backtrace: Add ability to lookup function names via libbfd

dladdr() is not always able to determine the function names while
libbfd often can in such cases.

diff --git a/src/libstrongswan/utils/backtrace.c b/src/libstrongswan/utils/backtrace.c
index 30f19cb1569f207b76663ccf5ee995be7db3b27a..2fdfab1ee039ffe11ea4319ab1454fa8f63c6c10 100644 (file)
--- a/src/libstrongswan/utils/backtrace.c
+++ b/src/libstrongswan/utils/backtrace.c
@@ -207,10 +207,16 @@ typedef struct {
        bfd_entry_t *entry;
        /** backtrace address */
        bfd_vma vma;
-       /** stream to log to */
-       FILE *file;
-       /** TRUE if complete */
+       /** TRUE if address found */
        bool found;
+       /** optional stream to log to */
+       FILE *file;
+       /** optional list of function names to match */
+       char **list;
+       /** optional number of names in list */
+       int count;
+       /** TRUE if found function name is in list */
+       bool in_list;
 } bfd_find_data_t;
 
 /**
@@ -279,39 +285,56 @@ static void find_addr(bfd *abfd, asection *section, bfd_find_data_t *data)
        const char *function;
        char fbuf[512] = "", sbuf[512] = "";
        u_int line;
+       int i;
+
+       if (data->found || (get_section_flags(abfd, section) & SEC_ALLOC) == 0)
+       {
+               return;
+       }
+       vma = get_section_vma(abfd, section);
+       if (data->vma < vma)
+       {
+               return;
+       }
+       size = get_section_size(section);
+       if (data->vma >= vma + size)
+       {
+               return;
+       }
 
-       if (!data->found || (get_section_flags(abfd, section) & SEC_ALLOC) != 0)
+       data->found = bfd_find_nearest_line(abfd, section, data->entry->syms,
+                                                                               data->vma - vma, &source, &function,
+                                                                               &line);
+       if (!data->found)
+       {
+               return;
+       }
+       if (data->count && function)
        {
-               vma = get_section_vma(abfd, section);
-               if (data->vma >= vma)
+               for (i = 0; i < data->count; i++)
                {
-                       size = get_section_size(section);
-                       if (data->vma < vma + size)
+                       if (streq(function, data->list[i]))
                        {
-                               data->found = bfd_find_nearest_line(abfd, section,
-                                                                                       data->entry->syms, data->vma - vma,
-                                                                                       &source, &function, &line);
-                               if (data->found)
-                               {
-                                       if (source || function)
-                                       {
-                                               if (function)
-                                               {
-                                                       snprintf(fbuf, sizeof(fbuf), "%s%s() ",
-                                                               esc(data->file, TTY_FG_BLUE), function);
-                                               }
-                                               if (source)
-                                               {
-                                                       snprintf(sbuf, sizeof(sbuf), "%s@ %s:%d",
-                                                               esc(data->file, TTY_FG_GREEN), source, line);
-                                               }
-                                               println(data->file, "    -> %s%s%s", fbuf, sbuf,
-                                                               esc(data->file, TTY_FG_DEF));
-                                       }
-                               }
+                               data->in_list = TRUE;
+                               break;
                        }
                }
        }
+       else if (data->file && (source || function))
+       {
+               if (function)
+               {
+                       snprintf(fbuf, sizeof(fbuf), "%s%s() ",
+                               esc(data->file, TTY_FG_BLUE), function);
+               }
+               if (source)
+               {
+                       snprintf(sbuf, sizeof(sbuf), "%s@ %s:%d",
+                               esc(data->file, TTY_FG_GREEN), source, line);
+               }
+               println(data->file, "    -> %s%s%s", fbuf, sbuf,
+                               esc(data->file, TTY_FG_DEF));
+       }
 }
 
 /**
@@ -380,15 +403,11 @@ static bfd_entry_t *get_bfd_entry(char *filename)
 }
 
 /**
- * Print the source file with line number to file, libbfd variant
+ * Lookup the given address
  */
-static void print_sourceline(FILE *file, char *filename, void *ptr, void *base)
+static void lookup_addr(char *filename, bfd_find_data_t *data)
 {
        bfd_entry_t *entry;
-       bfd_find_data_t data = {
-               .file = file,
-               .vma = (uintptr_t)ptr,
-       };
        bool old = FALSE;
 
        bfd_mutex->lock(bfd_mutex);
@@ -399,8 +418,8 @@ static void print_sourceline(FILE *file, char *filename, void *ptr, void *base)
        entry = get_bfd_entry(filename);
        if (entry)
        {
-               data.entry = entry;
-               bfd_map_over_sections(entry->abfd, (void*)find_addr, &data);
+               data->entry = entry;
+               bfd_map_over_sections(entry->abfd, (void*)find_addr, data);
        }
        if (lib && lib->leak_detective)
        {
@@ -409,6 +428,35 @@ static void print_sourceline(FILE *file, char *filename, void *ptr, void *base)
        bfd_mutex->unlock(bfd_mutex);
 }
 
+/**
+ * Print the source file with line number to file, libbfd variant
+ */
+static void print_sourceline(FILE *file, char *filename, void *ptr, void *base)
+{
+       bfd_find_data_t data = {
+               .file = file,
+               .vma = (uintptr_t)ptr,
+       };
+
+       lookup_addr(filename, &data);
+}
+
+/**
+ * Check if the function name of the source line is in the given list
+ */
+static bool contains_function_bfd(char *filename, void *ptr, char *list[],
+                                                                 int count)
+{
+       bfd_find_data_t data = {
+               .vma = (uintptr_t)ptr,
+               .list = list,
+               .count = count,
+       };
+
+       lookup_addr(filename, &data);
+       return data.in_list;
+}
+
 #else /* !HAVE_BFD_H */
 
 void backtrace_init() {}
@@ -619,15 +667,34 @@ METHOD(backtrace_t, contains_function, bool,
        {
                Dl_info info;
 
-               if (dladdr(this->frames[i], &info) && info.dli_sname)
+               if (dladdr(this->frames[i], &info))
                {
-                       for (j = 0; j < count; j++)
+                       if (info.dli_sname)
+                       {
+                               for (j = 0; j < count; j++)
+                               {
+                                       if (streq(info.dli_sname, function[j]))
+                                       {
+                                               return TRUE;
+                                       }
+                               }
+                       }
+#ifdef HAVE_BFD_H
+                       else if (info.dli_fname[0])
                        {
-                               if (streq(info.dli_sname, function[j]))
+                               void *ptr = this->frames[i];
+
+                               if (strstr(info.dli_fname, ".so"))
+                               {
+                                       ptr = (void*)(this->frames[i] - info.dli_fbase);
+                               }
+                               if (contains_function_bfd((char*)info.dli_fname, ptr,
+                                                                                 function, count))
                                {
                                        return TRUE;
                                }
                        }
+#endif /* HAVE_BFD_H */
                }
        }
 #elif defined(HAVE_DBGHELP)