/tools/perf/arch/arm/include/dwarf-regs-table.h
> > @@ -0,0 +1,9 @@
> > +#ifdef DEFINE_DWARF_REGSTR_TABLE
> > +/* This is included in perf/util/dwarf-regs.c */
> > +
> > +static const char * const arm_regstr_tbl[] = {
> > +	"%r0", "%r1", "%r2", "%r3", "%r4",
> > +	"%r5", "%r6", "%r7", "%r8", "%r9", "%r10",
> > +	"%fp", "%ip", "%sp", "%lr", "%pc",
> > +};
> > +#endif
> > diff --git a/tools/perf/arch/arm64/include/dwarf-regs-table.h b/tools/perf/arch/arm64/include/dwarf-regs-table.h
> > new file mode 100644
> > index 0000000..2675936
> > --- /dev/null
> > +++ b/tools/perf/arch/arm64/include/dwarf-regs-table.h
> > @@ -0,0 +1,13 @@
> > +#ifdef DEFINE_DWARF_REGSTR_TABLE
> > +/* This is included in perf/util/dwarf-regs.c */
> > +
> > +static const char * const aarch64_regstr_tbl[] = {
> > +	"%r0", "%r1", "%r2", "%r3", "%r4",
> > +	"%r5", "%r6", "%r7", "%r8", "%r9",
> > +	"%r10", "%r11", "%r12", "%r13", "%r14",
> > +	"%r15", "%r16", "%r17", "%r18", "%r19",
> > +	"%r20", "%r21", "%r22", "%r23", "%r24",
> > +	"%r25", "%r26", "%r27", "%r28", "%r29",
> > +	"%lr", "%sp",
> > +};
> > +#endif
> > diff --git a/tools/perf/arch/powerpc/include/dwarf-regs-table.h b/tools/perf/arch/powerpc/include/dwarf-regs-table.h
> > new file mode 100644
> > index 0000000..db4730f
> > --- /dev/null
> > +++ b/tools/perf/arch/powerpc/include/dwarf-regs-table.h
> > @@ -0,0 +1,27 @@
> > +#ifdef DEFINE_DWARF_REGSTR_TABLE
> > +/* This is included in perf/util/dwarf-regs.c */
> > +
> > +/*
> > + * Reference:
> > + * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
> > + * http://refspecs.linux-foundation.org/elf/elfspec_ppc.pdf
> > + */
> > +#define REG_DWARFNUM_NAME(reg, idx)	[idx] = "%" #reg
> > +
> > +static const char * const powerpc_regstr_tbl[] = {
> > +	"%gpr0", "%gpr1", "%gpr2", "%gpr3", "%gpr4",
> > +	"%gpr5", "%gpr6", "%gpr7", "%gpr8", "%gpr9",
> > +	"%gpr10", "%gpr11", "%gpr12", "%gpr13", "%gpr14",
> > +	"%gpr15", "%gpr16", "%gpr17", "%gpr18", "%gpr19",
> > +	"%gpr20", "%gpr21", "%gpr22", "%gpr23", "%gpr24",
> > +	"%gpr25", "%gpr26", "%gpr27", "%gpr28", "%gpr29",
> > +	"%gpr30", "%gpr31",
> > +	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),
> > +};
> > +
> > +#endif
> > diff --git a/tools/perf/arch/s390/include/dwarf-regs-table.h b/tools/perf/arch/s390/include/dwarf-regs-table.h
> > new file mode 100644
> > index 0000000..9da74a9
> > --- /dev/null
> > +++ b/tools/perf/arch/s390/include/dwarf-regs-table.h
> > @@ -0,0 +1,8 @@
> > +#ifdef DEFINE_DWARF_REGSTR_TABLE
> > +/* This is included in perf/util/dwarf-regs.c */
> > +
> > +static const char * const s390_regstr_tbl[] = {
> > +	"%r0", "%r1",  "%r2",  "%r3",  "%r4",  "%r5",  "%r6",  "%r7",
> > +	"%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15",
> > +};
> > +#endif
> > diff --git a/tools/perf/arch/sh/include/dwarf-regs-table.h b/tools/perf/arch/sh/include/dwarf-regs-table.h
> > new file mode 100644
> > index 0000000..3a2deaf
> > --- /dev/null
> > +++ b/tools/perf/arch/sh/include/dwarf-regs-table.h
> > @@ -0,0 +1,25 @@
> > +#ifdef DEFINE_DWARF_REGSTR_TABLE
> > +/* This is included in perf/util/dwarf-regs.c */
> > +
> > +const char * const sh_regstr_tbl[] = {
> > +	"r0",
> > +	"r1",
> > +	"r2",
> > +	"r3",
> > +	"r4",
> > +	"r5",
> > +	"r6",
> > +	"r7",
> > +	"r8",
> > +	"r9",
> > +	"r10",
> > +	"r11",
> > +	"r12",
> > +	"r13",
> > +	"r14",
> > +	"r15",
> > +	"pc",
> > +	"pr",
> > +};
> > +
> > +#endif
> > diff --git a/tools/perf/arch/sparc/include/dwarf-regs-table.h b/tools/perf/arch/sparc/include/dwarf-regs-table.h
> > new file mode 100644
> > index 0000000..12c0761
> > --- /dev/null
> > +++ b/tools/perf/arch/sparc/include/dwarf-regs-table.h
> > @@ -0,0 +1,18 @@
> > +#ifdef DEFINE_DWARF_REGSTR_TABLE
> > +/* This is included in perf/util/dwarf-regs.c */
> > +
> > +static const char * const sparc_regstr_tbl[] = {
> > +	"%g0", "%g1", "%g2", "%g3", "%g4", "%g5", "%g6", "%g7",
> > +	"%o0", "%o1", "%o2", "%o3", "%o4", "%o5", "%sp", "%o7",
> > +	"%l0", "%l1", "%l2", "%l3", "%l4", "%l5", "%l6", "%l7",
> > +	"%i0", "%i1", "%i2", "%i3", "%i4", "%i5", "%fp", "%i7",
> > +	"%f0", "%f1", "%f2", "%f3", "%f4", "%f5", "%f6", "%f7",
> > +	"%f8", "%f9", "%f10", "%f11", "%f12", "%f13", "%f14", "%f15",
> > +	"%f16", "%f17", "%f18", "%f19", "%f20", "%f21", "%f22", "%f23",
> > +	"%f24", "%f25", "%f26", "%f27", "%f28", "%f29", "%f30", "%f31",
> > +	"%f32", "%f33", "%f34", "%f35", "%f36", "%f37", "%f38", "%f39",
> > +	"%f40", "%f41", "%f42", "%f43", "%f44", "%f45", "%f46", "%f47",
> > +	"%f48", "%f49", "%f50", "%f51", "%f52", "%f53", "%f54", "%f55",
> > +	"%f56", "%f57", "%f58", "%f59", "%f60", "%f61", "%f62", "%f63",
> > +};
> > +#endif
> > diff --git a/tools/perf/arch/x86/include/dwarf-regs-table.h b/tools/perf/arch/x86/include/dwarf-regs-table.h
> > new file mode 100644
> > index 0000000..39ac7cb
> > --- /dev/null
> > +++ b/tools/perf/arch/x86/include/dwarf-regs-table.h
> > @@ -0,0 +1,14 @@
> > +#ifdef DEFINE_DWARF_REGSTR_TABLE
> > +/* This is included in perf/util/dwarf-regs.c */
> > +
> > +static const char * const x86_32_regstr_tbl[] = {
> > +	"%ax", "%cx", "%dx", "%bx", "$stack",/* Stack address instead of %sp */
> > +	"%bp", "%si", "%di",
> > +};
> > +
> > +static const char * const x86_64_regstr_tbl[] = {
> > +	"%ax", "dx", "%cx", "%bx", "%si", "%di",
> > +	"%bp", "%sp", "%r8", "%r9", "%r10", "%r11",
> > +	"%r12", "%r13", "%r14", "%r15",
> > +};
> > +#endif
> > diff --git a/tools/perf/arch/xtensa/include/dwarf-regs-table.h b/tools/perf/arch/xtensa/include/dwarf-regs-table.h
> > new file mode 100644
> > index 0000000..aa0444a
> > --- /dev/null
> > +++ b/tools/perf/arch/xtensa/include/dwarf-regs-table.h
> > @@ -0,0 +1,8 @@
> > +#ifdef DEFINE_DWARF_REGSTR_TABLE
> > +/* This is included in perf/util/dwarf-regs.c */
> > +
> > +static const char * const xtensa_regstr_tbl[] = {
> > +	"a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
> > +	"a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15",
> > +};
> > +#endif
> > diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> > index 91c5f6e..f1a6d17 100644
> > --- a/tools/perf/util/Build
> > +++ b/tools/perf/util/Build
> > @@ -98,6 +98,7 @@ endif
> >  
> >  libperf-$(CONFIG_DWARF) += probe-finder.o
> >  libperf-$(CONFIG_DWARF) += dwarf-aux.o
> > +libperf-$(CONFIG_DWARF) += dwarf-regs.o
> >  
> >  libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
> >  libperf-$(CONFIG_LOCAL_LIBUNWIND)    += unwind-libunwind-local.o
> > diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
> > new file mode 100644
> > index 0000000..ce15816
> > --- /dev/null
> > +++ b/tools/perf/util/dwarf-regs.c
> > @@ -0,0 +1,55 @@
> > +/*
> > + * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
> > + *
> > + * Written by: Masami Hiramatsu <mhiramat@kernel.org>
> > + */
> > +
> > +#include <util.h>
> > +#include <debug.h>
> > +#include <dwarf-regs.h>
> > +#include <elf.h>
> > +
> > +/* Define const char * {arch}_register_tbl[] */
> > +#define DEFINE_DWARF_REGSTR_TABLE
> > +#include "../arch/x86/include/dwarf-regs-table.h"
> > +#include "../arch/arm/include/dwarf-regs-table.h"
> > +#include "../arch/arm64/include/dwarf-regs-table.h"
> > +#include "../arch/sh/include/dwarf-regs-table.h"
> > +#include "../arch/powerpc/include/dwarf-regs-table.h"
> > +#include "../arch/s390/include/dwarf-regs-table.h"
> > +#include "../arch/sparc/include/dwarf-regs-table.h"
> > +#include "../arch/xtensa/include/dwarf-regs-table.h"
> > +
> > +#define __get_dwarf_regstr(tbl, n) (((n) < ARRAY_SIZE(tbl)) ? (tbl)[(n)] : NULL)
> > +
> > +/* Return architecture dependent register string (for kprobe-tracer) */
> > +const char *get_dwarf_regstr(unsigned int n, unsigned int machine)
> > +{
> > +	switch (machine) {
> > +	case EM_NONE:	/* Generic arch - use host arch */
> > +		return get_arch_regstr(n);
> > +	case EM_386:
> > +		return __get_dwarf_regstr(x86_32_regstr_tbl, n);
> > +	case EM_X86_64:
> > +		return __get_dwarf_regstr(x86_64_regstr_tbl, n);
> > +	case EM_ARM:
> > +		return __get_dwarf_regstr(arm_regstr_tbl, n);
> > +	case EM_AARCH64:
> > +		return __get_dwarf_regstr(aarch64_regstr_tbl, n);
> > +	case EM_SH:
> > +		return __get_dwarf_regstr(sh_regstr_tbl, n);
> > +	case EM_S390:
> > +		return __get_dwarf_regstr(s390_regstr_tbl, n);
> > +	case EM_PPC:
> > +	case EM_PPC64:
> > +		return __get_dwarf_regstr(powerpc_regstr_tbl, n);
> > +	case EM_SPARC:
> > +	case EM_SPARCV9:
> > +		return __get_dwarf_regstr(sparc_regstr_tbl, n);
> > +	case EM_XTENSA:
> > +		return __get_dwarf_regstr(xtensa_regstr_tbl, n);
> > +	default:
> > +		pr_err("ELF MACHINE %x is not supported.\n", machine);
> > +	}
> > +	return NULL;
> > +}
> > diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
> > index 07c644e..43bfd8d 100644
> > --- a/tools/perf/util/include/dwarf-regs.h
> > +++ b/tools/perf/util/include/dwarf-regs.h
> > @@ -3,6 +3,12 @@
> >  
> >  #ifdef HAVE_DWARF_SUPPORT
> >  const char *get_arch_regstr(unsigned int n);
> > +/*
> > + * get_dwarf_regstr - Returns ftrace register string from DWARF regnum
> > + * n: DWARF register number
> > + * machine: ELF machine signature (EM_*)
> > + */
> > +const char *get_dwarf_regstr(unsigned int n, unsigned int machine);
> >  #endif
> >  
> >  #ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
> > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> > index ac4740f..508b61c 100644
> > --- a/tools/perf/util/probe-finder.c
> > +++ b/tools/perf/util/probe-finder.c
> > @@ -171,6 +171,7 @@ static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
> >   */
> >  static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
> >  				     Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
> > +				     unsigned int machine,
> >  				     struct probe_trace_arg *tvar)
> >  {
> >  	Dwarf_Attribute attr;
> > @@ -266,7 +267,7 @@ static_var:
> >  	if (!tvar)
> >  		return ret2;
> >  
> > -	regs = get_arch_regstr(regn);
> > +	regs = get_dwarf_regstr(regn, machine);
> >  	if (!regs) {
> >  		/* This should be a bug in DWARF or this tool */
> >  		pr_warning("Mapping for the register number %u "
> > @@ -543,7 +544,7 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
> >  		 dwarf_diename(vr_die));
> >  
> >  	ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
> > -					&pf->sp_die, pf->tvar);
> > +					&pf->sp_die, pf->machine, pf->tvar);
> >  	if (ret == -ENOENT || ret == -EINVAL) {
> >  		pr_err("Failed to find the location of the '%s' variable at this address.\n"
> >  		       " Perhaps it has been optimized out.\n"
> > @@ -1106,11 +1107,8 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
> >  				  struct probe_finder *pf)
> >  {
> >  	int ret = 0;
> > -
> > -#if _ELFUTILS_PREREQ(0, 142)
> >  	Elf *elf;
> >  	GElf_Ehdr ehdr;
> > -	GElf_Shdr shdr;
> >  
> >  	if (pf->cfi_eh || pf->cfi_dbg)
> >  		return debuginfo__find_probe_location(dbg, pf);
> > @@ -1123,11 +1121,18 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
> >  	if (gelf_getehdr(elf, &ehdr) == NULL)
> >  		return -EINVAL;
> >  
> > -	if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
> > -	    shdr.sh_type == SHT_PROGBITS)
> > -		pf->cfi_eh = dwarf_getcfi_elf(elf);
> > +	pf->machine = ehdr.e_machine;
> > +
> > +#if _ELFUTILS_PREREQ(0, 142)
> > +	do {
> > +		GElf_Shdr shdr;
> > +
> > +		if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
> > +		    shdr.sh_type == SHT_PROGBITS)
> > +			pf->cfi_eh = dwarf_getcfi_elf(elf);
> >  
> > -	pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
> > +		pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
> > +	} while (0);
> >  #endif
> >  
> >  	ret = debuginfo__find_probe_location(dbg, pf);
> > @@ -1155,7 +1160,7 @@ static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
> >  	    (tag == DW_TAG_variable && vf->vars)) {
> >  		if (convert_variable_location(die_mem, vf->pf->addr,
> >  					      vf->pf->fb_ops, &pf->sp_die,
> > -					      NULL) == 0) {
> > +					      pf->machine, NULL) == 0) {
> >  			vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
> >  			if (vf->args[vf->nargs].var == NULL) {
> >  				vf->ret = -ENOMEM;
> > @@ -1318,7 +1323,7 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
> >  	    tag == DW_TAG_variable) {
> >  		ret = convert_variable_location(die_mem, af->pf.addr,
> >  						af->pf.fb_ops, &af->pf.sp_die,
> > -						NULL);
> > +						af->pf.machine, NULL);
> >  		if (ret == 0 || ret == -ERANGE) {
> >  			int ret2;
> >  			bool externs = !af->child;
> > diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
> > index 51137fc..f1d8558 100644
> > --- a/tools/perf/util/probe-finder.h
> > +++ b/tools/perf/util/probe-finder.h
> > @@ -80,6 +80,7 @@ struct probe_finder {
> >  	Dwarf_CFI		*cfi_dbg;
> >  #endif
> >  	Dwarf_Op		*fb_ops;	/* Frame base attribute */
> > +	unsigned int		machine;	/* Target machine arch */
> >  	struct perf_probe_arg	*pvar;		/* Current target variable */
> >  	struct probe_trace_arg	*tvar;		/* Current result variable */
> >  };


-- 
Masami Hiramatsu <mhiramat@kernel.org>

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#1476440 — [tip:perf/core] perf probe: Support probing on offline cross-arch binary

Fromtip-bot for Masami Hiramatsu <tipbot@zytor.com>
Date2016-09-05 15:30 +0200
Subject[tip:perf/core] perf probe: Support probing on offline cross-arch binary
Message-ID<se28j-4is-41@gated-at.bofh.it>
In reply to#1470263
Commit-ID:  293d5b43948309434568f4dcbb36cce4c3c51bd5
Gitweb:     http://git.kernel.org/tip/293d5b43948309434568f4dcbb36cce4c3c51bd5
Author:     Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Fri, 26 Aug 2016 01:24:57 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 1 Sep 2016 12:41:09 -0300

perf probe: Support probing on offline cross-arch binary

Support probing on offline cross-architecture binary by adding getting
the target machine arch from ELF and choose correct register string for
the machine.

Here is an example:
  -----
  $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
  p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
  -----

Here, we can get probe/do_sys_open from above and append it to to the target
machine's tracing/kprobe_events file in the tracefs mountput, usually
/sys/kernel/debug/tracing/kprobe_events (or /sys/kernel/tracing/kprobe_events).

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147214229717.23638.6440579792548044658.stgit@devbox
[ Add definition for EM_AARCH64 to fix the build on at least centos 6, debian 7 & ubuntu 12.04.5 ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/arch/arm/include/dwarf-regs-table.h     |  9 ++++
 tools/perf/arch/arm64/include/dwarf-regs-table.h   | 13 +++++
 tools/perf/arch/powerpc/include/dwarf-regs-table.h | 27 ++++++++++
 tools/perf/arch/s390/include/dwarf-regs-table.h    |  8 +++
 tools/perf/arch/sh/include/dwarf-regs-table.h      | 25 +++++++++
 tools/perf/arch/sparc/include/dwarf-regs-table.h   | 18 +++++++
 tools/perf/arch/x86/include/dwarf-regs-table.h     | 14 +++++
 tools/perf/arch/xtensa/include/dwarf-regs-table.h  |  8 +++
 tools/perf/util/Build                              |  1 +
 tools/perf/util/dwarf-regs.c                       | 59 ++++++++++++++++++++++
 tools/perf/util/include/dwarf-regs.h               |  6 +++
 tools/perf/util/probe-finder.c                     | 27 ++++++----
 tools/perf/util/probe-finder.h                     |  1 +
 13 files changed, 205 insertions(+), 11 deletions(-)

diff --git a/tools/perf/arch/arm/include/dwarf-regs-table.h b/tools/perf/arch/arm/include/dwarf-regs-table.h
new file mode 100644
index 0000000..f298d03
--- /dev/null
+++ b/tools/perf/arch/arm/include/dwarf-regs-table.h
@@ -0,0 +1,9 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const arm_regstr_tbl[] = {
+	"%r0", "%r1", "%r2", "%r3", "%r4",
+	"%r5", "%r6", "%r7", "%r8", "%r9", "%r10",
+	"%fp", "%ip", "%sp", "%lr", "%pc",
+};
+#endif
diff --git a/tools/perf/arch/arm64/include/dwarf-regs-table.h b/tools/perf/arch/arm64/include/dwarf-regs-table.h
new file mode 100644
index 0000000..2675936
--- /dev/null
+++ b/tools/perf/arch/arm64/include/dwarf-regs-table.h
@@ -0,0 +1,13 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const aarch64_regstr_tbl[] = {
+	"%r0", "%r1", "%r2", "%r3", "%r4",
+	"%r5", "%r6", "%r7", "%r8", "%r9",
+	"%r10", "%r11", "%r12", "%r13", "%r14",
+	"%r15", "%r16", "%r17", "%r18", "%r19",
+	"%r20", "%r21", "%r22", "%r23", "%r24",
+	"%r25", "%r26", "%r27", "%r28", "%r29",
+	"%lr", "%sp",
+};
+#endif
diff --git a/tools/perf/arch/powerpc/include/dwarf-regs-table.h b/tools/perf/arch/powerpc/include/dwarf-regs-table.h
new file mode 100644
index 0000000..db4730f
--- /dev/null
+++ b/tools/perf/arch/powerpc/include/dwarf-regs-table.h
@@ -0,0 +1,27 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+/*
+ * Reference:
+ * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
+ * http://refspecs.linux-foundation.org/elf/elfspec_ppc.pdf
+ */
+#define REG_DWARFNUM_NAME(reg, idx)	[idx] = "%" #reg
+
+static const char * const powerpc_regstr_tbl[] = {
+	"%gpr0", "%gpr1", "%gpr2", "%gpr3", "%gpr4",
+	"%gpr5", "%gpr6", "%gpr7", "%gpr8", "%gpr9",
+	"%gpr10", "%gpr11", "%gpr12", "%gpr13", "%gpr14",
+	"%gpr15", "%gpr16", "%gpr17", "%gpr18", "%gpr19",
+	"%gpr20", "%gpr21", "%gpr22", "%gpr23", "%gpr24",
+	"%gpr25", "%gpr26", "%gpr27", "%gpr28", "%gpr29",
+	"%gpr30", "%gpr31",
+	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),
+};
+
+#endif
diff --git a/tools/perf/arch/s390/include/dwarf-regs-table.h b/tools/perf/arch/s390/include/dwarf-regs-table.h
new file mode 100644
index 0000000..9da74a9
--- /dev/null
+++ b/tools/perf/arch/s390/include/dwarf-regs-table.h
@@ -0,0 +1,8 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const s390_regstr_tbl[] = {
+	"%r0", "%r1",  "%r2",  "%r3",  "%r4",  "%r5",  "%r6",  "%r7",
+	"%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15",
+};
+#endif
diff --git a/tools/perf/arch/sh/include/dwarf-regs-table.h b/tools/perf/arch/sh/include/dwarf-regs-table.h
new file mode 100644
index 0000000..3a2deaf
--- /dev/null
+++ b/tools/perf/arch/sh/include/dwarf-regs-table.h
@@ -0,0 +1,25 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+const char * const sh_regstr_tbl[] = {
+	"r0",
+	"r1",
+	"r2",
+	"r3",
+	"r4",
+	"r5",
+	"r6",
+	"r7",
+	"r8",
+	"r9",
+	"r10",
+	"r11",
+	"r12",
+	"r13",
+	"r14",
+	"r15",
+	"pc",
+	"pr",
+};
+
+#endif
diff --git a/tools/perf/arch/sparc/include/dwarf-regs-table.h b/tools/perf/arch/sparc/include/dwarf-regs-table.h
new file mode 100644
index 0000000..12c0761
--- /dev/null
+++ b/tools/perf/arch/sparc/include/dwarf-regs-table.h
@@ -0,0 +1,18 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const sparc_regstr_tbl[] = {
+	"%g0", "%g1", "%g2", "%g3", "%g4", "%g5", "%g6", "%g7",
+	"%o0", "%o1", "%o2", "%o3", "%o4", "%o5", "%sp", "%o7",
+	"%l0", "%l1", "%l2", "%l3", "%l4", "%l5", "%l6", "%l7",
+	"%i0", "%i1", "%i2", "%i3", "%i4", "%i5", "%fp", "%i7",
+	"%f0", "%f1", "%f2", "%f3", "%f4", "%f5", "%f6", "%f7",
+	"%f8", "%f9", "%f10", "%f11", "%f12", "%f13", "%f14", "%f15",
+	"%f16", "%f17", "%f18", "%f19", "%f20", "%f21", "%f22", "%f23",
+	"%f24", "%f25", "%f26", "%f27", "%f28", "%f29", "%f30", "%f31",
+	"%f32", "%f33", "%f34", "%f35", "%f36", "%f37", "%f38", "%f39",
+	"%f40", "%f41", "%f42", "%f43", "%f44", "%f45", "%f46", "%f47",
+	"%f48", "%f49", "%f50", "%f51", "%f52", "%f53", "%f54", "%f55",
+	"%f56", "%f57", "%f58", "%f59", "%f60", "%f61", "%f62", "%f63",
+};
+#endif
diff --git a/tools/perf/arch/x86/include/dwarf-regs-table.h b/tools/perf/arch/x86/include/dwarf-regs-table.h
new file mode 100644
index 0000000..39ac7cb
--- /dev/null
+++ b/tools/perf/arch/x86/include/dwarf-regs-table.h
@@ -0,0 +1,14 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const x86_32_regstr_tbl[] = {
+	"%ax", "%cx", "%dx", "%bx", "$stack",/* Stack address instead of %sp */
+	"%bp", "%si", "%di",
+};
+
+static const char * const x86_64_regstr_tbl[] = {
+	"%ax", "dx", "%cx", "%bx", "%si", "%di",
+	"%bp", "%sp", "%r8", "%r9", "%r10", "%r11",
+	"%r12", "%r13", "%r14", "%r15",
+};
+#endif
diff --git a/tools/perf/arch/xtensa/include/dwarf-regs-table.h b/tools/perf/arch/xtensa/include/dwarf-regs-table.h
new file mode 100644
index 0000000..aa0444a
--- /dev/null
+++ b/tools/perf/arch/xtensa/include/dwarf-regs-table.h
@@ -0,0 +1,8 @@
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
+
+static const char * const xtensa_regstr_tbl[] = {
+	"a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
+	"a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15",
+};
+#endif
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 91c5f6e..f1a6d17 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -98,6 +98,7 @@ endif
 
 libperf-$(CONFIG_DWARF) += probe-finder.o
 libperf-$(CONFIG_DWARF) += dwarf-aux.o
+libperf-$(CONFIG_DWARF) += dwarf-regs.o
 
 libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
 libperf-$(CONFIG_LOCAL_LIBUNWIND)    += unwind-libunwind-local.o
diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
new file mode 100644
index 0000000..62bc4a8
--- /dev/null
+++ b/tools/perf/util/dwarf-regs.c
@@ -0,0 +1,59 @@
+/*
+ * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
+ *
+ * Written by: Masami Hiramatsu <mhiramat@kernel.org>
+ */
+
+#include <util.h>
+#include <debug.h>
+#include <dwarf-regs.h>
+#include <elf.h>
+
+#ifndef EM_AARCH64
+#define EM_AARCH64	183  /* ARM 64 bit */
+#endif
+
+/* Define const char * {arch}_register_tbl[] */
+#define DEFINE_DWARF_REGSTR_TABLE
+#include "../arch/x86/include/dwarf-regs-table.h"
+#include "../arch/arm/include/dwarf-regs-table.h"
+#include "../arch/arm64/include/dwarf-regs-table.h"
+#include "../arch/sh/include/dwarf-regs-table.h"
+#include "../arch/powerpc/include/dwarf-regs-table.h"
+#include "../arch/s390/include/dwarf-regs-table.h"
+#include "../arch/sparc/include/dwarf-regs-table.h"
+#include "../arch/xtensa/include/dwarf-regs-table.h"
+
+#define __get_dwarf_regstr(tbl, n) (((n) < ARRAY_SIZE(tbl)) ? (tbl)[(n)] : NULL)
+
+/* Return architecture dependent register string (for kprobe-tracer) */
+const char *get_dwarf_regstr(unsigned int n, unsigned int machine)
+{
+	switch (machine) {
+	case EM_NONE:	/* Generic arch - use host arch */
+		return get_arch_regstr(n);
+	case EM_386:
+		return __get_dwarf_regstr(x86_32_regstr_tbl, n);
+	case EM_X86_64:
+		return __get_dwarf_regstr(x86_64_regstr_tbl, n);
+	case EM_ARM:
+		return __get_dwarf_regstr(arm_regstr_tbl, n);
+	case EM_AARCH64:
+		return __get_dwarf_regstr(aarch64_regstr_tbl, n);
+	case EM_SH:
+		return __get_dwarf_regstr(sh_regstr_tbl, n);
+	case EM_S390:
+		return __get_dwarf_regstr(s390_regstr_tbl, n);
+	case EM_PPC:
+	case EM_PPC64:
+		return __get_dwarf_regstr(powerpc_regstr_tbl, n);
+	case EM_SPARC:
+	case EM_SPARCV9:
+		return __get_dwarf_regstr(sparc_regstr_tbl, n);
+	case EM_XTENSA:
+		return __get_dwarf_regstr(xtensa_regstr_tbl, n);
+	default:
+		pr_err("ELF MACHINE %x is not supported.\n", machine);
+	}
+	return NULL;
+}
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
index 07c644e..43bfd8d 100644
--- a/tools/perf/util/include/dwarf-regs.h
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -3,6 +3,12 @@
 
 #ifdef HAVE_DWARF_SUPPORT
 const char *get_arch_regstr(unsigned int n);
+/*
+ * get_dwarf_regstr - Returns ftrace register string from DWARF regnum
+ * n: DWARF register number
+ * machine: ELF machine signature (EM_*)
+ */
+const char *get_dwarf_regstr(unsigned int n, unsigned int machine);
 #endif
 
 #ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index ac4740f..508b61c 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -171,6 +171,7 @@ static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
  */
 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
 				     Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
+				     unsigned int machine,
 				     struct probe_trace_arg *tvar)
 {
 	Dwarf_Attribute attr;
@@ -266,7 +267,7 @@ static_var:
 	if (!tvar)
 		return ret2;
 
-	regs = get_arch_regstr(regn);
+	regs = get_dwarf_regstr(regn, machine);
 	if (!regs) {
 		/* This should be a bug in DWARF or this tool */
 		pr_warning("Mapping for the register number %u "
@@ -543,7 +544,7 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 		 dwarf_diename(vr_die));
 
 	ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
-					&pf->sp_die, pf->tvar);
+					&pf->sp_die, pf->machine, pf->tvar);
 	if (ret == -ENOENT || ret == -EINVAL) {
 		pr_err("Failed to find the location of the '%s' variable at this address.\n"
 		       " Perhaps it has been optimized out.\n"
@@ -1106,11 +1107,8 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
 				  struct probe_finder *pf)
 {
 	int ret = 0;
-
-#if _ELFUTILS_PREREQ(0, 142)
 	Elf *elf;
 	GElf_Ehdr ehdr;
-	GElf_Shdr shdr;
 
 	if (pf->cfi_eh || pf->cfi_dbg)
 		return debuginfo__find_probe_location(dbg, pf);
@@ -1123,11 +1121,18 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
 	if (gelf_getehdr(elf, &ehdr) == NULL)
 		return -EINVAL;
 
-	if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
-	    shdr.sh_type == SHT_PROGBITS)
-		pf->cfi_eh = dwarf_getcfi_elf(elf);
+	pf->machine = ehdr.e_machine;
+
+#if _ELFUTILS_PREREQ(0, 142)
+	do {
+		GElf_Shdr shdr;
+
+		if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
+		    shdr.sh_type == SHT_PROGBITS)
+			pf->cfi_eh = dwarf_getcfi_elf(elf);
 
-	pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
+		pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
+	} while (0);
 #endif
 
 	ret = debuginfo__find_probe_location(dbg, pf);
@@ -1155,7 +1160,7 @@ static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
 	    (tag == DW_TAG_variable && vf->vars)) {
 		if (convert_variable_location(die_mem, vf->pf->addr,
 					      vf->pf->fb_ops, &pf->sp_die,
-					      NULL) == 0) {
+					      pf->machine, NULL) == 0) {
 			vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
 			if (vf->args[vf->nargs].var == NULL) {
 				vf->ret = -ENOMEM;
@@ -1318,7 +1323,7 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
 	    tag == DW_TAG_variable) {
 		ret = convert_variable_location(die_mem, af->pf.addr,
 						af->pf.fb_ops, &af->pf.sp_die,
-						NULL);
+						af->pf.machine, NULL);
 		if (ret == 0 || ret == -ERANGE) {
 			int ret2;
 			bool externs = !af->child;
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index 51137fc..f1d8558 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -80,6 +80,7 @@ struct probe_finder {
 	Dwarf_CFI		*cfi_dbg;
 #endif
 	Dwarf_Op		*fb_ops;	/* Frame base attribute */
+	unsigned int		machine;	/* Target machine arch */
 	struct perf_probe_arg	*pvar;		/* Current target variable */
 	struct probe_trace_arg	*tvar;		/* Current result variable */
 };

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#1470264 — [PATCH v2 1/3] perf-probe: Show trace event definition

FromMasami Hiramatsu <mhiramat@kernel.org>
Date2016-08-25 18:30 +0200
Subject[PATCH v2 1/3] perf-probe: Show trace event definition
Message-ID<sa5Hs-3mY-25@gated-at.bofh.it>
In reply to#1470262
Add --definition/-D option for showing the trace-event
definition in stdout. This can be useful in debugging
or combined with a shell script.

e.g.
  ----
  # perf probe --definition 'do_sys_open $params'
  p:probe/do_sys_open _text+2261728 dfd=%di:s32 filename=%si:u64 flags=%dx:s32 mode=%cx:u16
  ----

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Documentation/perf-probe.txt |    7 +++++
 tools/perf/builtin-probe.c              |   26 +++++++++++++-----
 tools/perf/util/probe-event.c           |   46 +++++++++++++++++++++++++++++++
 tools/perf/util/probe-event.h           |    1 +
 4 files changed, 73 insertions(+), 7 deletions(-)

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index f37d123..56db4d4 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -21,6 +21,8 @@ or
 'perf probe' [options] --vars='PROBEPOINT'
 or
 'perf probe' [options] --funcs
+or
+'perf probe' [options] --definition='PROBE' [...]
 
 DESCRIPTION
 -----------
@@ -96,6 +98,11 @@ OPTIONS
 	can also list functions in a user space executable / shared library.
 	This also can accept a FILTER rule argument.
 
+-D::
+--definition=::
+	Show trace-event definition converted from given probe-event instead
+	of write it into tracing/[k,u]probe_events.
+
 --filter=FILTER::
 	(Only for --vars and --funcs) Set filter. FILTER is a combination of glob
 	pattern, see FILTER PATTERN for detail.
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index ee5b421..7a3d8c4 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -326,6 +326,11 @@ static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
 	if (ret < 0)
 		goto out_cleanup;
 
+	if (params.command == 'D') {	/* it shows definition */
+		ret = show_probe_trace_events(pevs, npevs);
+		goto out_cleanup;
+	}
+
 	ret = apply_perf_probe_events(pevs, npevs);
 	if (ret < 0)
 		goto out_cleanup;
@@ -454,6 +459,14 @@ out:
 	return ret;
 }
 
+#ifdef HAVE_DWARF_SUPPORT
+#define PROBEDEF_STR	\
+	"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
+#else
+#define PROBEDEF_STR	"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
+#endif
+
+
 static int
 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 {
@@ -479,13 +492,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 			     opt_set_filter_with_command, DEFAULT_LIST_FILTER),
 	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 		     opt_set_filter_with_command),
-	OPT_CALLBACK('a', "add", NULL,
-#ifdef HAVE_DWARF_SUPPORT
-		"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
-		" [[NAME=]ARG ...]",
-#else
-		"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
-#endif
+	OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
 		"probe point definition, where\n"
 		"\t\tGROUP:\tGroup name (optional)\n"
 		"\t\tEVENT:\tEvent name\n"
@@ -503,6 +510,9 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 #endif
 		opt_add_probe_event),
+	OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
+		"Show trace event definition of given traceevent for k/uprobe_events.",
+		opt_add_probe_event),
 	OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
 		    " with existing name"),
 	OPT_CALLBACK('L', "line", NULL,
@@ -548,6 +558,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 
 	set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
 	set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
+	set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
 	set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
 #ifdef HAVE_DWARF_SUPPORT
 	set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
@@ -644,6 +655,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 		}
 		break;
 	case 'a':
+	case 'D':
 		/* Ensure the last given target is used */
 		if (params.target && !params.target_used) {
 			pr_err("  Error: -x/-m must follow the probe definitions.\n");
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 2873396..ad7094d 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -3207,6 +3207,52 @@ int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs)
 	return 0;
 }
 
+static int show_probe_trace_event(struct probe_trace_event *tev)
+{
+	char *buf = synthesize_probe_trace_command(tev);
+
+	if (!buf) {
+		pr_debug("Failed to synthesize probe trace event.\n");
+		return -EINVAL;
+	}
+
+	/* Showing definition always go stdout */
+	printf("%s\n", buf);
+	free(buf);
+
+	return 0;
+}
+
+int show_probe_trace_events(struct perf_probe_event *pevs, int npevs)
+{
+	struct strlist *namelist = strlist__new(NULL, NULL);
+	struct probe_trace_event *tev;
+	struct perf_probe_event *pev;
+	int i, j, ret = 0;
+
+	if (!namelist)
+		return -ENOMEM;
+
+	for (j = 0; j < npevs && !ret; j++) {
+		pev = &pevs[j];
+		for (i = 0; i < pev->ntevs && !ret; i++) {
+			tev = &pev->tevs[i];
+			/* Skip if the symbol is out of .text or blacklisted */
+			if (!tev->point.symbol && !pev->uprobes)
+				continue;
+
+			/* Set new name for tev (and update namelist) */
+			ret = probe_trace_event__set_name(tev, pev,
+							  namelist, true);
+			if (!ret)
+				ret = show_probe_trace_event(tev);
+		}
+	}
+	strlist__delete(namelist);
+
+	return ret;
+}
+
 int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs)
 {
 	int i, ret = 0;
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index f4f45db..6209408 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -147,6 +147,7 @@ int line_range__init(struct line_range *lr);
 int add_perf_probe_events(struct perf_probe_event *pevs, int npevs);
 int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs);
 int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs);
+int show_probe_trace_events(struct perf_probe_event *pevs, int npevs);
 void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs);
 int del_perf_probe_events(struct strfilter *filter);
 

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#1476456 — [tip:perf/core] perf probe: Show trace event definition

Fromtip-bot for Masami Hiramatsu <tipbot@zytor.com>
Date2016-09-05 15:30 +0200
Subject[tip:perf/core] perf probe: Show trace event definition
Message-ID<se28k-4is-83@gated-at.bofh.it>
In reply to#1470264
Commit-ID:  1c20b1d15473a91e2fccecbcd2809d80ff4b4924
Gitweb:     http://git.kernel.org/tip/1c20b1d15473a91e2fccecbcd2809d80ff4b4924
Author:     Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Fri, 26 Aug 2016 01:24:27 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 1 Sep 2016 09:44:13 -0300

perf probe: Show trace event definition

Add --definition/-D option for showing the trace-event definition in
stdout. This can be useful in debugging or combined with a shell script.

e.g.
  ----
  # perf probe --definition 'do_sys_open $params'
  p:probe/do_sys_open _text+2261728 dfd=%di:s32 filename=%si:u64 flags=%dx:s32 mode=%cx:u16
  ----

Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147214226712.23638.2240534040014013658.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Documentation/perf-probe.txt |  7 +++++
 tools/perf/builtin-probe.c              | 26 ++++++++++++++-----
 tools/perf/util/probe-event.c           | 46 +++++++++++++++++++++++++++++++++
 tools/perf/util/probe-event.h           |  1 +
 4 files changed, 73 insertions(+), 7 deletions(-)

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index f37d123..56db4d4 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -21,6 +21,8 @@ or
 'perf probe' [options] --vars='PROBEPOINT'
 or
 'perf probe' [options] --funcs
+or
+'perf probe' [options] --definition='PROBE' [...]
 
 DESCRIPTION
 -----------
@@ -96,6 +98,11 @@ OPTIONS
 	can also list functions in a user space executable / shared library.
 	This also can accept a FILTER rule argument.
 
+-D::
+--definition=::
+	Show trace-event definition converted from given probe-event instead
+	of write it into tracing/[k,u]probe_events.
+
 --filter=FILTER::
 	(Only for --vars and --funcs) Set filter. FILTER is a combination of glob
 	pattern, see FILTER PATTERN for detail.
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index ee5b421..7a3d8c4 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -326,6 +326,11 @@ static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
 	if (ret < 0)
 		goto out_cleanup;
 
+	if (params.command == 'D') {	/* it shows definition */
+		ret = show_probe_trace_events(pevs, npevs);
+		goto out_cleanup;
+	}
+
 	ret = apply_perf_probe_events(pevs, npevs);
 	if (ret < 0)
 		goto out_cleanup;
@@ -454,6 +459,14 @@ out:
 	return ret;
 }
 
+#ifdef HAVE_DWARF_SUPPORT
+#define PROBEDEF_STR	\
+	"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
+#else
+#define PROBEDEF_STR	"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
+#endif
+
+
 static int
 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 {
@@ -479,13 +492,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 			     opt_set_filter_with_command, DEFAULT_LIST_FILTER),
 	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 		     opt_set_filter_with_command),
-	OPT_CALLBACK('a', "add", NULL,
-#ifdef HAVE_DWARF_SUPPORT
-		"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
-		" [[NAME=]ARG ...]",
-#else
-		"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
-#endif
+	OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
 		"probe point definition, where\n"
 		"\t\tGROUP:\tGroup name (optional)\n"
 		"\t\tEVENT:\tEvent name\n"
@@ -503,6 +510,9 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 #endif
 		opt_add_probe_event),
+	OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
+		"Show trace event definition of given traceevent for k/uprobe_events.",
+		opt_add_probe_event),
 	OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
 		    " with existing name"),
 	OPT_CALLBACK('L', "line", NULL,
@@ -548,6 +558,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 
 	set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
 	set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
+	set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
 	set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
 #ifdef HAVE_DWARF_SUPPORT
 	set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
@@ -644,6 +655,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 		}
 		break;
 	case 'a':
+	case 'D':
 		/* Ensure the last given target is used */
 		if (params.target && !params.target_used) {
 			pr_err("  Error: -x/-m must follow the probe definitions.\n");
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 0bed2ee..4a49cb8 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -3207,6 +3207,52 @@ int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs)
 	return 0;
 }
 
+static int show_probe_trace_event(struct probe_trace_event *tev)
+{
+	char *buf = synthesize_probe_trace_command(tev);
+
+	if (!buf) {
+		pr_debug("Failed to synthesize probe trace event.\n");
+		return -EINVAL;
+	}
+
+	/* Showing definition always go stdout */
+	printf("%s\n", buf);
+	free(buf);
+
+	return 0;
+}
+
+int show_probe_trace_events(struct perf_probe_event *pevs, int npevs)
+{
+	struct strlist *namelist = strlist__new(NULL, NULL);
+	struct probe_trace_event *tev;
+	struct perf_probe_event *pev;
+	int i, j, ret = 0;
+
+	if (!namelist)
+		return -ENOMEM;
+
+	for (j = 0; j < npevs && !ret; j++) {
+		pev = &pevs[j];
+		for (i = 0; i < pev->ntevs && !ret; i++) {
+			tev = &pev->tevs[i];
+			/* Skip if the symbol is out of .text or blacklisted */
+			if (!tev->point.symbol && !pev->uprobes)
+				continue;
+
+			/* Set new name for tev (and update namelist) */
+			ret = probe_trace_event__set_name(tev, pev,
+							  namelist, true);
+			if (!ret)
+				ret = show_probe_trace_event(tev);
+		}
+	}
+	strlist__delete(namelist);
+
+	return ret;
+}
+
 int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs)
 {
 	int i, ret = 0;
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index f4f45db..6209408 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -147,6 +147,7 @@ int line_range__init(struct line_range *lr);
 int add_perf_probe_events(struct perf_probe_event *pevs, int npevs);
 int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs);
 int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs);
+int show_probe_trace_events(struct perf_probe_event *pevs, int npevs);
 void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs);
 int del_perf_probe_events(struct strfilter *filter);
 

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#1470782 — [PATCH v2 4/4] perf-probe: Ignore vmlinux Build-id when offline vmlinux given

FromMasami Hiramatsu <mhiramat@kernel.org>
Date2016-08-26 17:00 +0200
Subject[PATCH v2 4/4] perf-probe: Ignore vmlinux Build-id when offline vmlinux given
Message-ID<saqLT-8tm-5@gated-at.bofh.it>
In reply to#1470262
Ignore vmlinux build-id when user gives offline vmlinux if
the command does not affect running kernel.
perf-probe has several actions some of them does not change
the running kernel, like --lines, --vars, and --funcs.

e.g.
  -----
  $ ./perf probe -k ./vmlinux-arm -V do_sys_open:14
  Available variables at do_sys_open:14
          @<do_sys_open+202>
                  char*   filename
                  int     dfd
                  int     fd
                  int     flags
                  struct filename*        tmp
                  struct open_flags       op
                  umode_t mode
  -----


Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 tools/perf/builtin-probe.c |   15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index b4220cd..f87996b 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -611,6 +611,14 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 	 */
 	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 
+	/*
+	 * Except for --list, --del and --add, other command doesn't depend
+	 * nor change running kernel. So if user gives offline vmlinux,
+	 * ignore its buildid.
+	 */
+	if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
+		symbol_conf.ignore_vmlinux_buildid = true;
+
 	switch (params.command) {
 	case 'l':
 		if (params.uprobes) {
@@ -655,13 +663,6 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 		}
 		break;
 	case 'D':
-		/*
-		 * If user gives offline vmlinux, ignore buildid, since
-		 * --definition doesn't change running kernel.
-		 */
-		if (symbol_conf.vmlinux_name)
-			symbol_conf.ignore_vmlinux_buildid = true;
-		/* fall through */
 	case 'a':
 
 		/* Ensure the last given target is used */

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#1476441 — [tip:perf/core] perf probe: Ignore vmlinux Build-id when offline vmlinux given

Fromtip-bot for Masami Hiramatsu <tipbot@zytor.com>
Date2016-09-05 15:30 +0200
Subject[tip:perf/core] perf probe: Ignore vmlinux Build-id when offline vmlinux given
Message-ID<se28j-4is-43@gated-at.bofh.it>
In reply to#1470782
Commit-ID:  e50243bbeb528e92e31e03e560b557737c9def3c
Gitweb:     http://git.kernel.org/tip/e50243bbeb528e92e31e03e560b557737c9def3c
Author:     Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Fri, 26 Aug 2016 23:57:58 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 1 Sep 2016 12:42:22 -0300

perf probe: Ignore vmlinux Build-id when offline vmlinux given

Ignore vmlinux build-id when user gives offline vmlinux if the command
does not affect running kernel.

perf-probe has several actions some of them does not change the running
kernel, like --lines, --vars, and --funcs.

e.g.
  -----
  $ ./perf probe -k ./vmlinux-arm -V do_sys_open:14
  Available variables at do_sys_open:14
          @<do_sys_open+202>
                  char*   filename
                  int     dfd
                  int     fd
                  int     flags
                  struct filename*        tmp
                  struct open_flags       op
                  umode_t mode
  -----

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147222347320.5088.2582658035296667520.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-probe.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index b4220cd..f87996b 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -611,6 +611,14 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 	 */
 	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 
+	/*
+	 * Except for --list, --del and --add, other command doesn't depend
+	 * nor change running kernel. So if user gives offline vmlinux,
+	 * ignore its buildid.
+	 */
+	if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
+		symbol_conf.ignore_vmlinux_buildid = true;
+
 	switch (params.command) {
 	case 'l':
 		if (params.uprobes) {
@@ -655,13 +663,6 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 		}
 		break;
 	case 'D':
-		/*
-		 * If user gives offline vmlinux, ignore buildid, since
-		 * --definition doesn't change running kernel.
-		 */
-		if (symbol_conf.vmlinux_name)
-			symbol_conf.ignore_vmlinux_buildid = true;
-		/* fall through */
 	case 'a':
 
 		/* Ensure the last given target is used */

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#1472963

FromMasami Hiramatsu <mhiramat@kernel.org>
Date2016-08-31 03:10 +0200
Message-ID<sc2cp-44s-1@gated-at.bofh.it>
In reply to#1470262
ping?

On Fri, 26 Aug 2016 01:24:10 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:

> Hi,
> 
> Here is the 2nd version of remote cross-arch probe support on perf-probe.
> V1 is here:
>   https://lkml.org/lkml/2016/8/24/29
> 
> Currently perf-probe doesn't supoort cross/remote target. This means
> we have to cross-build the perf-tools including libraries (elfutils,
> libelf etc.), and to prepare vmlinux with debuginfo which can be 
> accessed from the target machine.
> This requires too much resource for a small embededd device.
> 
> If we can analyze the debuginfo by perf-probe on host machine,
> we do not need to cross-build perf-tools, nor copy vmlinux on the
> device. :)
> 
> For that purpose, this series adds --definition(-D) command for
> perf-probe, which shows trace event definition instead of adding
> it in running kernel, according to Arnaldo's comment.
> Using -D with --vmlinux(or -k)=OFFLINE-VMLINUX, perf-probe reads
> the vmlinux architecture and show definition with correct
> dwarf-registers.
> 
>   perf probe -k <cross-vmlinux> -D <probe-point> <arguments>
> 
> Here is an example:
>   -----
>   $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
>   p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
>   -----
> Here, we can get probe/do_sys_open event by "copy & paste" the
> definition to target-machine's debugfs/tracing/kprobe_events.
> 
> Note that it shows definition with direct symbol name instead of
> _text+offset. It is treated as an offline module.
> 
> Thanks,
> ---
> 
> Masami Hiramatsu (3):
>       perf-probe: Show trace event definition
>       perf-probe: Ignore vmlinux buildid if offline kernel is given
>       perf-probe: Support probing on offline cross-arch binary
> 
> 
>  tools/perf/Documentation/perf-probe.txt            |    9 +++
>  tools/perf/arch/arm/include/dwarf-regs-table.h     |    9 +++
>  tools/perf/arch/arm64/include/dwarf-regs-table.h   |   13 +++++
>  tools/perf/arch/powerpc/include/dwarf-regs-table.h |   27 ++++++++++
>  tools/perf/arch/s390/include/dwarf-regs-table.h    |    8 +++
>  tools/perf/arch/sh/include/dwarf-regs-table.h      |   25 +++++++++
>  tools/perf/arch/sparc/include/dwarf-regs-table.h   |   18 +++++++
>  tools/perf/arch/x86/include/dwarf-regs-table.h     |   14 +++++
>  tools/perf/arch/xtensa/include/dwarf-regs-table.h  |    8 +++
>  tools/perf/builtin-probe.c                         |   34 ++++++++++--
>  tools/perf/util/Build                              |    1 
>  tools/perf/util/dwarf-regs.c                       |   55 ++++++++++++++++++++
>  tools/perf/util/include/dwarf-regs.h               |    6 ++
>  tools/perf/util/probe-event.c                      |   50 ++++++++++++++++++
>  tools/perf/util/probe-event.h                      |    1 
>  tools/perf/util/probe-finder.c                     |   27 ++++++----
>  tools/perf/util/probe-finder.h                     |    1 
>  tools/perf/util/symbol-elf.c                       |    2 -
>  18 files changed, 289 insertions(+), 19 deletions(-)
>  create mode 100644 tools/perf/arch/arm/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/arm64/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/powerpc/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/s390/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/sh/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/sparc/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/x86/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/arch/xtensa/include/dwarf-regs-table.h
>  create mode 100644 tools/perf/util/dwarf-regs.c
> 
> --
> Masami Hiramatsu (Linaro Ltd.) <mhiramat@kernel.org>


-- 
Masami Hiramatsu <mhiramat@kernel.org>

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