[PATCH v2 0/4] Support for llvm-addr2line

[PATCH v2 0/4] Support for llvm-addr2line

[Ian Rogers]

The addr2line command is started and then addresses piped to it. In
order to determine the end of a addr2lines output a ',' it output with
an expectation to get '??\n??:0\n' as a reply. llvm-addr2line differs
in that ',' generates a reply of ','.

The approach detects and then caches the addr2line style. When records
are read the sentinel is detected appropriately.

Comparing the output there is a little more inline data on my machine
with llvm-addr2line:
$ sudo perf record -a -g sleep 1
$ sudo perf report --addr2line=addr2line > a.txt
$ sudo perf report --addr2line=llvm-addr2line > b.txt
$ wc -l a.txt b.txt
  12386 a.txt
  12477 b.txt

Some other small changes, switching to the api/io code to avoid file
streams wrapping the command's stdin/stdout. Ignore SIGPIPE for when
addr2line exits and writes fail.

v2. Address review comments from Arnaldo and Namhyung, fixing a
    realloc error path, argument ordering and a comment.

Ian Rogers (4):
  tools api: Add io__getline
  perf srcline: Simplify addr2line subprocess
  perf srcline: Support for llvm-addr2line
  perf srcline: Avoid addr2line SIGPIPEs

 tools/lib/api/io.h        |  45 ++++++++++
 tools/perf/tests/api-io.c |  36 ++++++++
 tools/perf/util/srcline.c | 171 +++++++++++++++++++++++---------------
 3 files changed, 184 insertions(+), 68 deletions(-)

-- 
2.40.0.348.gf938b09366-goog

[PATCH v2 1/4] tools api: Add io__getline

[Ian Rogers]

Reads a line to allocated memory up to a newline following the getline
API.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/api/io.h        | 45 +++++++++++++++++++++++++++++++++++++++
 tools/perf/tests/api-io.c | 36 +++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+)

diff --git a/tools/lib/api/io.h b/tools/lib/api/io.h
index 777c20f6b604..d5e8cf0dada0 100644
--- a/tools/lib/api/io.h
+++ b/tools/lib/api/io.h
@@ -7,7 +7,9 @@
 #ifndef __API_IO__
 #define __API_IO__
 
+#include <errno.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 struct io {
@@ -112,4 +114,47 @@ static inline int io__get_dec(struct io *io, __u64 *dec)
 	}
 }
 
+/* Read up to and including the first newline following the pattern of getline. */
+static inline ssize_t io__getline(struct io *io, char **line_out, size_t *line_len_out)
+{
+	char buf[128];
+	int buf_pos = 0;
+	char *line = NULL, *temp;
+	size_t line_len = 0;
+	int ch = 0;
+
+	/* TODO: reuse previously allocated memory. */
+	free(*line_out);
+	while (ch != '\n') {
+		ch = io__get_char(io);
+
+		if (ch < 0)
+			break;
+
+		if (buf_pos == sizeof(buf)) {
+			temp = realloc(line, line_len + sizeof(buf));
+			if (!temp)
+				goto err_out;
+			line = temp;
+			memcpy(&line[line_len], buf, sizeof(buf));
+			line_len += sizeof(buf);
+			buf_pos = 0;
+		}
+		buf[buf_pos++] = (char)ch;
+	}
+	temp = realloc(line, line_len + buf_pos + 1);
+	if (!temp)
+		goto err_out;
+	line = temp;
+	memcpy(&line[line_len], buf, buf_pos);
+	line[line_len + buf_pos] = '\0';
+	line_len += buf_pos;
+	*line_out = line;
+	*line_len_out = line_len;
+	return line_len;
+err_out:
+	free(line);
+	return -ENOMEM;
+}
+
 #endif /* __API_IO__ */
diff --git a/tools/perf/tests/api-io.c b/tools/perf/tests/api-io.c
index e91cf2c127f1..6aea84ca6673 100644
--- a/tools/perf/tests/api-io.c
+++ b/tools/perf/tests/api-io.c
@@ -289,6 +289,40 @@ static int test_get_dec(void)
 	return ret;
 }
 
+static int test_get_line(void)
+{
+	char path[PATH_MAX];
+	struct io io;
+	char test_string[1024];
+	char *line = NULL;
+	size_t i, line_len = 0;
+	size_t buf_size = 128;
+	int ret = 0;
+
+	for (i = 0; i < 512; i++)
+		test_string[i] = 'a';
+	test_string[512] = '\n';
+	for (i = 513; i < 1023; i++)
+		test_string[i] = 'b';
+	test_string[1023] = '\0';
+
+	if (setup_test(path, test_string, buf_size, &io))
+		return -1;
+
+	EXPECT_EQUAL((int)io__getline(&io, &line, &line_len), 513);
+	EXPECT_EQUAL((int)strlen(line), 513);
+	for (i = 0; i < 512; i++)
+		EXPECT_EQUAL(line[i], 'a');
+	EXPECT_EQUAL(line[512], '\n');
+	EXPECT_EQUAL((int)io__getline(&io, &line, &line_len), 510);
+	for (i = 0; i < 510; i++)
+		EXPECT_EQUAL(line[i], 'b');
+
+	free(line);
+	cleanup_test(path, &io);
+	return ret;
+}
+
 static int test__api_io(struct test_suite *test __maybe_unused,
 			int subtest __maybe_unused)
 {
@@ -300,6 +334,8 @@ static int test__api_io(struct test_suite *test __maybe_unused,
 		ret = TEST_FAIL;
 	if (test_get_dec())
 		ret = TEST_FAIL;
+	if (test_get_line())
+		ret = TEST_FAIL;
 	return ret;
 }
 
-- 
2.40.0.348.gf938b09366-goog

[PATCH v2 2/4] perf srcline: Simplify addr2line subprocess

[Ian Rogers]

Don't wrap stdin and stdout of subprocess with streams, use the api/io
library for buffering.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/srcline.c | 103 ++++++++++++++------------------------
 1 file changed, 38 insertions(+), 65 deletions(-)

diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index f0a96a834e4b..5339ab4c5e12 100644
--- a/tools/perf/util/srcline.c
+++ b/tools/perf/util/srcline.c
@@ -10,6 +10,8 @@
 #include <linux/string.h>
 #include <linux/zalloc.h>
 
+#include <api/io.h>
+
 #include "util/dso.h"
 #include "util/debug.h"
 #include "util/callchain.h"
@@ -366,12 +368,6 @@ void dso__free_a2l(struct dso *dso)
 
 #else /* HAVE_LIBBFD_SUPPORT */
 
-struct a2l_subprocess {
-	struct child_process addr2line;
-	FILE *to_child;
-	FILE *from_child;
-};
-
 static int filename_split(char *filename, unsigned int *line_nr)
 {
 	char *sep;
@@ -393,28 +389,18 @@ static int filename_split(char *filename, unsigned int *line_nr)
 	return 0;
 }
 
-static void addr2line_subprocess_cleanup(struct a2l_subprocess *a2l)
+static void addr2line_subprocess_cleanup(struct child_process *a2l)
 {
-	if (a2l->addr2line.pid != -1) {
-		kill(a2l->addr2line.pid, SIGKILL);
-		finish_command(&a2l->addr2line); /* ignore result, we don't care */
-		a2l->addr2line.pid = -1;
-	}
-
-	if (a2l->to_child != NULL) {
-		fclose(a2l->to_child);
-		a2l->to_child = NULL;
-	}
-
-	if (a2l->from_child != NULL) {
-		fclose(a2l->from_child);
-		a2l->from_child = NULL;
+	if (a2l->pid != -1) {
+		kill(a2l->pid, SIGKILL);
+		finish_command(a2l); /* ignore result, we don't care */
+		a2l->pid = -1;
 	}
 
 	free(a2l);
 }
 
-static struct a2l_subprocess *addr2line_subprocess_init(const char *addr2line_path,
+static struct child_process *addr2line_subprocess_init(const char *addr2line_path,
 							const char *binary_path)
 {
 	const char *argv[] = {
@@ -422,54 +408,34 @@ static struct a2l_subprocess *addr2line_subprocess_init(const char *addr2line_pa
 		"-e", binary_path,
 		"-i", "-f", NULL
 	};
-	struct a2l_subprocess *a2l = zalloc(sizeof(*a2l));
+	struct child_process *a2l = zalloc(sizeof(*a2l));
 	int start_command_status = 0;
 
-	if (a2l == NULL)
-		goto out;
-
-	a2l->to_child = NULL;
-	a2l->from_child = NULL;
+	if (a2l == NULL) {
+		pr_err("Failed to allocate memory for addr2line");
+		return NULL;
+	}
 
-	a2l->addr2line.pid = -1;
-	a2l->addr2line.in = -1;
-	a2l->addr2line.out = -1;
-	a2l->addr2line.no_stderr = 1;
+	a2l->pid = -1;
+	a2l->in = -1;
+	a2l->out = -1;
+	a2l->no_stderr = 1;
 
-	a2l->addr2line.argv = argv;
-	start_command_status = start_command(&a2l->addr2line);
-	a2l->addr2line.argv = NULL; /* it's not used after start_command; avoid dangling pointers */
+	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);
-		goto out;
-	}
-
-	a2l->to_child = fdopen(a2l->addr2line.in, "w");
-	if (a2l->to_child == NULL) {
-		pr_warning("could not open write-stream to addr2line (%s) of %s\n",
-			addr2line_path, binary_path);
-		goto out;
-	}
-
-	a2l->from_child = fdopen(a2l->addr2line.out, "r");
-	if (a2l->from_child == NULL) {
-		pr_warning("could not open read-stream from addr2line (%s) of %s\n",
-			addr2line_path, binary_path);
-		goto out;
+		addr2line_subprocess_cleanup(a2l);
+		return NULL;
 	}
 
 	return a2l;
-
-out:
-	if (a2l)
-		addr2line_subprocess_cleanup(a2l);
-
-	return NULL;
 }
 
-static int read_addr2line_record(struct a2l_subprocess *a2l,
+static int read_addr2line_record(struct io *io,
 				 char **function,
 				 char **filename,
 				 unsigned int *line_nr)
@@ -494,7 +460,7 @@ static int read_addr2line_record(struct a2l_subprocess *a2l,
 	if (line_nr != NULL)
 		*line_nr = 0;
 
-	if (getline(&line, &line_len, a2l->from_child) < 0 || !line_len)
+	if (io__getline(io, &line, &line_len) < 0 || !line_len)
 		goto error;
 	if (function != NULL)
 		*function = strdup(strim(line));
@@ -502,7 +468,7 @@ static int read_addr2line_record(struct a2l_subprocess *a2l,
 	zfree(&line);
 	line_len = 0;
 
-	if (getline(&line, &line_len, a2l->from_child) < 0 || !line_len)
+	if (io__getline(io, &line, &line_len) < 0 || !line_len)
 		goto error;
 
 	if (filename_split(line, line_nr == NULL ? &dummy_line_nr : line_nr) == 0) {
@@ -546,13 +512,17 @@ static int addr2line(const char *dso_name, u64 addr,
 		     struct inline_node *node,
 		     struct symbol *sym __maybe_unused)
 {
-	struct a2l_subprocess *a2l = dso->a2l;
+	struct child_process *a2l = dso->a2l;
 	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;
 
 	if (!a2l) {
 		if (!filename__has_section(dso_name, ".debug_line"))
@@ -578,13 +548,16 @@ static int addr2line(const char *dso_name, u64 addr,
 	 * though, because it may be genuinely unknown, in which case we'll get two sets of
 	 * "??"/"??:0" lines.
 	 */
-	if (fprintf(a2l->to_child, "%016"PRIx64"\n,\n", addr) < 0 || fflush(a2l->to_child) != 0) {
+	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));
 
-	switch (read_addr2line_record(a2l, &record_function, &record_filename, &record_line_nr)) {
+	switch (read_addr2line_record(&io, &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);
@@ -594,7 +567,7 @@ static int addr2line(const char *dso_name, u64 addr,
 		 * The first record was invalid, so return failure, but first read another
 		 * record, since we asked a junk question and have to clear the answer out.
 		 */
-		switch (read_addr2line_record(a2l, NULL, NULL, NULL)) {
+		switch (read_addr2line_record(&io, NULL, NULL, NULL)) {
 		case -1:
 			if (!symbol_conf.disable_add2line_warn)
 				pr_warning("%s %s: could not read delimiter record\n",
@@ -632,7 +605,7 @@ static int addr2line(const char *dso_name, u64 addr,
 	}
 
 	/* We have to read the records even if we don't care about the inline info. */
-	while ((record_status = read_addr2line_record(a2l,
+	while ((record_status = read_addr2line_record(&io,
 						      &record_function,
 						      &record_filename,
 						      &record_line_nr)) == 1) {
@@ -656,7 +629,7 @@ static int addr2line(const char *dso_name, u64 addr,
 
 void dso__free_a2l(struct dso *dso)
 {
-	struct a2l_subprocess *a2l = dso->a2l;
+	struct child_process *a2l = dso->a2l;
 
 	if (!a2l)
 		return;
-- 
2.40.0.348.gf938b09366-goog

[PATCH v2 3/4] perf srcline: Support for llvm-addr2line

[Ian Rogers]

The sentinel value differs for llvm-addr2line. Configure this once and
then detect when reading records.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/srcline.c | 74 +++++++++++++++++++++++++++++++++++----
 1 file changed, 67 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index 5339ab4c5e12..f4fcdada821b 100644
--- a/tools/perf/util/srcline.c
+++ b/tools/perf/util/srcline.c
@@ -435,7 +435,50 @@ static struct child_process *addr2line_subprocess_init(const char *addr2line_pat
 	return a2l;
 }
 
+enum a2l_style {
+	BROKEN,
+	GNU_BINUTILS,
+	LLVM,
+};
+
+static enum a2l_style addr2line_configure(struct child_process *a2l)
+{
+	static bool cached;
+	static enum a2l_style style;
+
+	if (!cached) {
+		char buf[128];
+		struct io io;
+		int ch;
+
+		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;
+		} else if (ch == '?') {
+			style = GNU_BINUTILS;
+			cached = true;
+		} else {
+			style = BROKEN;
+		}
+		do {
+			ch = io__get_char(&io);
+		} while (ch > 0 && ch != '\n');
+		if (style == GNU_BINUTILS) {
+			do {
+				ch = io__get_char(&io);
+			} while (ch > 0 && ch != '\n');
+		}
+	}
+	return style;
+}
+
 static int read_addr2line_record(struct io *io,
+				 enum a2l_style style,
 				 char **function,
 				 char **filename,
 				 unsigned int *line_nr)
@@ -462,6 +505,12 @@ static int read_addr2line_record(struct io *io,
 
 	if (io__getline(io, &line, &line_len) < 0 || !line_len)
 		goto error;
+
+	if (style == LLVM && line_len == 2 && line[0] == ',') {
+		zfree(&line);
+		return 0;
+	}
+
 	if (function != NULL)
 		*function = strdup(strim(line));
 
@@ -471,7 +520,8 @@ static int read_addr2line_record(struct io *io,
 	if (io__getline(io, &line, &line_len) < 0 || !line_len)
 		goto error;
 
-	if (filename_split(line, line_nr == NULL ? &dummy_line_nr : line_nr) == 0) {
+	if (filename_split(line, line_nr == NULL ? &dummy_line_nr : line_nr) == 0 &&
+	    style == GNU_BINUTILS) {
 		ret = 0;
 		goto error;
 	}
@@ -523,6 +573,7 @@ static int addr2line(const char *dso_name, u64 addr,
 	char buf[128];
 	ssize_t written;
 	struct io io;
+	enum a2l_style a2l_style;
 
 	if (!a2l) {
 		if (!filename__has_section(dso_name, ".debug_line"))
@@ -538,15 +589,22 @@ static int addr2line(const char *dso_name, u64 addr,
 			pr_warning("%s %s: addr2line_subprocess_init failed\n", __func__, dso_name);
 		goto out;
 	}
+	a2l_style = addr2line_configure(a2l);
+	if (a2l_style == BROKEN) {
+		if (!symbol_conf.disable_add2line_warn)
+			pr_warning("%s: addr2line configuration failed\n", __func__);
+		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 "??" and "??:0", so that we can detect when it has
-	 * finished giving us anything useful. We have to be careful about the first record,
-	 * though, because it may be genuinely unknown, in which case we'll get two sets of
-	 * "??"/"??:0" lines.
+	 * then to write out the lines "??" and "??:0", for GNU binutils, or "," for
+	 * llvm-addr2line, so that we can detect when it has finished giving us anything
+	 * useful. With GNU binutils, we have to be careful about the first record, though,
+	 * because it may be genuinely unknown, in which case we'll get two sets of "??"/"??:0"
+	 * lines.
 	 */
 	len = snprintf(buf, sizeof(buf), "%016"PRIx64"\n,\n", addr);
 	written = len > 0 ? write(a2l->in, buf, len) : -1;
@@ -557,7 +615,8 @@ static int addr2line(const char *dso_name, u64 addr,
 	}
 	io__init(&io, a2l->out, buf, sizeof(buf));
 
-	switch (read_addr2line_record(&io, &record_function, &record_filename, &record_line_nr)) {
+	switch (read_addr2line_record(&io, a2l_style,
+				      &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);
@@ -567,7 +626,7 @@ static int addr2line(const char *dso_name, u64 addr,
 		 * The first record was invalid, so return failure, but first read another
 		 * record, since we asked a junk question and have to clear the answer out.
 		 */
-		switch (read_addr2line_record(&io, NULL, NULL, NULL)) {
+		switch (read_addr2line_record(&io, a2l_style, NULL, NULL, NULL)) {
 		case -1:
 			if (!symbol_conf.disable_add2line_warn)
 				pr_warning("%s %s: could not read delimiter record\n",
@@ -606,6 +665,7 @@ static int addr2line(const char *dso_name, u64 addr,
 
 	/* We have to read the records even if we don't care about the inline info. */
 	while ((record_status = read_addr2line_record(&io,
+						      a2l_style,
 						      &record_function,
 						      &record_filename,
 						      &record_line_nr)) == 1) {
-- 
2.40.0.348.gf938b09366-goog

[PATCH v2 4/4] perf srcline: Avoid addr2line SIGPIPEs

[Ian Rogers]

Ignore SIGPIPEs when addr2line is configured.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/srcline.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index f4fcdada821b..cfca03abd6f8 100644
--- a/tools/perf/util/srcline.c
+++ b/tools/perf/util/srcline.c
@@ -473,6 +473,8 @@ static enum a2l_style addr2line_configure(struct child_process *a2l)
 				ch = io__get_char(&io);
 			} while (ch > 0 && ch != '\n');
 		}
+		/* Ignore SIGPIPE in the event addr2line exits. */
+		signal(SIGPIPE, SIG_IGN);
 	}
 	return style;
 }
-- 
2.40.0.348.gf938b09366-goog

Re: [PATCH v2 0/4] Support for llvm-addr2line

[Arnaldo Carvalho de Melo]

Em Mon, Apr 03, 2023 at 11:40:29AM -0700, Ian Rogers escreveu:
> The addr2line command is started and then addresses piped to it. In
> order to determine the end of a addr2lines output a ',' it output with
> an expectation to get '??\n??:0\n' as a reply. llvm-addr2line differs
> in that ',' generates a reply of ','.
> 
> The approach detects and then caches the addr2line style. When records
> are read the sentinel is detected appropriately.
> 
> Comparing the output there is a little more inline data on my machine
> with llvm-addr2line:
> $ sudo perf record -a -g sleep 1
> $ sudo perf report --addr2line=addr2line > a.txt
> $ sudo perf report --addr2line=llvm-addr2line > b.txt
> $ wc -l a.txt b.txt
>   12386 a.txt
>   12477 b.txt
> 
> Some other small changes, switching to the api/io code to avoid file
> streams wrapping the command's stdin/stdout. Ignore SIGPIPE for when
> addr2line exits and writes fail.
> 
> v2. Address review comments from Arnaldo and Namhyung, fixing a
>     realloc error path, argument ordering and a comment.

Added to local repo, build testing, will be in tmp.perf-tools-next soon.

- Arnaldo
 
> Ian Rogers (4):
>   tools api: Add io__getline
>   perf srcline: Simplify addr2line subprocess
>   perf srcline: Support for llvm-addr2line
>   perf srcline: Avoid addr2line SIGPIPEs
> 
>  tools/lib/api/io.h        |  45 ++++++++++
>  tools/perf/tests/api-io.c |  36 ++++++++
>  tools/perf/util/srcline.c | 171 +++++++++++++++++++++++---------------
>  3 files changed, 184 insertions(+), 68 deletions(-)
> 
> -- 
> 2.40.0.348.gf938b09366-goog
> 

-- 

- Arnaldo

Re: [PATCH v2 0/4] Support for llvm-addr2line

[Namhyung Kim]

Hi,

On Mon, Apr 3, 2023 at 1:24 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
>
> Em Mon, Apr 03, 2023 at 11:40:29AM -0700, Ian Rogers escreveu:
> > The addr2line command is started and then addresses piped to it. In
> > order to determine the end of a addr2lines output a ',' it output with
> > an expectation to get '??\n??:0\n' as a reply. llvm-addr2line differs
> > in that ',' generates a reply of ','.
> >
> > The approach detects and then caches the addr2line style. When records
> > are read the sentinel is detected appropriately.
> >
> > Comparing the output there is a little more inline data on my machine
> > with llvm-addr2line:
> > $ sudo perf record -a -g sleep 1
> > $ sudo perf report --addr2line=addr2line > a.txt
> > $ sudo perf report --addr2line=llvm-addr2line > b.txt
> > $ wc -l a.txt b.txt
> >   12386 a.txt
> >   12477 b.txt
> >
> > Some other small changes, switching to the api/io code to avoid file
> > streams wrapping the command's stdin/stdout. Ignore SIGPIPE for when
> > addr2line exits and writes fail.
> >
> > v2. Address review comments from Arnaldo and Namhyung, fixing a
> >     realloc error path, argument ordering and a comment.
>
> Added to local repo, build testing, will be in tmp.perf-tools-next soon.
>
> - Arnaldo
>
> > Ian Rogers (4):
> >   tools api: Add io__getline
> >   perf srcline: Simplify addr2line subprocess
> >   perf srcline: Support for llvm-addr2line
> >   perf srcline: Avoid addr2line SIGPIPEs

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung


> >
> >  tools/lib/api/io.h        |  45 ++++++++++
> >  tools/perf/tests/api-io.c |  36 ++++++++
> >  tools/perf/util/srcline.c | 171 +++++++++++++++++++++++---------------
> >  3 files changed, 184 insertions(+), 68 deletions(-)
> >
> > --
> > 2.40.0.348.gf938b09366-goog
> >
>
> --
>
> - Arnaldo

Re: [PATCH v2 0/4] Support for llvm-addr2line

[Arnaldo Carvalho de Melo]

Em Mon, Apr 03, 2023 at 10:18:47PM -0700, Namhyung Kim escreveu:
> Hi,
> 
> On Mon, Apr 3, 2023 at 1:24 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> >
> > Em Mon, Apr 03, 2023 at 11:40:29AM -0700, Ian Rogers escreveu:
> > > The addr2line command is started and then addresses piped to it. In
> > > order to determine the end of a addr2lines output a ',' it output with
> > > an expectation to get '??\n??:0\n' as a reply. llvm-addr2line differs
> > > in that ',' generates a reply of ','.
> > >
> > > The approach detects and then caches the addr2line style. When records
> > > are read the sentinel is detected appropriately.
> > >
> > > Comparing the output there is a little more inline data on my machine
> > > with llvm-addr2line:
> > > $ sudo perf record -a -g sleep 1
> > > $ sudo perf report --addr2line=addr2line > a.txt
> > > $ sudo perf report --addr2line=llvm-addr2line > b.txt
> > > $ wc -l a.txt b.txt
> > >   12386 a.txt
> > >   12477 b.txt
> > >
> > > Some other small changes, switching to the api/io code to avoid file
> > > streams wrapping the command's stdin/stdout. Ignore SIGPIPE for when
> > > addr2line exits and writes fail.
> > >
> > > v2. Address review comments from Arnaldo and Namhyung, fixing a
> > >     realloc error path, argument ordering and a comment.
> >
> > Added to local repo, build testing, will be in tmp.perf-tools-next soon.
> >
> > - Arnaldo
> >
> > > Ian Rogers (4):
> > >   tools api: Add io__getline
> > >   perf srcline: Simplify addr2line subprocess
> > >   perf srcline: Support for llvm-addr2line
> > >   perf srcline: Avoid addr2line SIGPIPEs
> 
> Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks, added to those patches.

- Arnaldo