[PATCH v6 10/11] perf callchain: Support x86 target platform

[He Kuang]

Support x86(32-bit) cross platform callchain unwind.

Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
---
 tools/perf/arch/Build                              |  1 +
 tools/perf/arch/x86/util/unwind-libunwind.c        |  7 ++++---
 tools/perf/arch/x86/util/unwind-libunwind_x86_32.c | 21 +++++++++++++++++++++
 tools/perf/util/unwind-libunwind-local.c           |  4 ++++
 tools/perf/util/unwind-libunwind.c                 | 19 +++++++++++++------
 tools/perf/util/unwind.h                           | 10 ++++++++++
 6 files changed, 53 insertions(+), 9 deletions(-)
 create mode 100644 tools/perf/arch/x86/util/unwind-libunwind_x86_32.c

diff --git a/tools/perf/arch/Build b/tools/perf/arch/Build
index 109eb75..3fc4af1 100644
--- a/tools/perf/arch/Build
+++ b/tools/perf/arch/Build
@@ -1,2 +1,3 @@
 libperf-y += common.o
 libperf-y += $(ARCH)/
+libperf-$(CONFIG_LIBUNWIND_X86)      += x86/util/unwind-libunwind_x86_32.o
diff --git a/tools/perf/arch/x86/util/unwind-libunwind.c b/tools/perf/arch/x86/util/unwind-libunwind.c
index db25e93..3b0be69 100644
--- a/tools/perf/arch/x86/util/unwind-libunwind.c
+++ b/tools/perf/arch/x86/util/unwind-libunwind.c
@@ -1,12 +1,13 @@
-
+#ifndef REMOTE_UNWIND_LIBUNWIND
 #include <errno.h>
 #include <libunwind.h>
 #include "perf_regs.h"
 #include "../../util/unwind.h"
 #include "../../util/debug.h"
+#endif
 
 #ifdef HAVE_ARCH_X86_64_SUPPORT
-int libunwind__arch_reg_id(int regnum)
+int LIBUNWIND__ARCH_REG_ID(int regnum)
 {
 	int id;
 
@@ -70,7 +71,7 @@ int libunwind__arch_reg_id(int regnum)
 	return id;
 }
 #else
-int libunwind__arch_reg_id(int regnum)
+int LIBUNWIND__ARCH_REG_ID(int regnum)
 {
 	int id;
 
diff --git a/tools/perf/arch/x86/util/unwind-libunwind_x86_32.c b/tools/perf/arch/x86/util/unwind-libunwind_x86_32.c
new file mode 100644
index 0000000..9d5359e
--- /dev/null
+++ b/tools/perf/arch/x86/util/unwind-libunwind_x86_32.c
@@ -0,0 +1,21 @@
+#define REMOTE_UNWIND_LIBUNWIND
+
+#define LIBUNWIND__ARCH_REG_ID libunwind__x86_reg_id
+
+#include "unwind.h"
+#include "debug.h"
+#include "libunwind-x86.h"
+#include <../../../../../arch/x86/include/uapi/asm/perf_regs.h>
+
+#undef HAVE_ARCH_X86_64_SUPPORT
+#include "unwind-libunwind.c"
+
+#undef NO_LIBUNWIND_DEBUG_FRAME
+#define NO_LIBUNWIND_DEBUG_FRAME
+#include "util/unwind-libunwind-local.c"
+
+int register_x86_32_unwind_libunwind_ops(struct thread *thread)
+{
+	thread->unwind_libunwind_ops = &_unwind_libunwind_ops;
+	return 0;
+}
diff --git a/tools/perf/util/unwind-libunwind-local.c b/tools/perf/util/unwind-libunwind-local.c
index b391e3e..849fec1 100644
--- a/tools/perf/util/unwind-libunwind-local.c
+++ b/tools/perf/util/unwind-libunwind-local.c
@@ -5,7 +5,9 @@
 #include <unistd.h>
 #include <sys/mman.h>
 #include <linux/list.h>
+#ifndef REMOTE_UNWIND_LIBUNWIND
 #include <libunwind.h>
+#endif
 #include "callchain.h"
 #include "thread.h"
 #include "session.h"
@@ -671,7 +673,9 @@ _unwind_libunwind_ops = {
 	.get_entries    = _unwind__get_entries,
 };
 
+#ifndef REMOTE_UNWIND_LIBUNWIND
 void register_local_unwind_libunwind_ops(struct thread *thread)
 {
 	thread->unwind_libunwind_ops = &_unwind_libunwind_ops;
 }
+#endif
diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
index 037ee72..c1d9d36 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -8,6 +8,9 @@ int unwind__prepare_access(struct thread *thread, struct map *map)
 {
 	const char *arch;
 	enum dso_type dso_type;
+	int use_local_unwind = 1;
+	int ret;
+	int (*register_func)(struct thread *thread) = NULL;
 
 	if (!thread->mg->machine->env)
 		return -1;
@@ -22,16 +25,20 @@ int unwind__prepare_access(struct thread *thread, struct map *map)
 
 	arch = normalize_arch(thread->mg->machine->env->arch);
 
-	if (!strcmp(arch, "x86")) {
+	if (!strcmp(arch, "x86"))
 		if (dso_type != DSO__TYPE_64BIT)
-#ifdef HAVE_LIBUNWIND_X86_SUPPORT
-			pr_err("unwind: target platform=%s is not implemented\n", arch);
-#else
+			register_func = register_x86_32_unwind_libunwind_ops;
+
+	if (register_func) {
+		ret = register_func(thread);
+		if (!ret)
+			use_local_unwind = 0;
+		else
 			pr_err("unwind: target platform=%s is not supported\n", arch);
-#endif
 	}
 
-	register_local_unwind_libunwind_ops(thread);
+	if (use_local_unwind)
+		register_local_unwind_libunwind_ops(thread);
 
 	return thread->unwind_libunwind_ops->prepare_access(thread);
 }
diff --git a/tools/perf/util/unwind.h b/tools/perf/util/unwind.h
index 9e4f545..43f9f66 100644
--- a/tools/perf/util/unwind.h
+++ b/tools/perf/util/unwind.h
@@ -46,6 +46,16 @@ static inline void
 register_local_unwind_libunwind_ops(struct thread *thread __maybe_unused) {}
 #endif
 
+#ifdef HAVE_LIBUNWIND_X86_SUPPORT
+int register_x86_32_unwind_libunwind_ops(struct thread *thread);
+#else
+static inline int
+register_x86_32_unwind_libunwind_ops(struct thread *thread __maybe_unused)
+{
+	return -1;
+}
+#endif
+
 #else
 static inline int
 unwind__get_entries(unwind_entry_cb_t cb __maybe_unused,
-- 
1.8.5.2