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/* Standard find_debuginfo callback for libdwfl.
Copyright (C) 2005 Red Hat, Inc.
This program is Open Source software; you can redistribute it and/or
modify it under the terms of the Open Software License version 1.0 as
published by the Open Source Initiative.
You should have received a copy of the Open Software License along
with this program; if not, you may obtain a copy of the Open Software
License version 1.0 from http://www.opensource.org/licenses/osl.php or
by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
3001 King Ranch Road, Ukiah, CA 95482. */
#include "libdwflP.h"
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include "system.h"
#define DEFAULT_DEBUGINFO_PATH ":.debug:/usr/lib/debug"
/* Try to open64 [DIR/][SUBDIR/]DEBUGLINK, return file descriptor or -1.
On success, *DEBUGINFO_FILE_NAME has the malloc'd name of the open file. */
static int
try_open (const char *dir, const char *subdir, const char *debuglink,
char **debuginfo_file_name)
{
char *fname = NULL;
if (dir == NULL && subdir == NULL)
fname = strdup (debuglink);
else if (subdir == NULL)
asprintf (&fname, "%s/%s", dir, debuglink);
else if (dir == NULL)
asprintf (&fname, "%s/%s", subdir, debuglink);
else
asprintf (&fname, "%s/%s/%s", dir, subdir, debuglink);
if (fname == NULL)
return -1;
int fd = TEMP_FAILURE_RETRY (open64 (fname, O_RDONLY));
if (fd < 0)
free (fname);
else
*debuginfo_file_name = fname;
return fd;
}
/* Return true iff the FD's contents CRC matches DEBUGLINK_CRC. */
static inline bool
check_crc (int fd, GElf_Word debuglink_crc)
{
uint32_t file_crc;
return (__libdwfl_crc32_file (fd, &file_crc) == 0
&& file_crc == debuglink_crc);
}
int
dwfl_standard_find_debuginfo (Dwfl_Module *mod,
void **userdata __attribute__ ((unused)),
const char *modname __attribute__ ((unused)),
GElf_Addr base __attribute__ ((unused)),
const char *file_name,
const char *debuglink_file,
GElf_Word debuglink_crc,
char **debuginfo_file_name)
{
bool cancheck = debuglink_crc != (GElf_Word) 0;
const char *file_basename = file_name == NULL ? NULL : basename (file_name);
if (debuglink_file == NULL)
{
if (file_basename == NULL)
{
errno = 0;
return -1;
}
size_t len = strlen (file_basename);
char *localname = alloca (len + sizeof ".debug");
memcpy (localname, file_basename, len);
memcpy (&localname[len], ".debug", sizeof ".debug");
debuglink_file = localname;
cancheck = false;
}
/* Look for a file named DEBUGLINK_FILE in the directories
indicated by the debug directory path setting. */
const Dwfl_Callbacks *const cb = mod->dwfl->callbacks;
char *path = strdupa ((cb->debuginfo_path ? *cb->debuginfo_path : NULL)
?: DEFAULT_DEBUGINFO_PATH);
/* A leading - or + in the whole path sets whether to check file CRCs. */
bool defcheck = true;
if (path[0] == '-' || path[0] == '+')
{
defcheck = path[0] == '+';
++path;
}
char *file_dirname = (file_basename == file_name ? NULL
: strndupa (file_name, file_basename - 1 - file_name));
char *p;
while ((p = strsep (&path, ":")) != NULL)
{
/* A leading - or + says whether to check file CRCs for this element. */
bool check = defcheck;
if (*p == '+' || *p == '-')
check = *p++ == '+';
check = check && cancheck;
const char *dir, *subdir;
switch (p[0])
{
case '\0':
/* An empty entry says to try the main file's directory. */
dir = file_dirname;
subdir = NULL;
break;
case '/':
/* An absolute path says to look there for a subdirectory
named by the main file's absolute directory.
This cannot be applied to a relative file name. */
if (file_dirname == NULL || file_dirname[0] != '/')
continue;
dir = p;
subdir = file_dirname + 1;
break;
default:
/* A relative path says to try a subdirectory of that name
in the main file's directory. */
dir = file_dirname;
subdir = p;
break;
}
char *fname;
int fd = try_open (dir, subdir, debuglink_file, &fname);
if (fd < 0)
switch (errno)
{
case ENOENT:
case ENOTDIR:
continue;
default:
return -1;
}
if (!check || check_crc (fd, debuglink_crc))
{
*debuginfo_file_name = fname;
return fd;
}
free (fname);
close (fd);
}
/* No dice. */
errno = 0;
return -1;
}
INTDEF (dwfl_standard_find_debuginfo)
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