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Message-Id: <20230403184033.1836023-4-irogers@google.com>
Date: Mon, 3 Apr 2023 11:40:32 -0700
From: Ian Rogers <irogers@...gle.com>
To: Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>,
Namhyung Kim <namhyung@...nel.org>,
Ian Rogers <irogers@...gle.com>,
Adrian Hunter <adrian.hunter@...el.com>,
Nathan Chancellor <nathan@...nel.org>,
Nick Desaulniers <ndesaulniers@...gle.com>,
Tom Rix <trix@...hat.com>, linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org, llvm@...ts.linux.dev
Subject: [PATCH v2 3/4] perf srcline: Support for llvm-addr2line
The sentinel value differs for llvm-addr2line. Configure this once and
then detect when reading records.
Signed-off-by: Ian Rogers <irogers@...gle.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
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