1 files changed, 142 insertions, 89 deletions

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 3e44a3e36519..555fc3864b90 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -612,12 +612,12 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
         return ret;
 }
 
-/* Find a variable in a subprogram die */
-static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
+/* Find a variable in a scope DIE */
+static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
 {
-        Dwarf_Die vr_die, *scopes;
+        Dwarf_Die vr_die;
         char buf[32], *ptr;
-        int ret, nscopes;
+        int ret = 0;
 
         if (!is_c_varname(pf->pvar->var)) {
                 /* Copy raw parameters */
@@ -652,30 +652,16 @@ static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
         if (pf->tvar->name == NULL)
                 return -ENOMEM;
 
-        pr_debug("Searching '%s' variable in context.\n",
-                 pf->pvar->var);
+        pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
         /* Search child die for local variables and parameters. */
-        if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
-                ret = convert_variable(&vr_die, pf);
-        else {
-                /* Search upper class */
-                nscopes = dwarf_getscopes_die(sp_die, &scopes);
-                while (nscopes-- > 1) {
-                        pr_debug("Searching variables in %s\n",
-                                 dwarf_diename(&scopes[nscopes]));
-                        /* We should check this scope, so give dummy address */
-                        if (die_find_variable_at(&scopes[nscopes],
-                                                 pf->pvar->var, 0,
-                                                 &vr_die)) {
-                                ret = convert_variable(&vr_die, pf);
-                                goto found;
-                        }
-                }
-                if (scopes)
-                        free(scopes);
-                ret = -ENOENT;
+        if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
+                /* Search again in global variables */
+                if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
+                        ret = -ENOENT;
         }
-found:
+        if (ret == 0)
+                ret = convert_variable(&vr_die, pf);
+
         if (ret < 0)
                 pr_warning("Failed to find '%s' in this function.\n",
                            pf->pvar->var);
@@ -718,26 +704,30 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
         return 0;
 }
 
-/* Call probe_finder callback with real subprogram DIE */
-static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
+/* Call probe_finder callback with scope DIE */
+static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
 {
-        Dwarf_Die die_mem;
         Dwarf_Attribute fb_attr;
         size_t nops;
         int ret;
 
-        /* If no real subprogram, find a real one */
-        if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
-                sp_die = die_find_realfunc(&pf->cu_die, pf->addr, &die_mem);
-                if (!sp_die) {
+        if (!sc_die) {
+                pr_err("Caller must pass a scope DIE. Program error.\n");
+                return -EINVAL;
+        }
+
+        /* If not a real subprogram, find a real one */
+        if (dwarf_tag(sc_die) != DW_TAG_subprogram) {
+                if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
                         pr_warning("Failed to find probe point in any "
                                    "functions.\n");
                         return -ENOENT;
                 }
-        }
+        } else
+                memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
 
-        /* Get the frame base attribute/ops */
-        dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
+        /* Get the frame base attribute/ops from subprogram */
+        dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
         if (ret <= 0 || nops == 0) {
                 pf->fb_ops = NULL;
@@ -755,7 +745,7 @@ static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
         }
 
         /* Call finder's callback handler */
-        ret = pf->callback(sp_die, pf);
+        ret = pf->callback(sc_die, pf);
 
         /* *pf->fb_ops will be cached in libdw. Don't free it. */
         pf->fb_ops = NULL;
@@ -763,17 +753,82 @@ static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
         return ret;
 }
 
+struct find_scope_param {
+        const char *function;
+        const char *file;
+        int line;
+        int diff;
+        Dwarf_Die *die_mem;
+        bool found;
+};
+
+static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
+{
+        struct find_scope_param *fsp = data;
+        const char *file;
+        int lno;
+
+        /* Skip if declared file name does not match */
+        if (fsp->file) {
+                file = dwarf_decl_file(fn_die);
+                if (!file || strcmp(fsp->file, file) != 0)
+                        return 0;
+        }
+        /* If the function name is given, that's what user expects */
+        if (fsp->function) {
+                if (die_compare_name(fn_die, fsp->function)) {
+                        memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
+                        fsp->found = true;
+                        return 1;
+                }
+        } else {
+                /* With the line number, find the nearest declared DIE */
+                dwarf_decl_line(fn_die, &lno);
+                if (lno < fsp->line && fsp->diff > fsp->line - lno) {
+                        /* Keep a candidate and continue */
+                        fsp->diff = fsp->line - lno;
+                        memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
+                        fsp->found = true;
+                }
+        }
+        return 0;
+}
+
+/* Find an appropriate scope fits to given conditions */
+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;
-        ret = call_probe_finder(NULL, pf);
+        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);
 
         /* Continue if no error, because the line will be in inline function */
         return ret < 0 ? ret : 0;
@@ -827,6 +882,7 @@ 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) ||
@@ -836,7 +892,14 @@ static int probe_point_lazy_walker(const char *fname, int lineno,
         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);
+        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);
 
         /*
          * Continue if no error, because the lazy pattern will match
@@ -861,42 +924,39 @@ static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 }
 
-/* Callback parameter with return value */
-struct dwarf_callback_param {
-        void *data;
-        int retval;
-};
-
 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 probe_finder *pf = data;
         struct perf_probe_point *pp = &pf->pev->point;
         Dwarf_Addr addr;
+        int ret;
 
         if (pp->lazy_line)
-                param->retval = find_probe_point_lazy(in_die, pf);
+                ret = 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;
+                        return -ENOENT;
                 }
                 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;
+                ret = call_probe_finder(in_die, pf);
         }
 
-        return DWARF_CB_OK;
+        return ret;
 }
 
+/* Callback parameter with return value for libdw */
+struct dwarf_callback_param {
+        void *data;
+        int retval;
+};
+
 /* Search function from function name */
 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 {
@@ -933,14 +993,10 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
                         /* 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};
+        } else
                 /* Inlined function: search instances */
-                dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
-                                            &_param);
-                param->retval = _param.retval;
-        }
+                param->retval = die_walk_instances(sp_die,
+                                        probe_point_inline_cb, (void *)pf);
 
         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
 }
@@ -1060,7 +1116,7 @@ found:
 }
 
 /* Add a found probe point into trace event list */
-static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
+static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
 {
         struct trace_event_finder *tf =
                         container_of(pf, struct trace_event_finder, pf);
@@ -1075,8 +1131,9 @@ static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
         }
         tev = &tf->tevs[tf->ntevs++];
 
-        ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
-                                     &tev->point);
+        /* Trace point should be converted from subprogram DIE */
+        ret = convert_to_trace_point(&pf->sp_die, pf->addr,
+                                     pf->pev->point.retprobe, &tev->point);
         if (ret < 0)
                 return ret;
 
@@ -1091,7 +1148,8 @@ static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
         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);
+                /* Variable should be found from scope DIE */
+                ret = find_variable(sc_die, pf);
                 if (ret != 0)
                         return ret;
         }
@@ -1159,13 +1217,13 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
 }
 
 /* Add a found vars into available variables list */
-static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
+static int add_available_vars(Dwarf_Die *sc_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;
+        Dwarf_Die die_mem;
+        int ret;
 
         /* Check number of tevs */
         if (af->nvls == af->max_vls) {
@@ -1174,8 +1232,9 @@ static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
         }
         vl = &af->vls[af->nvls++];
 
-        ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
-                                     &vl->point);
+        /* Trace point should be converted from subprogram DIE */
+        ret = convert_to_trace_point(&pf->sp_die, pf->addr,
+                                     pf->pev->point.retprobe, &vl->point);
         if (ret < 0)
                 return ret;
 
@@ -1187,19 +1246,14 @@ static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
         if (vl->vars == NULL)
                 return -ENOMEM;
         af->child = true;
-        die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
+        die_find_child(sc_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);
+        die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
 
 out:
         if (strlist__empty(vl->vars)) {
@@ -1391,10 +1445,14 @@ static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
 
 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
 {
-        struct dwarf_callback_param *param = data;
+        find_line_range_by_line(in_die, data);
 
-        param->retval = find_line_range_by_line(in_die, param->data);
-        return DWARF_CB_ABORT;  /* No need to find other instances */
+        /*
+         * We have to check all instances of inlined function, because
+         * some execution paths can be optimized out depends on the
+         * function argument of instances
+         */
+        return 0;
 }
 
 /* Search function from function name */
@@ -1422,15 +1480,10 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
                 lr->start = lf->lno_s;
                 lr->end = lf->lno_e;
-                if (dwarf_func_inline(sp_die)) {
-                        struct dwarf_callback_param _param;
-                        _param.data = (void *)lf;
-                        _param.retval = 0;
-                        dwarf_func_inline_instances(sp_die,
-                                                    line_range_inline_cb,
-                                                    &_param);
-                        param->retval = _param.retval;
-                } else
+                if (dwarf_func_inline(sp_die))
+                        param->retval = die_walk_instances(sp_die,
+                                                line_range_inline_cb, lf);
+                else
                         param->retval = find_line_range_by_line(sp_die, lf);
                 return DWARF_CB_ABORT;
         }