blob: 19acf4775d3587a44d6fd05ed43f5603d3b1b735 [file] [log] [blame] [edit]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* DWARF debug information handling code. Copied from probe-finder.c.
*
* Written by Masami Hiramatsu <mhiramat@redhat.com>
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/zalloc.h>
#include "build-id.h"
#include "dso.h"
#include "debug.h"
#include "debuginfo.h"
#include "symbol.h"
#ifdef HAVE_DEBUGINFOD_SUPPORT
#include <elfutils/debuginfod.h>
#endif
/* Dwarf FL wrappers */
static char *debuginfo_path; /* Currently dummy */
static const Dwfl_Callbacks offline_callbacks = {
.find_debuginfo = dwfl_standard_find_debuginfo,
.debuginfo_path = &debuginfo_path,
.section_address = dwfl_offline_section_address,
/* We use this table for core files too. */
.find_elf = dwfl_build_id_find_elf,
};
/* Get a Dwarf from offline image */
static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
const char *path)
{
GElf_Addr dummy;
int fd;
fd = open(path, O_RDONLY);
if (fd < 0)
return fd;
dbg->dwfl = dwfl_begin(&offline_callbacks);
if (!dbg->dwfl)
goto error;
dwfl_report_begin(dbg->dwfl);
dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
if (!dbg->mod)
goto error;
dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
if (!dbg->dbg)
goto error;
dwfl_module_build_id(dbg->mod, &dbg->build_id, &dummy);
dwfl_report_end(dbg->dwfl, NULL, NULL);
return 0;
error:
if (dbg->dwfl)
dwfl_end(dbg->dwfl);
else
close(fd);
memset(dbg, 0, sizeof(*dbg));
return -ENOENT;
}
static struct debuginfo *__debuginfo__new(const char *path)
{
struct debuginfo *dbg = zalloc(sizeof(*dbg));
if (!dbg)
return NULL;
if (debuginfo__init_offline_dwarf(dbg, path) < 0)
zfree(&dbg);
if (dbg)
pr_debug("Open Debuginfo file: %s\n", path);
return dbg;
}
enum dso_binary_type distro_dwarf_types[] = {
DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
DSO_BINARY_TYPE__NOT_FOUND,
};
struct debuginfo *debuginfo__new(const char *path)
{
enum dso_binary_type *type;
char buf[PATH_MAX], nil = '\0';
struct dso *dso;
struct debuginfo *dinfo = NULL;
struct build_id bid;
/* Try to open distro debuginfo files */
dso = dso__new(path);
if (!dso)
goto out;
/* Set the build id for DSO_BINARY_TYPE__BUILDID_DEBUGINFO */
if (is_regular_file(path) && filename__read_build_id(path, &bid) > 0)
dso__set_build_id(dso, &bid);
for (type = distro_dwarf_types;
!dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
type++) {
if (dso__read_binary_type_filename(dso, *type, &nil,
buf, PATH_MAX) < 0)
continue;
dinfo = __debuginfo__new(buf);
}
dso__put(dso);
out:
/* if failed to open all distro debuginfo, open given binary */
return dinfo ? : __debuginfo__new(path);
}
void debuginfo__delete(struct debuginfo *dbg)
{
if (dbg) {
if (dbg->dwfl)
dwfl_end(dbg->dwfl);
free(dbg);
}
}
/* For the kernel module, we need a special code to get a DIE */
int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,
bool adjust_offset)
{
int n, i;
Elf32_Word shndx;
Elf_Scn *scn;
Elf *elf;
GElf_Shdr mem, *shdr;
const char *p;
elf = dwfl_module_getelf(dbg->mod, &dbg->bias);
if (!elf)
return -EINVAL;
/* Get the number of relocations */
n = dwfl_module_relocations(dbg->mod);
if (n < 0)
return -ENOENT;
/* Search the relocation related .text section */
for (i = 0; i < n; i++) {
p = dwfl_module_relocation_info(dbg->mod, i, &shndx);
if (strcmp(p, ".text") == 0) {
/* OK, get the section header */
scn = elf_getscn(elf, shndx);
if (!scn)
return -ENOENT;
shdr = gelf_getshdr(scn, &mem);
if (!shdr)
return -ENOENT;
*offs = shdr->sh_addr;
if (adjust_offset)
*offs -= shdr->sh_offset;
}
}
return 0;
}
#ifdef HAVE_DEBUGINFOD_SUPPORT
int get_source_from_debuginfod(const char *raw_path,
const char *sbuild_id, char **new_path)
{
debuginfod_client *c = debuginfod_begin();
const char *p = raw_path;
int fd;
if (!c)
return -ENOMEM;
fd = debuginfod_find_source(c, (const unsigned char *)sbuild_id,
0, p, new_path);
pr_debug("Search %s from debuginfod -> %d\n", p, fd);
if (fd >= 0)
close(fd);
debuginfod_end(c);
if (fd < 0) {
pr_debug("Failed to find %s in debuginfod (%s)\n",
raw_path, sbuild_id);
return -ENOENT;
}
pr_debug("Got a source %s\n", *new_path);
return 0;
}
#endif /* HAVE_DEBUGINFOD_SUPPORT */