Feature #4096: Follow .gnu_debuglink section.
http://redmine.ruby-lang.org/issues/show/4096
起票者: Shinichiro Hamaji
ステータス: Open, 優先度: Normal
浜地です。
先日取り込んでいただいた行情報のパッチですが、
ディストリビューションなんかが配布する ruby バイナリは、
debug 情報を持っていない
/usr/bin/ruby
debug 情報を持っている
debug package をインストールした場合に存在する。
/usr/lib/debug/usr/bin/ruby
とかいう感じで二つに別れています。
バグレポートする人の中には debug package を入れている人も
いるかもしれませんし、これに対応するのは一定の価値があるかもなぁ
ということで書いたパッチです。
Subject: [PATCH] Follow .gnu_debuglink section.
With this patch, a user of distribution provided ruby will see line
info if s/he has a debug package for ruby.
addr2line.c | 97
+++++++++++++++++++++++++++++++++++++++++±---------------
1 files changed, 70 insertions(+), 27 deletions(-)
diff --git a/addr2line.c b/addr2line.c
index 443333f…97bd652 100644
— a/addr2line.c
+++ b/addr2line.c
@@ -382,14 +382,71 @@ parse_debug_line(int num_traces, void **traces,
/* read file and fill lines */
static void
-fill_lines(int num_traces, void **traces, char **syms,
-
char *file, line_info_t *lines)
+fill_lines(int num_traces, void **traces, char **syms, int
check_debuglink,
-
line_info_t *current_line, line_info_t *lines);
+static void
+follow_debuglink(char *debuglink, int num_traces, void **traces, char
**syms,
-
line_info_t *current_line, line_info_t *lines)
+{
- /* Ideally we should check 4 paths to follow gnu_debuglink,
-
but we handle only one case for now as this format is used -
by some linux distributions. See GDB's info for detail. */ - static const char global_debug_dir[] = “/usr/lib/debug”;
- char *p, *subdir;
- p = strrchr(binary_filename, ‘/’);
- if (!p) {
- return;
- }
- p[1] = ‘\0’;
- subdir = (char *)alloca(strlen(binary_filename) + 1);
- strcpy(subdir, binary_filename);
- strcpy(binary_filename, global_debug_dir);
- strncat(binary_filename, subdir,
-
PATH_MAX - strlen(binary_filename) - 1); - strncat(binary_filename, debuglink,
-
PATH_MAX - strlen(binary_filename) - 1); - munmap(current_line->mapped, current_line->mapped_size);
- close(current_line->fd);
- fill_lines(num_traces, traces, syms, 0, current_line, lines);
+}
+/* read file and fill lines */
+static void
+fill_lines(int num_traces, void **traces, char **syms, int
check_debuglink,
-
line_info_t *current_line, line_info_t *lines)
{
int i;
char *shstr;
char *section_name;
ElfW(Ehdr) *ehdr;
- ElfW(Shdr) *shdr, *shstr_shdr, *debug_line_shdr = NULL;
-
ElfW(Shdr) *shdr, *shstr_shdr;
-
ElfW(Shdr) *debug_line_shdr = NULL, *gnu_debuglink_shdr = NULL;
-
int fd;
-
off_t filesize;
-
char *file;
-
fd = open(binary_filename, O_RDONLY);
-
if (fd < 0) {
-
return;
-
}
-
filesize = lseek(fd, 0, SEEK_END);
-
lseek(fd, 0, SEEK_SET);
-
/* async-signal unsafe */
-
file = (char *)mmap(NULL, filesize, PROT_READ, MAP_SHARED, fd, 0);
-
if (file == MAP_FAILED) {
-
int e = errno;
-
close(fd);
-
fprintf(stderr, “mmap: %s\n”, strerror(e));
-
return;
-
}
-
current_line->fd = fd;
-
current_line->mapped = file;
-
current_line->mapped_size = filesize;
for (i = 0; i < num_traces; i++) {
const char *path;
@@ -411,11 +468,19 @@ fill_lines(int num_traces, void **traces, char
**syms,
if (!strcmp(section_name, “.debug_line”)) {
debug_line_shdr = shdr + i;
break; -
} else if (!strcmp(section_name, “.gnu_debuglink”)) {
-
gnu_debuglink_shdr = shdr + i;}
}if (!debug_line_shdr) {
- /* this file doesn’t have .debug_line section */
- /* This file doesn’t have .debug_line section,
-
let's check .gnu_debuglink section instead. */ - if (gnu_debuglink_shdr && check_debuglink) {
-
follow_debuglink(file + gnu_debuglink_shdr->sh_offset, -
num_traces, traces, syms, -
current_line, lines); - }
return;
}
@@ -458,12 +523,9 @@ void
rb_dump_backtrace_with_lines(int num_traces, void **trace, char **syms)
{
int i;
-
int fd;
/* async-signal unsafe */
line_info_t *lines = (line_info_t *)calloc(num_traces,
sizeof(line_info_t)); -
off_t filesize;
-
char *file;
/* Note that line info of shared objects might not be shown
if we don’t have dl_iterate_phdr */
@@ -491,26 +553,7 @@ rb_dump_backtrace_with_lines(int num_traces, void
**trace, char **syms)
strncpy(binary_filename, path, len);
binary_filename[len] = ‘\0’; -
fd = open(binary_filename, O_RDONLY);
-
if (fd < 0) {
-
continue; -
}
-
filesize = lseek(fd, 0, SEEK_END);
-
lseek(fd, 0, SEEK_SET);
-
/* async-signal unsafe */
-
file = (char *)mmap(NULL, filesize, PROT_READ, MAP_SHARED, fd, 0);
-
if (file == MAP_FAILED) {
-
int e = errno; -
close(fd); -
fprintf(stderr, "mmap: %s\n", strerror(e)); -
continue; -
}
-
lines[i].fd = fd;
-
lines[i].mapped = file;
-
lines[i].mapped_size = filesize;
-
fill_lines(num_traces, trace, syms, file, lines);
-
fill_lines(num_traces, trace, syms, 1, &lines[i], lines);
}/* fprintf may not be async-signal safe */
–
1.7.2.3