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[PATCH v2] Minor review cleanups to previously committed build-id patch
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From: Maynard J. <may...@us...> - 2012-12-18 16:31:16
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Minor review cleanups to previously committed build-id patch
Cleanups suggested by Will Cohen Suravee Suthikulpanit during review.
See oprofile-list for details.
Signed-off-by: Maynard Johnson <may...@us...>
---
libutil++/bfd_support.cpp | 76 +++++++++++++++++++++++++-------------------
1 files changed, 43 insertions(+), 33 deletions(-)
diff --git a/libutil++/bfd_support.cpp b/libutil++/bfd_support.cpp
index 6f4e8e1..5c3a365 100644
--- a/libutil++/bfd_support.cpp
+++ b/libutil++/bfd_support.cpp
@@ -18,9 +18,11 @@
#include "cverb.h"
#include "locate_images.h"
#include "op_libiberty.h"
+#include "op_exception.h"
#include <unistd.h>
-#include <limits.h>
+#include <errno.h>
+#include <elf.h>
#include <cstdlib>
#include <cstring>
#include <cassert>
@@ -37,10 +39,10 @@ extern verbose vbfd;
namespace {
-#define BUILD_ID_SIZE 20
#ifndef NT_GNU_BUILD_ID
#define NT_GNU_BUILD_ID 3
#endif
+static size_t build_id_size;
void check_format(string const & file, bfd ** ibfd)
@@ -86,7 +88,7 @@ bool separate_debug_file_exists(string & name, unsigned long const crc,
static bool find_debuginfo_file_by_buildid(unsigned char * buildid, string & debug_filename)
{
size_t build_id_fname_size = strlen (DEBUGDIR) + (sizeof "/.build-id/" - 1) + 1
- + (2 * BUILD_ID_SIZE) + (sizeof ".debug" - 1) + 1;
+ + (2 * build_id_size) + (sizeof ".debug" - 1) + 1;
char * buildid_symlink = (char *) xmalloc(build_id_fname_size);
char * sptr = buildid_symlink;
unsigned char * bptr = buildid;
@@ -100,7 +102,7 @@ static bool find_debuginfo_file_by_buildid(unsigned char * buildid, string & deb
sptr += build_id_segment_len;
sptr += sprintf(sptr, "%02x", (unsigned) *bptr++);
*sptr++ = '/';
- for (int i = BUILD_ID_SIZE - 1; i > 0; i--)
+ for (int i = build_id_size - 1; i > 0; i--)
sptr += sprintf(sptr, "%02x", (unsigned) *bptr++);
strcpy(sptr, ".debug");
@@ -121,11 +123,7 @@ static bool find_debuginfo_file_by_buildid(unsigned char * buildid, string & deb
static bool get_build_id(bfd * ibfd, unsigned char * build_id)
{
- struct op_elf_Note_hdr {
- unsigned int op_note_namesz;
- unsigned int op_note_descsz;
- unsigned int op_note_type;
- } op_note_hdr;
+ Elf32_Nhdr op_note_hdr;
asection * sect;
char * ptr;
bool retval = false;
@@ -139,36 +137,42 @@ static bool get_build_id(bfd * ibfd, unsigned char * build_id)
}
bfd_size_type buildid_sect_size = bfd_section_size(ibfd, sect);
- char contents[buildid_sect_size];
-
+ char * contents = (char *) xmalloc(buildid_sect_size);
+ errno = 0;
if (!bfd_get_section_contents(ibfd, sect,
reinterpret_cast<unsigned char *>(contents),
static_cast<file_ptr>(0), buildid_sect_size)) {
- bfd_perror("bfd_get_section_contents:get_debug:");
- exit(2);
+ string msg = "bfd_get_section_contents:get_build_id";
+ if (errno) {
+ msg += ": ";
+ msg += strerror(errno);
+ }
+ throw op_fatal_error(msg);
}
ptr = contents;
while (ptr < (contents + buildid_sect_size)) {
- op_note_hdr.op_note_namesz = bfd_get_32(ibfd,
- reinterpret_cast<bfd_byte *>(contents));
- op_note_hdr.op_note_descsz = bfd_get_32(ibfd,
- reinterpret_cast<bfd_byte *>(contents + 4));
- op_note_hdr.op_note_type = bfd_get_32(ibfd,
- reinterpret_cast<bfd_byte *>(contents + 8));
+ op_note_hdr.n_namesz = bfd_get_32(ibfd,
+ reinterpret_cast<bfd_byte *>(contents));
+ op_note_hdr.n_descsz = bfd_get_32(ibfd,
+ reinterpret_cast<bfd_byte *>(contents + 4));
+ op_note_hdr.n_type = bfd_get_32(ibfd,
+ reinterpret_cast<bfd_byte *>(contents + 8));
ptr += sizeof(op_note_hdr);
- if ((op_note_hdr.op_note_type == NT_GNU_BUILD_ID) &&
- (op_note_hdr.op_note_namesz == sizeof("GNU")) &&
+ if ((op_note_hdr.n_type == NT_GNU_BUILD_ID) &&
+ (op_note_hdr.n_namesz == sizeof("GNU")) &&
(strcmp("GNU", ptr ) == 0)) {
- memcpy(build_id, ptr + op_note_hdr.op_note_namesz, BUILD_ID_SIZE);
+ build_id_size = op_note_hdr.n_descsz;
+ memcpy(build_id, ptr + op_note_hdr.n_namesz, build_id_size);
retval = true;
cverb << vbfd << "Found build-id" << endl;
break;
}
- ptr += op_note_hdr.op_note_namesz + op_note_hdr.op_note_descsz;
+ ptr += op_note_hdr.n_namesz + op_note_hdr.n_descsz;
}
if (!retval)
cverb << vbfd << " No build-id found" << endl;
+ free(contents);
return retval;
}
@@ -184,15 +188,19 @@ bool get_debug_link_info(bfd * ibfd, string & filename, unsigned long & crc32)
return false;
bfd_size_type debuglink_size = bfd_section_size(ibfd, sect);
- char contents[debuglink_size];
+ char * contents = (char *) xmalloc(debuglink_size);
cverb << vbfd
<< ".gnu_debuglink section has size " << debuglink_size << endl;
if (!bfd_get_section_contents(ibfd, sect,
reinterpret_cast<unsigned char *>(contents),
static_cast<file_ptr>(0), debuglink_size)) {
- bfd_perror("bfd_get_section_contents:get_debug:");
- exit(2);
+ string msg = "bfd_get_section_contents:get_debug";
+ if (errno) {
+ msg += ": ";
+ msg += strerror(errno);
+ }
+ throw op_fatal_error(msg);
}
/* CRC value is stored after the filename, aligned up to 4 bytes. */
@@ -204,6 +212,7 @@ bool get_debug_link_info(bfd * ibfd, string & filename, unsigned long & crc32)
reinterpret_cast<bfd_byte *>(contents + crc_offset));
filename = string(contents, filename_len);
cverb << vbfd << ".gnu_debuglink filename is " << filename << endl;
+ free(contents);
return true;
}
@@ -395,17 +404,18 @@ bool find_separate_debug_file(bfd * ibfd, string const & filepath_in,
{
string filepath(filepath_in);
string basename;
- bool use_build_id = true;
unsigned long crc32 = 0;
- unsigned char buildid[BUILD_ID_SIZE];
+ // The readelf program uses a char [64], so that's what we'll use.
+ // To my knowledge, the build-id should not be bigger than 20 chars.
+ unsigned char buildid[64];
- if (!(use_build_id = get_build_id(ibfd, buildid)))
- if (!get_debug_link_info(ibfd, basename, crc32))
- return false;
-
- if (use_build_id && find_debuginfo_file_by_buildid(buildid, debug_filename))
+ if (get_build_id(ibfd, buildid) &&
+ find_debuginfo_file_by_buildid(buildid, debug_filename))
return true;
+ if (!get_debug_link_info(ibfd, basename, crc32))
+ return false;
+
/* Use old method of finding debuginfo file by comparing runtime binary's
* CRC with the CRC we calculate from the debuginfo file's contents.
* NOTE: This method breaks on systems where "MiniDebugInfo" is used
--
1.7.1
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