perf probe: Check function address range strictly in line finder
Masami Hiramatsu [Thu, 25 Feb 2010 13:35:57 +0000 (08:35 -0500)]
Check (inlined) function address range strictly for
improving output of probe-able lines of inline functions.

Without this change, perf probe --line <function> sometimes
showed other inline function bodies too, because it didn't
filter out inlined functions.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20100225133557.6725.20697.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/util/probe-finder.c
tools/perf/util/probe-finder.h

index 6305f34..a410356 100644 (file)
@@ -161,6 +161,31 @@ static Dwarf_Die *die_get_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
                return die_mem;
 }
 
+/* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
+static Dwarf_Die *die_get_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
+                                    Dwarf_Die *die_mem)
+{
+       Dwarf_Die child_die;
+       int ret;
+
+       ret = dwarf_child(sp_die, die_mem);
+       if (ret != 0)
+               return NULL;
+
+       do {
+               if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
+                   dwarf_haspc(die_mem, addr))
+                       return die_mem;
+
+               if (die_get_inlinefunc(die_mem, addr, &child_die)) {
+                       memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
+                       return die_mem;
+               }
+       } while (dwarf_siblingof(die_mem, die_mem) == 0);
+
+       return NULL;
+}
+
 /* Compare diename and tname */
 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
 {
@@ -534,7 +559,7 @@ found:
 }
 
 /* Find line range from its line number */
-static void find_line_range_by_line(struct line_finder *lf)
+static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
 {
        Dwarf_Lines *lines;
        Dwarf_Line *line;
@@ -543,6 +568,7 @@ static void find_line_range_by_line(struct line_finder *lf)
        int lineno;
        int ret;
        const char *src;
+       Dwarf_Die die_mem;
 
        INIT_LIST_HEAD(&lf->lr->line_list);
        ret = dwarf_getsrclines(&lf->cu_die, &lines, &nlines);
@@ -550,22 +576,28 @@ static void find_line_range_by_line(struct line_finder *lf)
 
        for (i = 0; i < nlines; i++) {
                line = dwarf_onesrcline(lines, i);
-               dwarf_lineno(line, &lineno);
+               ret = dwarf_lineno(line, &lineno);
+               DIE_IF(ret != 0);
                if (lf->lno_s > lineno || lf->lno_e < lineno)
                        continue;
 
+               if (sp_die) {
+                       /* Address filtering 1: does sp_die include addr? */
+                       ret = dwarf_lineaddr(line, &addr);
+                       DIE_IF(ret != 0);
+                       if (!dwarf_haspc(sp_die, addr))
+                               continue;
+
+                       /* Address filtering 2: No child include addr? */
+                       if (die_get_inlinefunc(sp_die, addr, &die_mem))
+                               continue;
+               }
+
                /* TODO: Get fileno from line, but how? */
                src = dwarf_linesrc(line, NULL, NULL);
                if (strtailcmp(src, lf->fname) != 0)
                        continue;
 
-               /* Filter line in the function address range */
-               if (lf->addr_s && lf->addr_e) {
-                       ret = dwarf_lineaddr(line, &addr);
-                       DIE_IF(ret != 0);
-                       if (lf->addr_s > addr || lf->addr_e <= addr)
-                               continue;
-               }
                /* Copy real path */
                if (!lf->lr->path)
                        lf->lr->path = strdup(src);
@@ -580,24 +612,20 @@ static void find_line_range_by_line(struct line_finder *lf)
        }
 }
 
+static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
+{
+       find_line_range_by_line(in_die, (struct line_finder *)data);
+       return DWARF_CB_ABORT;  /* No need to find other instances */
+}
+
 /* Search function from function name */
 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
 {
        struct line_finder *lf = (struct line_finder *)data;
        struct line_range *lr = lf->lr;
-       int ret;
 
        if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
            die_compare_name(sp_die, lr->function) == 0) {
-               /* Get the address range of this function */
-               ret = dwarf_highpc(sp_die, &lf->addr_e);
-               if (ret == 0)
-                       ret = dwarf_lowpc(sp_die, &lf->addr_s);
-               if (ret != 0) {
-                       lf->addr_s = 0;
-                       lf->addr_e = 0;
-               }
-
                lf->fname = dwarf_decl_file(sp_die);
                dwarf_decl_line(sp_die, &lr->offset);
                pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
@@ -608,7 +636,11 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
                        lf->lno_e = lr->offset + lr->end;
                lr->start = lf->lno_s;
                lr->end = lf->lno_e;
-               find_line_range_by_line(lf);
+               if (dwarf_func_inline(sp_die))
+                       dwarf_func_inline_instances(sp_die,
+                                                   line_range_inline_cb, lf);
+               else
+                       find_line_range_by_line(sp_die, lf);
                return 1;
        }
        return 0;
@@ -660,7 +692,7 @@ int find_line_range(int fd, struct line_range *lr)
                                        lf.lno_e = INT_MAX;
                                else
                                        lf.lno_e = lr->end;
-                               find_line_range_by_line(&lf);
+                               find_line_range_by_line(NULL, &lf);
                        }
                }
                off = noff;
index 74525ae..75a660d 100644 (file)
@@ -82,8 +82,6 @@ struct line_finder {
        const char              *fname;         /* File name */
        int                     lno_s;          /* Start line number */
        int                     lno_e;          /* End line number */
-       Dwarf_Addr              addr_s;         /* Start address */
-       Dwarf_Addr              addr_e;         /* End address */
        Dwarf_Die               cu_die;         /* Current CU */
        int                     found;
 };