Merge branch 'upstream/ticketlock-cleanup' of git://github.com/jsgf/linux-xen into...
[pandora-kernel.git] / tools / perf / util / probe-finder.c
index 3e44a3e..5d73262 100644 (file)
@@ -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;
        }