kconfig: allow long lines in config file

For some config options (CONFIG_EXTRA_FIRMWARE, for example), the length
of a config file line can exceed the 1024 byte buffer.

Switch from fgets to compat_getline to fix. compat_getline is an
internally implimented getline work-alike for portability purposes.

Signed-off-by: Cody Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 59 insertions, 2 deletions

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 52577f052bc1..13ddf1126c2a 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -182,10 +182,66 @@ static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
         return 0;
 }
 
+#define LINE_GROWTH 16
+static int add_byte(int c, char **lineptr, size_t slen, size_t *n)
+{
+        char *nline;
+        size_t new_size = slen + 1;
+        if (new_size > *n) {
+                new_size += LINE_GROWTH - 1;
+                new_size *= 2;
+                nline = realloc(*lineptr, new_size);
+                if (!nline)
+                        return -1;
+
+                *lineptr = nline;
+                *n = new_size;
+        }
+
+        (*lineptr)[slen] = c;
+
+        return 0;
+}
+
+static ssize_t compat_getline(char **lineptr, size_t *n, FILE *stream)
+{
+        char *line = *lineptr;
+        size_t slen = 0;
+
+        for (;;) {
+                int c = getc(stream);
+
+                switch (c) {
+                case '\n':
+                        if (add_byte(c, &line, slen, n) < 0)
+                                goto e_out;
+                        slen++;
+                        /* fall through */
+                case EOF:
+                        if (add_byte('\0', &line, slen, n) < 0)
+                                goto e_out;
+                        *lineptr = line;
+                        if (slen == 0)
+                                return -1;
+                        return slen;
+                default:
+                        if (add_byte(c, &line, slen, n) < 0)
+                                goto e_out;
+                        slen++;
+                }
+        }
+
+e_out:
+        line[slen-1] = '\0';
+        *lineptr = line;
+        return -1;
+}
+
 int conf_read_simple(const char *name, int def)
 {
         FILE *in = NULL;
-        char line[1024];
+        char   *line = NULL;
+        size_t  line_asize = 0;
         char *p, *p2;
         struct symbol *sym;
         int i, def_flags;
@@ -247,7 +303,7 @@ load:
                 }
         }
 
-        while (fgets(line, sizeof(line), in)) {
+        while (compat_getline(&line, &line_asize, in) != -1) {
                 conf_lineno++;
                 sym = NULL;
                 if (line[0] == '#') {
@@ -335,6 +391,7 @@ setsym:
                         cs->def[def].tri = EXPR_OR(cs->def[def].tri, sym->def[def].tri);
                 }
         }
+        free(line);
         fclose(in);
 
         if (modules_sym)