1 files changed, 400 insertions, 97 deletions

diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index 5b7d6c16d33f..7addc34afcf5 100644
--- a/tools/perf/util/srcline.c
+++ b/tools/perf/util/srcline.c
@@ -1,13 +1,17 @@
 // 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/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"
@@ -15,9 +19,14 @@
 #include "srcline.h"
 #include "string2.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;
 bool srcline_full_filename;
 
+char *srcline__unknown = (char *)"??:0";
+
 static const char *dso__name(struct dso *dso)
 {
 	const char *dso_name;
@@ -119,6 +128,8 @@ static struct symbol *new_inline_sym(struct dso *dso,
 	return inline_sym;
 }
 
+#define MAX_INLINE_NEST 1024
+
 #ifdef HAVE_LIBBFD_SUPPORT
 
 /*
@@ -273,8 +284,6 @@ static void addr2line_cleanup(struct a2l_data *a2l)
 	free(a2l);
 }
 
-#define MAX_INLINE_NEST 1024
-
 static int inline_list__append_dso_a2l(struct dso *dso,
 				       struct inline_node *node,
 				       struct symbol *sym)
@@ -361,24 +370,6 @@ void dso__free_a2l(struct dso *dso)
 	dso->a2l = NULL;
 }
 
-static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
-					struct dso *dso, struct symbol *sym)
-{
-	struct inline_node *node;
-
-	node = zalloc(sizeof(*node));
-	if (node == NULL) {
-		perror("not enough memory for the inline node");
-		return NULL;
-	}
-
-	INIT_LIST_HEAD(&node->val);
-	node->addr = addr;
-
-	addr2line(dso_name, addr, NULL, NULL, dso, true, node, sym);
-	return node;
-}
-
 #else /* HAVE_LIBBFD_SUPPORT */
 
 static int filename_split(char *filename, unsigned int *line_nr)
@@ -398,118 +389,425 @@ static int filename_split(char *filename, unsigned int *line_nr)
 		*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_debug("Detected LLVM addr2line style\n");
+		} else if (ch == '0') {
+			style = GNU_BINUTILS;
+			cached = true;
+			lines = 3;
+			pr_debug("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_debug("%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_debug("%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_debug("%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 __maybe_unused,
-		     bool unwind_inlines __maybe_unused,
-		     struct inline_node *node __maybe_unused,
+		     struct dso *dso,
+		     bool unwind_inlines,
+		     struct inline_node *node,
 		     struct symbol *sym __maybe_unused)
 {
-	FILE *fp;
-	char cmd[PATH_MAX];
-	char *filename = NULL;
-	size_t len;
+	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 = { .eof = false };
+	enum a2l_style a2l_style;
 
-	scnprintf(cmd, sizeof(cmd), "addr2line -e %s %016"PRIx64,
-		  dso_name, addr);
+	if (!a2l) {
+		if (!filename__has_section(dso_name, ".debug_line"))
+			goto out;
 
-	fp = popen(cmd, "r");
-	if (fp == NULL) {
-		pr_warning("popen failed for %s\n", dso_name);
-		return 0;
+		dso->a2l = addr2line_subprocess_init(symbol_conf.addr2line_path, dso_name);
+		a2l = dso->a2l;
 	}
 
-	if (getline(&filename, &len, fp) < 0 || !len) {
-		pr_warning("addr2line has no output for %s\n", dso_name);
+	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;
 
-	ret = filename_split(filename, line_nr);
-	if (ret != 1) {
-		free(filename);
+	/*
+	 * 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;
 	}
 
-	*file = filename;
+	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:
-	pclose(fp);
+	free(record_function);
+	free(record_filename);
+	if (io.eof) {
+		dso->a2l = NULL;
+		addr2line_subprocess_cleanup(a2l);
+	}
 	return ret;
 }
 
-void dso__free_a2l(struct dso *dso __maybe_unused)
+void dso__free_a2l(struct dso *dso)
 {
+	struct child_process *a2l = dso->a2l;
+
+	if (!a2l)
+		return;
+
+	addr2line_subprocess_cleanup(a2l);
+
+	dso->a2l = NULL;
 }
 
+#endif /* HAVE_LIBBFD_SUPPORT */
+
 static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
-					struct dso *dso __maybe_unused,
-					struct symbol *sym)
+					struct dso *dso, struct symbol *sym)
 {
-	FILE *fp;
-	char cmd[PATH_MAX];
 	struct inline_node *node;
-	char *filename = NULL;
-	char *funcname = NULL;
-	size_t filelen, funclen;
-	unsigned int line_nr = 0;
-
-	scnprintf(cmd, sizeof(cmd), "addr2line -e %s -i -f %016"PRIx64,
-		  dso_name, addr);
-
-	fp = popen(cmd, "r");
-	if (fp == NULL) {
-		pr_err("popen failed for %s\n", dso_name);
-		return NULL;
-	}
 
 	node = zalloc(sizeof(*node));
 	if (node == NULL) {
 		perror("not enough memory for the inline node");
-		goto out;
+		return NULL;
 	}
 
 	INIT_LIST_HEAD(&node->val);
 	node->addr = addr;
 
-	/* addr2line -f generates two lines for each inlined functions */
-	while (getline(&funcname, &funclen, fp) != -1) {
-		char *srcline;
-		struct symbol *inline_sym;
-
-		strim(funcname);
-
-		if (getline(&filename, &filelen, fp) == -1)
-			goto out;
-
-		if (filename_split(filename, &line_nr) != 1)
-			goto out;
-
-		srcline = srcline_from_fileline(filename, line_nr);
-		inline_sym = new_inline_sym(dso, sym, funcname);
-
-		if (inline_list__append(inline_sym, srcline, node) != 0) {
-			free(srcline);
-			if (inline_sym && inline_sym->inlined)
-				symbol__delete(inline_sym);
-			goto out;
-		}
-	}
-
-out:
-	pclose(fp);
-	free(filename);
-	free(funcname);
-
+	addr2line(dso_name, addr, NULL, NULL, dso, true, node, sym);
 	return node;
 }
 
-#endif /* HAVE_LIBBFD_SUPPORT */
-
 /*
  * Number of addr2line failures (without success) before disabling it for that
  * dso.
@@ -554,7 +852,7 @@ out:
 
 	if (!show_addr)
 		return (show_sym && sym) ?
-			    strndup(sym->name, sym->namelen) : NULL;
+			    strndup(sym->name, sym->namelen) : SRCLINE_UNKNOWN;
 
 	if (sym) {
 		if (asprintf(&srcline, "%s+%" PRIu64, show_sym ? sym->name : "",
@@ -593,10 +891,15 @@ out:
 	return NULL;
 }
 
-void free_srcline(char *srcline)
+void zfree_srcline(char **srcline)
 {
-	if (srcline && strcmp(srcline, SRCLINE_UNKNOWN) != 0)
-		free(srcline);
+	if (*srcline == NULL)
+		return;
+
+	if (*srcline != SRCLINE_UNKNOWN)
+		free(*srcline);
+
+	*srcline = NULL;
 }
 
 char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
@@ -669,7 +972,7 @@ void srcline__tree_delete(struct rb_root_cached *tree)
 		pos = rb_entry(next, struct srcline_node, rb_node);
 		next = rb_next(&pos->rb_node);
 		rb_erase_cached(&pos->rb_node, tree);
-		free_srcline(pos->srcline);
+		zfree_srcline(&pos->srcline);
 		zfree(&pos);
 	}
 }
@@ -692,7 +995,7 @@ void inline_node__delete(struct inline_node *node)
 
 	list_for_each_entry_safe(ilist, tmp, &node->val, list) {
 		list_del_init(&ilist->list);
-		free_srcline(ilist->srcline);
+		zfree_srcline(&ilist->srcline);
 		/* only the inlined symbols are owned by the list */
 		if (ilist->symbol && ilist->symbol->inlined)
 			symbol__delete(ilist->symbol);