Advertise when perf is built with the HAVE_LIBLLVM_SUPPORT option.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Documentation/perf-check.txt | 1 +
 tools/perf/builtin-check.c              | 1 +
 2 files changed, 2 insertions(+)

diff --git a/tools/perf/Documentation/perf-check.txt b/tools/perf/Documentation/perf-check.txt
index ee92042082f7..4c9ccda6ce91 100644
--- a/tools/perf/Documentation/perf-check.txt
+++ b/tools/perf/Documentation/perf-check.txt
@@ -56,6 +56,7 @@ feature::
                 libcapstone             /  HAVE_LIBCAPSTONE_SUPPORT
                 libdw-dwarf-unwind      /  HAVE_LIBDW_SUPPORT
                 libelf                  /  HAVE_LIBELF_SUPPORT
+                libLLVM                 /  HAVE_LIBLLVM_SUPPORT
                 libnuma                 /  HAVE_LIBNUMA_SUPPORT
                 libopencsd              /  HAVE_CSTRACE_SUPPORT
                 libperl                 /  HAVE_LIBPERL_SUPPORT
diff --git a/tools/perf/builtin-check.c b/tools/perf/builtin-check.c
index 8c0668911fb1..9ce2e71999df 100644
--- a/tools/perf/builtin-check.c
+++ b/tools/perf/builtin-check.c
@@ -48,6 +48,7 @@ struct feature_status supported_features[] = {
 	FEATURE_STATUS("libcapstone", HAVE_LIBCAPSTONE_SUPPORT),
 	FEATURE_STATUS("libdw-dwarf-unwind", HAVE_LIBDW_SUPPORT),
 	FEATURE_STATUS("libelf", HAVE_LIBELF_SUPPORT),
+	FEATURE_STATUS("libLLVM", HAVE_LIBLLVM_SUPPORT),
 	FEATURE_STATUS("libnuma", HAVE_LIBNUMA_SUPPORT),
 	FEATURE_STATUS("libopencsd", HAVE_CSTRACE_SUPPORT),
 	FEATURE_STATUS_TIP("libperl", HAVE_LIBPERL_SUPPORT, "Deprecated, use LIBPERL=1 and install perl-ExtUtils-Embed/libperl-dev to build with it"),
-- 
2.51.0.618.g983fd99d29-goog

Move the 3 LLVM initialization routines to be called in a single
init_llvm function that has its own bool to avoid repeated
initialization. Reduce the scope of triplet and avoid copying strings
for x86.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/llvm.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/tools/perf/util/llvm.c b/tools/perf/util/llvm.c
index ddc737194692..2356778955fe 100644
--- a/tools/perf/util/llvm.c
+++ b/tools/perf/util/llvm.c
@@ -74,6 +74,17 @@ void dso__free_a2l_llvm(struct dso *dso __maybe_unused)
 	/* Nothing to free. */
 }
 
+static void init_llvm(void)
+{
+	static bool init;
+
+	if (!init) {
+		LLVMInitializeAllTargetInfos();
+		LLVMInitializeAllTargetMCs();
+		LLVMInitializeAllDisassemblers();
+		init = true;
+	}
+}
 
 #if defined(HAVE_LIBLLVM_SUPPORT)
 struct find_file_offset_data {
@@ -184,7 +195,6 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 	u64 len;
 	u64 pc;
 	bool is_64bit;
-	char triplet[64];
 	char disasm_buf[2048];
 	size_t disasm_len;
 	struct disasm_line *dl;
@@ -197,26 +207,25 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 	if (args->options->objdump_path)
 		return -1;
 
-	LLVMInitializeAllTargetInfos();
-	LLVMInitializeAllTargetMCs();
-	LLVMInitializeAllDisassemblers();
-
 	buf = read_symbol(filename, map, sym, &len, &is_64bit);
 	if (buf == NULL)
 		return -1;
 
+	init_llvm();
 	if (arch__is(args->arch, "x86")) {
-		if (is_64bit)
-			scnprintf(triplet, sizeof(triplet), "x86_64-pc-linux");
-		else
-			scnprintf(triplet, sizeof(triplet), "i686-pc-linux");
+		const char *triplet = is_64bit ? "x86_64-pc-linux" : "i686-pc-linux";
+
+		disasm = LLVMCreateDisasm(triplet, &storage, /*tag_type=*/0,
+					  /*get_op_info=*/NULL, symbol_lookup_callback);
 	} else {
+		char triplet[64];
+
 		scnprintf(triplet, sizeof(triplet), "%s-linux-gnu",
 			  args->arch->name);
+		disasm = LLVMCreateDisasm(triplet, &storage, /*tag_type=*/0,
+					  /*get_op_info=*/NULL, symbol_lookup_callback);
 	}
 
-	disasm = LLVMCreateDisasm(triplet, &storage, 0, NULL,
-				  symbol_lookup_callback);
 	if (disasm == NULL)
 		goto err;
 
-- 
2.51.0.618.g983fd99d29-goog

Move the read_symbol function to dso.h, make the return type const and
add a mutable out_buf out parameter. In future changes this will allow
a code pointer to be returned without necessary allocating memory.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/capstone.c | 66 +++++-----------------------
 tools/perf/util/dso.c      | 67 +++++++++++++++++++++++++++++
 tools/perf/util/dso.h      |  4 ++
 tools/perf/util/llvm.c     | 88 +++++++-------------------------------
 4 files changed, 97 insertions(+), 128 deletions(-)

diff --git a/tools/perf/util/capstone.c b/tools/perf/util/capstone.c
index 01e47d5c8e3e..c23df911e91c 100644
--- a/tools/perf/util/capstone.c
+++ b/tools/perf/util/capstone.c
@@ -215,55 +215,6 @@ static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
 }
 #endif
 
-#ifdef HAVE_LIBCAPSTONE_SUPPORT
-static u8 *
-read_symbol(const char *filename, struct map *map, struct symbol *sym,
-	    u64 *len, bool *is_64bit)
-{
-	struct dso *dso = map__dso(map);
-	struct nscookie nsc;
-	u64 start = map__rip_2objdump(map, sym->start);
-	u64 end = map__rip_2objdump(map, sym->end);
-	int fd, count;
-	u8 *buf = NULL;
-	struct find_file_offset_data data = {
-		.ip = start,
-	};
-
-	*is_64bit = false;
-
-	nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
-	fd = open(filename, O_RDONLY);
-	nsinfo__mountns_exit(&nsc);
-	if (fd < 0)
-		return NULL;
-
-	if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data,
-			    is_64bit) == 0)
-		goto err;
-
-	*len = end - start;
-	buf = malloc(*len);
-	if (buf == NULL)
-		goto err;
-
-	count = pread(fd, buf, *len, data.offset);
-	close(fd);
-	fd = -1;
-
-	if ((u64)count != *len)
-		goto err;
-
-	return buf;
-
-err:
-	if (fd >= 0)
-		close(fd);
-	free(buf);
-	return NULL;
-}
-#endif
-
 int symbol__disassemble_capstone(const char *filename __maybe_unused,
 				 struct symbol *sym __maybe_unused,
 				 struct annotate_args *args __maybe_unused)
@@ -271,13 +222,17 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 #ifdef HAVE_LIBCAPSTONE_SUPPORT
 	struct annotation *notes = symbol__annotation(sym);
 	struct map *map = args->ms.map;
+	struct dso *dso = map__dso(map);
 	u64 start = map__rip_2objdump(map, sym->start);
-	u64 len;
 	u64 offset;
 	int i, count, free_count;
 	bool is_64bit = false;
 	bool needs_cs_close = false;
-	u8 *buf = NULL;
+	/* Malloc-ed buffer containing instructions read from disk. */
+	u8 *code_buf = NULL;
+	/* Pointer to code to be disassembled. */
+	const u8 *buf;
+	u64 buf_len;
 	csh handle;
 	cs_insn *insn = NULL;
 	char disasm_buf[512];
@@ -287,7 +242,8 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 	if (args->options->objdump_path)
 		return -1;
 
-	buf = read_symbol(filename, map, sym, &len, &is_64bit);
+	buf = dso__read_symbol(dso, filename, map, sym,
+			       &code_buf, &buf_len, &is_64bit);
 	if (buf == NULL)
 		return -1;
 
@@ -316,7 +272,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 
 	needs_cs_close = true;
 
-	free_count = count = cs_disasm(handle, buf, len, start, len, &insn);
+	free_count = count = cs_disasm(handle, buf, buf_len, start, buf_len, &insn);
 	for (i = 0, offset = 0; i < count; i++) {
 		int printed;
 
@@ -340,7 +296,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 	}
 
 	/* It failed in the middle: probably due to unknown instructions */
-	if (offset != len) {
+	if (offset != buf_len) {
 		struct list_head *list = &notes->src->source;
 
 		/* Discard all lines and fallback to objdump */
@@ -359,7 +315,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 		if (free_count > 0)
 			cs_free(insn, free_count);
 	}
-	free(buf);
+	free(code_buf);
 	return count < 0 ? count : 0;
 
 err:
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 282e3af85d5a..87d075942de6 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -1798,3 +1798,70 @@ bool is_perf_pid_map_name(const char *dso_name)
 
 	return perf_pid_map_tid(dso_name, &tid);
 }
+
+struct find_file_offset_data {
+	u64 ip;
+	u64 offset;
+};
+
+/* This will be called for each PHDR in an ELF binary */
+static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
+{
+	struct find_file_offset_data *data = arg;
+
+	if (start <= data->ip && data->ip < start + len) {
+		data->offset = pgoff + data->ip - start;
+		return 1;
+	}
+	return 0;
+}
+
+const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
+			   const struct map *map, const struct symbol *sym,
+			   u8 **out_buf, u64 *out_buf_len, bool *is_64bit)
+{
+	struct nscookie nsc;
+	u64 start = map__rip_2objdump(map, sym->start);
+	u64 end = map__rip_2objdump(map, sym->end);
+	int fd, count;
+	u8 *buf = NULL;
+	size_t len;
+	struct find_file_offset_data data = {
+		.ip = start,
+	};
+
+	*out_buf = NULL;
+	*out_buf_len = 0;
+	*is_64bit = false;
+
+	nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
+	fd = open(symfs_filename, O_RDONLY);
+	nsinfo__mountns_exit(&nsc);
+	if (fd < 0)
+		return NULL;
+
+	if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data, is_64bit) == 0)
+		goto err;
+
+	len = end - start;
+	buf = malloc(len);
+	if (buf == NULL)
+		goto err;
+
+	count = pread(fd, buf, len, data.offset);
+	close(fd);
+	fd = -1;
+
+	if ((u64)count != len)
+		goto err;
+
+	*out_buf = buf;
+	*out_buf_len = len;
+	return buf;
+
+err:
+	if (fd >= 0)
+		close(fd);
+	free(buf);
+	return NULL;
+}
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index fd8e95de77f7..f8ccb9816b89 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -924,4 +924,8 @@ static inline struct debuginfo *dso__debuginfo(struct dso *dso)
 	return debuginfo__new(dso__long_name(dso));
 }
 
+const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
+			   const struct map *map, const struct symbol *sym,
+			   u8 **out_buf, u64 *out_buf_len, bool *is_64bit);
+
 #endif /* __PERF_DSO */
diff --git a/tools/perf/util/llvm.c b/tools/perf/util/llvm.c
index 2356778955fe..0369f3adcdb6 100644
--- a/tools/perf/util/llvm.c
+++ b/tools/perf/util/llvm.c
@@ -86,72 +86,6 @@ static void init_llvm(void)
 	}
 }
 
-#if defined(HAVE_LIBLLVM_SUPPORT)
-struct find_file_offset_data {
-	u64 ip;
-	u64 offset;
-};
-
-/* This will be called for each PHDR in an ELF binary */
-static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
-{
-	struct find_file_offset_data *data = arg;
-
-	if (start <= data->ip && data->ip < start + len) {
-		data->offset = pgoff + data->ip - start;
-		return 1;
-	}
-	return 0;
-}
-
-static u8 *
-read_symbol(const char *filename, struct map *map, struct symbol *sym,
-	    u64 *len, bool *is_64bit)
-{
-	struct dso *dso = map__dso(map);
-	struct nscookie nsc;
-	u64 start = map__rip_2objdump(map, sym->start);
-	u64 end = map__rip_2objdump(map, sym->end);
-	int fd, count;
-	u8 *buf = NULL;
-	struct find_file_offset_data data = {
-		.ip = start,
-	};
-
-	*is_64bit = false;
-
-	nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
-	fd = open(filename, O_RDONLY);
-	nsinfo__mountns_exit(&nsc);
-	if (fd < 0)
-		return NULL;
-
-	if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data,
-			    is_64bit) == 0)
-		goto err;
-
-	*len = end - start;
-	buf = malloc(*len);
-	if (buf == NULL)
-		goto err;
-
-	count = pread(fd, buf, *len, data.offset);
-	close(fd);
-	fd = -1;
-
-	if ((u64)count != *len)
-		goto err;
-
-	return buf;
-
-err:
-	if (fd >= 0)
-		close(fd);
-	free(buf);
-	return NULL;
-}
-#endif
-
 /*
  * Whenever LLVM wants to resolve an address into a symbol, it calls this
  * callback. We don't ever actually _return_ anything (in particular, because
@@ -191,8 +125,11 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 	struct map *map = args->ms.map;
 	struct dso *dso = map__dso(map);
 	u64 start = map__rip_2objdump(map, sym->start);
-	u8 *buf;
-	u64 len;
+	/* Malloc-ed buffer containing instructions read from disk. */
+	u8 *code_buf = NULL;
+	/* Pointer to code to be disassembled. */
+	const u8 *buf;
+	u64 buf_len;
 	u64 pc;
 	bool is_64bit;
 	char disasm_buf[2048];
@@ -207,7 +144,8 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 	if (args->options->objdump_path)
 		return -1;
 
-	buf = read_symbol(filename, map, sym, &len, &is_64bit);
+	buf = dso__read_symbol(dso, filename, map, sym,
+			       &code_buf, &buf_len, &is_64bit);
 	if (buf == NULL)
 		return -1;
 
@@ -259,14 +197,18 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 	annotation_line__add(&dl->al, &notes->src->source);
 
 	pc = start;
-	for (u64 offset = 0; offset < len; ) {
+	for (u64 offset = 0; offset < buf_len; ) {
 		unsigned int ins_len;
 
 		storage.branch_addr = 0;
 		storage.pcrel_load_addr = 0;
 
-		ins_len = LLVMDisasmInstruction(disasm, buf + offset,
-						len - offset, pc,
+		/*
+		 * LLVM's API has the code be disassembled as non-const, cast
+		 * here as we may be disassembling from mapped read-only memory.
+		 */
+		ins_len = LLVMDisasmInstruction(disasm, (u8 *)(buf + offset),
+						buf_len - offset, pc,
 						disasm_buf, sizeof(disasm_buf));
 		if (ins_len == 0)
 			goto err;
@@ -324,7 +266,7 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 
 err:
 	LLVMDisasmDispose(disasm);
-	free(buf);
+	free(code_buf);
 	free(line_storage);
 	return ret;
 #else // HAVE_LIBLLVM_SUPPORT
-- 
2.51.0.618.g983fd99d29-goog

Set the buffer to the code in the BPF linear info. This enables BPF
JIT code disassembly by LLVM and capstone. Move the common but minimal
disassmble_bpf_image call to disassemble_objdump so that it is only
called after falling back to the objdump option. Similarly move the
disassmble_bpf function to disassemble_objdump and rename to
disassmble_bpf_libbfd to make it clearer that this support relies on
libbfd.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/disasm.c |  12 +++--
 tools/perf/util/dso.c    | 100 ++++++++++++++++++++++++++-------------
 tools/perf/util/libbfd.c |   4 +-
 tools/perf/util/libbfd.h |   6 +--
 4 files changed, 80 insertions(+), 42 deletions(-)

diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
index a1240543c89c..e64902e520ab 100644
--- a/tools/perf/util/disasm.c
+++ b/tools/perf/util/disasm.c
@@ -1521,6 +1521,12 @@ static int symbol__disassemble_objdump(const char *filename, struct symbol *sym,
 	struct child_process objdump_process;
 	int err;
 
+	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO)
+		return symbol__disassemble_bpf_libbfd(sym, args);
+
+	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_IMAGE)
+		return symbol__disassemble_bpf_image(sym, args);
+
 	err = asprintf(&command,
 		 "%s %s%s --start-address=0x%016" PRIx64
 		 " --stop-address=0x%016" PRIx64
@@ -1655,11 +1661,7 @@ int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
 
 	pr_debug("annotating [%p] %30s : [%p] %30s\n", dso, dso__long_name(dso), sym, sym->name);
 
-	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO) {
-		return symbol__disassemble_bpf(sym, args);
-	} else if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_IMAGE) {
-		return symbol__disassemble_bpf_image(sym, args);
-	} else if (dso__binary_type(dso) == DSO_BINARY_TYPE__NOT_FOUND) {
+	if (dso__binary_type(dso) == DSO_BINARY_TYPE__NOT_FOUND) {
 		return SYMBOL_ANNOTATE_ERRNO__COULDNT_DETERMINE_FILE_TYPE;
 	} else if (dso__is_kcore(dso)) {
 		kce.addr = map__rip_2objdump(map, sym->start);
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 87d075942de6..0aed5c8691bd 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -1816,23 +1816,17 @@ static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
 	return 0;
 }
 
-const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
-			   const struct map *map, const struct symbol *sym,
-			   u8 **out_buf, u64 *out_buf_len, bool *is_64bit)
+static const u8 *__dso__read_symbol(struct dso *dso, const char *symfs_filename,
+				    u64 start, size_t len,
+				    u8 **out_buf, u64 *out_buf_len, bool *is_64bit)
 {
 	struct nscookie nsc;
-	u64 start = map__rip_2objdump(map, sym->start);
-	u64 end = map__rip_2objdump(map, sym->end);
-	int fd, count;
-	u8 *buf = NULL;
-	size_t len;
+	int fd;
+	ssize_t count;
 	struct find_file_offset_data data = {
 		.ip = start,
 	};
-
-	*out_buf = NULL;
-	*out_buf_len = 0;
-	*is_64bit = false;
+	u8 *code_buf = NULL;
 
 	nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
 	fd = open(symfs_filename, O_RDONLY);
@@ -1840,28 +1834,70 @@ const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
 	if (fd < 0)
 		return NULL;
 
-	if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data, is_64bit) == 0)
-		goto err;
-
-	len = end - start;
-	buf = malloc(len);
-	if (buf == NULL)
-		goto err;
-
-	count = pread(fd, buf, len, data.offset);
+	if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data, is_64bit) == 0) {
+		close(fd);
+		return NULL;
+	}
+	code_buf = malloc(len);
+	if (code_buf == NULL) {
+		close(fd);
+		return NULL;
+	}
+	count = pread(fd, code_buf, len, data.offset);
 	close(fd);
-	fd = -1;
+	if ((u64)count != len) {
+		free(code_buf);
+		return NULL;
+	}
+	*out_buf = code_buf;
+	*out_buf_len = len;
+	return code_buf;
+}
 
-	if ((u64)count != len)
-		goto err;
+/*
+ * Read a symbol into memory for disassembly by a library like capstone of
+ * libLLVM. If memory is allocated out_buf holds it.
+ */
+const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
+			   const struct map *map, const struct symbol *sym,
+			   u8 **out_buf, u64 *out_buf_len, bool *is_64bit)
+{
+	u64 start = map__rip_2objdump(map, sym->start);
+	u64 end = map__rip_2objdump(map, sym->end);
+	size_t len = end - start;
 
-	*out_buf = buf;
-	*out_buf_len = len;
-	return buf;
+	*out_buf = NULL;
+	*out_buf_len = 0;
+	*is_64bit = false;
 
-err:
-	if (fd >= 0)
-		close(fd);
-	free(buf);
-	return NULL;
+	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_IMAGE) {
+		/*
+		 * Note, there is fallback BPF image disassembly in the objdump
+		 * version but it currently does nothing.
+		 */
+		return NULL;
+	}
+	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO) {
+#ifdef HAVE_LIBBPF_SUPPORT
+		struct bpf_prog_info_node *info_node;
+		struct perf_bpil *info_linear;
+
+		*is_64bit = sizeof(void *) == sizeof(u64);
+		info_node = perf_env__find_bpf_prog_info(dso__bpf_prog(dso)->env,
+							 dso__bpf_prog(dso)->id);
+		if (!info_node) {
+			errno = SYMBOL_ANNOTATE_ERRNO__BPF_MISSING_BTF;
+			return NULL;
+		}
+		info_linear = info_node->info_linear;
+		assert(len <= info_linear->info.jited_prog_len);
+		*out_buf_len = len;
+		return (const u8 *)(uintptr_t)(info_linear->info.jited_prog_insns);
+#else
+		pr_debug("No BPF program disassembly support\n");
+		return NULL;
+#endif
+	}
+	return __dso__read_symbol(dso, symfs_filename, start, len,
+				  out_buf, out_buf_len, is_64bit);
 }
diff --git a/tools/perf/util/libbfd.c b/tools/perf/util/libbfd.c
index 09a0eeb78a1a..01147fbf73b3 100644
--- a/tools/perf/util/libbfd.c
+++ b/tools/perf/util/libbfd.c
@@ -448,8 +448,8 @@ int libbfd_filename__read_debuglink(const char *filename, char *debuglink,
 	return err;
 }
 
-int symbol__disassemble_bpf(struct symbol *sym __maybe_unused,
-			    struct annotate_args *args  __maybe_unused)
+int symbol__disassemble_bpf_libbfd(struct symbol *sym __maybe_unused,
+				   struct annotate_args *args  __maybe_unused)
 {
 #ifdef HAVE_LIBBPF_SUPPORT
 	struct annotation *notes = symbol__annotation(sym);
diff --git a/tools/perf/util/libbfd.h b/tools/perf/util/libbfd.h
index 7441e95f8ec0..e300f171d1bd 100644
--- a/tools/perf/util/libbfd.h
+++ b/tools/perf/util/libbfd.h
@@ -29,7 +29,7 @@ int libbfd__read_build_id(const char *filename, struct build_id *bid, bool block
 
 int libbfd_filename__read_debuglink(const char *filename, char *debuglink, size_t size);
 
-int symbol__disassemble_bpf(struct symbol *sym, struct annotate_args *args);
+int symbol__disassemble_bpf_libbfd(struct symbol *sym, struct annotate_args *args);
 
 #else // !defined(HAVE_LIBBFD_SUPPORT)
 #include "annotate.h"
@@ -72,8 +72,8 @@ static inline int libbfd_filename__read_debuglink(const char *filename __always_
 	return -1;
 }
 
-static inline int symbol__disassemble_bpf(struct symbol *sym __always_unused,
-					  struct annotate_args *args __always_unused)
+static inline int symbol__disassemble_bpf_libbfd(struct symbol *sym __always_unused,
+						 struct annotate_args *args __always_unused)
 {
 	return SYMBOL_ANNOTATE_ERRNO__NO_LIBOPCODES_FOR_BPF;
 }
-- 
2.51.0.618.g983fd99d29-goog

Ensure errno is set and return to caller for error handling. Unusually
for perf the value isn't negated as expected by
symbol__strerror_disassemble.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/capstone.c |  3 ++-
 tools/perf/util/dso.c      | 15 ++++++++++++---
 tools/perf/util/llvm.c     |  3 ++-
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/capstone.c b/tools/perf/util/capstone.c
index c23df911e91c..be5fd44b1f9d 100644
--- a/tools/perf/util/capstone.c
+++ b/tools/perf/util/capstone.c
@@ -11,6 +11,7 @@
 #include "print_insn.h"
 #include "symbol.h"
 #include "thread.h"
+#include <errno.h>
 #include <fcntl.h>
 #include <string.h>
 
@@ -245,7 +246,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 	buf = dso__read_symbol(dso, filename, map, sym,
 			       &code_buf, &buf_len, &is_64bit);
 	if (buf == NULL)
-		return -1;
+		return errno;
 
 	/* add the function address and name */
 	scnprintf(disasm_buf, sizeof(disasm_buf), "%#"PRIx64" <%s>:",
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 0aed5c8691bd..344e689567ee 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -1827,26 +1827,33 @@ static const u8 *__dso__read_symbol(struct dso *dso, const char *symfs_filename,
 		.ip = start,
 	};
 	u8 *code_buf = NULL;
+	int saved_errno;
 
 	nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
 	fd = open(symfs_filename, O_RDONLY);
+	saved_errno = errno;
 	nsinfo__mountns_exit(&nsc);
-	if (fd < 0)
+	if (fd < 0) {
+		errno = saved_errno;
 		return NULL;
-
-	if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data, is_64bit) == 0) {
+	}
+	if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data, is_64bit) <= 0) {
 		close(fd);
+		errno = ENOENT;
 		return NULL;
 	}
 	code_buf = malloc(len);
 	if (code_buf == NULL) {
 		close(fd);
+		errno = ENOMEM;
 		return NULL;
 	}
 	count = pread(fd, code_buf, len, data.offset);
+	saved_errno = errno;
 	close(fd);
 	if ((u64)count != len) {
 		free(code_buf);
+		errno = saved_errno;
 		return NULL;
 	}
 	*out_buf = code_buf;
@@ -1875,6 +1882,7 @@ const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
 		 * Note, there is fallback BPF image disassembly in the objdump
 		 * version but it currently does nothing.
 		 */
+		errno = EOPNOTSUPP;
 		return NULL;
 	}
 	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO) {
@@ -1895,6 +1903,7 @@ const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
 		return (const u8 *)(uintptr_t)(info_linear->info.jited_prog_insns);
 #else
 		pr_debug("No BPF program disassembly support\n");
+		errno = EOPNOTSUPP;
 		return NULL;
 #endif
 	}
diff --git a/tools/perf/util/llvm.c b/tools/perf/util/llvm.c
index 0369f3adcdb6..2351393e33c5 100644
--- a/tools/perf/util/llvm.c
+++ b/tools/perf/util/llvm.c
@@ -7,6 +7,7 @@
 #include "namespaces.h"
 #include "srcline.h"
 #include "symbol.h"
+#include <errno.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <linux/zalloc.h>
@@ -147,7 +148,7 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 	buf = dso__read_symbol(dso, filename, map, sym,
 			       &code_buf, &buf_len, &is_64bit);
 	if (buf == NULL)
-		return -1;
+		return errno;
 
 	init_llvm();
 	if (arch__is(args->arch, "x86")) {
-- 
2.51.0.618.g983fd99d29-goog

Reduce the scope of ins__scnprintf and ins__is_nop that aren't used
outside of disasm.c.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/disasm.c | 6 +++---
 tools/perf/util/disasm.h | 3 ---
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
index e64902e520ab..50b9433f3f8e 100644
--- a/tools/perf/util/disasm.c
+++ b/tools/perf/util/disasm.c
@@ -247,8 +247,8 @@ static int ins__raw_scnprintf(struct ins *ins, char *bf, size_t size,
 	return scnprintf(bf, size, "%-*s %s", max_ins_name, ins->name, ops->raw);
 }
 
-int ins__scnprintf(struct ins *ins, char *bf, size_t size,
-		   struct ins_operands *ops, int max_ins_name)
+static int ins__scnprintf(struct ins *ins, char *bf, size_t size,
+			  struct ins_operands *ops, int max_ins_name)
 {
 	if (ins->ops->scnprintf)
 		return ins->ops->scnprintf(ins, bf, size, ops, max_ins_name);
@@ -828,7 +828,7 @@ static struct ins_ops ret_ops = {
 	.scnprintf = ins__raw_scnprintf,
 };
 
-bool ins__is_nop(const struct ins *ins)
+static bool ins__is_nop(const struct ins *ins)
 {
 	return ins->ops == &nop_ops;
 }
diff --git a/tools/perf/util/disasm.h b/tools/perf/util/disasm.h
index 2cb4e1a6bd30..09c86f540f7f 100644
--- a/tools/perf/util/disasm.h
+++ b/tools/perf/util/disasm.h
@@ -110,13 +110,10 @@ struct arch *arch__find(const char *name);
 bool arch__is(struct arch *arch, const char *name);
 
 struct ins_ops *ins__find(struct arch *arch, const char *name, struct disasm_line *dl);
-int ins__scnprintf(struct ins *ins, char *bf, size_t size,
-		   struct ins_operands *ops, int max_ins_name);
 
 bool ins__is_call(const struct ins *ins);
 bool ins__is_jump(const struct ins *ins);
 bool ins__is_fused(struct arch *arch, const char *ins1, const char *ins2);
-bool ins__is_nop(const struct ins *ins);
 bool ins__is_ret(const struct ins *ins);
 bool ins__is_lock(const struct ins *ins);
 
-- 
2.51.0.618.g983fd99d29-goog

Factor the addr2line function implementation into separate source
files (addr2line.[ch]) and rename the addr2line function
cmd__addr2line. In srcline replace the ifdef-ed addr2line
implementations with one that first tries the llvm__addr2line
implementation, then the deprecated libbfd__addr2line function and on
failure uses cmd__addr2line.

If HAVE_LIBLLVM_SUPPORT is enabled the llvm__addr2line will execute
against the libLLVM.so it is linked against.

If HAVE_LIBLLVM_DYNAMIC is enabled then libperf-llvm.so (that links
against libLLVM.so) will be dlopened. If the dlopen succeeds then the
behavior should match HAVE_LIBLLVM_SUPPORT. On failure cmd__addr2line
is used. The dlopen is only tried once.

If HAVE_LIBLLVM_DYNAMIC isn't enabled then llvm__addr2line immediately
fails and cmd__addr2line is used.

Clean up the dso__free_a2l logic, which is only needed in the non-LLVM
version and moved to addr2line.c.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/Build       |   1 +
 tools/perf/util/addr2line.c | 439 ++++++++++++++++++++++++++++++++
 tools/perf/util/addr2line.h |  20 ++
 tools/perf/util/config.c    |   2 +-
 tools/perf/util/llvm.c      |   5 -
 tools/perf/util/llvm.h      |   3 -
 tools/perf/util/srcline.c   | 495 ++----------------------------------
 tools/perf/util/srcline.h   |   1 -
 8 files changed, 485 insertions(+), 481 deletions(-)
 create mode 100644 tools/perf/util/addr2line.c
 create mode 100644 tools/perf/util/addr2line.h

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index e6b396d919bb..4be313cd115a 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -2,6 +2,7 @@ include $(srctree)/tools/scripts/Makefile.include
 include $(srctree)/tools/scripts/utilities.mak
 
 perf-util-y += arm64-frame-pointer-unwind-support.o
+perf-util-y += addr2line.o
 perf-util-y += addr_location.o
 perf-util-y += annotate.o
 perf-util-y += block-info.o
diff --git a/tools/perf/util/addr2line.c b/tools/perf/util/addr2line.c
new file mode 100644
index 000000000000..f2d94a3272d7
--- /dev/null
+++ b/tools/perf/util/addr2line.c
@@ -0,0 +1,439 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "addr2line.h"
+#include "debug.h"
+#include "dso.h"
+#include "string2.h"
+#include "srcline.h"
+#include "symbol.h"
+#include "symbol_conf.h"
+
+#include <api/io.h>
+#include <linux/zalloc.h>
+#include <subcmd/run-command.h>
+
+#include <inttypes.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MAX_INLINE_NEST 1024
+
+/* If addr2line doesn't return data for 1 second then timeout. */
+int addr2line_timeout_ms = 1 * 1000;
+
+static int filename_split(char *filename, unsigned int *line_nr)
+{
+	char *sep;
+
+	sep = strchr(filename, '\n');
+	if (sep)
+		*sep = '\0';
+
+	if (!strcmp(filename, "??:0"))
+		return 0;
+
+	sep = strchr(filename, ':');
+	if (sep) {
+		*sep++ = '\0';
+		*line_nr = strtoul(sep, NULL, 0);
+		return 1;
+	}
+	pr_debug("addr2line missing ':' in filename split\n");
+	return 0;
+}
+
+static void addr2line_subprocess_cleanup(struct child_process *a2l)
+{
+	if (a2l->pid != -1) {
+		kill(a2l->pid, SIGKILL);
+		finish_command(a2l); /* ignore result, we don't care */
+		a2l->pid = -1;
+		close(a2l->in);
+		close(a2l->out);
+	}
+
+	free(a2l);
+}
+
+static struct child_process *addr2line_subprocess_init(const char *addr2line_path,
+							const char *binary_path)
+{
+	const char *argv[] = {
+		addr2line_path ?: "addr2line",
+		"-e", binary_path,
+		"-a", "-i", "-f", NULL
+	};
+	struct child_process *a2l = zalloc(sizeof(*a2l));
+	int start_command_status = 0;
+
+	if (a2l == NULL) {
+		pr_err("Failed to allocate memory for addr2line");
+		return NULL;
+	}
+
+	a2l->pid = -1;
+	a2l->in = -1;
+	a2l->out = -1;
+	a2l->no_stderr = 1;
+
+	a2l->argv = argv;
+	start_command_status = start_command(a2l);
+	a2l->argv = NULL; /* it's not used after start_command; avoid dangling pointers */
+
+	if (start_command_status != 0) {
+		pr_warning("could not start addr2line (%s) for %s: start_command return code %d\n",
+			addr2line_path, binary_path, start_command_status);
+		addr2line_subprocess_cleanup(a2l);
+		return NULL;
+	}
+
+	return a2l;
+}
+
+enum a2l_style {
+	BROKEN,
+	GNU_BINUTILS,
+	LLVM,
+};
+
+static enum a2l_style addr2line_configure(struct child_process *a2l, const char *dso_name)
+{
+	static bool cached;
+	static enum a2l_style style;
+
+	if (!cached) {
+		char buf[128];
+		struct io io;
+		int ch;
+		int lines;
+
+		if (write(a2l->in, ",\n", 2) != 2)
+			return BROKEN;
+
+		io__init(&io, a2l->out, buf, sizeof(buf));
+		ch = io__get_char(&io);
+		if (ch == ',') {
+			style = LLVM;
+			cached = true;
+			lines = 1;
+			pr_debug3("Detected LLVM addr2line style\n");
+		} else if (ch == '0') {
+			style = GNU_BINUTILS;
+			cached = true;
+			lines = 3;
+			pr_debug3("Detected binutils addr2line style\n");
+		} else {
+			if (!symbol_conf.disable_add2line_warn) {
+				char *output = NULL;
+				size_t output_len;
+
+				io__getline(&io, &output, &output_len);
+				pr_warning("%s %s: addr2line configuration failed\n",
+					   __func__, dso_name);
+				pr_warning("\t%c%s", ch, output);
+			}
+			pr_debug("Unknown/broken addr2line style\n");
+			return BROKEN;
+		}
+		while (lines) {
+			ch = io__get_char(&io);
+			if (ch <= 0)
+				break;
+			if (ch == '\n')
+				lines--;
+		}
+		/* Ignore SIGPIPE in the event addr2line exits. */
+		signal(SIGPIPE, SIG_IGN);
+	}
+	return style;
+}
+
+static int read_addr2line_record(struct io *io,
+				 enum a2l_style style,
+				 const char *dso_name,
+				 u64 addr,
+				 bool first,
+				 char **function,
+				 char **filename,
+				 unsigned int *line_nr)
+{
+	/*
+	 * Returns:
+	 * -1 ==> error
+	 * 0 ==> sentinel (or other ill-formed) record read
+	 * 1 ==> a genuine record read
+	 */
+	char *line = NULL;
+	size_t line_len = 0;
+	unsigned int dummy_line_nr = 0;
+	int ret = -1;
+
+	if (function != NULL)
+		zfree(function);
+
+	if (filename != NULL)
+		zfree(filename);
+
+	if (line_nr != NULL)
+		*line_nr = 0;
+
+	/*
+	 * Read the first line. Without an error this will be:
+	 * - for the first line an address like 0x1234,
+	 * - the binutils sentinel 0x0000000000000000,
+	 * - the llvm-addr2line the sentinel ',' character,
+	 * - the function name line for an inlined function.
+	 */
+	if (io__getline(io, &line, &line_len) < 0 || !line_len)
+		goto error;
+
+	pr_debug3("%s %s: addr2line read address for sentinel: %s", __func__, dso_name, line);
+	if (style == LLVM && line_len == 2 && line[0] == ',') {
+		/* Found the llvm-addr2line sentinel character. */
+		zfree(&line);
+		return 0;
+	} else if (style == GNU_BINUTILS && (!first || addr != 0)) {
+		int zero_count = 0, non_zero_count = 0;
+		/*
+		 * Check for binutils sentinel ignoring it for the case the
+		 * requested address is 0.
+		 */
+
+		/* A given address should always start 0x. */
+		if (line_len >= 2 || line[0] != '0' || line[1] != 'x') {
+			for (size_t i = 2; i < line_len; i++) {
+				if (line[i] == '0')
+					zero_count++;
+				else if (line[i] != '\n')
+					non_zero_count++;
+			}
+			if (!non_zero_count) {
+				int ch;
+
+				if (first && !zero_count) {
+					/* Line was erroneous just '0x'. */
+					goto error;
+				}
+				/*
+				 * Line was 0x0..0, the sentinel for binutils. Remove
+				 * the function and filename lines.
+				 */
+				zfree(&line);
+				do {
+					ch = io__get_char(io);
+				} while (ch > 0 && ch != '\n');
+				do {
+					ch = io__get_char(io);
+				} while (ch > 0 && ch != '\n');
+				return 0;
+			}
+		}
+	}
+	/* Read the second function name line (if inline data then this is the first line). */
+	if (first && (io__getline(io, &line, &line_len) < 0 || !line_len))
+		goto error;
+
+	pr_debug3("%s %s: addr2line read line: %s", __func__, dso_name, line);
+	if (function != NULL)
+		*function = strdup(strim(line));
+
+	zfree(&line);
+	line_len = 0;
+
+	/* Read the third filename and line number line. */
+	if (io__getline(io, &line, &line_len) < 0 || !line_len)
+		goto error;
+
+	pr_debug3("%s %s: addr2line filename:number : %s", __func__, dso_name, line);
+	if (filename_split(line, line_nr == NULL ? &dummy_line_nr : line_nr) == 0 &&
+	    style == GNU_BINUTILS) {
+		ret = 0;
+		goto error;
+	}
+
+	if (filename != NULL)
+		*filename = strdup(line);
+
+	zfree(&line);
+	line_len = 0;
+
+	return 1;
+
+error:
+	free(line);
+	if (function != NULL)
+		zfree(function);
+	if (filename != NULL)
+		zfree(filename);
+	return ret;
+}
+
+static int inline_list__append_record(struct dso *dso,
+				      struct inline_node *node,
+				      struct symbol *sym,
+				      const char *function,
+				      const char *filename,
+				      unsigned int line_nr)
+{
+	struct symbol *inline_sym = new_inline_sym(dso, sym, function);
+
+	return inline_list__append(inline_sym, srcline_from_fileline(filename, line_nr), node);
+}
+
+int cmd__addr2line(const char *dso_name, u64 addr,
+		   char **file, unsigned int *line_nr,
+		   struct dso *dso,
+		   bool unwind_inlines,
+		   struct inline_node *node,
+		   struct symbol *sym __maybe_unused)
+{
+	struct child_process *a2l = dso__a2l(dso);
+	char *record_function = NULL;
+	char *record_filename = NULL;
+	unsigned int record_line_nr = 0;
+	int record_status = -1;
+	int ret = 0;
+	size_t inline_count = 0;
+	int len;
+	char buf[128];
+	ssize_t written;
+	struct io io = { .eof = false };
+	enum a2l_style a2l_style;
+
+	if (!a2l) {
+		if (!filename__has_section(dso_name, ".debug_line"))
+			goto out;
+
+		dso__set_a2l(dso,
+			     addr2line_subprocess_init(symbol_conf.addr2line_path, dso_name));
+		a2l = dso__a2l(dso);
+	}
+
+	if (a2l == NULL) {
+		if (!symbol_conf.disable_add2line_warn)
+			pr_warning("%s %s: addr2line_subprocess_init failed\n", __func__, dso_name);
+		goto out;
+	}
+	a2l_style = addr2line_configure(a2l, dso_name);
+	if (a2l_style == BROKEN)
+		goto out;
+
+	/*
+	 * Send our request and then *deliberately* send something that can't be
+	 * interpreted as a valid address to ask addr2line about (namely,
+	 * ","). This causes addr2line to first write out the answer to our
+	 * request, in an unbounded/unknown number of records, and then to write
+	 * out the lines "0x0...0", "??" and "??:0", for GNU binutils, or ","
+	 * for llvm-addr2line, so that we can detect when it has finished giving
+	 * us anything useful.
+	 */
+	len = snprintf(buf, sizeof(buf), "%016"PRIx64"\n,\n", addr);
+	written = len > 0 ? write(a2l->in, buf, len) : -1;
+	if (written != len) {
+		if (!symbol_conf.disable_add2line_warn)
+			pr_warning("%s %s: could not send request\n", __func__, dso_name);
+		goto out;
+	}
+	io__init(&io, a2l->out, buf, sizeof(buf));
+	io.timeout_ms = addr2line_timeout_ms;
+	switch (read_addr2line_record(&io, a2l_style, dso_name, addr, /*first=*/true,
+				      &record_function, &record_filename, &record_line_nr)) {
+	case -1:
+		if (!symbol_conf.disable_add2line_warn)
+			pr_warning("%s %s: could not read first record\n", __func__, dso_name);
+		goto out;
+	case 0:
+		/*
+		 * The first record was invalid, so return failure, but first
+		 * read another record, since we sent a sentinel ',' for the
+		 * sake of detected the last inlined function. Treat this as the
+		 * first of a record as the ',' generates a new start with GNU
+		 * binutils, also force a non-zero address as we're no longer
+		 * reading that record.
+		 */
+		switch (read_addr2line_record(&io, a2l_style, dso_name,
+					      /*addr=*/1, /*first=*/true,
+					      NULL, NULL, NULL)) {
+		case -1:
+			if (!symbol_conf.disable_add2line_warn)
+				pr_warning("%s %s: could not read sentinel record\n",
+					   __func__, dso_name);
+			break;
+		case 0:
+			/* The sentinel as expected. */
+			break;
+		default:
+			if (!symbol_conf.disable_add2line_warn)
+				pr_warning("%s %s: unexpected record instead of sentinel",
+					   __func__, dso_name);
+			break;
+		}
+		goto out;
+	default:
+		/* First record as expected. */
+		break;
+	}
+
+	if (file) {
+		*file = strdup(record_filename);
+		ret = 1;
+	}
+	if (line_nr)
+		*line_nr = record_line_nr;
+
+	if (unwind_inlines) {
+		if (node && inline_list__append_record(dso, node, sym,
+						       record_function,
+						       record_filename,
+						       record_line_nr)) {
+			ret = 0;
+			goto out;
+		}
+	}
+
+	/*
+	 * We have to read the records even if we don't care about the inline
+	 * info. This isn't the first record and force the address to non-zero
+	 * as we're reading records beyond the first.
+	 */
+	while ((record_status = read_addr2line_record(&io,
+						      a2l_style,
+						      dso_name,
+						      /*addr=*/1,
+						      /*first=*/false,
+						      &record_function,
+						      &record_filename,
+						      &record_line_nr)) == 1) {
+		if (unwind_inlines && node && inline_count++ < MAX_INLINE_NEST) {
+			if (inline_list__append_record(dso, node, sym,
+						       record_function,
+						       record_filename,
+						       record_line_nr)) {
+				ret = 0;
+				goto out;
+			}
+			ret = 1; /* found at least one inline frame */
+		}
+	}
+
+out:
+	free(record_function);
+	free(record_filename);
+	if (io.eof) {
+		dso__set_a2l(dso, NULL);
+		addr2line_subprocess_cleanup(a2l);
+	}
+	return ret;
+}
+
+void dso__free_a2l(struct dso *dso)
+{
+	struct child_process *a2l = dso__a2l(dso);
+
+	if (!a2l)
+		return;
+
+	addr2line_subprocess_cleanup(a2l);
+
+	dso__set_a2l(dso, NULL);
+}
diff --git a/tools/perf/util/addr2line.h b/tools/perf/util/addr2line.h
new file mode 100644
index 000000000000..d35a47ba8dab
--- /dev/null
+++ b/tools/perf/util/addr2line.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_ADDR2LINE_H
+#define __PERF_ADDR2LINE_H
+
+#include <linux/types.h>
+
+struct dso;
+struct inline_node;
+struct symbol;
+
+extern int addr2line_timeout_ms;
+
+int cmd__addr2line(const char *dso_name, u64 addr,
+		   char **file, unsigned int *line_nr,
+		   struct dso *dso,
+		   bool unwind_inlines,
+		   struct inline_node *node,
+		   struct symbol *sym);
+
+#endif /* __PERF_ADDR2LINE_H */
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index ae72b66b6ded..6f914620c6ff 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -19,7 +19,7 @@
 #include "util/hist.h"  /* perf_hist_config */
 #include "util/stat.h"  /* perf_stat__set_big_num */
 #include "util/evsel.h"  /* evsel__hw_names, evsel__use_bpf_counters */
-#include "util/srcline.h"  /* addr2line_timeout_ms */
+#include "util/addr2line.h"  /* addr2line_timeout_ms */
 #include "build-id.h"
 #include "debug.h"
 #include "config.h"
diff --git a/tools/perf/util/llvm.c b/tools/perf/util/llvm.c
index 2351393e33c5..565cad1969e5 100644
--- a/tools/perf/util/llvm.c
+++ b/tools/perf/util/llvm.c
@@ -70,11 +70,6 @@ int llvm__addr2line(const char *dso_name __maybe_unused, u64 addr __maybe_unused
 #endif
 }
 
-void dso__free_a2l_llvm(struct dso *dso __maybe_unused)
-{
-	/* Nothing to free. */
-}
-
 static void init_llvm(void)
 {
 	static bool init;
diff --git a/tools/perf/util/llvm.h b/tools/perf/util/llvm.h
index 8aa19bb6b068..57f6bafb24bb 100644
--- a/tools/perf/util/llvm.h
+++ b/tools/perf/util/llvm.h
@@ -15,9 +15,6 @@ int llvm__addr2line(const char *dso_name, u64 addr,
 		bool unwind_inlines, struct inline_node *node,
 		struct symbol *sym);
 
-
-void dso__free_a2l_llvm(struct dso *dso);
-
 int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 			     struct annotate_args *args);
 
diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index 23b942d4729e..27c0966611ab 100644
--- a/tools/perf/util/srcline.c
+++ b/tools/perf/util/srcline.c
@@ -1,30 +1,15 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <inttypes.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-
-#include <linux/compiler.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <linux/zalloc.h>
-
-#include <api/io.h>
-
-#include "util/dso.h"
-#include "util/debug.h"
-#include "util/callchain.h"
-#include "util/symbol_conf.h"
-#include "llvm.h"
 #include "srcline.h"
-#include "string2.h"
+#include "addr2line.h"
+#include "dso.h"
+#include "callchain.h"
+#include "libbfd.h"
+#include "llvm.h"
 #include "symbol.h"
-#include "subcmd/run-command.h"
 
-/* If addr2line doesn't return data for 1 second then timeout. */
-int addr2line_timeout_ms = 1 * 1000;
+#include <inttypes.h>
+#include <string.h>
+
 bool srcline_full_filename;
 
 char *srcline__unknown = (char *)"??:0";
@@ -129,458 +114,23 @@ struct symbol *new_inline_sym(struct dso *dso,
 	return inline_sym;
 }
 
-#ifdef HAVE_LIBLLVM_SUPPORT
-#include "llvm.h"
-
-static int addr2line(const char *dso_name, u64 addr,
-		     char **file, unsigned int *line, struct dso *dso,
-		      bool unwind_inlines, struct inline_node *node,
-		      struct symbol *sym)
-{
-	return llvm__addr2line(dso_name, addr, file, line, dso, unwind_inlines, node, sym);
-}
-
-void dso__free_a2l(struct dso *dso)
-{
-	dso__free_a2l_llvm(dso);
-}
-#elif defined(HAVE_LIBBFD_SUPPORT)
-#include "libbfd.h"
-
-static int addr2line(const char *dso_name, u64 addr,
-		     char **file, unsigned int *line, struct dso *dso,
-		     bool unwind_inlines, struct inline_node *node,
+static int addr2line(const char *dso_name, u64 addr, char **file, unsigned int *line_nr,
+		     struct dso *dso, bool unwind_inlines, struct inline_node *node,
 		     struct symbol *sym)
 {
-	return libbfd__addr2line(dso_name, addr, file, line, dso, unwind_inlines, node, sym);
-}
-
-void dso__free_a2l(struct dso *dso)
-{
-	dso__free_a2l_libbfd(dso);
-}
-
-#else /* HAVE_LIBBFD_SUPPORT */
-
-static int filename_split(char *filename, unsigned int *line_nr)
-{
-	char *sep;
-
-	sep = strchr(filename, '\n');
-	if (sep)
-		*sep = '\0';
-
-	if (!strcmp(filename, "??:0"))
-		return 0;
-
-	sep = strchr(filename, ':');
-	if (sep) {
-		*sep++ = '\0';
-		*line_nr = strtoul(sep, NULL, 0);
-		return 1;
-	}
-	pr_debug("addr2line missing ':' in filename split\n");
-	return 0;
-}
-
-static void addr2line_subprocess_cleanup(struct child_process *a2l)
-{
-	if (a2l->pid != -1) {
-		kill(a2l->pid, SIGKILL);
-		finish_command(a2l); /* ignore result, we don't care */
-		a2l->pid = -1;
-		close(a2l->in);
-		close(a2l->out);
-	}
-
-	free(a2l);
-}
-
-static struct child_process *addr2line_subprocess_init(const char *addr2line_path,
-							const char *binary_path)
-{
-	const char *argv[] = {
-		addr2line_path ?: "addr2line",
-		"-e", binary_path,
-		"-a", "-i", "-f", NULL
-	};
-	struct child_process *a2l = zalloc(sizeof(*a2l));
-	int start_command_status = 0;
-
-	if (a2l == NULL) {
-		pr_err("Failed to allocate memory for addr2line");
-		return NULL;
-	}
-
-	a2l->pid = -1;
-	a2l->in = -1;
-	a2l->out = -1;
-	a2l->no_stderr = 1;
-
-	a2l->argv = argv;
-	start_command_status = start_command(a2l);
-	a2l->argv = NULL; /* it's not used after start_command; avoid dangling pointers */
-
-	if (start_command_status != 0) {
-		pr_warning("could not start addr2line (%s) for %s: start_command return code %d\n",
-			addr2line_path, binary_path, start_command_status);
-		addr2line_subprocess_cleanup(a2l);
-		return NULL;
-	}
-
-	return a2l;
-}
-
-enum a2l_style {
-	BROKEN,
-	GNU_BINUTILS,
-	LLVM,
-};
-
-static enum a2l_style addr2line_configure(struct child_process *a2l, const char *dso_name)
-{
-	static bool cached;
-	static enum a2l_style style;
-
-	if (!cached) {
-		char buf[128];
-		struct io io;
-		int ch;
-		int lines;
-
-		if (write(a2l->in, ",\n", 2) != 2)
-			return BROKEN;
-
-		io__init(&io, a2l->out, buf, sizeof(buf));
-		ch = io__get_char(&io);
-		if (ch == ',') {
-			style = LLVM;
-			cached = true;
-			lines = 1;
-			pr_debug3("Detected LLVM addr2line style\n");
-		} else if (ch == '0') {
-			style = GNU_BINUTILS;
-			cached = true;
-			lines = 3;
-			pr_debug3("Detected binutils addr2line style\n");
-		} else {
-			if (!symbol_conf.disable_add2line_warn) {
-				char *output = NULL;
-				size_t output_len;
-
-				io__getline(&io, &output, &output_len);
-				pr_warning("%s %s: addr2line configuration failed\n",
-					   __func__, dso_name);
-				pr_warning("\t%c%s", ch, output);
-			}
-			pr_debug("Unknown/broken addr2line style\n");
-			return BROKEN;
-		}
-		while (lines) {
-			ch = io__get_char(&io);
-			if (ch <= 0)
-				break;
-			if (ch == '\n')
-				lines--;
-		}
-		/* Ignore SIGPIPE in the event addr2line exits. */
-		signal(SIGPIPE, SIG_IGN);
-	}
-	return style;
-}
-
-static int read_addr2line_record(struct io *io,
-				 enum a2l_style style,
-				 const char *dso_name,
-				 u64 addr,
-				 bool first,
-				 char **function,
-				 char **filename,
-				 unsigned int *line_nr)
-{
-	/*
-	 * Returns:
-	 * -1 ==> error
-	 * 0 ==> sentinel (or other ill-formed) record read
-	 * 1 ==> a genuine record read
-	 */
-	char *line = NULL;
-	size_t line_len = 0;
-	unsigned int dummy_line_nr = 0;
-	int ret = -1;
-
-	if (function != NULL)
-		zfree(function);
-
-	if (filename != NULL)
-		zfree(filename);
-
-	if (line_nr != NULL)
-		*line_nr = 0;
-
-	/*
-	 * Read the first line. Without an error this will be:
-	 * - for the first line an address like 0x1234,
-	 * - the binutils sentinel 0x0000000000000000,
-	 * - the llvm-addr2line the sentinel ',' character,
-	 * - the function name line for an inlined function.
-	 */
-	if (io__getline(io, &line, &line_len) < 0 || !line_len)
-		goto error;
-
-	pr_debug3("%s %s: addr2line read address for sentinel: %s", __func__, dso_name, line);
-	if (style == LLVM && line_len == 2 && line[0] == ',') {
-		/* Found the llvm-addr2line sentinel character. */
-		zfree(&line);
-		return 0;
-	} else if (style == GNU_BINUTILS && (!first || addr != 0)) {
-		int zero_count = 0, non_zero_count = 0;
-		/*
-		 * Check for binutils sentinel ignoring it for the case the
-		 * requested address is 0.
-		 */
-
-		/* A given address should always start 0x. */
-		if (line_len >= 2 || line[0] != '0' || line[1] != 'x') {
-			for (size_t i = 2; i < line_len; i++) {
-				if (line[i] == '0')
-					zero_count++;
-				else if (line[i] != '\n')
-					non_zero_count++;
-			}
-			if (!non_zero_count) {
-				int ch;
-
-				if (first && !zero_count) {
-					/* Line was erroneous just '0x'. */
-					goto error;
-				}
-				/*
-				 * Line was 0x0..0, the sentinel for binutils. Remove
-				 * the function and filename lines.
-				 */
-				zfree(&line);
-				do {
-					ch = io__get_char(io);
-				} while (ch > 0 && ch != '\n');
-				do {
-					ch = io__get_char(io);
-				} while (ch > 0 && ch != '\n');
-				return 0;
-			}
-		}
-	}
-	/* Read the second function name line (if inline data then this is the first line). */
-	if (first && (io__getline(io, &line, &line_len) < 0 || !line_len))
-		goto error;
-
-	pr_debug3("%s %s: addr2line read line: %s", __func__, dso_name, line);
-	if (function != NULL)
-		*function = strdup(strim(line));
-
-	zfree(&line);
-	line_len = 0;
-
-	/* Read the third filename and line number line. */
-	if (io__getline(io, &line, &line_len) < 0 || !line_len)
-		goto error;
-
-	pr_debug3("%s %s: addr2line filename:number : %s", __func__, dso_name, line);
-	if (filename_split(line, line_nr == NULL ? &dummy_line_nr : line_nr) == 0 &&
-	    style == GNU_BINUTILS) {
-		ret = 0;
-		goto error;
-	}
-
-	if (filename != NULL)
-		*filename = strdup(line);
-
-	zfree(&line);
-	line_len = 0;
-
-	return 1;
-
-error:
-	free(line);
-	if (function != NULL)
-		zfree(function);
-	if (filename != NULL)
-		zfree(filename);
-	return ret;
-}
-
-static int inline_list__append_record(struct dso *dso,
-				      struct inline_node *node,
-				      struct symbol *sym,
-				      const char *function,
-				      const char *filename,
-				      unsigned int line_nr)
-{
-	struct symbol *inline_sym = new_inline_sym(dso, sym, function);
-
-	return inline_list__append(inline_sym, srcline_from_fileline(filename, line_nr), node);
-}
-
-static int addr2line(const char *dso_name, u64 addr,
-		     char **file, unsigned int *line_nr,
-		     struct dso *dso,
-		     bool unwind_inlines,
-		     struct inline_node *node,
-		     struct symbol *sym __maybe_unused)
-{
-	struct child_process *a2l = dso__a2l(dso);
-	char *record_function = NULL;
-	char *record_filename = NULL;
-	unsigned int record_line_nr = 0;
-	int record_status = -1;
-	int ret = 0;
-	size_t inline_count = 0;
-	int len;
-	char buf[128];
-	ssize_t written;
-	struct io io = { .eof = false };
-	enum a2l_style a2l_style;
-
-	if (!a2l) {
-		if (!filename__has_section(dso_name, ".debug_line"))
-			goto out;
-
-		dso__set_a2l(dso,
-			     addr2line_subprocess_init(symbol_conf.addr2line_path, dso_name));
-		a2l = dso__a2l(dso);
-	}
-
-	if (a2l == NULL) {
-		if (!symbol_conf.disable_add2line_warn)
-			pr_warning("%s %s: addr2line_subprocess_init failed\n", __func__, dso_name);
-		goto out;
-	}
-	a2l_style = addr2line_configure(a2l, dso_name);
-	if (a2l_style == BROKEN)
-		goto out;
-
-	/*
-	 * Send our request and then *deliberately* send something that can't be
-	 * interpreted as a valid address to ask addr2line about (namely,
-	 * ","). This causes addr2line to first write out the answer to our
-	 * request, in an unbounded/unknown number of records, and then to write
-	 * out the lines "0x0...0", "??" and "??:0", for GNU binutils, or ","
-	 * for llvm-addr2line, so that we can detect when it has finished giving
-	 * us anything useful.
-	 */
-	len = snprintf(buf, sizeof(buf), "%016"PRIx64"\n,\n", addr);
-	written = len > 0 ? write(a2l->in, buf, len) : -1;
-	if (written != len) {
-		if (!symbol_conf.disable_add2line_warn)
-			pr_warning("%s %s: could not send request\n", __func__, dso_name);
-		goto out;
-	}
-	io__init(&io, a2l->out, buf, sizeof(buf));
-	io.timeout_ms = addr2line_timeout_ms;
-	switch (read_addr2line_record(&io, a2l_style, dso_name, addr, /*first=*/true,
-				      &record_function, &record_filename, &record_line_nr)) {
-	case -1:
-		if (!symbol_conf.disable_add2line_warn)
-			pr_warning("%s %s: could not read first record\n", __func__, dso_name);
-		goto out;
-	case 0:
-		/*
-		 * The first record was invalid, so return failure, but first
-		 * read another record, since we sent a sentinel ',' for the
-		 * sake of detected the last inlined function. Treat this as the
-		 * first of a record as the ',' generates a new start with GNU
-		 * binutils, also force a non-zero address as we're no longer
-		 * reading that record.
-		 */
-		switch (read_addr2line_record(&io, a2l_style, dso_name,
-					      /*addr=*/1, /*first=*/true,
-					      NULL, NULL, NULL)) {
-		case -1:
-			if (!symbol_conf.disable_add2line_warn)
-				pr_warning("%s %s: could not read sentinel record\n",
-					   __func__, dso_name);
-			break;
-		case 0:
-			/* The sentinel as expected. */
-			break;
-		default:
-			if (!symbol_conf.disable_add2line_warn)
-				pr_warning("%s %s: unexpected record instead of sentinel",
-					   __func__, dso_name);
-			break;
-		}
-		goto out;
-	default:
-		/* First record as expected. */
-		break;
-	}
-
-	if (file) {
-		*file = strdup(record_filename);
-		ret = 1;
-	}
-	if (line_nr)
-		*line_nr = record_line_nr;
-
-	if (unwind_inlines) {
-		if (node && inline_list__append_record(dso, node, sym,
-						       record_function,
-						       record_filename,
-						       record_line_nr)) {
-			ret = 0;
-			goto out;
-		}
-	}
-
-	/*
-	 * We have to read the records even if we don't care about the inline
-	 * info. This isn't the first record and force the address to non-zero
-	 * as we're reading records beyond the first.
-	 */
-	while ((record_status = read_addr2line_record(&io,
-						      a2l_style,
-						      dso_name,
-						      /*addr=*/1,
-						      /*first=*/false,
-						      &record_function,
-						      &record_filename,
-						      &record_line_nr)) == 1) {
-		if (unwind_inlines && node && inline_count++ < MAX_INLINE_NEST) {
-			if (inline_list__append_record(dso, node, sym,
-						       record_function,
-						       record_filename,
-						       record_line_nr)) {
-				ret = 0;
-				goto out;
-			}
-			ret = 1; /* found at least one inline frame */
-		}
-	}
-
-out:
-	free(record_function);
-	free(record_filename);
-	if (io.eof) {
-		dso__set_a2l(dso, NULL);
-		addr2line_subprocess_cleanup(a2l);
-	}
-	return ret;
-}
-
-void dso__free_a2l(struct dso *dso)
-{
-	struct child_process *a2l = dso__a2l(dso);
+	int ret;
 
-	if (!a2l)
-		return;
+	ret = llvm__addr2line(dso_name, addr, file, line_nr, dso, unwind_inlines, node, sym);
+	if (ret > 0)
+		return ret;
 
-	addr2line_subprocess_cleanup(a2l);
+	ret = libbfd__addr2line(dso_name, addr, file, line_nr, dso, unwind_inlines, node, sym);
+	if (ret > 0)
+		return ret;
 
-	dso__set_a2l(dso, NULL);
+	return cmd__addr2line(dso_name, addr, file, line_nr, dso, unwind_inlines, node, sym);
 }
 
-#endif /* HAVE_LIBBFD_SUPPORT */
-
 static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
 					struct dso *dso, struct symbol *sym)
 {
@@ -595,7 +145,9 @@ static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
 	INIT_LIST_HEAD(&node->val);
 	node->addr = addr;
 
-	addr2line(dso_name, addr, NULL, NULL, dso, true, node, sym);
+	addr2line(dso_name, addr, /*file=*/NULL, /*line_nr=*/NULL, dso,
+		  /*unwind_inlines=*/true, node, sym);
+
 	return node;
 }
 
@@ -622,7 +174,7 @@ char *__get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
 		goto out_err;
 
 	if (!addr2line(dso_name, addr, &file, &line, dso,
-		       unwind_inlines, NULL, sym))
+		       unwind_inlines, /*node=*/NULL, sym))
 		goto out_err;
 
 	srcline = srcline_from_fileline(file, line);
@@ -668,7 +220,8 @@ char *get_srcline_split(struct dso *dso, u64 addr, unsigned *line)
 	if (dso_name == NULL)
 		goto out_err;
 
-	if (!addr2line(dso_name, addr, &file, line, dso, true, NULL, NULL))
+	if (!addr2line(dso_name, addr, &file, line, dso, /*unwind_inlines=*/true,
+			/*node=*/NULL, /*sym=*/NULL))
 		goto out_err;
 
 	dso__set_a2l_fails(dso, 0);
diff --git a/tools/perf/util/srcline.h b/tools/perf/util/srcline.h
index 6e66ddbcc879..c36f573cd339 100644
--- a/tools/perf/util/srcline.h
+++ b/tools/perf/util/srcline.h
@@ -9,7 +9,6 @@
 struct dso;
 struct symbol;
 
-extern int addr2line_timeout_ms;
 extern bool srcline_full_filename;
 char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
 		  bool show_sym, bool show_addr, u64 ip);
-- 
2.51.0.618.g983fd99d29-goog

Set in symbol__annotate but never used.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/annotate.c | 1 -
 tools/perf/util/disasm.h   | 1 -
 2 files changed, 2 deletions(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index c9b220d9f924..a2e34f149a07 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1015,7 +1015,6 @@ int symbol__annotate(struct map_symbol *ms, struct evsel *evsel,
 	struct symbol *sym = ms->sym;
 	struct annotation *notes = symbol__annotation(sym);
 	struct annotate_args args = {
-		.evsel		= evsel,
 		.options	= &annotate_opts,
 	};
 	struct arch *arch = NULL;
diff --git a/tools/perf/util/disasm.h b/tools/perf/util/disasm.h
index 09c86f540f7f..d2cb555e4a3b 100644
--- a/tools/perf/util/disasm.h
+++ b/tools/perf/util/disasm.h
@@ -98,7 +98,6 @@ struct ins_ops {
 struct annotate_args {
 	struct arch		  *arch;
 	struct map_symbol	  ms;
-	struct evsel		  *evsel;
 	struct annotation_options *options;
 	s64			  offset;
 	char			  *line;
-- 
2.51.0.618.g983fd99d29-goog

If perf wasn't built against libcapstone, no HAVE_LIBCAPSTONE_SUPPORT,
support dlopen-ing libcapstone.so and then calling the necessary
functions by looking them up using dlsym. Reverse engineer the types
in the API using pahole, adding only what's used in the perf code or
necessary for the sake of struct size and alignment.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/capstone.c | 285 ++++++++++++++++++++++++++++++++-----
 1 file changed, 248 insertions(+), 37 deletions(-)

diff --git a/tools/perf/util/capstone.c b/tools/perf/util/capstone.c
index be5fd44b1f9d..88e270237443 100644
--- a/tools/perf/util/capstone.c
+++ b/tools/perf/util/capstone.c
@@ -11,20 +11,250 @@
 #include "print_insn.h"
 #include "symbol.h"
 #include "thread.h"
+#include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
 #include <string.h>
 
 #ifdef HAVE_LIBCAPSTONE_SUPPORT
 #include <capstone/capstone.h>
+#else
+typedef size_t csh;
+enum cs_arch {
+	CS_ARCH_ARM = 0,
+	CS_ARCH_ARM64 = 1,
+	CS_ARCH_X86 = 3,
+	CS_ARCH_SYSZ = 6,
+};
+enum cs_mode {
+	CS_MODE_ARM = 0,
+	CS_MODE_32 = 1 << 2,
+	CS_MODE_64 = 1 << 3,
+	CS_MODE_V8 = 1 << 6,
+	CS_MODE_BIG_ENDIAN = 1 << 31,
+};
+enum cs_opt_type {
+	CS_OPT_SYNTAX = 1,
+	CS_OPT_DETAIL = 2,
+};
+enum cs_opt_value {
+	CS_OPT_SYNTAX_ATT = 2,
+	CS_OPT_ON = 3,
+};
+enum cs_err {
+	CS_ERR_OK = 0,
+	CS_ERR_HANDLE = 3,
+};
+enum x86_op_type {
+	X86_OP_IMM = 2,
+	X86_OP_MEM = 3,
+};
+enum x86_reg {
+	X86_REG_RIP = 41,
+};
+typedef int32_t x86_avx_bcast;
+struct x86_op_mem {
+	enum x86_reg segment;
+	enum x86_reg base;
+	enum x86_reg index;
+	int scale;
+	int64_t disp;
+};
+
+struct cs_x86_op {
+	enum x86_op_type type;
+	union {
+		enum x86_reg  reg;
+		int64_t imm;
+		struct x86_op_mem mem;
+	};
+	uint8_t size;
+	uint8_t access;
+	x86_avx_bcast avx_bcast;
+	bool avx_zero_opmask;
+};
+struct cs_x86_encoding {
+	uint8_t modrm_offset;
+	uint8_t disp_offset;
+	uint8_t disp_size;
+	uint8_t imm_offset;
+	uint8_t imm_size;
+};
+typedef int32_t  x86_xop_cc;
+typedef int32_t  x86_sse_cc;
+typedef int32_t  x86_avx_cc;
+typedef int32_t  x86_avx_rm;
+struct cs_x86 {
+	uint8_t prefix[4];
+	uint8_t opcode[4];
+	uint8_t rex;
+	uint8_t addr_size;
+	uint8_t modrm;
+	uint8_t sib;
+	int64_t disp;
+	enum x86_reg sib_index;
+	int8_t sib_scale;
+	enum x86_reg sib_base;
+	x86_xop_cc xop_cc;
+	x86_sse_cc sse_cc;
+	x86_avx_cc avx_cc;
+	bool avx_sae;
+	x86_avx_rm avx_rm;
+	union {
+		uint64_t eflags;
+		uint64_t fpu_flags;
+	};
+	uint8_t op_count;
+	struct cs_x86_op operands[8];
+	struct cs_x86_encoding encoding;
+};
+struct cs_detail {
+	uint16_t regs_read[12];
+	uint8_t regs_read_count;
+	uint16_t regs_write[20];
+	uint8_t regs_write_count;
+	uint8_t groups[8];
+	uint8_t groups_count;
+
+	union {
+		struct cs_x86 x86;
+	};
+};
+struct cs_insn {
+	unsigned int id;
+	uint64_t address;
+	uint16_t size;
+	uint8_t bytes[16];
+	char mnemonic[32];
+	char op_str[160];
+	struct cs_detail *detail;
+};
+#endif
+
+#ifndef HAVE_LIBCAPSTONE_SUPPORT
+static void *perf_cs_dll_handle(void)
+{
+	static bool dll_handle_init;
+	static void *dll_handle;
+
+	if (!dll_handle_init) {
+		dll_handle_init = true;
+		dll_handle = dlopen("libcapstone.so", RTLD_LAZY);
+		if (!dll_handle)
+			pr_debug("dlopen failed for libcapstone.so\n");
+	}
+	return dll_handle;
+}
+#endif
+
+static enum cs_err perf_cs_open(enum cs_arch arch, enum cs_mode mode, csh *handle)
+{
+#ifdef HAVE_LIBCAPSTONE_SUPPORT
+	return cs_open(arch, mode, handle);
+#else
+	static bool fn_init;
+	static enum cs_err (*fn)(enum cs_arch arch, enum cs_mode mode, csh *handle);
+
+	if (!fn_init) {
+		fn = dlsym(perf_cs_dll_handle(), "cs_open");
+		if (!fn)
+			pr_debug("dlsym failed for cs_open\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return CS_ERR_HANDLE;
+	return fn(arch, mode, handle);
+#endif
+}
+
+static enum cs_err perf_cs_option(csh handle, enum cs_opt_type type, size_t value)
+{
+#ifdef HAVE_LIBCAPSTONE_SUPPORT
+	return cs_option(handle, type, value);
+#else
+	static bool fn_init;
+	static enum cs_err (*fn)(csh handle, enum cs_opt_type type, size_t value);
+
+	if (!fn_init) {
+		fn = dlsym(perf_cs_dll_handle(), "cs_option");
+		if (!fn)
+			pr_debug("dlsym failed for cs_option\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return CS_ERR_HANDLE;
+	return fn(handle, type, value);
+#endif
+}
+
+static size_t perf_cs_disasm(csh handle, const uint8_t *code, size_t code_size,
+			uint64_t address, size_t count, struct cs_insn **insn)
+{
+#ifdef HAVE_LIBCAPSTONE_SUPPORT
+	return cs_disasm(handle, code, code_size, address, count, insn);
+#else
+	static bool fn_init;
+	static enum cs_err (*fn)(csh handle, const uint8_t *code, size_t code_size,
+				 uint64_t address, size_t count, struct cs_insn **insn);
+
+	if (!fn_init) {
+		fn = dlsym(perf_cs_dll_handle(), "cs_disasm");
+		if (!fn)
+			pr_debug("dlsym failed for cs_disasm\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return CS_ERR_HANDLE;
+	return fn(handle, code, code_size, address, count, insn);
 #endif
+}
 
+static void perf_cs_free(struct cs_insn *insn, size_t count)
+{
 #ifdef HAVE_LIBCAPSTONE_SUPPORT
+	cs_free(insn, count);
+#else
+	static bool fn_init;
+	static void (*fn)(struct cs_insn *insn, size_t count);
+
+	if (!fn_init) {
+		fn = dlsym(perf_cs_dll_handle(), "cs_free");
+		if (!fn)
+			pr_debug("dlsym failed for cs_free\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return;
+	fn(insn, count);
+#endif
+}
+
+static enum cs_err perf_cs_close(csh *handle)
+{
+#ifdef HAVE_LIBCAPSTONE_SUPPORT
+	return cs_close(handle);
+#else
+	static bool fn_init;
+	static enum cs_err (*fn)(csh *handle);
+
+	if (!fn_init) {
+		fn = dlsym(perf_cs_dll_handle(), "cs_close");
+		if (!fn)
+			pr_debug("dlsym failed for cs_close\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return CS_ERR_HANDLE;
+	return fn(handle);
+#endif
+}
+
 static int capstone_init(struct machine *machine, csh *cs_handle, bool is64,
 			 bool disassembler_style)
 {
-	cs_arch arch;
-	cs_mode mode;
+	enum cs_arch arch;
+	enum cs_mode mode;
 
 	if (machine__is(machine, "x86_64") && is64) {
 		arch = CS_ARCH_X86;
@@ -45,7 +275,7 @@ static int capstone_init(struct machine *machine, csh *cs_handle, bool is64,
 		return -1;
 	}
 
-	if (cs_open(arch, mode, cs_handle) != CS_ERR_OK) {
+	if (perf_cs_open(arch, mode, cs_handle) != CS_ERR_OK) {
 		pr_warning_once("cs_open failed\n");
 		return -1;
 	}
@@ -57,27 +287,25 @@ static int capstone_init(struct machine *machine, csh *cs_handle, bool is64,
 		 * is set via annotation args
 		 */
 		if (disassembler_style)
-			cs_option(*cs_handle, CS_OPT_SYNTAX, CS_OPT_SYNTAX_ATT);
+			perf_cs_option(*cs_handle, CS_OPT_SYNTAX, CS_OPT_SYNTAX_ATT);
 		/*
 		 * Resolving address operands to symbols is implemented
 		 * on x86 by investigating instruction details.
 		 */
-		cs_option(*cs_handle, CS_OPT_DETAIL, CS_OPT_ON);
+		perf_cs_option(*cs_handle, CS_OPT_DETAIL, CS_OPT_ON);
 	}
 
 	return 0;
 }
-#endif
 
-#ifdef HAVE_LIBCAPSTONE_SUPPORT
-static size_t print_insn_x86(struct thread *thread, u8 cpumode, cs_insn *insn,
+static size_t print_insn_x86(struct thread *thread, u8 cpumode, struct cs_insn *insn,
 			     int print_opts, FILE *fp)
 {
 	struct addr_location al;
 	size_t printed = 0;
 
 	if (insn->detail && insn->detail->x86.op_count == 1) {
-		cs_x86_op *op = &insn->detail->x86.operands[0];
+		struct cs_x86_op *op = &insn->detail->x86.operands[0];
 
 		addr_location__init(&al);
 		if (op->type == X86_OP_IMM &&
@@ -95,7 +323,6 @@ static size_t print_insn_x86(struct thread *thread, u8 cpumode, cs_insn *insn,
 	printed += fprintf(fp, "%s %s", insn[0].mnemonic, insn[0].op_str);
 	return printed;
 }
-#endif
 
 
 ssize_t capstone__fprintf_insn_asm(struct machine *machine __maybe_unused,
@@ -106,9 +333,8 @@ ssize_t capstone__fprintf_insn_asm(struct machine *machine __maybe_unused,
 				   uint64_t ip __maybe_unused, int *lenp __maybe_unused,
 				   int print_opts __maybe_unused, FILE *fp __maybe_unused)
 {
-#ifdef HAVE_LIBCAPSTONE_SUPPORT
 	size_t printed;
-	cs_insn *insn;
+	struct cs_insn *insn;
 	csh cs_handle;
 	size_t count;
 	int ret;
@@ -118,7 +344,7 @@ ssize_t capstone__fprintf_insn_asm(struct machine *machine __maybe_unused,
 	if (ret < 0)
 		return ret;
 
-	count = cs_disasm(cs_handle, code, code_size, ip, 1, &insn);
+	count = perf_cs_disasm(cs_handle, code, code_size, ip, 1, &insn);
 	if (count > 0) {
 		if (machine__normalized_is(machine, "x86"))
 			printed = print_insn_x86(thread, cpumode, &insn[0], print_opts, fp);
@@ -126,20 +352,16 @@ ssize_t capstone__fprintf_insn_asm(struct machine *machine __maybe_unused,
 			printed = fprintf(fp, "%s %s", insn[0].mnemonic, insn[0].op_str);
 		if (lenp)
 			*lenp = insn->size;
-		cs_free(insn, count);
+		perf_cs_free(insn, count);
 	} else {
 		printed = -1;
 	}
 
-	cs_close(&cs_handle);
+	perf_cs_close(&cs_handle);
 	return printed;
-#else
-	return -1;
-#endif
 }
 
-#ifdef HAVE_LIBCAPSTONE_SUPPORT
-static void print_capstone_detail(cs_insn *insn, char *buf, size_t len,
+static void print_capstone_detail(struct cs_insn *insn, char *buf, size_t len,
 				  struct annotate_args *args, u64 addr)
 {
 	int i;
@@ -154,7 +376,7 @@ static void print_capstone_detail(cs_insn *insn, char *buf, size_t len,
 		return;
 
 	for (i = 0; i < insn->detail->x86.op_count; i++) {
-		cs_x86_op *op = &insn->detail->x86.operands[i];
+		struct cs_x86_op *op = &insn->detail->x86.operands[i];
 		u64 orig_addr;
 
 		if (op->type != X86_OP_MEM)
@@ -195,9 +417,7 @@ static void print_capstone_detail(cs_insn *insn, char *buf, size_t len,
 		break;
 	}
 }
-#endif
 
-#ifdef HAVE_LIBCAPSTONE_SUPPORT
 struct find_file_offset_data {
 	u64 ip;
 	u64 offset;
@@ -214,13 +434,11 @@ static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
 	}
 	return 0;
 }
-#endif
 
 int symbol__disassemble_capstone(const char *filename __maybe_unused,
 				 struct symbol *sym __maybe_unused,
 				 struct annotate_args *args __maybe_unused)
 {
-#ifdef HAVE_LIBCAPSTONE_SUPPORT
 	struct annotation *notes = symbol__annotation(sym);
 	struct map *map = args->ms.map;
 	struct dso *dso = map__dso(map);
@@ -235,7 +453,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 	const u8 *buf;
 	u64 buf_len;
 	csh handle;
-	cs_insn *insn = NULL;
+	struct cs_insn *insn = NULL;
 	char disasm_buf[512];
 	struct disasm_line *dl;
 	bool disassembler_style = false;
@@ -273,7 +491,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 
 	needs_cs_close = true;
 
-	free_count = count = cs_disasm(handle, buf, buf_len, start, buf_len, &insn);
+	free_count = count = perf_cs_disasm(handle, buf, buf_len, start, buf_len, &insn);
 	for (i = 0, offset = 0; i < count; i++) {
 		int printed;
 
@@ -312,9 +530,9 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 
 out:
 	if (needs_cs_close) {
-		cs_close(&handle);
+		perf_cs_close(&handle);
 		if (free_count > 0)
-			cs_free(insn, free_count);
+			perf_cs_free(insn, free_count);
 	}
 	free(code_buf);
 	return count < 0 ? count : 0;
@@ -334,16 +552,12 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
 	}
 	count = -1;
 	goto out;
-#else
-	return -1;
-#endif
 }
 
 int symbol__disassemble_capstone_powerpc(const char *filename __maybe_unused,
 					 struct symbol *sym __maybe_unused,
 					 struct annotate_args *args __maybe_unused)
 {
-#ifdef HAVE_LIBCAPSTONE_SUPPORT
 	struct annotation *notes = symbol__annotation(sym);
 	struct map *map = args->ms.map;
 	struct dso *dso = map__dso(map);
@@ -456,7 +670,7 @@ int symbol__disassemble_capstone_powerpc(const char *filename __maybe_unused,
 
 out:
 	if (needs_cs_close)
-		cs_close(&handle);
+		perf_cs_close(&handle);
 	free(buf);
 	return count < 0 ? count : 0;
 
@@ -465,7 +679,4 @@ int symbol__disassemble_capstone_powerpc(const char *filename __maybe_unused,
 		close(fd);
 	count = -1;
 	goto out;
-#else
-	return -1;
-#endif
 }
-- 
2.51.0.618.g983fd99d29-goog

If perf wasn't built against libLLVM, no HAVE_LIBLLVM_SUPPORT, support
dlopen-ing libLLVM.so and then calling the necessary functions by
looking them up using dlsym. As the C++ code in llvm-c-helpers used
for addr2line is problematic to call using dlsym, build that C++ code
against libLLVM.so as a separate shared object, and support dynamic
loading of it. This build option is enabled with LIBLLVM_DYNAMIC=1

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.config         |  13 ++
 tools/perf/Makefile.perf           |  23 ++-
 tools/perf/tests/make              |   2 +
 tools/perf/util/Build              |   2 +-
 tools/perf/util/llvm-c-helpers.cpp | 113 +++++++++++-
 tools/perf/util/llvm.c             | 273 +++++++++++++++++++++++++----
 6 files changed, 388 insertions(+), 38 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 0f09f30f1906..03bd11b6e248 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -960,6 +960,19 @@ ifndef NO_LIBLLVM
     NO_LIBLLVM := 1
   endif
 endif
+ifdef LIBLLVM_DYNAMIC
+  ifndef NO_LIBLLVM
+    $(error LIBLLVM_DYNAMIC should be used with NO_LIBLLVM)
+  endif
+  $(call feature_check,llvm-perf)
+  ifneq ($(feature-llvm-perf), 1)
+    $(warning LIBLLVM_DYNAMIC requires libLLVM.so which wasn't feature detected)
+  endif
+  CFLAGS += -DHAVE_LIBLLVM_DYNAMIC
+  CFLAGS += $(shell $(LLVM_CONFIG) --cflags)
+  CXXFLAGS += -DHAVE_LIBLLVM_DYNAMIC
+  CXXFLAGS += $(shell $(LLVM_CONFIG) --cxxflags)
+endif
 
 ifndef NO_DEMANGLE
   $(call feature_check,cxa-demangle)
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 7d6ac03a7109..fb888702bace 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -423,6 +423,12 @@ ifndef NO_JVMTI
 PROGRAMS += $(OUTPUT)$(LIBJVMTI)
 endif
 
+LIBPERF_LLVM = libperf-llvm.so
+
+ifdef LIBLLVM_DYNAMIC
+PROGRAMS += $(OUTPUT)$(LIBPERF_LLVM)
+endif
+
 DLFILTERS := dlfilter-test-api-v0.so dlfilter-test-api-v2.so dlfilter-show-cycles.so
 DLFILTERS := $(patsubst %,$(OUTPUT)dlfilters/%,$(DLFILTERS))
 
@@ -995,6 +1001,16 @@ $(LIBSYMBOL)-clean:
 	$(call QUIET_CLEAN, libsymbol)
 	$(Q)$(RM) -r -- $(LIBSYMBOL_OUTPUT)
 
+ifdef LIBLLVM_DYNAMIC
+LIBPERF_LLVM_CXXFLAGS := $(call filter-out,-DHAVE_LIBLLVM_DYNAMIC,$(CXXFLAGS)) -DHAVE_LIBLLVM_SUPPORT
+LIBPERF_LLVM_LIBS = -L$(shell $(LLVM_CONFIG) --libdir) $(LIBLLVM) -lstdc++
+
+$(OUTPUT)$(LIBPERF_LLVM): util/llvm-c-helpers.cpp
+	$(QUIET_LINK)$(CXX) $(LIBPERF_LLVM_CXXFLAGS) $(LIBPERF_LLVM_LIBS) -shared -o $@ $<
+
+$(OUTPUT)perf: $(OUTPUT)$(LIBPERF_LLVM)
+endif
+
 help:
 	@echo 'Perf make targets:'
 	@echo '  doc		- make *all* documentation (see below)'
@@ -1096,6 +1112,11 @@ ifndef NO_JVMTI
 	$(call QUIET_INSTALL, $(LIBJVMTI)) \
 		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(libdir_SQ)'; \
 		$(INSTALL) $(OUTPUT)$(LIBJVMTI) '$(DESTDIR_SQ)$(libdir_SQ)';
+endif
+ifdef LIBLLVM_DYNAMIC
+	$(call QUIET_INSTALL, $(LIBPERF_LLVM)) \
+		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(libdir_SQ)'; \
+		$(INSTALL) $(OUTPUT)$(LIBPERF_LLVM) '$(DESTDIR_SQ)$(libdir_SQ)';
 endif
 	$(call QUIET_INSTALL, libexec) \
 		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)'
@@ -1281,7 +1302,7 @@ clean:: $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBSYMBOL)-clean $(
 		-name '\.*.cmd' -delete -o -name '\.*.d' -delete -o -name '*.shellcheck_log' -delete
 	$(Q)$(RM) $(OUTPUT).config-detected
 	$(call QUIET_CLEAN, core-progs) $(RM) $(ALL_PROGRAMS) perf perf-read-vdso32 \
-		perf-read-vdsox32 $(OUTPUT)$(LIBJVMTI).so
+		perf-read-vdsox32 $(OUTPUT)$(LIBJVMTI) $(OUTPUT)$(LIBPERF_LLVM)
 	$(call QUIET_CLEAN, core-gen)   $(RM)  *.spec *.pyc *.pyo */*.pyc */*.pyo \
 		$(OUTPUT)common-cmds.h TAGS tags cscope* $(OUTPUT)PERF-VERSION-FILE \
 		$(OUTPUT)FEATURE-DUMP $(OUTPUT)util/*-bison* $(OUTPUT)util/*-flex* \
diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index b650ce8864ed..691c7a7fc463 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -93,6 +93,7 @@ make_no_libbpf	    := NO_LIBBPF=1
 make_libbpf_dynamic := LIBBPF_DYNAMIC=1
 make_no_libbpf_DEBUG := NO_LIBBPF=1 DEBUG=1
 make_no_libllvm     := NO_LIBLLVM=1
+make_libllvm_dynamic := NO_LIBLLVM=1 LIBLLVM_DYNAMIC=1
 make_with_babeltrace:= LIBBABELTRACE=1
 make_with_coresight := CORESIGHT=1
 make_no_sdt	    := NO_SDT=1
@@ -162,6 +163,7 @@ run += make_no_auxtrace
 run += make_no_libbpf
 run += make_no_libbpf_DEBUG
 run += make_no_libllvm
+run += make_libllvm_dynamic
 run += make_no_sdt
 run += make_no_syscall_tbl
 run += make_with_babeltrace
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 4be313cd115a..8cc9b08790a3 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -27,6 +27,7 @@ perf-util-y += find_bit.o
 perf-util-y += levenshtein.o
 perf-util-$(CONFIG_LIBBFD) += libbfd.o
 perf-util-y += llvm.o
+perf-util-y += llvm-c-helpers.o
 perf-util-y += mmap.o
 perf-util-y += memswap.o
 perf-util-y += parse-events.o
@@ -249,7 +250,6 @@ perf-util-$(CONFIG_CXX_DEMANGLE) += demangle-cxx.o
 perf-util-y += demangle-ocaml.o
 perf-util-y += demangle-java.o
 perf-util-y += demangle-rust-v0.o
-perf-util-$(CONFIG_LIBLLVM) += llvm-c-helpers.o
 
 CFLAGS_demangle-rust-v0.o += -Wno-shadow -Wno-declaration-after-statement \
     -Wno-switch-default -Wno-switch-enum -Wno-missing-field-initializers
diff --git a/tools/perf/util/llvm-c-helpers.cpp b/tools/perf/util/llvm-c-helpers.cpp
index 004081bd12c9..5a6f76e6b705 100644
--- a/tools/perf/util/llvm-c-helpers.cpp
+++ b/tools/perf/util/llvm-c-helpers.cpp
@@ -5,17 +5,23 @@
  * macros (e.g. noinline) that conflict with compiler builtins used
  * by LLVM.
  */
+#ifdef HAVE_LIBLLVM_SUPPORT
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-parameter"  /* Needed for LLVM <= 15 */
 #include <llvm/DebugInfo/Symbolize/Symbolize.h>
 #include <llvm/Support/TargetSelect.h>
 #pragma GCC diagnostic pop
+#endif
 
+#if !defined(HAVE_LIBLLVM_SUPPORT) || defined(HAVE_LIBLLVM_DYNAMIC)
+#include <dlfcn.h>
+#endif
 #include <inttypes.h>
 #include <stdio.h>
 #include <sys/types.h>
 #include <linux/compiler.h>
 extern "C" {
+#include "debug.h"
 #include <linux/zalloc.h>
 }
 #include "llvm-c-helpers.h"
@@ -23,14 +29,33 @@ extern "C" {
 extern "C"
 char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name);
 
+#ifdef HAVE_LIBLLVM_SUPPORT
 using namespace llvm;
 using llvm::symbolize::LLVMSymbolizer;
+#endif
+
+#if !defined(HAVE_LIBLLVM_SUPPORT) && defined(HAVE_LIBLLVM_DYNAMIC)
+static void *perf_llvm_c_helpers_dll_handle(void)
+{
+	static bool dll_handle_init;
+	static void *dll_handle;
+
+	if (!dll_handle_init) {
+		dll_handle_init = true;
+		dll_handle = dlopen("libperf-llvm.so", RTLD_LAZY);
+		if (!dll_handle)
+			pr_debug("dlopen failed for libperf-llvm.so\n");
+	}
+	return dll_handle;
+}
+#endif
 
 /*
  * Allocate a static LLVMSymbolizer, which will live to the end of the program.
  * Unlike the bfd paths, LLVMSymbolizer has its own cache, so we do not need
  * to store anything in the dso struct.
  */
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 static LLVMSymbolizer *get_symbolizer()
 {
 	static LLVMSymbolizer *instance = nullptr;
@@ -49,8 +74,10 @@ static LLVMSymbolizer *get_symbolizer()
 	}
 	return instance;
 }
+#endif
 
 /* Returns 0 on error, 1 on success. */
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 static int extract_file_and_line(const DILineInfo &line_info, char **file,
 				 unsigned int *line)
 {
@@ -69,13 +96,15 @@ static int extract_file_and_line(const DILineInfo &line_info, char **file,
 		*line = line_info.Line;
 	return 1;
 }
+#endif
 
 extern "C"
-int llvm_addr2line(const char *dso_name, u64 addr,
-		   char **file, unsigned int *line,
-		   bool unwind_inlines,
-		   llvm_a2l_frame **inline_frames)
+int llvm_addr2line(const char *dso_name __maybe_unused, u64 addr __maybe_unused,
+		   char **file __maybe_unused, unsigned int *line __maybe_unused,
+		   bool unwind_inlines __maybe_unused,
+		   llvm_a2l_frame **inline_frames __maybe_unused)
 {
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 	LLVMSymbolizer *symbolizer = get_symbolizer();
 	object::SectionedAddress sectioned_addr = {
 		addr,
@@ -135,8 +164,33 @@ int llvm_addr2line(const char *dso_name, u64 addr,
 			return 0;
 		return extract_file_and_line(*res_or_err, file, line);
 	}
+#elif defined(HAVE_LIBLLVM_DYNAMIC)
+	static bool fn_init;
+	static int (*fn)(const char *dso_name, u64 addr,
+			 char **file, unsigned int *line,
+			 bool unwind_inlines,
+			 llvm_a2l_frame **inline_frames);
+
+	if (!fn_init) {
+		void * handle = perf_llvm_c_helpers_dll_handle();
+
+		if (!handle)
+			return 0;
+
+		fn = reinterpret_cast<decltype(fn)>(dlsym(handle, "llvm_addr2line"));
+		if (!fn)
+			pr_debug("dlsym failed for llvm_addr2line\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return 0;
+	return fn(dso_name, addr, file, line, unwind_inlines, inline_frames);
+#else
+	return 0;
+#endif
 }
 
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 static char *
 make_symbol_relative_string(struct dso *dso, const char *sym_name,
 			    u64 addr, u64 base_addr)
@@ -158,10 +212,13 @@ make_symbol_relative_string(struct dso *dso, const char *sym_name,
 			return strdup(sym_name);
 	}
 }
+#endif
 
 extern "C"
-char *llvm_name_for_code(struct dso *dso, const char *dso_name, u64 addr)
+char *llvm_name_for_code(struct dso *dso __maybe_unused, const char *dso_name __maybe_unused,
+			 u64 addr __maybe_unused)
 {
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 	LLVMSymbolizer *symbolizer = get_symbolizer();
 	object::SectionedAddress sectioned_addr = {
 		addr,
@@ -175,11 +232,34 @@ char *llvm_name_for_code(struct dso *dso, const char *dso_name, u64 addr)
 	return make_symbol_relative_string(
 		dso, res_or_err->FunctionName.c_str(),
 		addr, res_or_err->StartAddress ? *res_or_err->StartAddress : 0);
+#elif defined(HAVE_LIBLLVM_DYNAMIC)
+	static bool fn_init;
+	static char *(*fn)(struct dso *dso, const char *dso_name, u64 addr);
+
+	if (!fn_init) {
+		void * handle = perf_llvm_c_helpers_dll_handle();
+
+		if (!handle)
+			return NULL;
+
+		fn = reinterpret_cast<decltype(fn)>(dlsym(handle, "llvm_name_for_code"));
+		if (!fn)
+			pr_debug("dlsym failed for llvm_name_for_code\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return NULL;
+	return fn(dso, dso_name, addr);
+#else
+	return 0;
+#endif
 }
 
 extern "C"
-char *llvm_name_for_data(struct dso *dso, const char *dso_name, u64 addr)
+char *llvm_name_for_data(struct dso *dso __maybe_unused, const char *dso_name __maybe_unused,
+			 u64 addr __maybe_unused)
 {
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 	LLVMSymbolizer *symbolizer = get_symbolizer();
 	object::SectionedAddress sectioned_addr = {
 		addr,
@@ -193,4 +273,25 @@ char *llvm_name_for_data(struct dso *dso, const char *dso_name, u64 addr)
 	return make_symbol_relative_string(
 		dso, res_or_err->Name.c_str(),
 		addr, res_or_err->Start);
+#elif defined(HAVE_LIBLLVM_DYNAMIC)
+	static bool fn_init;
+	static char *(*fn)(struct dso *dso, const char *dso_name, u64 addr);
+
+	if (!fn_init) {
+		void * handle = perf_llvm_c_helpers_dll_handle();
+
+		if (!handle)
+			return NULL;
+
+		fn = reinterpret_cast<decltype(fn)>(dlsym(handle, "llvm_name_for_data"));
+		if (!fn)
+			pr_debug("dlsym failed for llvm_name_for_data\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return NULL;
+	return fn(dso, dso_name, addr);
+#else
+	return 0;
+#endif
 }
diff --git a/tools/perf/util/llvm.c b/tools/perf/util/llvm.c
index 565cad1969e5..10def66ce8b2 100644
--- a/tools/perf/util/llvm.c
+++ b/tools/perf/util/llvm.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include "llvm.h"
+#include "llvm-c-helpers.h"
 #include "annotate.h"
 #include "debug.h"
 #include "dso.h"
@@ -7,18 +8,244 @@
 #include "namespaces.h"
 #include "srcline.h"
 #include "symbol.h"
+#include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
 #include <unistd.h>
 #include <linux/zalloc.h>
 
-#ifdef HAVE_LIBLLVM_SUPPORT
-#include "llvm-c-helpers.h"
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 #include <llvm-c/Disassembler.h>
 #include <llvm-c/Target.h>
+#else
+typedef void *LLVMDisasmContextRef;
+typedef int (*LLVMOpInfoCallback)(void *dis_info, uint64_t pc, uint64_t offset,
+				  uint64_t op_size, uint64_t inst_size,
+				  int tag_type, void *tag_buf);
+typedef const char *(*LLVMSymbolLookupCallback)(void *dis_info,
+						uint64_t reference_value,
+						uint64_t *reference_type,
+						uint64_t reference_pc,
+						const char **reference_name);
+#define LLVMDisassembler_ReferenceType_InOut_None 0
+#define LLVMDisassembler_ReferenceType_In_Branch 1
+#define LLVMDisassembler_ReferenceType_In_PCrel_Load 2
+#define LLVMDisassembler_Option_PrintImmHex 2
+#define LLVMDisassembler_Option_AsmPrinterVariant 4
+const char *llvm_targets[] = {
+	"AMDGPU",
+	"ARM",
+	"AVR",
+	"BPF",
+	"Hexagon",
+	"Lanai",
+	"LoongArch",
+	"Mips",
+	"MSP430",
+	"NVPTX",
+	"PowerPC",
+	"RISCV",
+	"Sparc",
+	"SystemZ",
+	"VE",
+	"WebAssembly",
+	"X86",
+	"XCore",
+	"M68k",
+	"Xtensa",
+};
+#endif
+
+#if !defined(HAVE_LIBLLVM_SUPPORT) || defined(HAVE_LIBLLVM_DYNAMIC)
+static void *perf_llvm_dll_handle(void)
+{
+	static bool dll_handle_init;
+	static void *dll_handle;
+
+	if (!dll_handle_init) {
+		dll_handle_init = true;
+		dll_handle = dlopen("libLLVM.so", RTLD_LAZY);
+		if (!dll_handle)
+			pr_debug("dlopen failed for libLLVM.so\n");
+	}
+	return dll_handle;
+}
+#endif
+
+#if !defined(HAVE_LIBLLVM_SUPPORT) || defined(HAVE_LIBLLVM_DYNAMIC)
+static void *perf_llvm_dll_fun(const char *fmt, const char *target)
+{
+	char buf[128];
+	void *fn;
+
+	snprintf(buf, sizeof(buf), fmt, target);
+	fn = dlsym(perf_llvm_dll_handle(), buf);
+	if (!fn)
+		pr_debug("dlsym failed for %s\n", buf);
+
+	return fn;
+}
+#endif
+
+static void perf_LLVMInitializeAllTargetInfos(void)
+{
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
+	LLVMInitializeAllTargetInfos();
+#else
+	/* LLVMInitializeAllTargetInfos is a header file function not available as a symbol. */
+	static bool done_init;
+
+	if (done_init)
+		return;
+
+	for (size_t i = 0; i < ARRAY_SIZE(llvm_targets); i++) {
+		void (*fn)(void) = perf_llvm_dll_fun("LLVMInitialize%sTargetInfo",
+						     llvm_targets[i]);
+
+		if (!fn)
+			continue;
+		fn();
+	}
+	done_init = true;
+#endif
+}
+
+static void perf_LLVMInitializeAllTargetMCs(void)
+{
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
+	LLVMInitializeAllTargetMCs();
+#else
+	/* LLVMInitializeAllTargetMCs is a header file function not available as a symbol. */
+	static bool done_init;
+
+	if (done_init)
+		return;
+
+	for (size_t i = 0; i < ARRAY_SIZE(llvm_targets); i++) {
+		void (*fn)(void) = perf_llvm_dll_fun("LLVMInitialize%sTargetMC",
+						     llvm_targets[i]);
+
+		if (!fn)
+			continue;
+		fn();
+	}
+	done_init = true;
+#endif
+}
+
+static void perf_LLVMInitializeAllDisassemblers(void)
+{
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
+	LLVMInitializeAllDisassemblers();
+#else
+	/* LLVMInitializeAllDisassemblers is a header file function not available as a symbol. */
+	static bool done_init;
+
+	if (done_init)
+		return;
+
+	for (size_t i = 0; i < ARRAY_SIZE(llvm_targets); i++) {
+		void (*fn)(void) = perf_llvm_dll_fun("LLVMInitialize%sDisassembler",
+						     llvm_targets[i]);
+
+		if (!fn)
+			continue;
+		fn();
+	}
+	done_init = true;
+#endif
+}
+
+static LLVMDisasmContextRef perf_LLVMCreateDisasm(const char *triple_name, void *dis_info,
+						int tag_type, LLVMOpInfoCallback get_op_info,
+						LLVMSymbolLookupCallback symbol_lookup)
+{
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
+	return LLVMCreateDisasm(triple_name, dis_info, tag_type, get_op_info, symbol_lookup);
+#else
+	static bool fn_init;
+	static LLVMDisasmContextRef (*fn)(const char *triple_name, void *dis_info,
+					int tag_type, LLVMOpInfoCallback get_op_info,
+					LLVMSymbolLookupCallback symbol_lookup);
+
+	if (!fn_init) {
+		fn = dlsym(perf_llvm_dll_handle(), "LLVMCreateDisasm");
+		if (!fn)
+			pr_debug("dlsym failed for LLVMCreateDisasm\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return NULL;
+	return fn(triple_name, dis_info, tag_type, get_op_info, symbol_lookup);
+#endif
+}
+
+static int perf_LLVMSetDisasmOptions(LLVMDisasmContextRef context, uint64_t options)
+{
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
+	return LLVMSetDisasmOptions(context, options);
+#else
+	static bool fn_init;
+	static int (*fn)(LLVMDisasmContextRef context, uint64_t options);
+
+	if (!fn_init) {
+		fn = dlsym(perf_llvm_dll_handle(), "LLVMSetDisasmOptions");
+		if (!fn)
+			pr_debug("dlsym failed for LLVMSetDisasmOptions\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return 0;
+	return fn(context, options);
+#endif
+}
+
+static size_t perf_LLVMDisasmInstruction(LLVMDisasmContextRef context, uint8_t *bytes,
+					uint64_t bytes_size, uint64_t pc,
+					char *out_string, size_t out_string_size)
+{
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
+	return LLVMDisasmInstruction(context, bytes, bytes_size, pc, out_string, out_string_size);
+#else
+	static bool fn_init;
+	static int (*fn)(LLVMDisasmContextRef context, uint8_t *bytes,
+			uint64_t bytes_size, uint64_t pc,
+			char *out_string, size_t out_string_size);
+
+	if (!fn_init) {
+		fn = dlsym(perf_llvm_dll_handle(), "LLVMDisasmInstruction");
+		if (!fn)
+			pr_debug("dlsym failed for LLVMDisasmInstruction\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return 0;
+	return fn(context, bytes, bytes_size, pc, out_string, out_string_size);
+#endif
+}
+
+static void perf_LLVMDisasmDispose(LLVMDisasmContextRef context)
+{
+#if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
+	LLVMDisasmDispose(context);
+#else
+	static bool fn_init;
+	static int (*fn)(LLVMDisasmContextRef context);
+
+	if (!fn_init) {
+		fn = dlsym(perf_llvm_dll_handle(), "LLVMDisasmDispose");
+		if (!fn)
+			pr_debug("dlsym failed for LLVMDisasmDispose\n");
+		fn_init = true;
+	}
+	if (!fn)
+		return;
+	fn(context);
 #endif
+}
+
 
-#ifdef HAVE_LIBLLVM_SUPPORT
 static void free_llvm_inline_frames(struct llvm_a2l_frame *inline_frames,
 				    int num_frames)
 {
@@ -30,14 +257,12 @@ static void free_llvm_inline_frames(struct llvm_a2l_frame *inline_frames,
 		zfree(&inline_frames);
 	}
 }
-#endif
 
 int llvm__addr2line(const char *dso_name __maybe_unused, u64 addr __maybe_unused,
 		     char **file __maybe_unused, unsigned int *line __maybe_unused,
 		     struct dso *dso __maybe_unused, bool unwind_inlines __maybe_unused,
 		     struct inline_node *node __maybe_unused, struct symbol *sym __maybe_unused)
 {
-#ifdef HAVE_LIBLLVM_SUPPORT
 	struct llvm_a2l_frame *inline_frames = NULL;
 	int num_frames = llvm_addr2line(dso_name, addr, file, line,
 					node && unwind_inlines, &inline_frames);
@@ -65,9 +290,6 @@ int llvm__addr2line(const char *dso_name __maybe_unused, u64 addr __maybe_unused
 	free_llvm_inline_frames(inline_frames, num_frames);
 
 	return num_frames;
-#else
-	return -1;
-#endif
 }
 
 static void init_llvm(void)
@@ -75,9 +297,9 @@ static void init_llvm(void)
 	static bool init;
 
 	if (!init) {
-		LLVMInitializeAllTargetInfos();
-		LLVMInitializeAllTargetMCs();
-		LLVMInitializeAllDisassemblers();
+		perf_LLVMInitializeAllTargetInfos();
+		perf_LLVMInitializeAllTargetMCs();
+		perf_LLVMInitializeAllDisassemblers();
 		init = true;
 	}
 }
@@ -90,7 +312,6 @@ static void init_llvm(void)
  * should add some textual annotation for after the instruction. The caller
  * will use this information to add the actual annotation.
  */
-#ifdef HAVE_LIBLLVM_SUPPORT
 struct symbol_lookup_storage {
 	u64 branch_addr;
 	u64 pcrel_load_addr;
@@ -111,12 +332,10 @@ symbol_lookup_callback(void *disinfo, uint64_t value,
 	*ref_type = LLVMDisassembler_ReferenceType_InOut_None;
 	return NULL;
 }
-#endif
 
 int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 			     struct annotate_args *args __maybe_unused)
 {
-#ifdef HAVE_LIBLLVM_SUPPORT
 	struct annotation *notes = symbol__annotation(sym);
 	struct map *map = args->ms.map;
 	struct dso *dso = map__dso(map);
@@ -149,15 +368,15 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 	if (arch__is(args->arch, "x86")) {
 		const char *triplet = is_64bit ? "x86_64-pc-linux" : "i686-pc-linux";
 
-		disasm = LLVMCreateDisasm(triplet, &storage, /*tag_type=*/0,
-					  /*get_op_info=*/NULL, symbol_lookup_callback);
+		disasm = perf_LLVMCreateDisasm(triplet, &storage, /*tag_type=*/0,
+					       /*get_op_info=*/NULL, symbol_lookup_callback);
 	} else {
 		char triplet[64];
 
 		scnprintf(triplet, sizeof(triplet), "%s-linux-gnu",
 			  args->arch->name);
-		disasm = LLVMCreateDisasm(triplet, &storage, /*tag_type=*/0,
-					  /*get_op_info=*/NULL, symbol_lookup_callback);
+		disasm = perf_LLVMCreateDisasm(triplet, &storage, /*tag_type=*/0,
+					       /*get_op_info=*/NULL, symbol_lookup_callback);
 	}
 
 	if (disasm == NULL)
@@ -165,8 +384,7 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 
 	if (args->options->disassembler_style &&
 	    !strcmp(args->options->disassembler_style, "intel"))
-		LLVMSetDisasmOptions(disasm,
-				     LLVMDisassembler_Option_AsmPrinterVariant);
+		perf_LLVMSetDisasmOptions(disasm, LLVMDisassembler_Option_AsmPrinterVariant);
 
 	/*
 	 * This needs to be set after AsmPrinterVariant, due to a bug in LLVM;
@@ -174,7 +392,7 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 	 * forget about the PrintImmHex flag (which is applied before if both
 	 * are given to the same call).
 	 */
-	LLVMSetDisasmOptions(disasm, LLVMDisassembler_Option_PrintImmHex);
+	perf_LLVMSetDisasmOptions(disasm, LLVMDisassembler_Option_PrintImmHex);
 
 	/* add the function address and name */
 	scnprintf(disasm_buf, sizeof(disasm_buf), "%#"PRIx64" <%s>:",
@@ -203,9 +421,9 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 		 * LLVM's API has the code be disassembled as non-const, cast
 		 * here as we may be disassembling from mapped read-only memory.
 		 */
-		ins_len = LLVMDisasmInstruction(disasm, (u8 *)(buf + offset),
-						buf_len - offset, pc,
-						disasm_buf, sizeof(disasm_buf));
+		ins_len = perf_LLVMDisasmInstruction(disasm, (u8 *)(buf + offset),
+						     buf_len - offset, pc,
+						     disasm_buf, sizeof(disasm_buf));
 		if (ins_len == 0)
 			goto err;
 		disasm_len = strlen(disasm_buf);
@@ -261,13 +479,8 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
 	ret = 0;
 
 err:
-	LLVMDisasmDispose(disasm);
+	perf_LLVMDisasmDispose(disasm);
 	free(code_buf);
 	free(line_storage);
 	return ret;
-#else // HAVE_LIBLLVM_SUPPORT
-	pr_debug("The LLVM disassembler isn't linked in for %s in %s\n",
-		 sym->name, filename);
-	return -1;
-#endif
 }
-- 
2.51.0.618.g983fd99d29-goog

For a function like llvm_addr2line having the libperf-llvm.so exported
symbol named llvm_addr2line meant that the perf llvm_addr2line could
sometimes erroneously be returned. This led to infinite recursion and
eventual stack overflow. To avoid this conflict add a new
BUILDING_PERF_LLVMSO when libperf-llvm.so is being built and use it to
alter the behavior of MANGLE_PERF_LLVM_API, a macro that prefixes the
name when libperf-llvm.so is being built. The prefixed named avoids
the name collision.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.perf           |  3 ++-
 tools/perf/util/llvm-c-helpers.cpp | 29 ++++++++++++++++++-----------
 tools/perf/util/llvm-c-helpers.h   | 24 ++++++++++++++++--------
 3 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index fb888702bace..7e6054072cf1 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -1002,7 +1002,8 @@ $(LIBSYMBOL)-clean:
 	$(Q)$(RM) -r -- $(LIBSYMBOL_OUTPUT)
 
 ifdef LIBLLVM_DYNAMIC
-LIBPERF_LLVM_CXXFLAGS := $(call filter-out,-DHAVE_LIBLLVM_DYNAMIC,$(CXXFLAGS)) -DHAVE_LIBLLVM_SUPPORT
+LIBPERF_LLVM_CXXFLAGS := $(call filter-out,-DHAVE_LIBLLVM_DYNAMIC,$(CXXFLAGS))
+LIBPERF_LLVM_CXXFLAGS += -DHAVE_LIBLLVM_SUPPORT -DBUILDING_PERF_LLVMSO
 LIBPERF_LLVM_LIBS = -L$(shell $(LLVM_CONFIG) --libdir) $(LIBLLVM) -lstdc++
 
 $(OUTPUT)$(LIBPERF_LLVM): util/llvm-c-helpers.cpp
diff --git a/tools/perf/util/llvm-c-helpers.cpp b/tools/perf/util/llvm-c-helpers.cpp
index 5a6f76e6b705..8cea380be5c2 100644
--- a/tools/perf/util/llvm-c-helpers.cpp
+++ b/tools/perf/util/llvm-c-helpers.cpp
@@ -99,10 +99,12 @@ static int extract_file_and_line(const DILineInfo &line_info, char **file,
 #endif
 
 extern "C"
-int llvm_addr2line(const char *dso_name __maybe_unused, u64 addr __maybe_unused,
-		   char **file __maybe_unused, unsigned int *line __maybe_unused,
-		   bool unwind_inlines __maybe_unused,
-		   llvm_a2l_frame **inline_frames __maybe_unused)
+int MANGLE_PERF_LLVM_API(llvm_addr2line)(const char *dso_name __maybe_unused,
+                                         u64 addr __maybe_unused,
+                                         char **file __maybe_unused,
+                                         unsigned int *line __maybe_unused,
+                                         bool unwind_inlines __maybe_unused,
+                                         llvm_a2l_frame **inline_frames __maybe_unused)
 {
 #if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 	LLVMSymbolizer *symbolizer = get_symbolizer();
@@ -177,7 +179,8 @@ int llvm_addr2line(const char *dso_name __maybe_unused, u64 addr __maybe_unused,
 		if (!handle)
 			return 0;
 
-		fn = reinterpret_cast<decltype(fn)>(dlsym(handle, "llvm_addr2line"));
+		fn = reinterpret_cast<decltype(fn)>(
+			dlsym(handle, MANGLE_PERF_LLVM_API_STR(llvm_addr2line)));
 		if (!fn)
 			pr_debug("dlsym failed for llvm_addr2line\n");
 		fn_init = true;
@@ -215,8 +218,9 @@ make_symbol_relative_string(struct dso *dso, const char *sym_name,
 #endif
 
 extern "C"
-char *llvm_name_for_code(struct dso *dso __maybe_unused, const char *dso_name __maybe_unused,
-			 u64 addr __maybe_unused)
+char *MANGLE_PERF_LLVM_API(llvm_name_for_code)(struct dso *dso __maybe_unused,
+					       const char *dso_name __maybe_unused,
+					       u64 addr __maybe_unused)
 {
 #if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 	LLVMSymbolizer *symbolizer = get_symbolizer();
@@ -242,7 +246,8 @@ char *llvm_name_for_code(struct dso *dso __maybe_unused, const char *dso_name __
 		if (!handle)
 			return NULL;
 
-		fn = reinterpret_cast<decltype(fn)>(dlsym(handle, "llvm_name_for_code"));
+		fn = reinterpret_cast<decltype(fn)>(
+			dlsym(handle, MANGLE_PERF_LLVM_API_STR(llvm_name_for_code)));
 		if (!fn)
 			pr_debug("dlsym failed for llvm_name_for_code\n");
 		fn_init = true;
@@ -256,8 +261,9 @@ char *llvm_name_for_code(struct dso *dso __maybe_unused, const char *dso_name __
 }
 
 extern "C"
-char *llvm_name_for_data(struct dso *dso __maybe_unused, const char *dso_name __maybe_unused,
-			 u64 addr __maybe_unused)
+char *MANGLE_PERF_LLVM_API(llvm_name_for_data)(struct dso *dso __maybe_unused,
+					       const char *dso_name __maybe_unused,
+					       u64 addr __maybe_unused)
 {
 #if defined(HAVE_LIBLLVM_SUPPORT) && !defined(HAVE_LIBLLVM_DYNAMIC)
 	LLVMSymbolizer *symbolizer = get_symbolizer();
@@ -283,7 +289,8 @@ char *llvm_name_for_data(struct dso *dso __maybe_unused, const char *dso_name __
 		if (!handle)
 			return NULL;
 
-		fn = reinterpret_cast<decltype(fn)>(dlsym(handle, "llvm_name_for_data"));
+		fn = reinterpret_cast<decltype(fn)>(
+			dlsym(handle, MANGLE_PERF_LLVM_API_STR(llvm_name_for_data)));
 		if (!fn)
 			pr_debug("dlsym failed for llvm_name_for_data\n");
 		fn_init = true;
diff --git a/tools/perf/util/llvm-c-helpers.h b/tools/perf/util/llvm-c-helpers.h
index d2b99637a28a..cfcfd540cdae 100644
--- a/tools/perf/util/llvm-c-helpers.h
+++ b/tools/perf/util/llvm-c-helpers.h
@@ -13,6 +13,14 @@
 extern "C" {
 #endif
 
+/* Support name mangling so that libperf_llvm.so's names don't match those in perf. */
+#ifdef BUILDING_PERF_LLVMSO
+#define MANGLE_PERF_LLVM_API(x) PERF_LLVM_SO_ ## x
+#else
+#define MANGLE_PERF_LLVM_API(x) x
+#endif
+#define MANGLE_PERF_LLVM_API_STR(x) "PERF_LLVM_SO_" #x
+
 struct dso;
 
 struct llvm_a2l_frame {
@@ -37,12 +45,12 @@ struct llvm_a2l_frame {
  * a newly allocated array with that length. The caller is then responsible
  * for freeing both the strings and the array itself.
  */
-int llvm_addr2line(const char* dso_name,
-                   u64 addr,
-                   char** file,
-                   unsigned int* line,
-                   bool unwind_inlines,
-                   struct llvm_a2l_frame** inline_frames);
+int MANGLE_PERF_LLVM_API(llvm_addr2line)(const char *dso_name,
+					 u64 addr,
+					 char **file,
+					 unsigned int *line,
+					 bool unwind_inlines,
+					 struct llvm_a2l_frame **inline_frames);
 
 /*
  * Simple symbolizers for addresses; will convert something like
@@ -50,8 +58,8 @@ int llvm_addr2line(const char* dso_name,
  *
  * The returned value must be freed by the caller, with free().
  */
-char *llvm_name_for_code(struct dso *dso, const char *dso_name, u64 addr);
-char *llvm_name_for_data(struct dso *dso, const char *dso_name, u64 addr);
+char *MANGLE_PERF_LLVM_API(llvm_name_for_code)(struct dso *dso, const char *dso_name, u64 addr);
+char *MANGLE_PERF_LLVM_API(llvm_name_for_data)(struct dso *dso, const char *dso_name, u64 addr);
 
 #ifdef __cplusplus
 }
-- 
2.51.0.618.g983fd99d29-goog