coredump: add __printf attribute to cn_*printf functions

This allows detecting improper format string at build time, like:

  fs/coredump.c:225:5: warning: format '%ld' expects argument of type 'long int', but argument 3 has type 'int' [-Wformat=]
       err = cn_printf(cn, "%ld", cprm->siginfo->si_signo);
       ^

As si_signo is always an int, the format should be %d here.

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/coredump.c b/fs/coredump.c
index 833a57b..e52e006 100644 (file)
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -70,7 +70,8 @@ static int expand_corename(struct core_name *cn, int size)
        return 0;
 }
 
-static int cn_vprintf(struct core_name *cn, const char *fmt, va_list arg)
+static __printf(2, 0) int cn_vprintf(struct core_name *cn, const char *fmt,
+                                    va_list arg)
 {
        int free, need;
        va_list arg_copy;
@@ -93,7 +94,7 @@ again:
        return -ENOMEM;
 }
 
-static int cn_printf(struct core_name *cn, const char *fmt, ...)
+static __printf(2, 3) int cn_printf(struct core_name *cn, const char *fmt, ...)
 {
        va_list arg;
        int ret;
@@ -105,7 +106,8 @@ static int cn_printf(struct core_name *cn, const char *fmt, ...)
        return ret;
 }
 
-static int cn_esc_printf(struct core_name *cn, const char *fmt, ...)
+static __printf(2, 3)
+int cn_esc_printf(struct core_name *cn, const char *fmt, ...)
 {
        int cur = cn->used;
        va_list arg;
@@ -225,7 +227,8 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
                                break;
                        /* signal that caused the coredump */
                        case 's':
-                               err = cn_printf(cn, "%ld", cprm->siginfo->si_signo);
+                               err = cn_printf(cn, "%d",
+                                               cprm->siginfo->si_signo);
                                break;
                        /* UNIX time of coredump */
                        case 't': {