static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
{
struct probe_finder *pf = data;
struct perf_probe_point *pp = &pf->pev->point;
Dwarf_Addr addr;
int ret;
if (pp->lazy_line)
ret = find_probe_point_lazy(in_die, pf);
else {
if (dwarf_entrypc(in_die, &addr) != 0) {
pr_warning("Failed to get entry address of %s.\n",
dwarf_diename(in_die));
return -ENOENT;
}
pf->addr = addr;
pf->addr += pp->offset;
pr_debug("found inline addr: 0x%jx\n",
(uintmax_t)pf->addr);
ret = call_probe_finder(in_die, pf);
}
return ret;
}
static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
{
struct dwarf_callback_param *param = data;
struct probe_finder *pf = param->data;
struct perf_probe_point *pp = &pf->pev->point;
Dwarf_Addr addr;
if (pp->lazy_line)
param->retval = find_probe_point_lazy(in_die, pf);
else {
/* Get probe address */
if (dwarf_entrypc(in_die, &addr) != 0) {
pr_warning("Failed to get entry address of %s.\n",
dwarf_diename(in_die));
param->retval = -ENOENT;
return DWARF_CB_ABORT;
}
pf->addr = addr;
pf->addr += pp->offset;
pr_debug("found inline addr: 0x%jx\n",
(uintmax_t)pf->addr);
param->retval = call_probe_finder(in_die, pf);
if (param->retval < 0)
return DWARF_CB_ABORT;
}
return DWARF_CB_OK;
}
static int probe_point_lazy_walker(const char *fname, int lineno,
Dwarf_Addr addr, void *data)
{
struct probe_finder *pf = data;
Dwarf_Die *sc_die, die_mem;
int ret;
if (!line_list__has_line(&pf->lcache, lineno) ||
strtailcmp(fname, pf->fname) != 0)
return 0;
pr_debug("Probe line found: line:%d addr:0x%llx\n",
lineno, (unsigned long long)addr);
pf->addr = addr;
pf->lno = lineno;
sc_die = find_best_scope(pf, &die_mem);
if (!sc_die) {
pr_warning("Failed to find scope of probe point.\n");
return -ENOENT;
}
ret = call_probe_finder(sc_die, pf);
return ret < 0 ? ret : 0;
}
static int probe_point_line_walker(const char *fname, int lineno,
Dwarf_Addr addr, void *data)
{
struct probe_finder *pf = data;
int ret;
if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
return 0;
pf->addr = addr;
ret = call_probe_finder(NULL, pf);
/* Continue if no error, because the line will be in inline function */
return ret < 0 ? ret : 0;
}
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;
Dwarf_Attribute attr;
if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
!die_compare_name(sp_die, pp->function) ||
dwarf_attr(sp_die, DW_AT_declaration, &attr))
return DWARF_CB_OK;
if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
return DWARF_CB_OK;
pf->fname = dwarf_decl_file(sp_die);
if (pp->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)) {
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;
param->retval = call_probe_finder(sp_die, pf);
}
} else
param->retval = die_walk_instances(sp_die,
probe_point_inline_cb, (void *)pf);
return DWARF_CB_ABORT;
}
/* 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;
/* Check declared file */
if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
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
/* Inlined function: search instances */
param->retval = die_walk_instances(sp_die,
probe_point_inline_cb, (void *)pf);
return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
}
static int probe_point_lazy_walker(const char *fname, int lineno,
Dwarf_Addr addr, void *data)
{
struct probe_finder *pf = data;
int ret;
if (!line_list__has_line(&pf->lcache, lineno) ||
strtailcmp(fname, pf->fname) != 0)
return 0;
pr_debug("Probe line found: line:%d addr:0x%llx\n",
lineno, (unsigned long long)addr);
pf->addr = addr;
ret = call_probe_finder(NULL, pf);
/*
* Continue if no error, because the lazy pattern will match
* to other lines
*/
return ret < 0 ? ret : 0;
}
static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
{
struct find_scope_param fsp = {
.function = pf->pev->point.function,
.file = pf->fname,
.line = pf->lno,
.diff = INT_MAX,
.die_mem = die_mem,
.found = false,
};
cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
return fsp.found ? die_mem : NULL;
}
static int probe_point_line_walker(const char *fname, int lineno,
Dwarf_Addr addr, void *data)
{
struct probe_finder *pf = data;
Dwarf_Die *sc_die, die_mem;
int ret;
if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
return 0;
pf->addr = addr;
sc_die = find_best_scope(pf, &die_mem);
if (!sc_die) {
pr_warning("Failed to find scope of probe point.\n");
return -ENOENT;
}
ret = call_probe_finder(sc_die, pf);
return ret < 0 ? ret : 0;
}
static int find_probe_point_by_line(struct probe_finder *pf)
{
return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
}
static int find_lazy_match_lines(struct list_head *head,
const char *fname, const char *pat)
{
FILE *fp;
char *line = NULL;
size_t line_len;
ssize_t len;
int count = 0, linenum = 1;
fp = fopen(fname, "r");
if (!fp) {
pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
return -errno;
}
while ((len = getline(&line, &line_len, fp)) > 0) {
if (line[len - 1] == '\n')
line[len - 1] = '\0';
if (strlazymatch(line, pat)) {
line_list__add_line(head, linenum);
count++;
}
linenum++;
}
if (ferror(fp))
count = -errno;
free(line);
fclose(fp);
if (count == 0)
pr_debug("No matched lines found in %s.\n", fname);
return count;
}
/* 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;
}
