X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=plugins%2Flttng-utils%2Fdebug-info%2Fbin-info.c;h=bad796d225dd7aa43921ca0e49bd3865f857b986;hb=3fadfbc0c91f82c46bd36e6e0657ea93570c9db1;hp=dd42f41cfbcd6301dcfef11e25964a4edb7f1447;hpb=1e638f98d6c4f2c799d4ea4c826f711a59d9f531;p=babeltrace.git

diff --git a/plugins/lttng-utils/debug-info/bin-info.c b/plugins/lttng-utils/debug-info/bin-info.c
index dd42f41c..bad796d2 100644
--- a/plugins/lttng-utils/debug-info/bin-info.c
+++ b/plugins/lttng-utils/debug-info/bin-info.c
@@ -42,6 +42,8 @@
 
 #include <glib.h>
 
+#include <babeltrace2/common-internal.h>
+
 #include "bin-info.h"
 #include "crc32.h"
 #include "dwarf.h"
@@ -88,8 +90,7 @@ struct bin_info *bin_info_create(struct bt_fd_cache *fdc, const char *path,
 	}
 
 	if (target_prefix) {
-		bin->elf_path = g_build_path("/", target_prefix,
-						path, NULL);
+		bin->elf_path = g_build_filename(target_prefix,	path, NULL);
 	} else {
 		bin->elf_path = g_strdup(path);
 	}
@@ -165,21 +166,22 @@ int bin_info_set_elf_file(struct bin_info *bin)
 		BT_LOGD("Failed to open %s", bin->elf_path);
 		goto error;
 	}
+	bin->elf_handle = elf_handle;
 
-	elf_file = elf_begin(bt_fd_cache_handle_get_fd(elf_handle),
+	elf_file = elf_begin(bt_fd_cache_handle_get_fd(bin->elf_handle),
 		ELF_C_READ, NULL);
 	if (!elf_file) {
 		BT_LOGE("elf_begin failed: %s", elf_errmsg(-1));
 		goto error;
 	}
 
+	bin->elf_file = elf_file;
+
 	if (elf_kind(elf_file) != ELF_K_ELF) {
 		BT_LOGE("Error: %s is not an ELF object", bin->elf_path);
 		goto error;
 	}
 
-	bin->elf_handle = elf_handle;
-	bin->elf_file = elf_file;
 	return 0;
 
 error:
@@ -189,39 +191,43 @@ error:
 }
 
 /**
- * From a note section data buffer, check if it is a build id note.
+ * From a note section data struct, check if it is a build id note.
  *
- * @param buf			Pointer to a note section
+ * @param note_data		Pointer to a note section
  *
  * @returns			1 on match, 0 if `buf` does not contain a
  *				valid build id note
  */
 static
-int is_build_id_note_section(uint8_t *buf)
+int is_build_id_note_section(Elf_Data *note_data)
 {
+	size_t name_offset, desc_offset;
+	GElf_Nhdr note_header;
 	int ret = 0;
-	uint32_t name_sz, desc_sz, note_type;
 
-	/* The note section header has 3 32bit integer for the following:
-	 * - Section name size
-	 * - Description size
-	 * - Note type
+	/*
+	 * Discard the return value as it contains the size of the note section
+	 * and we don't need it.
 	 */
-	name_sz = (uint32_t) *buf;
-	buf += sizeof(name_sz);
+	(void) gelf_getnote(note_data, 0, &note_header, &name_offset,
+		&desc_offset);
 
-	buf += sizeof(desc_sz);
-
-	note_type = (uint32_t) *buf;
-	buf += sizeof(note_type);
+	/*
+	 * Check the note name length. The name_sz field includes the
+	 * terminating null byte.
+	 */
+	if (note_header.n_namesz != sizeof(BUILD_ID_NOTE_NAME)) {
+		goto invalid;
+	}
 
 	/* Check the note type. */
-	if (note_type != NT_GNU_BUILD_ID) {
+	if (note_header.n_type != NT_GNU_BUILD_ID) {
 		goto invalid;
 	}
 
 	/* Check the note name. */
-	if (memcmp(buf, BUILD_ID_NOTE_NAME, name_sz) != 0) {
+	if (memcmp(note_data->d_buf + name_offset, BUILD_ID_NOTE_NAME,
+			note_header.n_namesz) != 0) {
 		goto invalid;
 	}
 
@@ -232,46 +238,38 @@ invalid:
 }
 
 /**
- *  From a build id note section data buffer, check if the build id it contains
+ *  From a build id note section data struct, check if the build id it contains
  *  is identical to the build id passed as parameter.
  *
- * @param file_build_id_note	Pointer to the file build id note section.
+ * @param note_data		Pointer to the file build id note section.
  * @param build_id		Pointer to a build id to compare to.
  * @param build_id_len		length of the build id.
  *
  * @returns			1 on match, 0 otherwise.
  */
 static
-int is_build_id_note_section_matching(uint8_t *file_build_id_note,
+int is_build_id_note_section_matching(Elf_Data *note_data,
 		uint8_t *build_id, size_t build_id_len)
 {
-	uint32_t name_sz, desc_sz, note_type;
+	size_t name_offset, desc_offset;
+	GElf_Nhdr note_header;
 
 	if (build_id_len <= 0) {
 		goto end;
 	}
 
-	/* The note section header has 3 32bit integer for the following:
-	 * - Section name size
-	 * - Description size
-	 * - Note type
-	 */
-	name_sz = (uint32_t) *file_build_id_note;
-	file_build_id_note += sizeof(name_sz);
-	file_build_id_note += sizeof(desc_sz);
-	file_build_id_note += sizeof(note_type);
-
 	/*
-	 * Move the pointer pass the name char array. This corresponds to the
-	 * beginning of the description section. The description is the build
-	 * id in the case of a build id note.
+	 * Discard the return value as it contains the size of the note section
+	 * and we don't need it.
 	 */
-	file_build_id_note += name_sz;
+	(void) gelf_getnote(note_data, 0, &note_header, &name_offset,
+		&desc_offset);
 
 	/*
 	 * Compare the binary build id with the supplied build id.
 	 */
-	if (memcmp(build_id, file_build_id_note, build_id_len) == 0) {
+	if (memcmp(build_id, note_data->d_buf + desc_offset,
+			build_id_len) == 0) {
 		return 1;
 	}
 end:
@@ -295,8 +293,7 @@ int is_build_id_matching(struct bin_info *bin)
 {
 	int ret, is_build_id, is_matching = 0;
 	Elf_Scn *curr_section = NULL, *next_section = NULL;
-	Elf_Data *note_data = NULL;
-	GElf_Shdr *curr_section_hdr = NULL;
+	GElf_Shdr curr_section_hdr;
 
 	if (!bin->build_id) {
 		goto error;
@@ -311,37 +308,35 @@ int is_build_id_matching(struct bin_info *bin)
 		}
 	}
 
-	curr_section_hdr = g_new0(GElf_Shdr, 1);
-	if (!curr_section_hdr) {
-		goto error;
-	}
-
 	next_section = elf_nextscn(bin->elf_file, curr_section);
 	if (!next_section) {
 		goto error;
 	}
 
 	while (next_section) {
+		Elf_Data *note_data = NULL;
+
 		curr_section = next_section;
 		next_section = elf_nextscn(bin->elf_file, curr_section);
 
-		curr_section_hdr = gelf_getshdr(curr_section, curr_section_hdr);
-
-		if (!curr_section_hdr) {
+		if (!gelf_getshdr(curr_section, &curr_section_hdr)) {
 			goto error;
 		}
 
-		if (curr_section_hdr->sh_type != SHT_NOTE) {
+		if (curr_section_hdr.sh_type != SHT_NOTE) {
 			continue;
 		}
 
+		/*
+		 * elf_getdata() translates the data to native byte order.
+		 */
 		note_data = elf_getdata(curr_section, NULL);
 		if (!note_data) {
 			goto error;
 		}
 
 		/* Check if the note is of the build-id type. */
-		is_build_id = is_build_id_note_section(note_data->d_buf);
+		is_build_id = is_build_id_note_section(note_data);
 		if (!is_build_id) {
 			continue;
 		}
@@ -350,14 +345,13 @@ int is_build_id_matching(struct bin_info *bin)
 		 * Compare the build id of the on-disk file and
 		 * the build id recorded in the trace.
 		 */
-		is_matching = is_build_id_note_section_matching(note_data->d_buf,
-				bin->build_id, bin->build_id_len);
+		is_matching = is_build_id_note_section_matching(
+			note_data, bin->build_id, bin->build_id_len);
 		if (!is_matching) {
 			break;
 		}
 	}
 error:
-	g_free(curr_section_hdr);
 	return is_matching;
 }
 
@@ -507,9 +501,9 @@ static
 int bin_info_set_dwarf_info_build_id(struct bin_info *bin)
 {
 	int i = 0, ret = 0;
-	char *path = NULL, *build_id_file = NULL;
+	char *path = NULL, *build_id_prefix_dir = NULL, *build_id_file = NULL;
 	const char *dbg_dir = NULL;
-	size_t build_id_file_len;
+	size_t build_id_char_len, build_id_suffix_char_len, build_id_file_len;
 
 	if (!bin || !bin->build_id) {
 		goto error;
@@ -517,23 +511,49 @@ int bin_info_set_dwarf_info_build_id(struct bin_info *bin)
 
 	dbg_dir = bin->debug_info_dir ? bin->debug_info_dir : DEFAULT_DEBUG_DIR;
 
-	/* 2 characters per byte printed in hex, +1 for '/' and +1 for '\0' */
-	build_id_file_len = (2 * bin->build_id_len) + 1 +
-			strlen(BUILD_ID_SUFFIX) + 1;
+	/*
+	 * The prefix dir is the first byte of the build id, represented in
+	 * lowercase hex as two characters per byte, +1 for '\0'.
+	 */
+	build_id_prefix_dir = g_new0(gchar, BUILD_ID_PREFIX_DIR_LEN + 1);
+	if (!build_id_prefix_dir) {
+		goto error;
+	}
+	g_snprintf(build_id_prefix_dir, BUILD_ID_PREFIX_DIR_LEN + 1, "%02x", bin->build_id[0]);
+
+	/*
+	 * The build id file is the remaining bytes of the build id,
+	 * represented in lowercase hex, as two characters per byte.
+	 */
+	build_id_char_len = (2 * (bin->build_id_len - 1));
+
+	/* To which the build id suffix is added, +1 for '\0'. */
+	build_id_suffix_char_len = strlen(BUILD_ID_SUFFIX) + 1;
+
+	/*
+	 * The resulting filename string is the concatenation of the
+	 * hex build id and the suffix.
+	 */
+	build_id_file_len =  build_id_char_len + build_id_suffix_char_len;
 	build_id_file = g_new0(gchar, build_id_file_len);
 	if (!build_id_file) {
 		goto error;
 	}
 
-	g_snprintf(build_id_file, 4, "%02x/", bin->build_id[0]);
+	/*
+	 * For each byte, starting at offset 1, append two characters
+	 * in lowercase hex.
+	 */
 	for (i = 1; i < bin->build_id_len; ++i) {
-		int path_idx = 3 + 2 * (i - 1);
+		int path_idx = 2 * (i - 1);
 
 		g_snprintf(&build_id_file[path_idx], 3, "%02x", bin->build_id[i]);
 	}
-	g_strconcat(build_id_file, BUILD_ID_SUFFIX, NULL);
+	/* Append the suffix to the generated string, including the '\0'. */
+	g_snprintf(&build_id_file[build_id_char_len], build_id_suffix_char_len,
+		BUILD_ID_SUFFIX);
 
-	path = g_build_path("/", dbg_dir, BUILD_ID_SUBDIR, build_id_file, NULL);
+	path = g_build_filename(dbg_dir, BUILD_ID_SUBDIR, build_id_prefix_dir, build_id_file, NULL);
 	if (!path) {
 		goto error;
 	}
@@ -548,8 +568,9 @@ int bin_info_set_dwarf_info_build_id(struct bin_info *bin)
 error:
 	ret = -1;
 end:
-	free(build_id_file);
-	free(path);
+	g_free(build_id_prefix_dir);
+	g_free(build_id_file);
+	g_free(path);
 
 	return ret;
 }
@@ -610,22 +631,17 @@ int bin_info_set_dwarf_info_debug_link(struct bin_info *bin)
 {
 	int ret = 0;
 	const gchar *dbg_dir = NULL;
-	gchar *bin_dir = NULL, *dir_name = NULL, *path = NULL;
+	gchar *bin_dir = NULL, *path = NULL;
 
 	if (!bin || !bin->dbg_link_filename) {
 		goto error;
 	}
 
 	dbg_dir = bin->debug_info_dir ? bin->debug_info_dir : DEFAULT_DEBUG_DIR;
-	dir_name = g_path_get_dirname(bin->elf_path);
-	if (!dir_name) {
-		goto error;
-	}
-
-	bin_dir = g_strconcat(dir_name, "/", NULL);
+	bin_dir = g_path_get_dirname(bin->elf_path);
 
 	/* First look in the executable's dir */
-	path = g_strconcat(bin_dir, bin->dbg_link_filename, NULL);
+	path = g_build_filename(bin_dir, bin->dbg_link_filename, NULL);
 
 	if (is_valid_debug_file(bin, path, bin->dbg_link_crc)) {
 		goto found;
@@ -633,7 +649,7 @@ int bin_info_set_dwarf_info_debug_link(struct bin_info *bin)
 
 	/* If not found, look in .debug subdir */
 	g_free(path);
-	path = g_strconcat(bin_dir, DEBUG_SUBDIR, bin->dbg_link_filename, NULL);
+	path = g_build_filename(bin_dir, DEBUG_SUBDIR, bin->dbg_link_filename, NULL);
 
 	if (is_valid_debug_file(bin, path, bin->dbg_link_crc)) {
 		goto found;
@@ -642,7 +658,7 @@ int bin_info_set_dwarf_info_debug_link(struct bin_info *bin)
 	/* Lastly, look under the global debug directory */
 	g_free(path);
 
-	path = g_strconcat(dbg_dir, bin_dir, bin->dbg_link_filename, NULL);
+	path = g_build_filename(dbg_dir, bin_dir, bin->dbg_link_filename, NULL);
 	if (is_valid_debug_file(bin, path, bin->dbg_link_crc)) {
 		goto found;
 	}
@@ -650,7 +666,7 @@ int bin_info_set_dwarf_info_debug_link(struct bin_info *bin)
 error:
 	ret = -1;
 end:
-	g_free(dir_name);
+	g_free(bin_dir);
 	g_free(path);
 
 	return ret;
@@ -738,7 +754,6 @@ int bin_info_append_offset_str(const char *base_str, uint64_t low_addr,
 	uint64_t offset;
 	char *_result = NULL;
 
-
 	if (!base_str || !result) {
 		goto error;
 	}
@@ -1367,7 +1382,9 @@ error:
  * @param cu		bt_dwarf_cu instance in which to look for the address
  * @param addr		The address for which to look for
  * @param src_loc	Out parameter, the source location (filename and
- *			line number) for the address
+ *			line number) for the address. Set only if the address
+ *			is found and resolved successfully
+ *
  * @returns		0 on success, -1 on failure
  */
 static
@@ -1379,7 +1396,7 @@ int bin_info_lookup_cu_src_loc_no_inl(struct bt_dwarf_cu *cu, uint64_t addr,
 	const char *filename = NULL;
 	Dwarf_Line *line = NULL;
 	Dwarf_Addr line_addr;
-	int ret, line_no;
+	int ret = 0, line_no;
 
 	if (!cu || !src_loc) {
 		goto error;
@@ -1392,7 +1409,8 @@ int bin_info_lookup_cu_src_loc_no_inl(struct bt_dwarf_cu *cu, uint64_t addr,
 
 	line = dwarf_getsrc_die(die->dwarf_die, addr);
 	if (!line) {
-		goto error;
+		/* This is not an error. The caller needs to keep looking. */
+		goto end;
 	}
 
 	ret = dwarf_lineaddr(line, &line_addr);
@@ -1420,18 +1438,18 @@ int bin_info_lookup_cu_src_loc_no_inl(struct bt_dwarf_cu *cu, uint64_t addr,
 		_src_loc->filename = g_strdup(filename);
 	}
 
-	bt_dwarf_die_destroy(die);
-
 	if (_src_loc) {
 		*src_loc = _src_loc;
 	}
 
-	return 0;
+	goto end;
 
 error:
 	source_location_destroy(_src_loc);
+	ret = -1;
+end:
 	bt_dwarf_die_destroy(die);
-	return -1;
+	return ret;
 }
 
 /**