Add option libbfd support for tracing code

CONFIG_WPA_TRACE=y and CONFIG_WPA_TRACE_BFD=y can now be used to get
even more complete symbols (func/file/line and inline functions) for
backtraces.

diff --git a/hostapd/Makefile b/hostapd/Makefile
index 0d52c81..ad4ad05 100644 (file)
--- a/hostapd/Makefile
+++ b/hostapd/Makefile
@@ -51,6 +51,13 @@ CFLAGS += -DHOSTAPD
 ifdef CONFIG_WPA_TRACE
 CFLAGS += -DWPA_TRACE
 OBJS += ../src/utils/trace.o
+LDFLAGS += -rdynamic
+CFLAGS += -funwind-tables
+ifdef CONFIG_WPA_TRACE_BFD
+CFLAGS += -DWPA_TRACE_BFD
+LIBS += -lbfd
+LIBS_c += -lbfd
+endif
 endif
 
 OBJS += ../src/utils/eloop.o
@@ -725,7 +732,7 @@ OBJS_c += ../src/utils/trace.o
 OBJS_c += ../src/utils/wpa_debug.o
 endif
 hostapd_cli: $(OBJS_c)
-       $(CC) $(LDFLAGS) -o hostapd_cli $(OBJS_c)
+       $(CC) $(LDFLAGS) -o hostapd_cli $(OBJS_c) $(LIBS_c)
 
 NOBJS = nt_password_hash.o ../src/crypto/ms_funcs.o $(SHA1OBJS) ../src/crypto/rc4.o ../src/crypto/md5.o
 ifdef CONFIG_INTERNAL_MD5

diff --git a/src/utils/trace.c b/src/utils/trace.c
index 18502e3..cf10010 100644 (file)
--- a/src/utils/trace.c
+++ b/src/utils/trace.c
@@ -19,16 +19,228 @@
 
 #ifdef WPA_TRACE
 
+#ifdef WPA_TRACE_BFD
+#include <bfd.h>
+#include <demangle.h>
+
+static char *prg_fname = NULL;
+static bfd *cached_abfd = NULL;
+static asymbol **syms = NULL;
+
+static void get_prg_fname(void)
+{
+       char exe[50], fname[512];
+       int len;
+       os_snprintf(exe, sizeof(exe) - 1, "/proc/%u/exe", getpid());
+       len = readlink(exe, fname, sizeof(fname) - 1);
+       if (len < 0 || len >= (int) sizeof(fname)) {
+               perror("readlink");
+               return;
+       }
+       fname[len] = '\0';
+       prg_fname = strdup(fname);
+}
+
+
+static bfd * open_bfd(const char *fname)
+{
+       bfd *abfd;
+       char **matching;
+
+       abfd = bfd_openr(prg_fname, NULL);
+       if (abfd == NULL) {
+               wpa_printf(MSG_INFO, "bfd_openr failed");
+               return NULL;
+       }
+
+       if (bfd_check_format(abfd, bfd_archive)) {
+               wpa_printf(MSG_INFO, "bfd_check_format failed");
+               bfd_close(abfd);
+               return NULL;
+       }
+
+       if (!bfd_check_format_matches(abfd, bfd_object, &matching)) {
+               wpa_printf(MSG_INFO, "bfd_check_format_matches failed");
+               free(matching);
+               bfd_close(abfd);
+               return NULL;
+       }
+
+       return abfd;
+}
+
+
+static void read_syms(bfd *abfd)
+{
+       long storage, symcount;
+       bfd_boolean dynamic = FALSE;
+
+       if (syms)
+               return;
+
+       if (!(bfd_get_file_flags(abfd) & HAS_SYMS)) {
+               wpa_printf(MSG_INFO, "No symbols");
+               return;
+       }
+
+       storage = bfd_get_symtab_upper_bound(abfd);
+       if (storage == 0) {
+               storage = bfd_get_dynamic_symtab_upper_bound(abfd);
+               dynamic = TRUE;
+       }
+       if (storage < 0) {
+               wpa_printf(MSG_INFO, "Unknown symtab upper bound");
+               return;
+       }
+
+       syms = malloc(storage);
+       if (syms == NULL) {
+               wpa_printf(MSG_INFO, "Failed to allocate memory for symtab "
+                          "(%ld bytes)", storage);
+               return;
+       }
+       if (dynamic)
+               symcount = bfd_canonicalize_dynamic_symtab(abfd, syms);
+       else
+               symcount = bfd_canonicalize_symtab(abfd, syms);
+       if (symcount < 0) {
+               wpa_printf(MSG_INFO, "Failed to canonicalize %ssymtab",
+                          dynamic ? "dynamic " : "");
+               free(syms);
+               syms = NULL;
+               return;
+       }
+       wpa_printf(MSG_INFO, "BFD: Read %ld symbols (%ld bytes)",
+                  symcount, storage);
+}
+
+
+struct bfd_data {
+       bfd_vma pc;
+       bfd_boolean found;
+       const char *filename;
+       const char *function;
+       unsigned int line;
+};
+
+
+static void find_addr_sect(bfd *abfd, asection *section, void *obj)
+{
+       struct bfd_data *data = obj;
+       bfd_vma vma;
+       bfd_size_type size;
+
+       if (data->found)
+               return;
+
+       if (!(bfd_get_section_vma(abfd, section)))
+               return;
+
+       vma = bfd_get_section_vma(abfd, section);
+       if (data->pc < vma)
+               return;
+
+       size = bfd_get_section_size(section);
+       if (data->pc >= vma + size)
+               return;
+
+       data->found = bfd_find_nearest_line(abfd, section, syms,
+                                           data->pc - vma,
+                                           &data->filename,
+                                           &data->function,
+                                           &data->line);
+}
+
+
+static void wpa_trace_bfd_addr(void *pc)
+{
+       bfd *abfd = cached_abfd;
+       struct bfd_data data;
+       const char *name;
+       char *aname = NULL;
+       const char *filename;
+
+       if (abfd == NULL)
+               return;
+
+       data.pc = (bfd_vma) pc;
+       data.found = FALSE;
+       bfd_map_over_sections(abfd, find_addr_sect, &data);
+
+       if (!data.found)
+               return;
+
+       do {
+               if (data.function)
+                       aname = bfd_demangle(abfd, data.function,
+                                            DMGL_ANSI | DMGL_PARAMS);
+               name = aname ? aname : data.function;
+               filename = data.filename;
+               if (filename) {
+                       char *end = os_strrchr(filename, '/');
+                       int i = 0;
+                       while (*filename && *filename == prg_fname[i] &&
+                              filename <= end) {
+                               filename++;
+                               i++;
+                       }
+               }
+               wpa_printf(MSG_INFO, "     %s() %s:%u",
+                          name, filename, data.line);
+               free(aname);
+
+               data.found = bfd_find_inliner_info(abfd, &data.filename,
+                                                  &data.function, &data.line);
+       } while (data.found);
+}
+
+
+static void wpa_trace_bfd_init(void)
+{
+       if (!prg_fname) {
+               get_prg_fname();
+               if (!prg_fname)
+                       return;
+               wpa_printf(MSG_INFO, "BFD[%s]", prg_fname);
+       }
+
+       if (!cached_abfd) {
+               cached_abfd = open_bfd(prg_fname);
+               if (!cached_abfd) {
+                       wpa_printf(MSG_INFO, "Failed to open bfd");
+                       return;
+               }
+       }
+
+       read_syms(cached_abfd);
+       if (!syms) {
+               wpa_printf(MSG_INFO, "Failed to read symbols");
+               return;
+       }
+}
+
+#else /* WPA_TRACE_BFD */
+
+#define wpa_trace_bfd_init() do { } while (0)
+#define wpa_trace_bfd_addr(pc) do { } while (0)
+
+#endif /* WPA_TRACE_BFD */
+
 void wpa_trace_dump_func(const char *title, void **btrace, int btrace_num)
 {
        char **sym;
        int i;
 
+       wpa_trace_bfd_init();
        wpa_printf(MSG_INFO, "WPA_TRACE: %s - START", title);
        sym = backtrace_symbols(btrace, btrace_num);
-       for (i = 0; i < btrace_num; i++)
-               wpa_printf(MSG_INFO, "[%d]: %p: %s",
-                          i, btrace[i], sym ? sym[i] : "");
+       for (i = 0; i < btrace_num; i++) {
+               if (sym)
+                       wpa_printf(MSG_INFO, "[%d]: %s", i, sym[i]);
+               else
+                       wpa_printf(MSG_INFO, "[%d]: ?? [%p]", i, btrace[i]);
+               wpa_trace_bfd_addr(btrace[i]);
+       }
        free(sym);
        wpa_printf(MSG_INFO, "WPA_TRACE: %s - END", title);
 }

diff --git a/wpa_supplicant/Makefile b/wpa_supplicant/Makefile
index 783cbd9..f2c3148 100644 (file)
--- a/wpa_supplicant/Makefile
+++ b/wpa_supplicant/Makefile
@@ -74,6 +74,14 @@ OBJS += ../src/utils/trace.o
 OBJS_p += ../src/utils/trace.o
 OBJS_c += ../src/utils/trace.o
 OBJS_c += ../src/utils/wpa_debug.o
+LDFLAGS += -rdynamic
+CFLAGS += -funwind-tables
+ifdef CONFIG_WPA_TRACE_BFD
+CFLAGS += -DWPA_TRACE_BFD
+LIBS += -lbfd
+LIBS_p += -lbfd
+LIBS_c += -lbfd
+endif
 endif
 
 ifndef CONFIG_ELOOP