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[tcpdump] / instrument-functions.c

diff --git a/instrument-functions.c b/instrument-functions.c
index fb2314dd3f02c25561e9bca7b342b76192d10f37..ba0a56a5309ff572e6a94d24c2d3d7c7ec31ef74 100644 (file)
--- a/instrument-functions.c
+++ b/instrument-functions.c
@@ -14,8 +14,6 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 #include <unistd.h>
 #include <bfd.h>
 
@@ -33,14 +31,10 @@
  * If entering in a function it prints also the calling function name with
  * file name and line number.
  *
- * To configure the printing of only the global functions names:
- * $ make instrument_global
- *
- * To go back to print all the functions names:
- * $ make instrument_all
- *
- * To print nothing, like with no instrumentation:
- * $ make instrument_off
+ * If the environment variable INSTRUMENT is
+ * unset or set to an empty string, print nothing, like with no instrumentation
+ * set to "all" or "a", print all the functions names
+ * set to "global" or "g", print only the global functions names
  */
 
 #define ND_NO_INSTRUMENT __attribute__((no_instrument_function))
@@ -73,12 +67,6 @@ __cyg_profile_func_exit(void *this_fn, void *call_site)
        print_debug(this_fn, call_site, EXIT);
 }
 
-/* If this file exists, print only the global functions */
-#define ND_FILE_FLAG_GLOBAL "instrument_functions_global.devel"
-
-/* If this file exists, print nothing, like with no instrumentation */
-#define ND_FILE_FLAG_OFF "instrument_functions_off.devel"
-
 static void print_debug(void *this_fn, void *call_site, action_type action)
 {
        static bfd* abfd;
@@ -86,35 +74,53 @@ static void print_debug(void *this_fn, void *call_site, action_type action)
        static long symcount;
        static asection *text;
        static bfd_vma vma;
+       static int instrument_set;
        static int instrument_off;
-       static int print_only_global;
-       symbol_info syminfo;
-       struct stat statbuf;
-       int i;
-
-       if (!instrument_off) {
-               /* one-time test */
-               if (!stat(ND_FILE_FLAG_OFF, &statbuf)) {
+       static int instrument_global;
+
+       if (!instrument_set) {
+               static char *instrument_type;
+
+               /* Get the configuration environment variable INSTRUMENT value if any */
+               instrument_type = getenv("INSTRUMENT");
+               /* unset or set to an empty string ? */
+               if (instrument_type == NULL ||
+                       !strncmp(instrument_type, "", sizeof(""))) {
                        instrument_off = 1;
-                       return;
+               } else {
+                       /* set to "global" or "g" ? */
+                       if (!strncmp(instrument_type, "global", sizeof("global")) ||
+                               !strncmp(instrument_type, "g", sizeof("g")))
+                               instrument_global = 1;
+                       else if (strncmp(instrument_type, "all", sizeof("all")) &&
+                                        strncmp(instrument_type, "a", sizeof("a"))) {
+                               fprintf(stderr, "INSTRUMENT can be only \"\", \"all\", \"a\", "
+                                               "\"global\" or \"g\".\n");
+                               exit(1);
+                       }
                }
-       } else
-               return;
+               instrument_set = 1;
+       }
+
+       if (instrument_off)
+                       return;
 
        /* If no errors, this block should be executed one time */
        if (!abfd) {
                char pgm_name[1024];
                long symsize;
 
-               if (!stat(ND_FILE_FLAG_GLOBAL, &statbuf))
-                       print_only_global = 1;
-
                ssize_t ret = readlink("/proc/self/exe", pgm_name, sizeof(pgm_name));
                if (ret == -1) {
-                       perror("failed to find executable\n");
+                       perror("failed to find executable");
+                       return;
+               }
+               if (ret == sizeof(pgm_name)) {
+                       /* no space for the '\0' */
+                       printf("truncation may have occurred\n");
                        return;
                }
-               pgm_name[ret] = 0;
+               pgm_name[ret] = '\0';
 
                bfd_init();
 
@@ -134,11 +140,11 @@ static void print_debug(void *this_fn, void *call_site, action_type action)
                        return;
                }
 
-               symtab = (asymbol **)malloc(symsize);
+               symtab = (asymbol **)malloc((size_t)symsize);
                symcount = bfd_canonicalize_symtab(abfd, symtab);
                if (symcount < 0) {
-                       free (symtab);
-                       bfd_perror ("bfd_canonicalize_symtab");
+                       free(symtab);
+                       bfd_perror("bfd_canonicalize_symtab");
                        return;
                }
 
@@ -149,8 +155,10 @@ static void print_debug(void *this_fn, void *call_site, action_type action)
                vma = text->vma;
        }
 
-       if (print_only_global) {
+       if (instrument_global) {
+               symbol_info syminfo;
                int found;
+               long i;
 
                i = 0;
                found = 0;
@@ -178,6 +186,8 @@ static void print_debug(void *this_fn, void *call_site, action_type action)
                                                                   &file, &func, &line)) {
                        printf("[ERROR bfd_find_nearest_line this_fn]");
                } else {
+                       int i;
+
                        if (action == ENTER)
                                profile_func_level += 1;
                        /* Indentation */
@@ -194,7 +204,8 @@ static void print_debug(void *this_fn, void *call_site, action_type action)
                                printf("%s", func);
                        printf(" (%d)", profile_func_level);
                        /* Print the "from" part except for the main function) */
-                       if (action == ENTER && strncmp(func, "main", sizeof("main"))) {
+                       if (action == ENTER && func != NULL &&
+                               strncmp(func, "main", sizeof("main"))) {
                                /* Calling function */
                                if ((bfd_vma)call_site < vma) {
                                        printf("[ERROR address call_site]");