scripts/kallsyms: add sym_name() to mitigate cast ugliness

sym_entry::sym is (unsigned char *) instead of (char *) because
kallsyms exploits the MSB for compression, and the characters are
used as the index of token_profit array.

However, it requires casting (unsigned char *) to (char *) in some
places since standard library functions such as strcmp(), strlen()
expect (char *).

Introduce a new helper, sym_name(), which advances the given pointer
by 1 and casts it to (char *).

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index a57636c..baa2fa5 100644 (file)
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -74,6 +74,11 @@ static void usage(void)
        exit(1);
 }
 
+static char *sym_name(const struct sym_entry *s)
+{
+       return (char *)s->sym + 1;
+}
+
 static int check_symbol_range(const char *sym, unsigned long long addr,
                              struct addr_range *ranges, int entries)
 {
@@ -154,7 +159,7 @@ static int read_symbol(FILE *in, struct sym_entry *s)
                        "unable to allocate required amount of memory\n");
                exit(EXIT_FAILURE);
        }
-       strcpy((char *)s->sym + 1, sym);
+       strcpy(sym_name(s), sym);
        s->sym[0] = stype;
 
        s->percpu_absolute = 0;
@@ -215,7 +220,7 @@ static int symbol_valid(struct sym_entry *s)
                NULL };
 
        int i;
-       char *sym_name = (char *)s->sym + 1;
+       const char *name = sym_name(s);
 
        /* if --all-symbols is not specified, then symbols outside the text
         * and inittext sections are discarded */
@@ -230,30 +235,28 @@ static int symbol_valid(struct sym_entry *s)
                 * rules.
                 */
                if ((s->addr == text_range_text->end &&
-                               strcmp(sym_name,
-                                      text_range_text->end_sym)) ||
+                    strcmp(name, text_range_text->end_sym)) ||
                    (s->addr == text_range_inittext->end &&
-                               strcmp(sym_name,
-                                      text_range_inittext->end_sym)))
+                    strcmp(name, text_range_inittext->end_sym)))
                        return 0;
        }
 
        /* Exclude symbols which vary between passes. */
        for (i = 0; special_symbols[i]; i++)
-               if (strcmp(sym_name, special_symbols[i]) == 0)
+               if (strcmp(name, special_symbols[i]) == 0)
                        return 0;
 
        for (i = 0; special_prefixes[i]; i++) {
                int l = strlen(special_prefixes[i]);
 
-               if (strncmp(sym_name, special_prefixes[i], l) == 0)
+               if (strncmp(name, special_prefixes[i], l) == 0)
                        return 0;
        }
 
        for (i = 0; special_suffixes[i]; i++) {
-               int l = strlen(sym_name) - strlen(special_suffixes[i]);
+               int l = strlen(name) - strlen(special_suffixes[i]);
 
-               if (l >= 0 && strcmp(sym_name + l, special_suffixes[i]) == 0)
+               if (l >= 0 && strcmp(name + l, special_suffixes[i]) == 0)
                        return 0;
        }
 
@@ -626,7 +629,7 @@ static void optimize_token_table(void)
 /* guess for "linker script provide" symbol */
 static int may_be_linker_script_provide_symbol(const struct sym_entry *se)
 {
-       const char *symbol = (char *)se->sym + 1;
+       const char *symbol = sym_name(se);
        int len = se->len - 1;
 
        if (len < 8)
@@ -696,8 +699,8 @@ static int compare_symbols(const void *a, const void *b)
                return wa - wb;
 
        /* sort by the number of prefix underscores */
-       wa = prefix_underscores_count((const char *)sa->sym + 1);
-       wb = prefix_underscores_count((const char *)sb->sym + 1);
+       wa = prefix_underscores_count(sym_name(sa));
+       wb = prefix_underscores_count(sym_name(sb));
        if (wa != wb)
                return wa - wb;