/* Get a Dwarf from offline image */
static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
const char *path)
{
int fd;
fd = open(path, O_RDONLY);
if (fd < 0)
return fd;
dbg->dwfl = dwfl_begin(&offline_callbacks);
if (!dbg->dwfl)
goto error;
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;
return 0;
error:
if (dbg->dwfl)
dwfl_end(dbg->dwfl);
else
close(fd);
memset(dbg, 0, sizeof(*dbg));
return -ENOENT;
}
/* Get a Dwarf from live kernel image */
static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
Dwarf_Addr *bias)
{
Dwarf *dbg;
if (!dwflp)
return NULL;
*dwflp = dwfl_begin(&kernel_callbacks);
if (!*dwflp)
return NULL;
/* Load the kernel dwarves: Don't care the result here */
dwfl_linux_kernel_report_kernel(*dwflp);
dwfl_linux_kernel_report_modules(*dwflp);
dbg = dwfl_addrdwarf(*dwflp, addr, bias);
/* Here, check whether we could get a real dwarf */
if (!dbg) {
pr_debug("Failed to find kernel dwarf at %lx\n",
(unsigned long)addr);
dwfl_end(*dwflp);
*dwflp = NULL;
}
return dbg;
}
static int debuginfo__init_offline_dwarf(struct debuginfo *self,
const char *path)
{
Dwfl_Module *mod;
int fd;
fd = open(path, O_RDONLY);
if (fd < 0)
return fd;
self->dwfl = dwfl_begin(&offline_callbacks);
if (!self->dwfl)
goto error;
mod = dwfl_report_offline(self->dwfl, "", "", fd);
if (!mod)
goto error;
self->dbg = dwfl_module_getdwarf(mod, &self->bias);
if (!self->dbg)
goto error;
return 0;
error:
if (self->dwfl)
dwfl_end(self->dwfl);
else
close(fd);
memset(self, 0, sizeof(*self));
return -ENOENT;
}
int
main (int argc, char **argv)
{
char* args[3];
int res = 0;
Dwfl *dwfl;
Dwarf_Addr bias;
if (argc != 2)
fprintf(stderr, "Usage %s <file>", argv[0]);
// Pretend "dwarfsrcfiles -e <file>" was given, so we can use standard
// dwfl argp parser to open the file for us and get our Dwfl. Useful
// in case argument is an ET_REL file (like kernel modules). libdwfl
// will fix up relocations for us.
args[0] = argv[0];
args[1] = "-e";
args[2] = argv[1];
argp_parse (dwfl_standard_argp (), 3, args, 0, NULL, &dwfl);
Dwarf_Die *cu = NULL;
while ((cu = dwfl_nextcu (dwfl, cu, &bias)) != NULL)
res |= process_cu (cu);
dwfl_end (dwfl);
return res;
}
void debuginfo__delete(struct debuginfo *dbg)
{
if (dbg) {
if (dbg->dwfl)
dwfl_end(dbg->dwfl);
free(dbg);
}
}
void debuginfo__delete(struct debuginfo *self)
{
if (self) {
if (self->dwfl)
dwfl_end(self->dwfl);
free(self);
}
}
void
refl_end (struct refl *refl)
{
if (refl != NULL)
{
dwfl_end (refl->dwfl);
}
free (refl);
}
int
main (int argc, char *argv[])
{
int remaining;
/* Set locale. */
(void) setlocale (LC_ALL, "");
Dwfl *dwfl = NULL;
(void) argp_parse (dwfl_standard_argp (), argc, argv, 0, &remaining, &dwfl);
assert (dwfl != NULL);
int result = 0;
/* Now handle the addresses. In case none are given on the command
line, read from stdin. */
if (remaining == argc)
{
/* We use no threads here which can interfere with handling a stream. */
(void) __fsetlocking (stdin, FSETLOCKING_BYCALLER);
char *buf = NULL;
size_t len = 0;
while (!feof_unlocked (stdin))
{
if (getline (&buf, &len, stdin) < 0)
break;
char *endp;
uintmax_t addr = strtoumax (buf, &endp, 0);
if (endp != buf)
result |= handle_address (addr, dwfl);
else
result = 1;
}
free (buf);
}
else
{
do
{
char *endp;
uintmax_t addr = strtoumax (argv[remaining], &endp, 0);
if (endp != argv[remaining])
result |= handle_address (addr, dwfl);
else
result = 1;
}
while (++remaining < argc);
}
dwfl_end (dwfl);
return result;
}
// Create a libdw session with DWARF information for all loaded modules
LibdwSession *libdwInit() {
LibdwSession *session = stgCallocBytes(1, sizeof(LibdwSession),
"libdwInit");
// Initialize ELF library
if (elf_version(EV_CURRENT) == EV_NONE) {
sysErrorBelch("libelf version too old!");
return NULL;
}
// Initialize a libdwfl session
static char *debuginfo_path;
static const Dwfl_Callbacks proc_callbacks =
{
.find_debuginfo = dwfl_standard_find_debuginfo,
.debuginfo_path = &debuginfo_path,
.find_elf = dwfl_linux_proc_find_elf,
};
session->dwfl = dwfl_begin (&proc_callbacks);
if (session->dwfl == NULL) {
sysErrorBelch("dwfl_begin failed: %s", dwfl_errmsg(dwfl_errno()));
free(session);
return NULL;
}
// Report the loaded modules
int ret = dwfl_linux_proc_report(session->dwfl, getpid());
if (ret < 0) {
sysErrorBelch("dwfl_linux_proc_report failed: %s",
dwfl_errmsg(dwfl_errno()));
goto fail;
}
if (dwfl_report_end (session->dwfl, NULL, NULL) != 0) {
sysErrorBelch("dwfl_report_end failed: %s", dwfl_errmsg(dwfl_errno()));
goto fail;
}
pid_t pid = getpid();
if (! dwfl_attach_state(session->dwfl, NULL, pid, &thread_cbs, NULL)) {
sysErrorBelch("dwfl_attach_state failed: %s",
dwfl_errmsg(dwfl_errno()));
goto fail;
}
return session;
fail:
dwfl_end(session->dwfl);
free(session);
return NULL;
}
int
main (void)
{
Dwfl *dwfl = dwfl_begin (&callbacks);
for (int i = 0; i < 5; ++i)
{
dwfl_report_begin (dwfl);
dwfl_report_module (dwfl, "module1", 0, 10);
dwfl_report_end (dwfl, NULL, NULL);
}
dwfl_end (dwfl);
return 0;
}
int main(void)
{
Dwfl *dw;
Dwfl_Module *mod;
Dwarf_Addr bias;
Dwarf_Die *die = NULL;
dw = dwfl_begin(&cb);
if (!dw)
errx(1, "dwfl_begin %s", dwfl_errmsg(-1));
mod = dwfl_report_offline(dw, "", "tst", -1);
if (!mod)
errx(1, "dwfl_begin %s", dwfl_errmsg(-1));
while ((die = dwfl_nextcu(dw, die, &bias))) {
print_die_rec(die, -1);
printf("\n");
}
dwfl_end(dw);
return 0;
}
/* Get a Dwarf from live kernel image */
static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
Dwarf_Addr addr)
{
self->dwfl = dwfl_begin(&kernel_callbacks);
if (!self->dwfl)
return -EINVAL;
/* Load the kernel dwarves: Don't care the result here */
dwfl_linux_kernel_report_kernel(self->dwfl);
dwfl_linux_kernel_report_modules(self->dwfl);
self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias);
/* Here, check whether we could get a real dwarf */
if (!self->dbg) {
pr_debug("Failed to find kernel dwarf at %lx\n",
(unsigned long)addr);
dwfl_end(self->dwfl);
memset(self, 0, sizeof(*self));
return -ENOENT;
}
return 0;
}
static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
Dwarf_Addr addr)
{
self->dwfl = dwfl_begin(&kernel_callbacks);
if (!self->dwfl)
return -EINVAL;
dwfl_linux_kernel_report_kernel(self->dwfl);
dwfl_linux_kernel_report_modules(self->dwfl);
self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias);
if (!self->dbg) {
pr_debug("Failed to find kernel dwarf at %lx\n",
(unsigned long)addr);
dwfl_end(self->dwfl);
memset(self, 0, sizeof(*self));
return -ENOENT;
}
return 0;
}
void
core_handle_free(struct core_handle *ch)
{
if (ch)
{
struct exe_mapping_data *seg = ch->segments, *next;
while (seg)
{
free(seg->filename);
next = seg->next;
free(seg);
seg = next;
}
if (ch->dwfl)
dwfl_end(ch->dwfl);
if (ch->eh)
elf_end(ch->eh);
if (ch->fd > 0)
close(ch->fd);
free(ch);
}
}
/* Get a Dwarf from offline image */
static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
{
Dwfl_Module *mod;
Dwarf *dbg = NULL;
if (!dwflp)
return NULL;
*dwflp = dwfl_begin(&offline_callbacks);
if (!*dwflp)
return NULL;
mod = dwfl_report_offline(*dwflp, "", "", fd);
if (!mod)
goto error;
dbg = dwfl_module_getdwarf(mod, bias);
if (!dbg) {
error:
dwfl_end(*dwflp);
*dwflp = NULL;
}
return dbg;
}
int
main (int argc, char *argv[])
{
int remaining;
/* Set locale. */
(void) setlocale (LC_ALL, "");
struct args a = { .dwfl = NULL, .cu = NULL };
(void) argp_parse (dwfl_standard_argp (), argc, argv, 0, &remaining,
&a.dwfl);
assert (a.dwfl != NULL);
a.argv = &argv[remaining];
int result = 0;
while ((a.cu = dwfl_nextcu (a.dwfl, a.cu, &a.dwbias)) != NULL)
dwarf_getfuncs (a.cu, &handle_function, &a, 0);
dwfl_end (a.dwfl);
return result;
}
struct core_handle *
open_coredump(const char *elf_file, const char *exe_file, char **error_msg)
{
struct core_handle *ch = sr_mallocz(sizeof(*ch));
struct exe_mapping_data *head = NULL, **tail = &head;
/* Initialize libelf, open the file and get its Elf handle. */
if (elf_version(EV_CURRENT) == EV_NONE)
{
set_error_elf("elf_version");
goto fail_free;
}
/* Open input file, and parse it. */
ch->fd = open(elf_file, O_RDONLY);
if (ch->fd < 0)
{
set_error("Unable to open '%s': %s", elf_file, strerror(errno));
goto fail_free;
}
ch->eh = elf_begin(ch->fd, ELF_C_READ_MMAP, NULL);
if (ch->eh == NULL)
{
set_error_elf("elf_begin");
goto fail_close;
}
/* Check that we are working with a coredump. */
GElf_Ehdr ehdr;
if (gelf_getehdr(ch->eh, &ehdr) == NULL || ehdr.e_type != ET_CORE)
{
set_error("File '%s' is not a coredump", elf_file);
goto fail_elf;
}
executable_file = exe_file;
ch->cb.find_elf = find_elf_core;
ch->cb.find_debuginfo = find_debuginfo_none;
ch->cb.section_address = dwfl_offline_section_address;
ch->dwfl = dwfl_begin(&ch->cb);
#if _ELFUTILS_PREREQ(0, 158)
if (dwfl_core_file_report(ch->dwfl, ch->eh, exe_file) == -1)
#else
if (dwfl_core_file_report(ch->dwfl, ch->eh) == -1)
#endif
{
set_error_dwfl("dwfl_core_file_report");
goto fail_dwfl;
}
if (dwfl_report_end(ch->dwfl, NULL, NULL) != 0)
{
set_error_dwfl("dwfl_report_end");
goto fail_dwfl;
}
/* needed so that module filenames are available during unwinding */
ptrdiff_t ret = dwfl_getmodules(ch->dwfl, touch_module, &tail, 0);
if (ret == -1)
{
set_error_dwfl("dwfl_getmodules");
goto fail_dwfl;
}
ch->segments = head;
if (!head)
{
if (error_msg && !*error_msg)
set_error("No segments found in coredump '%s'", elf_file);
goto fail_dwfl;
}
return ch;
fail_dwfl:
dwfl_end(ch->dwfl);
fail_elf:
elf_end(ch->eh);
fail_close:
close(ch->fd);
fail_free:
free(ch);
return NULL;
}
int
main (int argc, char *argv[])
{
int remaining;
int result = 0;
/* We use no threads here which can interfere with handling a stream. */
(void) __fsetlocking (stdout, FSETLOCKING_BYCALLER);
/* Set locale. */
(void) setlocale (LC_ALL, "");
/* Make sure the message catalog can be found. */
(void) bindtextdomain (PACKAGE_TARNAME, LOCALEDIR);
/* Initialize the message catalog. */
(void) textdomain (PACKAGE_TARNAME);
/* Parse and process arguments. This includes opening the modules. */
argp_children[0].argp = dwfl_standard_argp ();
argp_children[0].group = 1;
Dwfl *dwfl = NULL;
(void) argp_parse (&argp, argc, argv, 0, &remaining, &dwfl);
assert (dwfl != NULL);
/* Now handle the addresses. In case none are given on the command
line, read from stdin. */
if (remaining == argc)
{
/* We use no threads here which can interfere with handling a stream. */
(void) __fsetlocking (stdin, FSETLOCKING_BYCALLER);
char *buf = NULL;
size_t len = 0;
ssize_t chars;
while (!feof_unlocked (stdin))
{
if ((chars = getline (&buf, &len, stdin)) < 0)
break;
if (buf[chars - 1] == '\n')
buf[chars - 1] = '\0';
result = handle_address (buf, dwfl);
}
free (buf);
}
else
{
do
result = handle_address (argv[remaining], dwfl);
while (++remaining < argc);
}
dwfl_end (dwfl);
#ifdef USE_DEMANGLE
free (demangle_buffer);
#endif
return result;
}
int coredump_make_stack_trace(int fd, const char *executable, char **ret) {
static const Dwfl_Callbacks callbacks = {
.find_elf = dwfl_build_id_find_elf,
.find_debuginfo = dwfl_standard_find_debuginfo,
};
struct stack_context c = {};
char *buf = NULL;
size_t sz = 0;
int r;
assert(fd >= 0);
assert(ret);
if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
return -errno;
c.f = open_memstream(&buf, &sz);
if (!c.f)
return -ENOMEM;
elf_version(EV_CURRENT);
c.elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
if (!c.elf) {
r = -EINVAL;
goto finish;
}
c.dwfl = dwfl_begin(&callbacks);
if (!c.dwfl) {
r = -EINVAL;
goto finish;
}
if (dwfl_core_file_report(c.dwfl, c.elf, executable) < 0) {
r = -EINVAL;
goto finish;
}
if (dwfl_report_end(c.dwfl, NULL, NULL) != 0) {
r = -EINVAL;
goto finish;
}
if (dwfl_core_file_attach(c.dwfl, c.elf) < 0) {
r = -EINVAL;
goto finish;
}
if (dwfl_getthreads(c.dwfl, thread_callback, &c) < 0) {
r = -EINVAL;
goto finish;
}
c.f = safe_fclose(c.f);
*ret = buf;
buf = NULL;
r = 0;
finish:
if (c.dwfl)
dwfl_end(c.dwfl);
if (c.elf)
elf_end(c.elf);
safe_fclose(c.f);
free(buf);
return r;
}
/* Search function from function name */
static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
{
struct dwarf_callback_param *param = data;
struct probe_finder *pf = param->data;
struct perf_probe_point *pp = &pf->pev->point;
/* Check tag and diename */
if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
!die_compare_name(sp_die, pp->function))
return DWARF_CB_OK;
pf->fname = dwarf_decl_file(sp_die);
if (pp->line) { /* Function relative line */
dwarf_decl_line(sp_die, &pf->lno);
pf->lno += pp->line;
param->retval = find_probe_point_by_line(pf);
} else if (!dwarf_func_inline(sp_die)) {
/* Real function */
if (pp->lazy_line)
param->retval = find_probe_point_lazy(sp_die, pf);
else {
if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
pr_warning("Failed to get entry address of "
"%s.\n", dwarf_diename(sp_die));
param->retval = -ENOENT;
return DWARF_CB_ABORT;
}
pf->addr += pp->offset;
/* TODO: Check the address in this function */
param->retval = call_probe_finder(sp_die, pf);
}
} else {
struct dwarf_callback_param _param = {.data = (void *)pf,
.retval = 0};
/* Inlined function: search instances */
dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
&_param);
param->retval = _param.retval;
}
return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
}
static int find_probe_point_by_func(struct probe_finder *pf)
{
struct dwarf_callback_param _param = {.data = (void *)pf,
.retval = 0};
dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
return _param.retval;
}
/* Find probe points from debuginfo */
static int find_probes(int fd, struct probe_finder *pf)
{
struct perf_probe_point *pp = &pf->pev->point;
Dwarf_Off off, noff;
size_t cuhl;
Dwarf_Die *diep;
Dwarf *dbg = NULL;
Dwfl *dwfl;
Dwarf_Addr bias; /* Currently ignored */
int ret = 0;
dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
if (!dbg) {
pr_warning("No debug information found in the vmlinux - "
"please rebuild with CONFIG_DEBUG_INFO=y.\n");
return -EBADF;
}
#if _ELFUTILS_PREREQ(0, 142)
/* Get the call frame information from this dwarf */
pf->cfi = dwarf_getcfi(dbg);
#endif
off = 0;
line_list__init(&pf->lcache);
/* Loop on CUs (Compilation Unit) */
while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
/* Get the DIE(Debugging Information Entry) of this CU */
diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
if (!diep)
continue;
/* Check if target file is included. */
if (pp->file)
pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
else
pf->fname = NULL;
if (!pp->file || pf->fname) {
if (pp->function)
ret = find_probe_point_by_func(pf);
else if (pp->lazy_line)
ret = find_probe_point_lazy(NULL, pf);
else {
pf->lno = pp->line;
ret = find_probe_point_by_line(pf);
}
if (ret < 0)
break;
}
off = noff;
}
line_list__free(&pf->lcache);
if (dwfl)
dwfl_end(dwfl);
return ret;
}
/* Add a found probe point into trace event list */
static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
{
struct trace_event_finder *tf =
container_of(pf, struct trace_event_finder, pf);
struct probe_trace_event *tev;
int ret, i;
/* Check number of tevs */
if (tf->ntevs == tf->max_tevs) {
pr_warning("Too many( > %d) probe point found.\n",
tf->max_tevs);
return -ERANGE;
}
tev = &tf->tevs[tf->ntevs++];
ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
&tev->point);
if (ret < 0)
return ret;
pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
tev->point.offset);
/* Find each argument */
tev->nargs = pf->pev->nargs;
tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
if (tev->args == NULL)
return -ENOMEM;
for (i = 0; i < pf->pev->nargs; i++) {
pf->pvar = &pf->pev->args[i];
pf->tvar = &tev->args[i];
ret = find_variable(sp_die, pf);
if (ret != 0)
return ret;
}
return 0;
}
/* Find probe_trace_events specified by perf_probe_event from debuginfo */
int find_probe_trace_events(int fd, struct perf_probe_event *pev,
struct probe_trace_event **tevs, int max_tevs)
{
struct trace_event_finder tf = {
.pf = {.pev = pev, .callback = add_probe_trace_event},
.max_tevs = max_tevs};
int ret;
/* Allocate result tevs array */
*tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
if (*tevs == NULL)
return -ENOMEM;
tf.tevs = *tevs;
tf.ntevs = 0;
ret = find_probes(fd, &tf.pf);
if (ret < 0) {
free(*tevs);
*tevs = NULL;
return ret;
}
return (ret < 0) ? ret : tf.ntevs;
}
#define MAX_VAR_LEN 64
/* Collect available variables in this scope */
static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
{
struct available_var_finder *af = data;
struct variable_list *vl;
char buf[MAX_VAR_LEN];
int tag, ret;
vl = &af->vls[af->nvls - 1];
tag = dwarf_tag(die_mem);
if (tag == DW_TAG_formal_parameter ||
tag == DW_TAG_variable) {
ret = convert_variable_location(die_mem, af->pf.addr,
af->pf.fb_ops, NULL);
if (ret == 0) {
ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
pr_debug2("Add new var: %s\n", buf);
if (ret > 0)
strlist__add(vl->vars, buf);
}
}
if (af->child && dwarf_haspc(die_mem, af->pf.addr))
return DIE_FIND_CB_CONTINUE;
else
return DIE_FIND_CB_SIBLING;
}
/* Add a found vars into available variables list */
static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
{
struct available_var_finder *af =
container_of(pf, struct available_var_finder, pf);
struct variable_list *vl;
Dwarf_Die die_mem, *scopes = NULL;
int ret, nscopes;
/* Check number of tevs */
if (af->nvls == af->max_vls) {
pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
return -ERANGE;
}
vl = &af->vls[af->nvls++];
ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
&vl->point);
if (ret < 0)
return ret;
pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
vl->point.offset);
/* Find local variables */
vl->vars = strlist__new(true, NULL);
if (vl->vars == NULL)
return -ENOMEM;
af->child = true;
die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
/* Find external variables */
if (!af->externs)
goto out;
/* Don't need to search child DIE for externs. */
af->child = false;
nscopes = dwarf_getscopes_die(sp_die, &scopes);
while (nscopes-- > 1)
die_find_child(&scopes[nscopes], collect_variables_cb,
(void *)af, &die_mem);
if (scopes)
free(scopes);
out:
if (strlist__empty(vl->vars)) {
strlist__delete(vl->vars);
vl->vars = NULL;
}
return ret;
}
/* Find available variables at given probe point */
int find_available_vars_at(int fd, struct perf_probe_event *pev,
struct variable_list **vls, int max_vls,
bool externs)
{
struct available_var_finder af = {
.pf = {.pev = pev, .callback = add_available_vars},
.max_vls = max_vls, .externs = externs};
int ret;
/* Allocate result vls array */
*vls = zalloc(sizeof(struct variable_list) * max_vls);
if (*vls == NULL)
return -ENOMEM;
af.vls = *vls;
af.nvls = 0;
ret = find_probes(fd, &af.pf);
if (ret < 0) {
/* Free vlist for error */
while (af.nvls--) {
if (af.vls[af.nvls].point.symbol)
free(af.vls[af.nvls].point.symbol);
if (af.vls[af.nvls].vars)
strlist__delete(af.vls[af.nvls].vars);
}
free(af.vls);
*vls = NULL;
return ret;
}
return (ret < 0) ? ret : af.nvls;
}
/* Reverse search */
int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
{
Dwarf_Die cudie, spdie, indie;
Dwarf *dbg = NULL;
Dwfl *dwfl = NULL;
Dwarf_Line *line;
Dwarf_Addr laddr, eaddr, bias = 0;
const char *tmp;
int lineno, ret = 0;
bool found = false;
/* Open the live linux kernel */
dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
if (!dbg) {
pr_warning("No debug information found in the vmlinux - "
"please rebuild with CONFIG_DEBUG_INFO=y.\n");
ret = -EINVAL;
goto end;
}
/* Adjust address with bias */
addr += bias;
/* Find cu die */
if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
pr_warning("Failed to find debug information for address %lx\n",
addr);
ret = -EINVAL;
goto end;
}
/* Find a corresponding line */
line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
if (line) {
if (dwarf_lineaddr(line, &laddr) == 0 &&
(Dwarf_Addr)addr == laddr &&
dwarf_lineno(line, &lineno) == 0) {
tmp = dwarf_linesrc(line, NULL, NULL);
if (tmp) {
ppt->line = lineno;
ppt->file = strdup(tmp);
if (ppt->file == NULL) {
ret = -ENOMEM;
goto end;
}
found = true;
}
}
}
/* Find a corresponding function */
if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
tmp = dwarf_diename(&spdie);
if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
goto end;
if (ppt->line) {
if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
&indie)) {
/* addr in an inline function */
tmp = dwarf_diename(&indie);
if (!tmp)
goto end;
ret = dwarf_decl_line(&indie, &lineno);
} else {
if (eaddr == addr) { /* Function entry */
lineno = ppt->line;
ret = 0;
} else
ret = dwarf_decl_line(&spdie, &lineno);
}
if (ret == 0) {
/* Make a relative line number */
ppt->line -= lineno;
goto found;
}
}
/* We don't have a line number, let's use offset */
ppt->offset = addr - (unsigned long)eaddr;
found:
ppt->function = strdup(tmp);
if (ppt->function == NULL) {
ret = -ENOMEM;
goto end;
}
found = true;
}
end:
if (dwfl)
dwfl_end(dwfl);
if (ret >= 0)
ret = found ? 1 : 0;
return ret;
}
static int find_line_range_by_func(struct line_finder *lf)
{
struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0);
return param.retval;
}
int find_line_range(int fd, struct line_range *lr)
{
struct line_finder lf = {.lr = lr, .found = 0};
int ret = 0;
Dwarf_Off off = 0, noff;
size_t cuhl;
Dwarf_Die *diep;
Dwarf *dbg = NULL;
Dwfl *dwfl;
Dwarf_Addr bias; /* Currently ignored */
const char *comp_dir;
dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
if (!dbg) {
pr_warning("No debug information found in the vmlinux - "
"please rebuild with CONFIG_DEBUG_INFO=y.\n");
return -EBADF;
}
/* Loop on CUs (Compilation Unit) */
while (!lf.found && ret >= 0) {
if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
break;
/* Get the DIE(Debugging Information Entry) of this CU */
diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
if (!diep)
continue;
/* Check if target file is included. */
if (lr->file)
lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
else
lf.fname = 0;
if (!lr->file || lf.fname) {
if (lr->function)
ret = find_line_range_by_func(&lf);
else {
lf.lno_s = lr->start;
lf.lno_e = lr->end;
ret = find_line_range_by_line(NULL, &lf);
}
}
off = noff;
}
/* Store comp_dir */
if (lf.found) {
comp_dir = cu_get_comp_dir(&lf.cu_die);
if (comp_dir) {
lr->comp_dir = strdup(comp_dir);
if (!lr->comp_dir)
ret = -ENOMEM;
}
}
pr_debug("path: %s\n", lr->path);
dwfl_end(dwfl);
return (ret < 0) ? ret : lf.found;
}
void libdwFree(LibdwSession *session) {
if (session == NULL)
return;
dwfl_end(session->dwfl);
stgFree(session);
}
/*
* Return:
* 0 if return address for the program counter @pc is on stack
* 1 if return address is in LR and no new stack frame was allocated
* 2 if return address is in LR and a new frame was allocated (but not
* yet used)
* -1 in case of errors
*/
static int check_return_addr(struct dso *dso, u64 map_start, Dwarf_Addr pc)
{
int rc = -1;
Dwfl *dwfl;
Dwfl_Module *mod;
Dwarf_Frame *frame;
int ra_regno;
Dwarf_Addr start = pc;
Dwarf_Addr end = pc;
bool signalp;
const char *exec_file = dso->long_name;
dwfl = dso->dwfl;
if (!dwfl) {
dwfl = dwfl_begin(&offline_callbacks);
if (!dwfl) {
pr_debug("dwfl_begin() failed: %s\n", dwarf_errmsg(-1));
return -1;
}
mod = dwfl_report_elf(dwfl, exec_file, exec_file, -1,
map_start, false);
if (!mod) {
pr_debug("dwfl_report_elf() failed %s\n",
dwarf_errmsg(-1));
/*
* We normally cache the DWARF debug info and never
* call dwfl_end(). But to prevent fd leak, free in
* case of error.
*/
dwfl_end(dwfl);
goto out;
}
dso->dwfl = dwfl;
}
mod = dwfl_addrmodule(dwfl, pc);
if (!mod) {
pr_debug("dwfl_addrmodule() failed, %s\n", dwarf_errmsg(-1));
goto out;
}
/*
* To work with split debug info files (eg: glibc), check both
* .eh_frame and .debug_frame sections of the ELF header.
*/
frame = get_eh_frame(mod, pc);
if (!frame) {
frame = get_dwarf_frame(mod, pc);
if (!frame)
goto out;
}
ra_regno = dwarf_frame_info(frame, &start, &end, &signalp);
if (ra_regno < 0) {
pr_debug("Return address register unavailable: %s\n",
dwarf_errmsg(-1));
goto out;
}
rc = check_return_reg(ra_regno, frame);
out:
return rc;
}
int
main (int argc, char *argv[])
{
int cnt;
Dwfl *dwfl = NULL;
(void) argp_parse (dwfl_standard_argp (), argc, argv, 0, &cnt, &dwfl);
assert (dwfl != NULL);
Dwarf_Die *cu = NULL;
Dwarf_Addr bias;
do
{
cu = dwfl_nextcu (dwfl, cu, &bias);
if (cu != NULL)
{
Dwfl_Module *mod = dwfl_cumodule (cu);
const char *modname = (dwfl_module_info (mod, NULL, NULL, NULL,
NULL, NULL, NULL, NULL)
?: "<unknown>");
const char *cuname = (dwarf_diename (cu) ?: "<unknown>");
printf ("mod: %s CU: [%" PRIx64 "] %s\n", modname,
dwarf_dieoffset (cu), cuname);
size_t lines;
if (dwfl_getsrclines (cu, &lines) != 0)
continue; // No lines...
for (size_t i = 0; i < lines; i++)
{
Dwfl_Line *line = dwfl_onesrcline (cu, i);
Dwarf_Addr addr;
int lineno;
int colno;
Dwarf_Word mtime;
Dwarf_Word length;
const char *src = dwfl_lineinfo (line, &addr, &lineno, &colno,
&mtime, &length);
Dwarf_Addr dw_bias;
Dwarf_Line *dw_line = dwfl_dwarf_line (line, &dw_bias);
assert (bias == dw_bias);
Dwarf_Addr dw_addr;
if (dwarf_lineaddr (dw_line, &dw_addr) != 0)
error (EXIT_FAILURE, 0, "dwarf_lineaddr: %s",
dwarf_errmsg (-1));
assert (addr == dw_addr + dw_bias);
unsigned int dw_op_index;
if (dwarf_lineop_index (dw_line, &dw_op_index) != 0)
error (EXIT_FAILURE, 0, "dwarf_lineop_index: %s",
dwarf_errmsg (-1));
int dw_lineno;
if (dwarf_lineno (dw_line, &dw_lineno) != 0)
error (EXIT_FAILURE, 0, "dwarf_lineno: %s",
dwarf_errmsg (-1));
assert (lineno == dw_lineno);
int dw_colno;
if (dwarf_linecol (dw_line, &dw_colno) != 0)
error (EXIT_FAILURE, 0, "dwarf_lineno: %s",
dwarf_errmsg (-1));
assert (colno == dw_colno);
bool begin;
if (dwarf_linebeginstatement (dw_line, &begin) != 0)
error (EXIT_FAILURE, 0, "dwarf_linebeginstatement: %s",
dwarf_errmsg (-1));
bool end;
if (dwarf_lineendsequence (dw_line, &end) != 0)
error (EXIT_FAILURE, 0, "dwarf_lineendsequence: %s",
dwarf_errmsg (-1));
bool pend;
if (dwarf_lineprologueend (dw_line, &pend) != 0)
error (EXIT_FAILURE, 0, "dwarf_lineprologueend: %s",
dwarf_errmsg (-1));
bool ebegin;
if (dwarf_lineepiloguebegin (dw_line, &ebegin) != 0)
error (EXIT_FAILURE, 0, "dwarf_lineepiloguebegin: %s",
dwarf_errmsg (-1));
bool block;
if (dwarf_lineblock (dw_line, &block) != 0)
error (EXIT_FAILURE, 0, "dwarf_lineblock: %s",
dwarf_errmsg (-1));
unsigned int isa;
if (dwarf_lineisa (dw_line, &isa) != 0)
error (EXIT_FAILURE, 0, "dwarf_lineisa: %s",
dwarf_errmsg (-1));
unsigned int disc;
if (dwarf_linediscriminator (dw_line, &disc) != 0)
error (EXIT_FAILURE, 0, "dwarf_linediscriminator: %s",
dwarf_errmsg (-1));
const char *dw_src;
Dwarf_Word dw_mtime;
Dwarf_Word dw_length;
dw_src = dwarf_linesrc (dw_line, &dw_mtime, &dw_length);
assert (strcmp (src, dw_src) == 0);
assert (mtime == dw_mtime);
assert (length == dw_length);
printf ("%zd %#" PRIx64 " %s:%d:%d\n"
" time: %#" PRIX64 ", len: %" PRIu64
", idx: %d, b: %d, e: %d"
", pe: %d, eb: %d, block: %d"
", isa: %d, disc: %d\n",
i, addr, src, lineno, colno, mtime, length,
dw_op_index, begin, end, pend, ebegin, block, isa, disc);
Dwarf_Die *linecu = dwfl_linecu (line);
assert (cu == linecu);
Dwfl_Module *linemod = dwfl_linemodule (line);
assert (mod == linemod);
}
}
}
while (cu != NULL);
dwfl_end (dwfl);
return 0;
}
