2019-09-07 09:23:41

by Joshua Watt

[permalink] [raw]
Subject: [nfs-utils PATCH] Add printf format checking

Adds a configure time check for __attribute__((format)) and then uses it
to enforce checking the format of several printf-like functions. Several
invalid uses of format codes that were discovered have now been fixed.

Signed-off-by: Joshua Watt <[email protected]>
---
aclocal/ax_gcc_func_attribute.m4 | 238 +++++++++++++++++++++++++++++++
configure.ac | 1 +
support/include/xcommon.h | 18 ++-
support/include/xlog.h | 20 ++-
support/nfs/svc_create.c | 2 +-
support/nsm/rpc.c | 2 +-
utils/exportfs/exportfs.c | 3 +
utils/mountd/cache.c | 3 +-
utils/mountd/mountd.c | 4 +-
utils/nfsdcld/nfsdcld.c | 2 +-
utils/nfsdcld/sqlite.c | 2 +-
utils/nfsidmap/nfsidmap.c | 8 +-
utils/statd/rmtcall.c | 2 +-
utils/statd/statd.c | 2 +-
utils/statd/svc_run.c | 2 +-
15 files changed, 285 insertions(+), 24 deletions(-)
create mode 100644 aclocal/ax_gcc_func_attribute.m4

diff --git a/aclocal/ax_gcc_func_attribute.m4 b/aclocal/ax_gcc_func_attribute.m4
new file mode 100644
index 00000000..098c9aad
--- /dev/null
+++ b/aclocal/ax_gcc_func_attribute.m4
@@ -0,0 +1,238 @@
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_gcc_func_attribute.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_GCC_FUNC_ATTRIBUTE(ATTRIBUTE)
+#
+# DESCRIPTION
+#
+# This macro checks if the compiler supports one of GCC's function
+# attributes; many other compilers also provide function attributes with
+# the same syntax. Compiler warnings are used to detect supported
+# attributes as unsupported ones are ignored by default so quieting
+# warnings when using this macro will yield false positives.
+#
+# The ATTRIBUTE parameter holds the name of the attribute to be checked.
+#
+# If ATTRIBUTE is supported define HAVE_FUNC_ATTRIBUTE_<ATTRIBUTE>.
+#
+# The macro caches its result in the ax_cv_have_func_attribute_<attribute>
+# variable.
+#
+# The macro currently supports the following function attributes:
+#
+# alias
+# aligned
+# alloc_size
+# always_inline
+# artificial
+# cold
+# const
+# constructor
+# constructor_priority for constructor attribute with priority
+# deprecated
+# destructor
+# dllexport
+# dllimport
+# error
+# externally_visible
+# fallthrough
+# flatten
+# format
+# format_arg
+# gnu_inline
+# hot
+# ifunc
+# leaf
+# malloc
+# noclone
+# noinline
+# nonnull
+# noreturn
+# nothrow
+# optimize
+# pure
+# sentinel
+# sentinel_position
+# unused
+# used
+# visibility
+# warning
+# warn_unused_result
+# weak
+# weakref
+#
+# Unsupported function attributes will be tested with a prototype
+# returning an int and not accepting any arguments and the result of the
+# check might be wrong or meaningless so use with care.
+#
+# LICENSE
+#
+# Copyright (c) 2013 Gabriele Svelto <[email protected]>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 9
+
+AC_DEFUN([AX_GCC_FUNC_ATTRIBUTE], [
+ AS_VAR_PUSHDEF([ac_var], [ax_cv_have_func_attribute_$1])
+
+ AC_CACHE_CHECK([for __attribute__(($1))], [ac_var], [
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([
+ m4_case([$1],
+ [alias], [
+ int foo( void ) { return 0; }
+ int bar( void ) __attribute__(($1("foo")));
+ ],
+ [aligned], [
+ int foo( void ) __attribute__(($1(32)));
+ ],
+ [alloc_size], [
+ void *foo(int a) __attribute__(($1(1)));
+ ],
+ [always_inline], [
+ inline __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [artificial], [
+ inline __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [cold], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [const], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [constructor_priority], [
+ int foo( void ) __attribute__((__constructor__(65535/2)));
+ ],
+ [constructor], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [deprecated], [
+ int foo( void ) __attribute__(($1("")));
+ ],
+ [destructor], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [dllexport], [
+ __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [dllimport], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [error], [
+ int foo( void ) __attribute__(($1("")));
+ ],
+ [externally_visible], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [fallthrough], [
+ int foo( void ) {switch (0) { case 1: __attribute__(($1)); case 2: break ; }};
+ ],
+ [flatten], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [format], [
+ int foo(const char *p, ...) __attribute__(($1(printf, 1, 2)));
+ ],
+ [format_arg], [
+ char *foo(const char *p) __attribute__(($1(1)));
+ ],
+ [gnu_inline], [
+ inline __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [hot], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [ifunc], [
+ int my_foo( void ) { return 0; }
+ static int (*resolve_foo(void))(void) { return my_foo; }
+ int foo( void ) __attribute__(($1("resolve_foo")));
+ ],
+ [leaf], [
+ __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [malloc], [
+ void *foo( void ) __attribute__(($1));
+ ],
+ [noclone], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [noinline], [
+ __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [nonnull], [
+ int foo(char *p) __attribute__(($1(1)));
+ ],
+ [noreturn], [
+ void foo( void ) __attribute__(($1));
+ ],
+ [nothrow], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [optimize], [
+ __attribute__(($1(3))) int foo( void ) { return 0; }
+ ],
+ [pure], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [sentinel], [
+ int foo(void *p, ...) __attribute__(($1));
+ ],
+ [sentinel_position], [
+ int foo(void *p, ...) __attribute__(($1(1)));
+ ],
+ [returns_nonnull], [
+ void *foo( void ) __attribute__(($1));
+ ],
+ [unused], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [used], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [visibility], [
+ int foo_def( void ) __attribute__(($1("default")));
+ int foo_hid( void ) __attribute__(($1("hidden")));
+ int foo_int( void ) __attribute__(($1("internal")));
+ int foo_pro( void ) __attribute__(($1("protected")));
+ ],
+ [warning], [
+ int foo( void ) __attribute__(($1("")));
+ ],
+ [warn_unused_result], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [weak], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [weakref], [
+ static int foo( void ) { return 0; }
+ static int bar( void ) __attribute__(($1("foo")));
+ ],
+ [
+ m4_warn([syntax], [Unsupported attribute $1, the test may fail])
+ int foo( void ) __attribute__(($1));
+ ]
+ )], [])
+ ],
+ dnl GCC doesn't exit with an error if an unknown attribute is
+ dnl provided but only outputs a warning, so accept the attribute
+ dnl only if no warning were issued.
+ [AS_IF([test -s conftest.err],
+ [AS_VAR_SET([ac_var], [no])],
+ [AS_VAR_SET([ac_var], [yes])])],
+ [AS_VAR_SET([ac_var], [no])])
+ ])
+
+ AS_IF([test yes = AS_VAR_GET([ac_var])],
+ [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_FUNC_ATTRIBUTE_$1), 1,
+ [Define to 1 if the system has the `$1' function attribute])], [])
+
+ AS_VAR_POPDEF([ac_var])
+])
diff --git a/configure.ac b/configure.ac
index 37096944..639199a9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -619,6 +619,7 @@ CHECK_CCSUPPORT([-Werror=format-overflow=2], [flg1])
CHECK_CCSUPPORT([-Werror=int-conversion], [flg2])
CHECK_CCSUPPORT([-Werror=incompatible-pointer-types], [flg3])
CHECK_CCSUPPORT([-Werror=misleading-indentation], [flg4])
+AX_GCC_FUNC_ATTRIBUTE([format])

AC_SUBST([AM_CFLAGS], ["$my_am_cflags $flg1 $flg2 $flg3 $flg4"])

diff --git a/support/include/xcommon.h b/support/include/xcommon.h
index 23c9a135..30b0403b 100644
--- a/support/include/xcommon.h
+++ b/support/include/xcommon.h
@@ -9,6 +9,10 @@
#ifndef _XMALLOC_H
#define _MALLOC_H

+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
#include <sys/types.h>
#include <fcntl.h>
#include <limits.h>
@@ -25,9 +29,15 @@

#define streq(s, t) (strcmp ((s), (t)) == 0)

-/* Functions in sundries.c that are used in mount.c and umount.c */
+#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
+#define X_FORMAT(_x) __attribute__((__format__ _x))
+#else
+#define X_FORMAT(_x)
+#endif
+
+/* Functions in sundries.c that are used in mount.c and umount.c */
char *canonicalize (const char *path);
-void nfs_error (const char *fmt, ...);
+void nfs_error (const char *fmt, ...) X_FORMAT((printf, 1, 2));
void *xmalloc (size_t size);
void *xrealloc(void *p, size_t size);
void xfree(void *);
@@ -36,9 +46,9 @@ char *xstrndup (const char *s, int n);
char *xstrconcat2 (const char *, const char *);
char *xstrconcat3 (const char *, const char *, const char *);
char *xstrconcat4 (const char *, const char *, const char *, const char *);
-void die (int errcode, const char *fmt, ...);
+void die (int errcode, const char *fmt, ...) X_FORMAT((printf, 2, 3));

-extern void die(int err, const char *fmt, ...);
+extern void die(int err, const char *fmt, ...) X_FORMAT((printf, 2, 3));
extern void (*at_die)(void);

/* exit status - bits below are ORed */
diff --git a/support/include/xlog.h b/support/include/xlog.h
index a11463ed..32ff5a1b 100644
--- a/support/include/xlog.h
+++ b/support/include/xlog.h
@@ -7,6 +7,10 @@
#ifndef XLOG_H
#define XLOG_H

+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
#include <stdarg.h>

/* These are logged always. L_FATAL also does exit(1) */
@@ -35,6 +39,12 @@ struct xlog_debugfac {
int df_fac;
};

+#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
+#define XLOG_FORMAT(_x) __attribute__((__format__ _x))
+#else
+#define XLOG_FORMAT(_x)
+#endif
+
extern int export_errno;
void xlog_open(char *progname);
void xlog_stderr(int on);
@@ -43,10 +53,10 @@ void xlog_config(int fac, int on);
void xlog_sconfig(char *, int on);
void xlog_from_conffile(char *);
int xlog_enabled(int fac);
-void xlog(int fac, const char *fmt, ...);
-void xlog_warn(const char *fmt, ...);
-void xlog_err(const char *fmt, ...);
-void xlog_errno(int err, const char *fmt, ...);
-void xlog_backend(int fac, const char *fmt, va_list args);
+void xlog(int fac, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
+void xlog_warn(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
+void xlog_err(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
+void xlog_errno(int err, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
+void xlog_backend(int fac, const char *fmt, va_list args) XLOG_FORMAT((printf, 2, 0));

#endif /* XLOG_H */
diff --git a/support/nfs/svc_create.c b/support/nfs/svc_create.c
index 4e14430d..976c2d29 100644
--- a/support/nfs/svc_create.c
+++ b/support/nfs/svc_create.c
@@ -184,7 +184,7 @@ svc_create_sock(const struct sockaddr *sap, socklen_t salen,
type = SOCK_STREAM;
break;
default:
- xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %u",
+ xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %lu",
__func__, nconf->nc_semantics);
return -1;
}
diff --git a/support/nsm/rpc.c b/support/nsm/rpc.c
index ae49006c..08b4746f 100644
--- a/support/nsm/rpc.c
+++ b/support/nsm/rpc.c
@@ -182,7 +182,7 @@ nsm_xmit_getport(const int sock, const struct sockaddr_in *sin,
uint32_t xid;
XDR xdr;

- xlog(D_CALL, "Sending PMAP_GETPORT for %u, %u, udp", program, version);
+ xlog(D_CALL, "Sending PMAP_GETPORT for %lu, %lu, udp", program, version);

nsm_init_xdrmem(msgbuf, NSM_MAXMSGSIZE, &xdr);
xid = nsm_init_rpc_header(PMAPPROG, PMAPVERS,
diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
index 5cca4175..a04a7898 100644
--- a/utils/exportfs/exportfs.c
+++ b/utils/exportfs/exportfs.c
@@ -651,6 +651,9 @@ out:
return result;
}

+#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
+__attribute__((format (printf, 2, 3)))
+#endif
static char
dumpopt(char c, char *fmt, ...)
{
diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index e25a4337..3861f84a 100644
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -987,8 +987,7 @@ lookup_export(char *dom, char *path, struct addrinfo *ai)
} else if (found_type == i && found->m_warned == 0) {
xlog(L_WARNING, "%s exported to both %s and %s, "
"arbitrarily choosing options from first",
- path, found->m_client->m_hostname, exp->m_client->m_hostname,
- dom);
+ path, found->m_client->m_hostname, exp->m_client->m_hostname);
found->m_warned = 1;
}
}
diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
index 33571ecb..66366434 100644
--- a/utils/mountd/mountd.c
+++ b/utils/mountd/mountd.c
@@ -210,10 +210,10 @@ killer (int sig)
}

static void
-sig_hup (int sig)
+sig_hup (int UNUSED(sig))
{
/* don't exit on SIGHUP */
- xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n", sig);
+ xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n");
return;
}

diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
index cbf71fc6..7e894e49 100644
--- a/utils/nfsdcld/nfsdcld.c
+++ b/utils/nfsdcld/nfsdcld.c
@@ -212,7 +212,7 @@ cld_inotify_cb(int UNUSED(fd), short which, void *data)
default:
/* anything else is fatal */
xlog(L_FATAL, "%s: unable to open new pipe (%d). Aborting.",
- ret, __func__);
+ __func__, ret);
exit(ret);
}

diff --git a/utils/nfsdcld/sqlite.c b/utils/nfsdcld/sqlite.c
index fa81df87..afa63499 100644
--- a/utils/nfsdcld/sqlite.c
+++ b/utils/nfsdcld/sqlite.c
@@ -473,7 +473,7 @@ sqlite_fix_table_name(const char *name)
}
ret = sqlite3_exec(dbh, (const char *)buf, NULL, NULL, &err);
if (ret != SQLITE_OK) {
- xlog(L_ERROR, "Unable to fix table for epoch %d: %s",
+ xlog(L_ERROR, "Unable to fix table for epoch %"PRIu64": %s",
val, err);
goto out;
}
diff --git a/utils/nfsidmap/nfsidmap.c b/utils/nfsidmap/nfsidmap.c
index fc00da7a..cf7f65e9 100644
--- a/utils/nfsidmap/nfsidmap.c
+++ b/utils/nfsidmap/nfsidmap.c
@@ -18,7 +18,7 @@
#include "xcommon.h"

int verbose = 0;
-char *usage = "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]";
+#define USAGE "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]"

#define MAX_ID_LEN 11
#define IDMAP_NAMESZ 128
@@ -403,7 +403,7 @@ int main(int argc, char **argv)
break;
case 'h':
default:
- xlog_warn(usage, progname);
+ xlog_warn(USAGE, progname);
exit(opt == 'h' ? 0 : 1);
}
}
@@ -435,7 +435,7 @@ int main(int argc, char **argv)
xlog_stderr(verbose);
if ((argc - optind) != 2) {
xlog_warn("Bad arg count. Check /etc/request-key.conf");
- xlog_warn(usage, progname);
+ xlog_warn(USAGE, progname);
return EXIT_FAILURE;
}

@@ -453,7 +453,7 @@ int main(int argc, char **argv)
return EXIT_FAILURE;
}
if (verbose) {
- xlog_warn("key: 0x%lx type: %s value: %s timeout %ld",
+ xlog_warn("key: 0x%x type: %s value: %s timeout %d",
key, type, value, timeout);
}

diff --git a/utils/statd/rmtcall.c b/utils/statd/rmtcall.c
index c4f6364f..5b261480 100644
--- a/utils/statd/rmtcall.c
+++ b/utils/statd/rmtcall.c
@@ -247,7 +247,7 @@ process_reply(FD_SET_TYPE *rfds)
xlog_warn("%s: service %d not registered on localhost",
__func__, NL_MY_PROG(lp));
} else {
- xlog(D_GENERAL, "%s: Callback to %s (for %d) succeeded",
+ xlog(D_GENERAL, "%s: Callback to %s (for %s) succeeded",
__func__, NL_MY_NAME(lp), NL_MON_NAME(lp));
}
nlist_free(&notify, lp);
diff --git a/utils/statd/statd.c b/utils/statd/statd.c
index 14673800..8eef2ff2 100644
--- a/utils/statd/statd.c
+++ b/utils/statd/statd.c
@@ -136,7 +136,7 @@ static void log_modes(void)
strcat(buf, "TI-RPC ");
#endif

- xlog_warn(buf);
+ xlog_warn("%s", buf);
}

/*
diff --git a/utils/statd/svc_run.c b/utils/statd/svc_run.c
index d1dbd74a..ec61cd11 100644
--- a/utils/statd/svc_run.c
+++ b/utils/statd/svc_run.c
@@ -104,7 +104,7 @@ my_svc_run(int sockfd)

tv.tv_sec = NL_WHEN(notify) - now;
tv.tv_usec = 0;
- xlog(D_GENERAL, "Waiting for reply... (timeo %d)",
+ xlog(D_GENERAL, "Waiting for reply... (timeo %jd)",
tv.tv_sec);
selret = select(FD_SETSIZE, &readfds,
(void *) 0, (void *) 0, &tv);
--
2.21.0


2019-09-07 17:50:03

by Joshua Watt

[permalink] [raw]
Subject: [nfs-utils PATCH v2] Add printf format checking

Adds a configure time check for __attribute__((format)) and then uses it
to enforce checking the format of several printf-like functions. Several
invalid uses of format codes that were discovered have now been fixed.

V2: Fix use of "%jd" format code on an argument that wasn't intmax_t

Signed-off-by: Joshua Watt <[email protected]>
---
aclocal/ax_gcc_func_attribute.m4 | 238 +++++++++++++++++++++++++++++++
configure.ac | 1 +
support/include/xcommon.h | 18 ++-
support/include/xlog.h | 20 ++-
support/nfs/svc_create.c | 2 +-
support/nsm/rpc.c | 2 +-
utils/exportfs/exportfs.c | 3 +
utils/mountd/cache.c | 3 +-
utils/mountd/mountd.c | 4 +-
utils/nfsdcld/nfsdcld.c | 2 +-
utils/nfsdcld/sqlite.c | 2 +-
utils/nfsidmap/nfsidmap.c | 8 +-
utils/statd/rmtcall.c | 2 +-
utils/statd/statd.c | 2 +-
utils/statd/svc_run.c | 5 +-
15 files changed, 287 insertions(+), 25 deletions(-)
create mode 100644 aclocal/ax_gcc_func_attribute.m4

diff --git a/aclocal/ax_gcc_func_attribute.m4 b/aclocal/ax_gcc_func_attribute.m4
new file mode 100644
index 00000000..098c9aad
--- /dev/null
+++ b/aclocal/ax_gcc_func_attribute.m4
@@ -0,0 +1,238 @@
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_gcc_func_attribute.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_GCC_FUNC_ATTRIBUTE(ATTRIBUTE)
+#
+# DESCRIPTION
+#
+# This macro checks if the compiler supports one of GCC's function
+# attributes; many other compilers also provide function attributes with
+# the same syntax. Compiler warnings are used to detect supported
+# attributes as unsupported ones are ignored by default so quieting
+# warnings when using this macro will yield false positives.
+#
+# The ATTRIBUTE parameter holds the name of the attribute to be checked.
+#
+# If ATTRIBUTE is supported define HAVE_FUNC_ATTRIBUTE_<ATTRIBUTE>.
+#
+# The macro caches its result in the ax_cv_have_func_attribute_<attribute>
+# variable.
+#
+# The macro currently supports the following function attributes:
+#
+# alias
+# aligned
+# alloc_size
+# always_inline
+# artificial
+# cold
+# const
+# constructor
+# constructor_priority for constructor attribute with priority
+# deprecated
+# destructor
+# dllexport
+# dllimport
+# error
+# externally_visible
+# fallthrough
+# flatten
+# format
+# format_arg
+# gnu_inline
+# hot
+# ifunc
+# leaf
+# malloc
+# noclone
+# noinline
+# nonnull
+# noreturn
+# nothrow
+# optimize
+# pure
+# sentinel
+# sentinel_position
+# unused
+# used
+# visibility
+# warning
+# warn_unused_result
+# weak
+# weakref
+#
+# Unsupported function attributes will be tested with a prototype
+# returning an int and not accepting any arguments and the result of the
+# check might be wrong or meaningless so use with care.
+#
+# LICENSE
+#
+# Copyright (c) 2013 Gabriele Svelto <[email protected]>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 9
+
+AC_DEFUN([AX_GCC_FUNC_ATTRIBUTE], [
+ AS_VAR_PUSHDEF([ac_var], [ax_cv_have_func_attribute_$1])
+
+ AC_CACHE_CHECK([for __attribute__(($1))], [ac_var], [
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([
+ m4_case([$1],
+ [alias], [
+ int foo( void ) { return 0; }
+ int bar( void ) __attribute__(($1("foo")));
+ ],
+ [aligned], [
+ int foo( void ) __attribute__(($1(32)));
+ ],
+ [alloc_size], [
+ void *foo(int a) __attribute__(($1(1)));
+ ],
+ [always_inline], [
+ inline __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [artificial], [
+ inline __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [cold], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [const], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [constructor_priority], [
+ int foo( void ) __attribute__((__constructor__(65535/2)));
+ ],
+ [constructor], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [deprecated], [
+ int foo( void ) __attribute__(($1("")));
+ ],
+ [destructor], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [dllexport], [
+ __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [dllimport], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [error], [
+ int foo( void ) __attribute__(($1("")));
+ ],
+ [externally_visible], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [fallthrough], [
+ int foo( void ) {switch (0) { case 1: __attribute__(($1)); case 2: break ; }};
+ ],
+ [flatten], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [format], [
+ int foo(const char *p, ...) __attribute__(($1(printf, 1, 2)));
+ ],
+ [format_arg], [
+ char *foo(const char *p) __attribute__(($1(1)));
+ ],
+ [gnu_inline], [
+ inline __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [hot], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [ifunc], [
+ int my_foo( void ) { return 0; }
+ static int (*resolve_foo(void))(void) { return my_foo; }
+ int foo( void ) __attribute__(($1("resolve_foo")));
+ ],
+ [leaf], [
+ __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [malloc], [
+ void *foo( void ) __attribute__(($1));
+ ],
+ [noclone], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [noinline], [
+ __attribute__(($1)) int foo( void ) { return 0; }
+ ],
+ [nonnull], [
+ int foo(char *p) __attribute__(($1(1)));
+ ],
+ [noreturn], [
+ void foo( void ) __attribute__(($1));
+ ],
+ [nothrow], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [optimize], [
+ __attribute__(($1(3))) int foo( void ) { return 0; }
+ ],
+ [pure], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [sentinel], [
+ int foo(void *p, ...) __attribute__(($1));
+ ],
+ [sentinel_position], [
+ int foo(void *p, ...) __attribute__(($1(1)));
+ ],
+ [returns_nonnull], [
+ void *foo( void ) __attribute__(($1));
+ ],
+ [unused], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [used], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [visibility], [
+ int foo_def( void ) __attribute__(($1("default")));
+ int foo_hid( void ) __attribute__(($1("hidden")));
+ int foo_int( void ) __attribute__(($1("internal")));
+ int foo_pro( void ) __attribute__(($1("protected")));
+ ],
+ [warning], [
+ int foo( void ) __attribute__(($1("")));
+ ],
+ [warn_unused_result], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [weak], [
+ int foo( void ) __attribute__(($1));
+ ],
+ [weakref], [
+ static int foo( void ) { return 0; }
+ static int bar( void ) __attribute__(($1("foo")));
+ ],
+ [
+ m4_warn([syntax], [Unsupported attribute $1, the test may fail])
+ int foo( void ) __attribute__(($1));
+ ]
+ )], [])
+ ],
+ dnl GCC doesn't exit with an error if an unknown attribute is
+ dnl provided but only outputs a warning, so accept the attribute
+ dnl only if no warning were issued.
+ [AS_IF([test -s conftest.err],
+ [AS_VAR_SET([ac_var], [no])],
+ [AS_VAR_SET([ac_var], [yes])])],
+ [AS_VAR_SET([ac_var], [no])])
+ ])
+
+ AS_IF([test yes = AS_VAR_GET([ac_var])],
+ [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_FUNC_ATTRIBUTE_$1), 1,
+ [Define to 1 if the system has the `$1' function attribute])], [])
+
+ AS_VAR_POPDEF([ac_var])
+])
diff --git a/configure.ac b/configure.ac
index 37096944..639199a9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -619,6 +619,7 @@ CHECK_CCSUPPORT([-Werror=format-overflow=2], [flg1])
CHECK_CCSUPPORT([-Werror=int-conversion], [flg2])
CHECK_CCSUPPORT([-Werror=incompatible-pointer-types], [flg3])
CHECK_CCSUPPORT([-Werror=misleading-indentation], [flg4])
+AX_GCC_FUNC_ATTRIBUTE([format])

AC_SUBST([AM_CFLAGS], ["$my_am_cflags $flg1 $flg2 $flg3 $flg4"])

diff --git a/support/include/xcommon.h b/support/include/xcommon.h
index 23c9a135..30b0403b 100644
--- a/support/include/xcommon.h
+++ b/support/include/xcommon.h
@@ -9,6 +9,10 @@
#ifndef _XMALLOC_H
#define _MALLOC_H

+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
#include <sys/types.h>
#include <fcntl.h>
#include <limits.h>
@@ -25,9 +29,15 @@

#define streq(s, t) (strcmp ((s), (t)) == 0)

-/* Functions in sundries.c that are used in mount.c and umount.c */
+#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
+#define X_FORMAT(_x) __attribute__((__format__ _x))
+#else
+#define X_FORMAT(_x)
+#endif
+
+/* Functions in sundries.c that are used in mount.c and umount.c */
char *canonicalize (const char *path);
-void nfs_error (const char *fmt, ...);
+void nfs_error (const char *fmt, ...) X_FORMAT((printf, 1, 2));
void *xmalloc (size_t size);
void *xrealloc(void *p, size_t size);
void xfree(void *);
@@ -36,9 +46,9 @@ char *xstrndup (const char *s, int n);
char *xstrconcat2 (const char *, const char *);
char *xstrconcat3 (const char *, const char *, const char *);
char *xstrconcat4 (const char *, const char *, const char *, const char *);
-void die (int errcode, const char *fmt, ...);
+void die (int errcode, const char *fmt, ...) X_FORMAT((printf, 2, 3));

-extern void die(int err, const char *fmt, ...);
+extern void die(int err, const char *fmt, ...) X_FORMAT((printf, 2, 3));
extern void (*at_die)(void);

/* exit status - bits below are ORed */
diff --git a/support/include/xlog.h b/support/include/xlog.h
index a11463ed..32ff5a1b 100644
--- a/support/include/xlog.h
+++ b/support/include/xlog.h
@@ -7,6 +7,10 @@
#ifndef XLOG_H
#define XLOG_H

+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
#include <stdarg.h>

/* These are logged always. L_FATAL also does exit(1) */
@@ -35,6 +39,12 @@ struct xlog_debugfac {
int df_fac;
};

+#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
+#define XLOG_FORMAT(_x) __attribute__((__format__ _x))
+#else
+#define XLOG_FORMAT(_x)
+#endif
+
extern int export_errno;
void xlog_open(char *progname);
void xlog_stderr(int on);
@@ -43,10 +53,10 @@ void xlog_config(int fac, int on);
void xlog_sconfig(char *, int on);
void xlog_from_conffile(char *);
int xlog_enabled(int fac);
-void xlog(int fac, const char *fmt, ...);
-void xlog_warn(const char *fmt, ...);
-void xlog_err(const char *fmt, ...);
-void xlog_errno(int err, const char *fmt, ...);
-void xlog_backend(int fac, const char *fmt, va_list args);
+void xlog(int fac, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
+void xlog_warn(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
+void xlog_err(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
+void xlog_errno(int err, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
+void xlog_backend(int fac, const char *fmt, va_list args) XLOG_FORMAT((printf, 2, 0));

#endif /* XLOG_H */
diff --git a/support/nfs/svc_create.c b/support/nfs/svc_create.c
index 4e14430d..976c2d29 100644
--- a/support/nfs/svc_create.c
+++ b/support/nfs/svc_create.c
@@ -184,7 +184,7 @@ svc_create_sock(const struct sockaddr *sap, socklen_t salen,
type = SOCK_STREAM;
break;
default:
- xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %u",
+ xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %lu",
__func__, nconf->nc_semantics);
return -1;
}
diff --git a/support/nsm/rpc.c b/support/nsm/rpc.c
index ae49006c..08b4746f 100644
--- a/support/nsm/rpc.c
+++ b/support/nsm/rpc.c
@@ -182,7 +182,7 @@ nsm_xmit_getport(const int sock, const struct sockaddr_in *sin,
uint32_t xid;
XDR xdr;

- xlog(D_CALL, "Sending PMAP_GETPORT for %u, %u, udp", program, version);
+ xlog(D_CALL, "Sending PMAP_GETPORT for %lu, %lu, udp", program, version);

nsm_init_xdrmem(msgbuf, NSM_MAXMSGSIZE, &xdr);
xid = nsm_init_rpc_header(PMAPPROG, PMAPVERS,
diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
index 5cca4175..a04a7898 100644
--- a/utils/exportfs/exportfs.c
+++ b/utils/exportfs/exportfs.c
@@ -651,6 +651,9 @@ out:
return result;
}

+#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
+__attribute__((format (printf, 2, 3)))
+#endif
static char
dumpopt(char c, char *fmt, ...)
{
diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index e25a4337..3861f84a 100644
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -987,8 +987,7 @@ lookup_export(char *dom, char *path, struct addrinfo *ai)
} else if (found_type == i && found->m_warned == 0) {
xlog(L_WARNING, "%s exported to both %s and %s, "
"arbitrarily choosing options from first",
- path, found->m_client->m_hostname, exp->m_client->m_hostname,
- dom);
+ path, found->m_client->m_hostname, exp->m_client->m_hostname);
found->m_warned = 1;
}
}
diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
index 33571ecb..66366434 100644
--- a/utils/mountd/mountd.c
+++ b/utils/mountd/mountd.c
@@ -210,10 +210,10 @@ killer (int sig)
}

static void
-sig_hup (int sig)
+sig_hup (int UNUSED(sig))
{
/* don't exit on SIGHUP */
- xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n", sig);
+ xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n");
return;
}

diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
index cbf71fc6..7e894e49 100644
--- a/utils/nfsdcld/nfsdcld.c
+++ b/utils/nfsdcld/nfsdcld.c
@@ -212,7 +212,7 @@ cld_inotify_cb(int UNUSED(fd), short which, void *data)
default:
/* anything else is fatal */
xlog(L_FATAL, "%s: unable to open new pipe (%d). Aborting.",
- ret, __func__);
+ __func__, ret);
exit(ret);
}

diff --git a/utils/nfsdcld/sqlite.c b/utils/nfsdcld/sqlite.c
index fa81df87..afa63499 100644
--- a/utils/nfsdcld/sqlite.c
+++ b/utils/nfsdcld/sqlite.c
@@ -473,7 +473,7 @@ sqlite_fix_table_name(const char *name)
}
ret = sqlite3_exec(dbh, (const char *)buf, NULL, NULL, &err);
if (ret != SQLITE_OK) {
- xlog(L_ERROR, "Unable to fix table for epoch %d: %s",
+ xlog(L_ERROR, "Unable to fix table for epoch %"PRIu64": %s",
val, err);
goto out;
}
diff --git a/utils/nfsidmap/nfsidmap.c b/utils/nfsidmap/nfsidmap.c
index fc00da7a..cf7f65e9 100644
--- a/utils/nfsidmap/nfsidmap.c
+++ b/utils/nfsidmap/nfsidmap.c
@@ -18,7 +18,7 @@
#include "xcommon.h"

int verbose = 0;
-char *usage = "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]";
+#define USAGE "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]"

#define MAX_ID_LEN 11
#define IDMAP_NAMESZ 128
@@ -403,7 +403,7 @@ int main(int argc, char **argv)
break;
case 'h':
default:
- xlog_warn(usage, progname);
+ xlog_warn(USAGE, progname);
exit(opt == 'h' ? 0 : 1);
}
}
@@ -435,7 +435,7 @@ int main(int argc, char **argv)
xlog_stderr(verbose);
if ((argc - optind) != 2) {
xlog_warn("Bad arg count. Check /etc/request-key.conf");
- xlog_warn(usage, progname);
+ xlog_warn(USAGE, progname);
return EXIT_FAILURE;
}

@@ -453,7 +453,7 @@ int main(int argc, char **argv)
return EXIT_FAILURE;
}
if (verbose) {
- xlog_warn("key: 0x%lx type: %s value: %s timeout %ld",
+ xlog_warn("key: 0x%x type: %s value: %s timeout %d",
key, type, value, timeout);
}

diff --git a/utils/statd/rmtcall.c b/utils/statd/rmtcall.c
index c4f6364f..5b261480 100644
--- a/utils/statd/rmtcall.c
+++ b/utils/statd/rmtcall.c
@@ -247,7 +247,7 @@ process_reply(FD_SET_TYPE *rfds)
xlog_warn("%s: service %d not registered on localhost",
__func__, NL_MY_PROG(lp));
} else {
- xlog(D_GENERAL, "%s: Callback to %s (for %d) succeeded",
+ xlog(D_GENERAL, "%s: Callback to %s (for %s) succeeded",
__func__, NL_MY_NAME(lp), NL_MON_NAME(lp));
}
nlist_free(&notify, lp);
diff --git a/utils/statd/statd.c b/utils/statd/statd.c
index 14673800..8eef2ff2 100644
--- a/utils/statd/statd.c
+++ b/utils/statd/statd.c
@@ -136,7 +136,7 @@ static void log_modes(void)
strcat(buf, "TI-RPC ");
#endif

- xlog_warn(buf);
+ xlog_warn("%s", buf);
}

/*
diff --git a/utils/statd/svc_run.c b/utils/statd/svc_run.c
index d1dbd74a..e343c768 100644
--- a/utils/statd/svc_run.c
+++ b/utils/statd/svc_run.c
@@ -53,6 +53,7 @@

#include <errno.h>
#include <time.h>
+#include <inttypes.h>
#include "statd.h"
#include "notlist.h"

@@ -104,8 +105,8 @@ my_svc_run(int sockfd)

tv.tv_sec = NL_WHEN(notify) - now;
tv.tv_usec = 0;
- xlog(D_GENERAL, "Waiting for reply... (timeo %d)",
- tv.tv_sec);
+ xlog(D_GENERAL, "Waiting for reply... (timeo %jd)",
+ (intmax_t)tv.tv_sec);
selret = select(FD_SETSIZE, &readfds,
(void *) 0, (void *) 0, &tv);
} else {
--
2.21.0

2019-09-16 21:39:26

by Joshua Watt

[permalink] [raw]
Subject: Re: [nfs-utils PATCH v2] Add printf format checking

On 9/6/19 3:24 PM, Joshua Watt wrote:
> Adds a configure time check for __attribute__((format)) and then uses it
> to enforce checking the format of several printf-like functions. Several
> invalid uses of format codes that were discovered have now been fixed.
>
> V2: Fix use of "%jd" format code on an argument that wasn't intmax_t

ping?

>
> Signed-off-by: Joshua Watt <[email protected]>
> ---
> aclocal/ax_gcc_func_attribute.m4 | 238 +++++++++++++++++++++++++++++++
> configure.ac | 1 +
> support/include/xcommon.h | 18 ++-
> support/include/xlog.h | 20 ++-
> support/nfs/svc_create.c | 2 +-
> support/nsm/rpc.c | 2 +-
> utils/exportfs/exportfs.c | 3 +
> utils/mountd/cache.c | 3 +-
> utils/mountd/mountd.c | 4 +-
> utils/nfsdcld/nfsdcld.c | 2 +-
> utils/nfsdcld/sqlite.c | 2 +-
> utils/nfsidmap/nfsidmap.c | 8 +-
> utils/statd/rmtcall.c | 2 +-
> utils/statd/statd.c | 2 +-
> utils/statd/svc_run.c | 5 +-
> 15 files changed, 287 insertions(+), 25 deletions(-)
> create mode 100644 aclocal/ax_gcc_func_attribute.m4
>
> diff --git a/aclocal/ax_gcc_func_attribute.m4 b/aclocal/ax_gcc_func_attribute.m4
> new file mode 100644
> index 00000000..098c9aad
> --- /dev/null
> +++ b/aclocal/ax_gcc_func_attribute.m4
> @@ -0,0 +1,238 @@
> +# ===========================================================================
> +# https://www.gnu.org/software/autoconf-archive/ax_gcc_func_attribute.html
> +# ===========================================================================
> +#
> +# SYNOPSIS
> +#
> +# AX_GCC_FUNC_ATTRIBUTE(ATTRIBUTE)
> +#
> +# DESCRIPTION
> +#
> +# This macro checks if the compiler supports one of GCC's function
> +# attributes; many other compilers also provide function attributes with
> +# the same syntax. Compiler warnings are used to detect supported
> +# attributes as unsupported ones are ignored by default so quieting
> +# warnings when using this macro will yield false positives.
> +#
> +# The ATTRIBUTE parameter holds the name of the attribute to be checked.
> +#
> +# If ATTRIBUTE is supported define HAVE_FUNC_ATTRIBUTE_<ATTRIBUTE>.
> +#
> +# The macro caches its result in the ax_cv_have_func_attribute_<attribute>
> +# variable.
> +#
> +# The macro currently supports the following function attributes:
> +#
> +# alias
> +# aligned
> +# alloc_size
> +# always_inline
> +# artificial
> +# cold
> +# const
> +# constructor
> +# constructor_priority for constructor attribute with priority
> +# deprecated
> +# destructor
> +# dllexport
> +# dllimport
> +# error
> +# externally_visible
> +# fallthrough
> +# flatten
> +# format
> +# format_arg
> +# gnu_inline
> +# hot
> +# ifunc
> +# leaf
> +# malloc
> +# noclone
> +# noinline
> +# nonnull
> +# noreturn
> +# nothrow
> +# optimize
> +# pure
> +# sentinel
> +# sentinel_position
> +# unused
> +# used
> +# visibility
> +# warning
> +# warn_unused_result
> +# weak
> +# weakref
> +#
> +# Unsupported function attributes will be tested with a prototype
> +# returning an int and not accepting any arguments and the result of the
> +# check might be wrong or meaningless so use with care.
> +#
> +# LICENSE
> +#
> +# Copyright (c) 2013 Gabriele Svelto <[email protected]>
> +#
> +# Copying and distribution of this file, with or without modification, are
> +# permitted in any medium without royalty provided the copyright notice
> +# and this notice are preserved. This file is offered as-is, without any
> +# warranty.
> +
> +#serial 9
> +
> +AC_DEFUN([AX_GCC_FUNC_ATTRIBUTE], [
> + AS_VAR_PUSHDEF([ac_var], [ax_cv_have_func_attribute_$1])
> +
> + AC_CACHE_CHECK([for __attribute__(($1))], [ac_var], [
> + AC_LINK_IFELSE([AC_LANG_PROGRAM([
> + m4_case([$1],
> + [alias], [
> + int foo( void ) { return 0; }
> + int bar( void ) __attribute__(($1("foo")));
> + ],
> + [aligned], [
> + int foo( void ) __attribute__(($1(32)));
> + ],
> + [alloc_size], [
> + void *foo(int a) __attribute__(($1(1)));
> + ],
> + [always_inline], [
> + inline __attribute__(($1)) int foo( void ) { return 0; }
> + ],
> + [artificial], [
> + inline __attribute__(($1)) int foo( void ) { return 0; }
> + ],
> + [cold], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [const], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [constructor_priority], [
> + int foo( void ) __attribute__((__constructor__(65535/2)));
> + ],
> + [constructor], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [deprecated], [
> + int foo( void ) __attribute__(($1("")));
> + ],
> + [destructor], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [dllexport], [
> + __attribute__(($1)) int foo( void ) { return 0; }
> + ],
> + [dllimport], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [error], [
> + int foo( void ) __attribute__(($1("")));
> + ],
> + [externally_visible], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [fallthrough], [
> + int foo( void ) {switch (0) { case 1: __attribute__(($1)); case 2: break ; }};
> + ],
> + [flatten], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [format], [
> + int foo(const char *p, ...) __attribute__(($1(printf, 1, 2)));
> + ],
> + [format_arg], [
> + char *foo(const char *p) __attribute__(($1(1)));
> + ],
> + [gnu_inline], [
> + inline __attribute__(($1)) int foo( void ) { return 0; }
> + ],
> + [hot], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [ifunc], [
> + int my_foo( void ) { return 0; }
> + static int (*resolve_foo(void))(void) { return my_foo; }
> + int foo( void ) __attribute__(($1("resolve_foo")));
> + ],
> + [leaf], [
> + __attribute__(($1)) int foo( void ) { return 0; }
> + ],
> + [malloc], [
> + void *foo( void ) __attribute__(($1));
> + ],
> + [noclone], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [noinline], [
> + __attribute__(($1)) int foo( void ) { return 0; }
> + ],
> + [nonnull], [
> + int foo(char *p) __attribute__(($1(1)));
> + ],
> + [noreturn], [
> + void foo( void ) __attribute__(($1));
> + ],
> + [nothrow], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [optimize], [
> + __attribute__(($1(3))) int foo( void ) { return 0; }
> + ],
> + [pure], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [sentinel], [
> + int foo(void *p, ...) __attribute__(($1));
> + ],
> + [sentinel_position], [
> + int foo(void *p, ...) __attribute__(($1(1)));
> + ],
> + [returns_nonnull], [
> + void *foo( void ) __attribute__(($1));
> + ],
> + [unused], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [used], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [visibility], [
> + int foo_def( void ) __attribute__(($1("default")));
> + int foo_hid( void ) __attribute__(($1("hidden")));
> + int foo_int( void ) __attribute__(($1("internal")));
> + int foo_pro( void ) __attribute__(($1("protected")));
> + ],
> + [warning], [
> + int foo( void ) __attribute__(($1("")));
> + ],
> + [warn_unused_result], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [weak], [
> + int foo( void ) __attribute__(($1));
> + ],
> + [weakref], [
> + static int foo( void ) { return 0; }
> + static int bar( void ) __attribute__(($1("foo")));
> + ],
> + [
> + m4_warn([syntax], [Unsupported attribute $1, the test may fail])
> + int foo( void ) __attribute__(($1));
> + ]
> + )], [])
> + ],
> + dnl GCC doesn't exit with an error if an unknown attribute is
> + dnl provided but only outputs a warning, so accept the attribute
> + dnl only if no warning were issued.
> + [AS_IF([test -s conftest.err],
> + [AS_VAR_SET([ac_var], [no])],
> + [AS_VAR_SET([ac_var], [yes])])],
> + [AS_VAR_SET([ac_var], [no])])
> + ])
> +
> + AS_IF([test yes = AS_VAR_GET([ac_var])],
> + [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_FUNC_ATTRIBUTE_$1), 1,
> + [Define to 1 if the system has the `$1' function attribute])], [])
> +
> + AS_VAR_POPDEF([ac_var])
> +])
> diff --git a/configure.ac b/configure.ac
> index 37096944..639199a9 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -619,6 +619,7 @@ CHECK_CCSUPPORT([-Werror=format-overflow=2], [flg1])
> CHECK_CCSUPPORT([-Werror=int-conversion], [flg2])
> CHECK_CCSUPPORT([-Werror=incompatible-pointer-types], [flg3])
> CHECK_CCSUPPORT([-Werror=misleading-indentation], [flg4])
> +AX_GCC_FUNC_ATTRIBUTE([format])
>
> AC_SUBST([AM_CFLAGS], ["$my_am_cflags $flg1 $flg2 $flg3 $flg4"])
>
> diff --git a/support/include/xcommon.h b/support/include/xcommon.h
> index 23c9a135..30b0403b 100644
> --- a/support/include/xcommon.h
> +++ b/support/include/xcommon.h
> @@ -9,6 +9,10 @@
> #ifndef _XMALLOC_H
> #define _MALLOC_H
>
> +#ifdef HAVE_CONFIG_H
> +#include <config.h>
> +#endif
> +
> #include <sys/types.h>
> #include <fcntl.h>
> #include <limits.h>
> @@ -25,9 +29,15 @@
>
> #define streq(s, t) (strcmp ((s), (t)) == 0)
>
> -/* Functions in sundries.c that are used in mount.c and umount.c */
> +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
> +#define X_FORMAT(_x) __attribute__((__format__ _x))
> +#else
> +#define X_FORMAT(_x)
> +#endif
> +
> +/* Functions in sundries.c that are used in mount.c and umount.c */
> char *canonicalize (const char *path);
> -void nfs_error (const char *fmt, ...);
> +void nfs_error (const char *fmt, ...) X_FORMAT((printf, 1, 2));
> void *xmalloc (size_t size);
> void *xrealloc(void *p, size_t size);
> void xfree(void *);
> @@ -36,9 +46,9 @@ char *xstrndup (const char *s, int n);
> char *xstrconcat2 (const char *, const char *);
> char *xstrconcat3 (const char *, const char *, const char *);
> char *xstrconcat4 (const char *, const char *, const char *, const char *);
> -void die (int errcode, const char *fmt, ...);
> +void die (int errcode, const char *fmt, ...) X_FORMAT((printf, 2, 3));
>
> -extern void die(int err, const char *fmt, ...);
> +extern void die(int err, const char *fmt, ...) X_FORMAT((printf, 2, 3));
> extern void (*at_die)(void);
>
> /* exit status - bits below are ORed */
> diff --git a/support/include/xlog.h b/support/include/xlog.h
> index a11463ed..32ff5a1b 100644
> --- a/support/include/xlog.h
> +++ b/support/include/xlog.h
> @@ -7,6 +7,10 @@
> #ifndef XLOG_H
> #define XLOG_H
>
> +#ifdef HAVE_CONFIG_H
> +#include <config.h>
> +#endif
> +
> #include <stdarg.h>
>
> /* These are logged always. L_FATAL also does exit(1) */
> @@ -35,6 +39,12 @@ struct xlog_debugfac {
> int df_fac;
> };
>
> +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
> +#define XLOG_FORMAT(_x) __attribute__((__format__ _x))
> +#else
> +#define XLOG_FORMAT(_x)
> +#endif
> +
> extern int export_errno;
> void xlog_open(char *progname);
> void xlog_stderr(int on);
> @@ -43,10 +53,10 @@ void xlog_config(int fac, int on);
> void xlog_sconfig(char *, int on);
> void xlog_from_conffile(char *);
> int xlog_enabled(int fac);
> -void xlog(int fac, const char *fmt, ...);
> -void xlog_warn(const char *fmt, ...);
> -void xlog_err(const char *fmt, ...);
> -void xlog_errno(int err, const char *fmt, ...);
> -void xlog_backend(int fac, const char *fmt, va_list args);
> +void xlog(int fac, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
> +void xlog_warn(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
> +void xlog_err(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
> +void xlog_errno(int err, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
> +void xlog_backend(int fac, const char *fmt, va_list args) XLOG_FORMAT((printf, 2, 0));
>
> #endif /* XLOG_H */
> diff --git a/support/nfs/svc_create.c b/support/nfs/svc_create.c
> index 4e14430d..976c2d29 100644
> --- a/support/nfs/svc_create.c
> +++ b/support/nfs/svc_create.c
> @@ -184,7 +184,7 @@ svc_create_sock(const struct sockaddr *sap, socklen_t salen,
> type = SOCK_STREAM;
> break;
> default:
> - xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %u",
> + xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %lu",
> __func__, nconf->nc_semantics);
> return -1;
> }
> diff --git a/support/nsm/rpc.c b/support/nsm/rpc.c
> index ae49006c..08b4746f 100644
> --- a/support/nsm/rpc.c
> +++ b/support/nsm/rpc.c
> @@ -182,7 +182,7 @@ nsm_xmit_getport(const int sock, const struct sockaddr_in *sin,
> uint32_t xid;
> XDR xdr;
>
> - xlog(D_CALL, "Sending PMAP_GETPORT for %u, %u, udp", program, version);
> + xlog(D_CALL, "Sending PMAP_GETPORT for %lu, %lu, udp", program, version);
>
> nsm_init_xdrmem(msgbuf, NSM_MAXMSGSIZE, &xdr);
> xid = nsm_init_rpc_header(PMAPPROG, PMAPVERS,
> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
> index 5cca4175..a04a7898 100644
> --- a/utils/exportfs/exportfs.c
> +++ b/utils/exportfs/exportfs.c
> @@ -651,6 +651,9 @@ out:
> return result;
> }
>
> +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
> +__attribute__((format (printf, 2, 3)))
> +#endif
> static char
> dumpopt(char c, char *fmt, ...)
> {
> diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
> index e25a4337..3861f84a 100644
> --- a/utils/mountd/cache.c
> +++ b/utils/mountd/cache.c
> @@ -987,8 +987,7 @@ lookup_export(char *dom, char *path, struct addrinfo *ai)
> } else if (found_type == i && found->m_warned == 0) {
> xlog(L_WARNING, "%s exported to both %s and %s, "
> "arbitrarily choosing options from first",
> - path, found->m_client->m_hostname, exp->m_client->m_hostname,
> - dom);
> + path, found->m_client->m_hostname, exp->m_client->m_hostname);
> found->m_warned = 1;
> }
> }
> diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
> index 33571ecb..66366434 100644
> --- a/utils/mountd/mountd.c
> +++ b/utils/mountd/mountd.c
> @@ -210,10 +210,10 @@ killer (int sig)
> }
>
> static void
> -sig_hup (int sig)
> +sig_hup (int UNUSED(sig))
> {
> /* don't exit on SIGHUP */
> - xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n", sig);
> + xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n");
> return;
> }
>
> diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
> index cbf71fc6..7e894e49 100644
> --- a/utils/nfsdcld/nfsdcld.c
> +++ b/utils/nfsdcld/nfsdcld.c
> @@ -212,7 +212,7 @@ cld_inotify_cb(int UNUSED(fd), short which, void *data)
> default:
> /* anything else is fatal */
> xlog(L_FATAL, "%s: unable to open new pipe (%d). Aborting.",
> - ret, __func__);
> + __func__, ret);
> exit(ret);
> }
>
> diff --git a/utils/nfsdcld/sqlite.c b/utils/nfsdcld/sqlite.c
> index fa81df87..afa63499 100644
> --- a/utils/nfsdcld/sqlite.c
> +++ b/utils/nfsdcld/sqlite.c
> @@ -473,7 +473,7 @@ sqlite_fix_table_name(const char *name)
> }
> ret = sqlite3_exec(dbh, (const char *)buf, NULL, NULL, &err);
> if (ret != SQLITE_OK) {
> - xlog(L_ERROR, "Unable to fix table for epoch %d: %s",
> + xlog(L_ERROR, "Unable to fix table for epoch %"PRIu64": %s",
> val, err);
> goto out;
> }
> diff --git a/utils/nfsidmap/nfsidmap.c b/utils/nfsidmap/nfsidmap.c
> index fc00da7a..cf7f65e9 100644
> --- a/utils/nfsidmap/nfsidmap.c
> +++ b/utils/nfsidmap/nfsidmap.c
> @@ -18,7 +18,7 @@
> #include "xcommon.h"
>
> int verbose = 0;
> -char *usage = "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]";
> +#define USAGE "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]"
>
> #define MAX_ID_LEN 11
> #define IDMAP_NAMESZ 128
> @@ -403,7 +403,7 @@ int main(int argc, char **argv)
> break;
> case 'h':
> default:
> - xlog_warn(usage, progname);
> + xlog_warn(USAGE, progname);
> exit(opt == 'h' ? 0 : 1);
> }
> }
> @@ -435,7 +435,7 @@ int main(int argc, char **argv)
> xlog_stderr(verbose);
> if ((argc - optind) != 2) {
> xlog_warn("Bad arg count. Check /etc/request-key.conf");
> - xlog_warn(usage, progname);
> + xlog_warn(USAGE, progname);
> return EXIT_FAILURE;
> }
>
> @@ -453,7 +453,7 @@ int main(int argc, char **argv)
> return EXIT_FAILURE;
> }
> if (verbose) {
> - xlog_warn("key: 0x%lx type: %s value: %s timeout %ld",
> + xlog_warn("key: 0x%x type: %s value: %s timeout %d",
> key, type, value, timeout);
> }
>
> diff --git a/utils/statd/rmtcall.c b/utils/statd/rmtcall.c
> index c4f6364f..5b261480 100644
> --- a/utils/statd/rmtcall.c
> +++ b/utils/statd/rmtcall.c
> @@ -247,7 +247,7 @@ process_reply(FD_SET_TYPE *rfds)
> xlog_warn("%s: service %d not registered on localhost",
> __func__, NL_MY_PROG(lp));
> } else {
> - xlog(D_GENERAL, "%s: Callback to %s (for %d) succeeded",
> + xlog(D_GENERAL, "%s: Callback to %s (for %s) succeeded",
> __func__, NL_MY_NAME(lp), NL_MON_NAME(lp));
> }
> nlist_free(&notify, lp);
> diff --git a/utils/statd/statd.c b/utils/statd/statd.c
> index 14673800..8eef2ff2 100644
> --- a/utils/statd/statd.c
> +++ b/utils/statd/statd.c
> @@ -136,7 +136,7 @@ static void log_modes(void)
> strcat(buf, "TI-RPC ");
> #endif
>
> - xlog_warn(buf);
> + xlog_warn("%s", buf);
> }
>
> /*
> diff --git a/utils/statd/svc_run.c b/utils/statd/svc_run.c
> index d1dbd74a..e343c768 100644
> --- a/utils/statd/svc_run.c
> +++ b/utils/statd/svc_run.c
> @@ -53,6 +53,7 @@
>
> #include <errno.h>
> #include <time.h>
> +#include <inttypes.h>
> #include "statd.h"
> #include "notlist.h"
>
> @@ -104,8 +105,8 @@ my_svc_run(int sockfd)
>
> tv.tv_sec = NL_WHEN(notify) - now;
> tv.tv_usec = 0;
> - xlog(D_GENERAL, "Waiting for reply... (timeo %d)",
> - tv.tv_sec);
> + xlog(D_GENERAL, "Waiting for reply... (timeo %jd)",
> + (intmax_t)tv.tv_sec);
> selret = select(FD_SETSIZE, &readfds,
> (void *) 0, (void *) 0, &tv);
> } else {

2019-09-20 20:16:56

by Steve Dickson

[permalink] [raw]
Subject: Re: [nfs-utils PATCH v2] Add printf format checking



On 9/16/19 2:33 PM, Joshua Watt wrote:
> On 9/6/19 3:24 PM, Joshua Watt wrote:
>> Adds a configure time check for __attribute__((format)) and then uses it
>> to enforce checking the format of several printf-like functions. Several
>> invalid uses of format codes that were discovered have now been fixed.
>>
>> V2: Fix use of "%jd" format code on an argument that wasn't intmax_t
>
> ping?
>
>>
>> Signed-off-by: Joshua Watt <[email protected]>
Committed... Thanks for the ping!

steved.
>> ---
>>   aclocal/ax_gcc_func_attribute.m4 | 238 +++++++++++++++++++++++++++++++
>>   configure.ac                     |   1 +
>>   support/include/xcommon.h        |  18 ++-
>>   support/include/xlog.h           |  20 ++-
>>   support/nfs/svc_create.c         |   2 +-
>>   support/nsm/rpc.c                |   2 +-
>>   utils/exportfs/exportfs.c        |   3 +
>>   utils/mountd/cache.c             |   3 +-
>>   utils/mountd/mountd.c            |   4 +-
>>   utils/nfsdcld/nfsdcld.c          |   2 +-
>>   utils/nfsdcld/sqlite.c           |   2 +-
>>   utils/nfsidmap/nfsidmap.c        |   8 +-
>>   utils/statd/rmtcall.c            |   2 +-
>>   utils/statd/statd.c              |   2 +-
>>   utils/statd/svc_run.c            |   5 +-
>>   15 files changed, 287 insertions(+), 25 deletions(-)
>>   create mode 100644 aclocal/ax_gcc_func_attribute.m4
>>
>> diff --git a/aclocal/ax_gcc_func_attribute.m4 b/aclocal/ax_gcc_func_attribute.m4
>> new file mode 100644
>> index 00000000..098c9aad
>> --- /dev/null
>> +++ b/aclocal/ax_gcc_func_attribute.m4
>> @@ -0,0 +1,238 @@
>> +# ===========================================================================
>> +#  https://www.gnu.org/software/autoconf-archive/ax_gcc_func_attribute.html
>> +# ===========================================================================
>> +#
>> +# SYNOPSIS
>> +#
>> +#   AX_GCC_FUNC_ATTRIBUTE(ATTRIBUTE)
>> +#
>> +# DESCRIPTION
>> +#
>> +#   This macro checks if the compiler supports one of GCC's function
>> +#   attributes; many other compilers also provide function attributes with
>> +#   the same syntax. Compiler warnings are used to detect supported
>> +#   attributes as unsupported ones are ignored by default so quieting
>> +#   warnings when using this macro will yield false positives.
>> +#
>> +#   The ATTRIBUTE parameter holds the name of the attribute to be checked.
>> +#
>> +#   If ATTRIBUTE is supported define HAVE_FUNC_ATTRIBUTE_<ATTRIBUTE>.
>> +#
>> +#   The macro caches its result in the ax_cv_have_func_attribute_<attribute>
>> +#   variable.
>> +#
>> +#   The macro currently supports the following function attributes:
>> +#
>> +#    alias
>> +#    aligned
>> +#    alloc_size
>> +#    always_inline
>> +#    artificial
>> +#    cold
>> +#    const
>> +#    constructor
>> +#    constructor_priority for constructor attribute with priority
>> +#    deprecated
>> +#    destructor
>> +#    dllexport
>> +#    dllimport
>> +#    error
>> +#    externally_visible
>> +#    fallthrough
>> +#    flatten
>> +#    format
>> +#    format_arg
>> +#    gnu_inline
>> +#    hot
>> +#    ifunc
>> +#    leaf
>> +#    malloc
>> +#    noclone
>> +#    noinline
>> +#    nonnull
>> +#    noreturn
>> +#    nothrow
>> +#    optimize
>> +#    pure
>> +#    sentinel
>> +#    sentinel_position
>> +#    unused
>> +#    used
>> +#    visibility
>> +#    warning
>> +#    warn_unused_result
>> +#    weak
>> +#    weakref
>> +#
>> +#   Unsupported function attributes will be tested with a prototype
>> +#   returning an int and not accepting any arguments and the result of the
>> +#   check might be wrong or meaningless so use with care.
>> +#
>> +# LICENSE
>> +#
>> +#   Copyright (c) 2013 Gabriele Svelto <[email protected]>
>> +#
>> +#   Copying and distribution of this file, with or without modification, are
>> +#   permitted in any medium without royalty provided the copyright notice
>> +#   and this notice are preserved.  This file is offered as-is, without any
>> +#   warranty.
>> +
>> +#serial 9
>> +
>> +AC_DEFUN([AX_GCC_FUNC_ATTRIBUTE], [
>> +    AS_VAR_PUSHDEF([ac_var], [ax_cv_have_func_attribute_$1])
>> +
>> +    AC_CACHE_CHECK([for __attribute__(($1))], [ac_var], [
>> +        AC_LINK_IFELSE([AC_LANG_PROGRAM([
>> +            m4_case([$1],
>> +                [alias], [
>> +                    int foo( void ) { return 0; }
>> +                    int bar( void ) __attribute__(($1("foo")));
>> +                ],
>> +                [aligned], [
>> +                    int foo( void ) __attribute__(($1(32)));
>> +                ],
>> +                [alloc_size], [
>> +                    void *foo(int a) __attribute__(($1(1)));
>> +                ],
>> +                [always_inline], [
>> +                    inline __attribute__(($1)) int foo( void ) { return 0; }
>> +                ],
>> +                [artificial], [
>> +                    inline __attribute__(($1)) int foo( void ) { return 0; }
>> +                ],
>> +                [cold], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [const], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [constructor_priority], [
>> +                    int foo( void ) __attribute__((__constructor__(65535/2)));
>> +                ],
>> +                [constructor], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [deprecated], [
>> +                    int foo( void ) __attribute__(($1("")));
>> +                ],
>> +                [destructor], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [dllexport], [
>> +                    __attribute__(($1)) int foo( void ) { return 0; }
>> +                ],
>> +                [dllimport], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [error], [
>> +                    int foo( void ) __attribute__(($1("")));
>> +                ],
>> +                [externally_visible], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [fallthrough], [
>> +                    int foo( void ) {switch (0) { case 1: __attribute__(($1)); case 2: break ; }};
>> +                ],
>> +                [flatten], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [format], [
>> +                    int foo(const char *p, ...) __attribute__(($1(printf, 1, 2)));
>> +                ],
>> +                [format_arg], [
>> +                    char *foo(const char *p) __attribute__(($1(1)));
>> +                ],
>> +                [gnu_inline], [
>> +                    inline __attribute__(($1)) int foo( void ) { return 0; }
>> +                ],
>> +                [hot], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [ifunc], [
>> +                    int my_foo( void ) { return 0; }
>> +                    static int (*resolve_foo(void))(void) { return my_foo; }
>> +                    int foo( void ) __attribute__(($1("resolve_foo")));
>> +                ],
>> +                [leaf], [
>> +                    __attribute__(($1)) int foo( void ) { return 0; }
>> +                ],
>> +                [malloc], [
>> +                    void *foo( void ) __attribute__(($1));
>> +                ],
>> +                [noclone], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [noinline], [
>> +                    __attribute__(($1)) int foo( void ) { return 0; }
>> +                ],
>> +                [nonnull], [
>> +                    int foo(char *p) __attribute__(($1(1)));
>> +                ],
>> +                [noreturn], [
>> +                    void foo( void ) __attribute__(($1));
>> +                ],
>> +                [nothrow], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [optimize], [
>> +                    __attribute__(($1(3))) int foo( void ) { return 0; }
>> +                ],
>> +                [pure], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [sentinel], [
>> +                    int foo(void *p, ...) __attribute__(($1));
>> +                ],
>> +                [sentinel_position], [
>> +                    int foo(void *p, ...) __attribute__(($1(1)));
>> +                ],
>> +                [returns_nonnull], [
>> +                    void *foo( void ) __attribute__(($1));
>> +                ],
>> +                [unused], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [used], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [visibility], [
>> +                    int foo_def( void ) __attribute__(($1("default")));
>> +                    int foo_hid( void ) __attribute__(($1("hidden")));
>> +                    int foo_int( void ) __attribute__(($1("internal")));
>> +                    int foo_pro( void ) __attribute__(($1("protected")));
>> +                ],
>> +                [warning], [
>> +                    int foo( void ) __attribute__(($1("")));
>> +                ],
>> +                [warn_unused_result], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [weak], [
>> +                    int foo( void ) __attribute__(($1));
>> +                ],
>> +                [weakref], [
>> +                    static int foo( void ) { return 0; }
>> +                    static int bar( void ) __attribute__(($1("foo")));
>> +                ],
>> +                [
>> +                 m4_warn([syntax], [Unsupported attribute $1, the test may fail])
>> +                 int foo( void ) __attribute__(($1));
>> +                ]
>> +            )], [])
>> +            ],
>> +            dnl GCC doesn't exit with an error if an unknown attribute is
>> +            dnl provided but only outputs a warning, so accept the attribute
>> +            dnl only if no warning were issued.
>> +            [AS_IF([test -s conftest.err],
>> +                [AS_VAR_SET([ac_var], [no])],
>> +                [AS_VAR_SET([ac_var], [yes])])],
>> +            [AS_VAR_SET([ac_var], [no])])
>> +    ])
>> +
>> +    AS_IF([test yes = AS_VAR_GET([ac_var])],
>> +        [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_FUNC_ATTRIBUTE_$1), 1,
>> +            [Define to 1 if the system has the `$1' function attribute])], [])
>> +
>> +    AS_VAR_POPDEF([ac_var])
>> +])
>> diff --git a/configure.ac b/configure.ac
>> index 37096944..639199a9 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -619,6 +619,7 @@ CHECK_CCSUPPORT([-Werror=format-overflow=2], [flg1])
>>   CHECK_CCSUPPORT([-Werror=int-conversion], [flg2])
>>   CHECK_CCSUPPORT([-Werror=incompatible-pointer-types], [flg3])
>>   CHECK_CCSUPPORT([-Werror=misleading-indentation], [flg4])
>> +AX_GCC_FUNC_ATTRIBUTE([format])
>>     AC_SUBST([AM_CFLAGS], ["$my_am_cflags $flg1 $flg2 $flg3 $flg4"])
>>   diff --git a/support/include/xcommon.h b/support/include/xcommon.h
>> index 23c9a135..30b0403b 100644
>> --- a/support/include/xcommon.h
>> +++ b/support/include/xcommon.h
>> @@ -9,6 +9,10 @@
>>   #ifndef _XMALLOC_H
>>   #define _MALLOC_H
>>   +#ifdef HAVE_CONFIG_H
>> +#include <config.h>
>> +#endif
>> +
>>   #include <sys/types.h>
>>   #include <fcntl.h>
>>   #include <limits.h>
>> @@ -25,9 +29,15 @@
>>     #define streq(s, t)    (strcmp ((s), (t)) == 0)
>>   -/* Functions in sundries.c that are used in mount.c and umount.c  */
>> +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
>> +#define X_FORMAT(_x) __attribute__((__format__ _x))
>> +#else
>> +#define X_FORMAT(_x)
>> +#endif
>> +
>> +/* Functions in sundries.c that are used in mount.c and umount.c  */
>>   char *canonicalize (const char *path);
>> -void nfs_error (const char *fmt, ...);
>> +void nfs_error (const char *fmt, ...) X_FORMAT((printf, 1, 2));
>>   void *xmalloc (size_t size);
>>   void *xrealloc(void *p, size_t size);
>>   void xfree(void *);
>> @@ -36,9 +46,9 @@ char *xstrndup (const char *s, int n);
>>   char *xstrconcat2 (const char *, const char *);
>>   char *xstrconcat3 (const char *, const char *, const char *);
>>   char *xstrconcat4 (const char *, const char *, const char *, const char *);
>> -void die (int errcode, const char *fmt, ...);
>> +void die (int errcode, const char *fmt, ...) X_FORMAT((printf, 2, 3));
>>   -extern void die(int err, const char *fmt, ...);
>> +extern void die(int err, const char *fmt, ...) X_FORMAT((printf, 2, 3));
>>   extern void (*at_die)(void);
>>     /* exit status - bits below are ORed */
>> diff --git a/support/include/xlog.h b/support/include/xlog.h
>> index a11463ed..32ff5a1b 100644
>> --- a/support/include/xlog.h
>> +++ b/support/include/xlog.h
>> @@ -7,6 +7,10 @@
>>   #ifndef XLOG_H
>>   #define XLOG_H
>>   +#ifdef HAVE_CONFIG_H
>> +#include <config.h>
>> +#endif
>> +
>>   #include <stdarg.h>
>>     /* These are logged always. L_FATAL also does exit(1) */
>> @@ -35,6 +39,12 @@ struct xlog_debugfac {
>>       int        df_fac;
>>   };
>>   +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
>> +#define XLOG_FORMAT(_x) __attribute__((__format__ _x))
>> +#else
>> +#define XLOG_FORMAT(_x)
>> +#endif
>> +
>>   extern int export_errno;
>>   void            xlog_open(char *progname);
>>   void            xlog_stderr(int on);
>> @@ -43,10 +53,10 @@ void            xlog_config(int fac, int on);
>>   void            xlog_sconfig(char *, int on);
>>   void            xlog_from_conffile(char *);
>>   int            xlog_enabled(int fac);
>> -void            xlog(int fac, const char *fmt, ...);
>> -void            xlog_warn(const char *fmt, ...);
>> -void            xlog_err(const char *fmt, ...);
>> -void            xlog_errno(int err, const char *fmt, ...);
>> -void            xlog_backend(int fac, const char *fmt, va_list args);
>> +void            xlog(int fac, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
>> +void            xlog_warn(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
>> +void            xlog_err(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
>> +void            xlog_errno(int err, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
>> +void            xlog_backend(int fac, const char *fmt, va_list args) XLOG_FORMAT((printf, 2, 0));
>>     #endif /* XLOG_H */
>> diff --git a/support/nfs/svc_create.c b/support/nfs/svc_create.c
>> index 4e14430d..976c2d29 100644
>> --- a/support/nfs/svc_create.c
>> +++ b/support/nfs/svc_create.c
>> @@ -184,7 +184,7 @@ svc_create_sock(const struct sockaddr *sap, socklen_t salen,
>>           type = SOCK_STREAM;
>>           break;
>>       default:
>> -        xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %u",
>> +        xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %lu",
>>               __func__, nconf->nc_semantics);
>>           return -1;
>>       }
>> diff --git a/support/nsm/rpc.c b/support/nsm/rpc.c
>> index ae49006c..08b4746f 100644
>> --- a/support/nsm/rpc.c
>> +++ b/support/nsm/rpc.c
>> @@ -182,7 +182,7 @@ nsm_xmit_getport(const int sock, const struct sockaddr_in *sin,
>>       uint32_t xid;
>>       XDR xdr;
>>   -    xlog(D_CALL, "Sending PMAP_GETPORT for %u, %u, udp", program, version);
>> +    xlog(D_CALL, "Sending PMAP_GETPORT for %lu, %lu, udp", program, version);
>>         nsm_init_xdrmem(msgbuf, NSM_MAXMSGSIZE, &xdr);
>>       xid = nsm_init_rpc_header(PMAPPROG, PMAPVERS,
>> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
>> index 5cca4175..a04a7898 100644
>> --- a/utils/exportfs/exportfs.c
>> +++ b/utils/exportfs/exportfs.c
>> @@ -651,6 +651,9 @@ out:
>>       return result;
>>   }
>>   +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
>> +__attribute__((format (printf, 2, 3)))
>> +#endif
>>   static char
>>   dumpopt(char c, char *fmt, ...)
>>   {
>> diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
>> index e25a4337..3861f84a 100644
>> --- a/utils/mountd/cache.c
>> +++ b/utils/mountd/cache.c
>> @@ -987,8 +987,7 @@ lookup_export(char *dom, char *path, struct addrinfo *ai)
>>               } else if (found_type == i && found->m_warned == 0) {
>>                   xlog(L_WARNING, "%s exported to both %s and %s, "
>>                        "arbitrarily choosing options from first",
>> -                     path, found->m_client->m_hostname, exp->m_client->m_hostname,
>> -                     dom);
>> +                     path, found->m_client->m_hostname, exp->m_client->m_hostname);
>>                   found->m_warned = 1;
>>               }
>>           }
>> diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
>> index 33571ecb..66366434 100644
>> --- a/utils/mountd/mountd.c
>> +++ b/utils/mountd/mountd.c
>> @@ -210,10 +210,10 @@ killer (int sig)
>>   }
>>     static void
>> -sig_hup (int sig)
>> +sig_hup (int UNUSED(sig))
>>   {
>>       /* don't exit on SIGHUP */
>> -    xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n", sig);
>> +    xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n");
>>       return;
>>   }
>>   diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
>> index cbf71fc6..7e894e49 100644
>> --- a/utils/nfsdcld/nfsdcld.c
>> +++ b/utils/nfsdcld/nfsdcld.c
>> @@ -212,7 +212,7 @@ cld_inotify_cb(int UNUSED(fd), short which, void *data)
>>       default:
>>           /* anything else is fatal */
>>           xlog(L_FATAL, "%s: unable to open new pipe (%d). Aborting.",
>> -            ret, __func__);
>> +            __func__, ret);
>>           exit(ret);
>>       }
>>   diff --git a/utils/nfsdcld/sqlite.c b/utils/nfsdcld/sqlite.c
>> index fa81df87..afa63499 100644
>> --- a/utils/nfsdcld/sqlite.c
>> +++ b/utils/nfsdcld/sqlite.c
>> @@ -473,7 +473,7 @@ sqlite_fix_table_name(const char *name)
>>       }
>>       ret = sqlite3_exec(dbh, (const char *)buf, NULL, NULL, &err);
>>       if (ret != SQLITE_OK) {
>> -        xlog(L_ERROR, "Unable to fix table for epoch %d: %s",
>> +        xlog(L_ERROR, "Unable to fix table for epoch %"PRIu64": %s",
>>                val, err);
>>           goto out;
>>       }
>> diff --git a/utils/nfsidmap/nfsidmap.c b/utils/nfsidmap/nfsidmap.c
>> index fc00da7a..cf7f65e9 100644
>> --- a/utils/nfsidmap/nfsidmap.c
>> +++ b/utils/nfsidmap/nfsidmap.c
>> @@ -18,7 +18,7 @@
>>   #include "xcommon.h"
>>     int verbose = 0;
>> -char *usage = "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]";
>> +#define USAGE "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]"
>>     #define MAX_ID_LEN   11
>>   #define IDMAP_NAMESZ 128
>> @@ -403,7 +403,7 @@ int main(int argc, char **argv)
>>               break;
>>           case 'h':
>>           default:
>> -            xlog_warn(usage, progname);
>> +            xlog_warn(USAGE, progname);
>>               exit(opt == 'h' ? 0 : 1);
>>           }
>>       }
>> @@ -435,7 +435,7 @@ int main(int argc, char **argv)
>>       xlog_stderr(verbose);
>>       if ((argc - optind) != 2) {
>>           xlog_warn("Bad arg count. Check /etc/request-key.conf");
>> -        xlog_warn(usage, progname);
>> +        xlog_warn(USAGE, progname);
>>           return EXIT_FAILURE;
>>       }
>>   @@ -453,7 +453,7 @@ int main(int argc, char **argv)
>>           return EXIT_FAILURE;
>>       }
>>       if (verbose) {
>> -        xlog_warn("key: 0x%lx type: %s value: %s timeout %ld",
>> +        xlog_warn("key: 0x%x type: %s value: %s timeout %d",
>>               key, type, value, timeout);
>>       }
>>   diff --git a/utils/statd/rmtcall.c b/utils/statd/rmtcall.c
>> index c4f6364f..5b261480 100644
>> --- a/utils/statd/rmtcall.c
>> +++ b/utils/statd/rmtcall.c
>> @@ -247,7 +247,7 @@ process_reply(FD_SET_TYPE *rfds)
>>           xlog_warn("%s: service %d not registered on localhost",
>>               __func__, NL_MY_PROG(lp));
>>       } else {
>> -        xlog(D_GENERAL, "%s: Callback to %s (for %d) succeeded",
>> +        xlog(D_GENERAL, "%s: Callback to %s (for %s) succeeded",
>>               __func__, NL_MY_NAME(lp), NL_MON_NAME(lp));
>>       }
>>       nlist_free(&notify, lp);
>> diff --git a/utils/statd/statd.c b/utils/statd/statd.c
>> index 14673800..8eef2ff2 100644
>> --- a/utils/statd/statd.c
>> +++ b/utils/statd/statd.c
>> @@ -136,7 +136,7 @@ static void log_modes(void)
>>       strcat(buf, "TI-RPC ");
>>   #endif
>>   -    xlog_warn(buf);
>> +    xlog_warn("%s", buf);
>>   }
>>     /*
>> diff --git a/utils/statd/svc_run.c b/utils/statd/svc_run.c
>> index d1dbd74a..e343c768 100644
>> --- a/utils/statd/svc_run.c
>> +++ b/utils/statd/svc_run.c
>> @@ -53,6 +53,7 @@
>>     #include <errno.h>
>>   #include <time.h>
>> +#include <inttypes.h>
>>   #include "statd.h"
>>   #include "notlist.h"
>>   @@ -104,8 +105,8 @@ my_svc_run(int sockfd)
>>                 tv.tv_sec  = NL_WHEN(notify) - now;
>>               tv.tv_usec = 0;
>> -            xlog(D_GENERAL, "Waiting for reply... (timeo %d)",
>> -                            tv.tv_sec);
>> +            xlog(D_GENERAL, "Waiting for reply... (timeo %jd)",
>> +                            (intmax_t)tv.tv_sec);
>>               selret = select(FD_SETSIZE, &readfds,
>>                   (void *) 0, (void *) 0, &tv);
>>           } else {

2019-09-24 17:53:38

by Joshua Watt

[permalink] [raw]
Subject: Re: [nfs-utils PATCH v2] Add printf format checking


On 9/20/19 9:05 AM, Steve Dickson wrote:
>
> On 9/16/19 2:33 PM, Joshua Watt wrote:
>> On 9/6/19 3:24 PM, Joshua Watt wrote:
>>> Adds a configure time check for __attribute__((format)) and then uses it
>>> to enforce checking the format of several printf-like functions. Several
>>> invalid uses of format codes that were discovered have now been fixed.
>>>
>>> V2: Fix use of "%jd" format code on an argument that wasn't intmax_t
>> ping?
>>
>>> Signed-off-by: Joshua Watt <[email protected]>
> Committed... Thanks for the ping!

I haven't seen this commit land in the git repository
git.linux-nfs.org/projects/steved/nfs-utils.git yet. Is there a
different one I should be looking at?

Thanks

>
> steved.
>>> ---
>>>   aclocal/ax_gcc_func_attribute.m4 | 238 +++++++++++++++++++++++++++++++
>>>   configure.ac                     |   1 +
>>>   support/include/xcommon.h        |  18 ++-
>>>   support/include/xlog.h           |  20 ++-
>>>   support/nfs/svc_create.c         |   2 +-
>>>   support/nsm/rpc.c                |   2 +-
>>>   utils/exportfs/exportfs.c        |   3 +
>>>   utils/mountd/cache.c             |   3 +-
>>>   utils/mountd/mountd.c            |   4 +-
>>>   utils/nfsdcld/nfsdcld.c          |   2 +-
>>>   utils/nfsdcld/sqlite.c           |   2 +-
>>>   utils/nfsidmap/nfsidmap.c        |   8 +-
>>>   utils/statd/rmtcall.c            |   2 +-
>>>   utils/statd/statd.c              |   2 +-
>>>   utils/statd/svc_run.c            |   5 +-
>>>   15 files changed, 287 insertions(+), 25 deletions(-)
>>>   create mode 100644 aclocal/ax_gcc_func_attribute.m4
>>>
>>> diff --git a/aclocal/ax_gcc_func_attribute.m4 b/aclocal/ax_gcc_func_attribute.m4
>>> new file mode 100644
>>> index 00000000..098c9aad
>>> --- /dev/null
>>> +++ b/aclocal/ax_gcc_func_attribute.m4
>>> @@ -0,0 +1,238 @@
>>> +# ===========================================================================
>>> +#  https://www.gnu.org/software/autoconf-archive/ax_gcc_func_attribute.html
>>> +# ===========================================================================
>>> +#
>>> +# SYNOPSIS
>>> +#
>>> +#   AX_GCC_FUNC_ATTRIBUTE(ATTRIBUTE)
>>> +#
>>> +# DESCRIPTION
>>> +#
>>> +#   This macro checks if the compiler supports one of GCC's function
>>> +#   attributes; many other compilers also provide function attributes with
>>> +#   the same syntax. Compiler warnings are used to detect supported
>>> +#   attributes as unsupported ones are ignored by default so quieting
>>> +#   warnings when using this macro will yield false positives.
>>> +#
>>> +#   The ATTRIBUTE parameter holds the name of the attribute to be checked.
>>> +#
>>> +#   If ATTRIBUTE is supported define HAVE_FUNC_ATTRIBUTE_<ATTRIBUTE>.
>>> +#
>>> +#   The macro caches its result in the ax_cv_have_func_attribute_<attribute>
>>> +#   variable.
>>> +#
>>> +#   The macro currently supports the following function attributes:
>>> +#
>>> +#    alias
>>> +#    aligned
>>> +#    alloc_size
>>> +#    always_inline
>>> +#    artificial
>>> +#    cold
>>> +#    const
>>> +#    constructor
>>> +#    constructor_priority for constructor attribute with priority
>>> +#    deprecated
>>> +#    destructor
>>> +#    dllexport
>>> +#    dllimport
>>> +#    error
>>> +#    externally_visible
>>> +#    fallthrough
>>> +#    flatten
>>> +#    format
>>> +#    format_arg
>>> +#    gnu_inline
>>> +#    hot
>>> +#    ifunc
>>> +#    leaf
>>> +#    malloc
>>> +#    noclone
>>> +#    noinline
>>> +#    nonnull
>>> +#    noreturn
>>> +#    nothrow
>>> +#    optimize
>>> +#    pure
>>> +#    sentinel
>>> +#    sentinel_position
>>> +#    unused
>>> +#    used
>>> +#    visibility
>>> +#    warning
>>> +#    warn_unused_result
>>> +#    weak
>>> +#    weakref
>>> +#
>>> +#   Unsupported function attributes will be tested with a prototype
>>> +#   returning an int and not accepting any arguments and the result of the
>>> +#   check might be wrong or meaningless so use with care.
>>> +#
>>> +# LICENSE
>>> +#
>>> +#   Copyright (c) 2013 Gabriele Svelto <[email protected]>
>>> +#
>>> +#   Copying and distribution of this file, with or without modification, are
>>> +#   permitted in any medium without royalty provided the copyright notice
>>> +#   and this notice are preserved.  This file is offered as-is, without any
>>> +#   warranty.
>>> +
>>> +#serial 9
>>> +
>>> +AC_DEFUN([AX_GCC_FUNC_ATTRIBUTE], [
>>> +    AS_VAR_PUSHDEF([ac_var], [ax_cv_have_func_attribute_$1])
>>> +
>>> +    AC_CACHE_CHECK([for __attribute__(($1))], [ac_var], [
>>> +        AC_LINK_IFELSE([AC_LANG_PROGRAM([
>>> +            m4_case([$1],
>>> +                [alias], [
>>> +                    int foo( void ) { return 0; }
>>> +                    int bar( void ) __attribute__(($1("foo")));
>>> +                ],
>>> +                [aligned], [
>>> +                    int foo( void ) __attribute__(($1(32)));
>>> +                ],
>>> +                [alloc_size], [
>>> +                    void *foo(int a) __attribute__(($1(1)));
>>> +                ],
>>> +                [always_inline], [
>>> +                    inline __attribute__(($1)) int foo( void ) { return 0; }
>>> +                ],
>>> +                [artificial], [
>>> +                    inline __attribute__(($1)) int foo( void ) { return 0; }
>>> +                ],
>>> +                [cold], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [const], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [constructor_priority], [
>>> +                    int foo( void ) __attribute__((__constructor__(65535/2)));
>>> +                ],
>>> +                [constructor], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [deprecated], [
>>> +                    int foo( void ) __attribute__(($1("")));
>>> +                ],
>>> +                [destructor], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [dllexport], [
>>> +                    __attribute__(($1)) int foo( void ) { return 0; }
>>> +                ],
>>> +                [dllimport], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [error], [
>>> +                    int foo( void ) __attribute__(($1("")));
>>> +                ],
>>> +                [externally_visible], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [fallthrough], [
>>> +                    int foo( void ) {switch (0) { case 1: __attribute__(($1)); case 2: break ; }};
>>> +                ],
>>> +                [flatten], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [format], [
>>> +                    int foo(const char *p, ...) __attribute__(($1(printf, 1, 2)));
>>> +                ],
>>> +                [format_arg], [
>>> +                    char *foo(const char *p) __attribute__(($1(1)));
>>> +                ],
>>> +                [gnu_inline], [
>>> +                    inline __attribute__(($1)) int foo( void ) { return 0; }
>>> +                ],
>>> +                [hot], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [ifunc], [
>>> +                    int my_foo( void ) { return 0; }
>>> +                    static int (*resolve_foo(void))(void) { return my_foo; }
>>> +                    int foo( void ) __attribute__(($1("resolve_foo")));
>>> +                ],
>>> +                [leaf], [
>>> +                    __attribute__(($1)) int foo( void ) { return 0; }
>>> +                ],
>>> +                [malloc], [
>>> +                    void *foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [noclone], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [noinline], [
>>> +                    __attribute__(($1)) int foo( void ) { return 0; }
>>> +                ],
>>> +                [nonnull], [
>>> +                    int foo(char *p) __attribute__(($1(1)));
>>> +                ],
>>> +                [noreturn], [
>>> +                    void foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [nothrow], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [optimize], [
>>> +                    __attribute__(($1(3))) int foo( void ) { return 0; }
>>> +                ],
>>> +                [pure], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [sentinel], [
>>> +                    int foo(void *p, ...) __attribute__(($1));
>>> +                ],
>>> +                [sentinel_position], [
>>> +                    int foo(void *p, ...) __attribute__(($1(1)));
>>> +                ],
>>> +                [returns_nonnull], [
>>> +                    void *foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [unused], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [used], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [visibility], [
>>> +                    int foo_def( void ) __attribute__(($1("default")));
>>> +                    int foo_hid( void ) __attribute__(($1("hidden")));
>>> +                    int foo_int( void ) __attribute__(($1("internal")));
>>> +                    int foo_pro( void ) __attribute__(($1("protected")));
>>> +                ],
>>> +                [warning], [
>>> +                    int foo( void ) __attribute__(($1("")));
>>> +                ],
>>> +                [warn_unused_result], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [weak], [
>>> +                    int foo( void ) __attribute__(($1));
>>> +                ],
>>> +                [weakref], [
>>> +                    static int foo( void ) { return 0; }
>>> +                    static int bar( void ) __attribute__(($1("foo")));
>>> +                ],
>>> +                [
>>> +                 m4_warn([syntax], [Unsupported attribute $1, the test may fail])
>>> +                 int foo( void ) __attribute__(($1));
>>> +                ]
>>> +            )], [])
>>> +            ],
>>> +            dnl GCC doesn't exit with an error if an unknown attribute is
>>> +            dnl provided but only outputs a warning, so accept the attribute
>>> +            dnl only if no warning were issued.
>>> +            [AS_IF([test -s conftest.err],
>>> +                [AS_VAR_SET([ac_var], [no])],
>>> +                [AS_VAR_SET([ac_var], [yes])])],
>>> +            [AS_VAR_SET([ac_var], [no])])
>>> +    ])
>>> +
>>> +    AS_IF([test yes = AS_VAR_GET([ac_var])],
>>> +        [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_FUNC_ATTRIBUTE_$1), 1,
>>> +            [Define to 1 if the system has the `$1' function attribute])], [])
>>> +
>>> +    AS_VAR_POPDEF([ac_var])
>>> +])
>>> diff --git a/configure.ac b/configure.ac
>>> index 37096944..639199a9 100644
>>> --- a/configure.ac
>>> +++ b/configure.ac
>>> @@ -619,6 +619,7 @@ CHECK_CCSUPPORT([-Werror=format-overflow=2], [flg1])
>>>   CHECK_CCSUPPORT([-Werror=int-conversion], [flg2])
>>>   CHECK_CCSUPPORT([-Werror=incompatible-pointer-types], [flg3])
>>>   CHECK_CCSUPPORT([-Werror=misleading-indentation], [flg4])
>>> +AX_GCC_FUNC_ATTRIBUTE([format])
>>>     AC_SUBST([AM_CFLAGS], ["$my_am_cflags $flg1 $flg2 $flg3 $flg4"])
>>>   diff --git a/support/include/xcommon.h b/support/include/xcommon.h
>>> index 23c9a135..30b0403b 100644
>>> --- a/support/include/xcommon.h
>>> +++ b/support/include/xcommon.h
>>> @@ -9,6 +9,10 @@
>>>   #ifndef _XMALLOC_H
>>>   #define _MALLOC_H
>>>   +#ifdef HAVE_CONFIG_H
>>> +#include <config.h>
>>> +#endif
>>> +
>>>   #include <sys/types.h>
>>>   #include <fcntl.h>
>>>   #include <limits.h>
>>> @@ -25,9 +29,15 @@
>>>     #define streq(s, t)    (strcmp ((s), (t)) == 0)
>>>   -/* Functions in sundries.c that are used in mount.c and umount.c  */
>>> +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
>>> +#define X_FORMAT(_x) __attribute__((__format__ _x))
>>> +#else
>>> +#define X_FORMAT(_x)
>>> +#endif
>>> +
>>> +/* Functions in sundries.c that are used in mount.c and umount.c  */
>>>   char *canonicalize (const char *path);
>>> -void nfs_error (const char *fmt, ...);
>>> +void nfs_error (const char *fmt, ...) X_FORMAT((printf, 1, 2));
>>>   void *xmalloc (size_t size);
>>>   void *xrealloc(void *p, size_t size);
>>>   void xfree(void *);
>>> @@ -36,9 +46,9 @@ char *xstrndup (const char *s, int n);
>>>   char *xstrconcat2 (const char *, const char *);
>>>   char *xstrconcat3 (const char *, const char *, const char *);
>>>   char *xstrconcat4 (const char *, const char *, const char *, const char *);
>>> -void die (int errcode, const char *fmt, ...);
>>> +void die (int errcode, const char *fmt, ...) X_FORMAT((printf, 2, 3));
>>>   -extern void die(int err, const char *fmt, ...);
>>> +extern void die(int err, const char *fmt, ...) X_FORMAT((printf, 2, 3));
>>>   extern void (*at_die)(void);
>>>     /* exit status - bits below are ORed */
>>> diff --git a/support/include/xlog.h b/support/include/xlog.h
>>> index a11463ed..32ff5a1b 100644
>>> --- a/support/include/xlog.h
>>> +++ b/support/include/xlog.h
>>> @@ -7,6 +7,10 @@
>>>   #ifndef XLOG_H
>>>   #define XLOG_H
>>>   +#ifdef HAVE_CONFIG_H
>>> +#include <config.h>
>>> +#endif
>>> +
>>>   #include <stdarg.h>
>>>     /* These are logged always. L_FATAL also does exit(1) */
>>> @@ -35,6 +39,12 @@ struct xlog_debugfac {
>>>       int        df_fac;
>>>   };
>>>   +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
>>> +#define XLOG_FORMAT(_x) __attribute__((__format__ _x))
>>> +#else
>>> +#define XLOG_FORMAT(_x)
>>> +#endif
>>> +
>>>   extern int export_errno;
>>>   void            xlog_open(char *progname);
>>>   void            xlog_stderr(int on);
>>> @@ -43,10 +53,10 @@ void            xlog_config(int fac, int on);
>>>   void            xlog_sconfig(char *, int on);
>>>   void            xlog_from_conffile(char *);
>>>   int            xlog_enabled(int fac);
>>> -void            xlog(int fac, const char *fmt, ...);
>>> -void            xlog_warn(const char *fmt, ...);
>>> -void            xlog_err(const char *fmt, ...);
>>> -void            xlog_errno(int err, const char *fmt, ...);
>>> -void            xlog_backend(int fac, const char *fmt, va_list args);
>>> +void            xlog(int fac, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
>>> +void            xlog_warn(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
>>> +void            xlog_err(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
>>> +void            xlog_errno(int err, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
>>> +void            xlog_backend(int fac, const char *fmt, va_list args) XLOG_FORMAT((printf, 2, 0));
>>>     #endif /* XLOG_H */
>>> diff --git a/support/nfs/svc_create.c b/support/nfs/svc_create.c
>>> index 4e14430d..976c2d29 100644
>>> --- a/support/nfs/svc_create.c
>>> +++ b/support/nfs/svc_create.c
>>> @@ -184,7 +184,7 @@ svc_create_sock(const struct sockaddr *sap, socklen_t salen,
>>>           type = SOCK_STREAM;
>>>           break;
>>>       default:
>>> -        xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %u",
>>> +        xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %lu",
>>>               __func__, nconf->nc_semantics);
>>>           return -1;
>>>       }
>>> diff --git a/support/nsm/rpc.c b/support/nsm/rpc.c
>>> index ae49006c..08b4746f 100644
>>> --- a/support/nsm/rpc.c
>>> +++ b/support/nsm/rpc.c
>>> @@ -182,7 +182,7 @@ nsm_xmit_getport(const int sock, const struct sockaddr_in *sin,
>>>       uint32_t xid;
>>>       XDR xdr;
>>>   -    xlog(D_CALL, "Sending PMAP_GETPORT for %u, %u, udp", program, version);
>>> +    xlog(D_CALL, "Sending PMAP_GETPORT for %lu, %lu, udp", program, version);
>>>         nsm_init_xdrmem(msgbuf, NSM_MAXMSGSIZE, &xdr);
>>>       xid = nsm_init_rpc_header(PMAPPROG, PMAPVERS,
>>> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
>>> index 5cca4175..a04a7898 100644
>>> --- a/utils/exportfs/exportfs.c
>>> +++ b/utils/exportfs/exportfs.c
>>> @@ -651,6 +651,9 @@ out:
>>>       return result;
>>>   }
>>>   +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
>>> +__attribute__((format (printf, 2, 3)))
>>> +#endif
>>>   static char
>>>   dumpopt(char c, char *fmt, ...)
>>>   {
>>> diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
>>> index e25a4337..3861f84a 100644
>>> --- a/utils/mountd/cache.c
>>> +++ b/utils/mountd/cache.c
>>> @@ -987,8 +987,7 @@ lookup_export(char *dom, char *path, struct addrinfo *ai)
>>>               } else if (found_type == i && found->m_warned == 0) {
>>>                   xlog(L_WARNING, "%s exported to both %s and %s, "
>>>                        "arbitrarily choosing options from first",
>>> -                     path, found->m_client->m_hostname, exp->m_client->m_hostname,
>>> -                     dom);
>>> +                     path, found->m_client->m_hostname, exp->m_client->m_hostname);
>>>                   found->m_warned = 1;
>>>               }
>>>           }
>>> diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
>>> index 33571ecb..66366434 100644
>>> --- a/utils/mountd/mountd.c
>>> +++ b/utils/mountd/mountd.c
>>> @@ -210,10 +210,10 @@ killer (int sig)
>>>   }
>>>     static void
>>> -sig_hup (int sig)
>>> +sig_hup (int UNUSED(sig))
>>>   {
>>>       /* don't exit on SIGHUP */
>>> -    xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n", sig);
>>> +    xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n");
>>>       return;
>>>   }
>>>   diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
>>> index cbf71fc6..7e894e49 100644
>>> --- a/utils/nfsdcld/nfsdcld.c
>>> +++ b/utils/nfsdcld/nfsdcld.c
>>> @@ -212,7 +212,7 @@ cld_inotify_cb(int UNUSED(fd), short which, void *data)
>>>       default:
>>>           /* anything else is fatal */
>>>           xlog(L_FATAL, "%s: unable to open new pipe (%d). Aborting.",
>>> -            ret, __func__);
>>> +            __func__, ret);
>>>           exit(ret);
>>>       }
>>>   diff --git a/utils/nfsdcld/sqlite.c b/utils/nfsdcld/sqlite.c
>>> index fa81df87..afa63499 100644
>>> --- a/utils/nfsdcld/sqlite.c
>>> +++ b/utils/nfsdcld/sqlite.c
>>> @@ -473,7 +473,7 @@ sqlite_fix_table_name(const char *name)
>>>       }
>>>       ret = sqlite3_exec(dbh, (const char *)buf, NULL, NULL, &err);
>>>       if (ret != SQLITE_OK) {
>>> -        xlog(L_ERROR, "Unable to fix table for epoch %d: %s",
>>> +        xlog(L_ERROR, "Unable to fix table for epoch %"PRIu64": %s",
>>>                val, err);
>>>           goto out;
>>>       }
>>> diff --git a/utils/nfsidmap/nfsidmap.c b/utils/nfsidmap/nfsidmap.c
>>> index fc00da7a..cf7f65e9 100644
>>> --- a/utils/nfsidmap/nfsidmap.c
>>> +++ b/utils/nfsidmap/nfsidmap.c
>>> @@ -18,7 +18,7 @@
>>>   #include "xcommon.h"
>>>     int verbose = 0;
>>> -char *usage = "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]";
>>> +#define USAGE "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]"
>>>     #define MAX_ID_LEN   11
>>>   #define IDMAP_NAMESZ 128
>>> @@ -403,7 +403,7 @@ int main(int argc, char **argv)
>>>               break;
>>>           case 'h':
>>>           default:
>>> -            xlog_warn(usage, progname);
>>> +            xlog_warn(USAGE, progname);
>>>               exit(opt == 'h' ? 0 : 1);
>>>           }
>>>       }
>>> @@ -435,7 +435,7 @@ int main(int argc, char **argv)
>>>       xlog_stderr(verbose);
>>>       if ((argc - optind) != 2) {
>>>           xlog_warn("Bad arg count. Check /etc/request-key.conf");
>>> -        xlog_warn(usage, progname);
>>> +        xlog_warn(USAGE, progname);
>>>           return EXIT_FAILURE;
>>>       }
>>>   @@ -453,7 +453,7 @@ int main(int argc, char **argv)
>>>           return EXIT_FAILURE;
>>>       }
>>>       if (verbose) {
>>> -        xlog_warn("key: 0x%lx type: %s value: %s timeout %ld",
>>> +        xlog_warn("key: 0x%x type: %s value: %s timeout %d",
>>>               key, type, value, timeout);
>>>       }
>>>   diff --git a/utils/statd/rmtcall.c b/utils/statd/rmtcall.c
>>> index c4f6364f..5b261480 100644
>>> --- a/utils/statd/rmtcall.c
>>> +++ b/utils/statd/rmtcall.c
>>> @@ -247,7 +247,7 @@ process_reply(FD_SET_TYPE *rfds)
>>>           xlog_warn("%s: service %d not registered on localhost",
>>>               __func__, NL_MY_PROG(lp));
>>>       } else {
>>> -        xlog(D_GENERAL, "%s: Callback to %s (for %d) succeeded",
>>> +        xlog(D_GENERAL, "%s: Callback to %s (for %s) succeeded",
>>>               __func__, NL_MY_NAME(lp), NL_MON_NAME(lp));
>>>       }
>>>       nlist_free(&notify, lp);
>>> diff --git a/utils/statd/statd.c b/utils/statd/statd.c
>>> index 14673800..8eef2ff2 100644
>>> --- a/utils/statd/statd.c
>>> +++ b/utils/statd/statd.c
>>> @@ -136,7 +136,7 @@ static void log_modes(void)
>>>       strcat(buf, "TI-RPC ");
>>>   #endif
>>>   -    xlog_warn(buf);
>>> +    xlog_warn("%s", buf);
>>>   }
>>>     /*
>>> diff --git a/utils/statd/svc_run.c b/utils/statd/svc_run.c
>>> index d1dbd74a..e343c768 100644
>>> --- a/utils/statd/svc_run.c
>>> +++ b/utils/statd/svc_run.c
>>> @@ -53,6 +53,7 @@
>>>     #include <errno.h>
>>>   #include <time.h>
>>> +#include <inttypes.h>
>>>   #include "statd.h"
>>>   #include "notlist.h"
>>>   @@ -104,8 +105,8 @@ my_svc_run(int sockfd)
>>>                 tv.tv_sec  = NL_WHEN(notify) - now;
>>>               tv.tv_usec = 0;
>>> -            xlog(D_GENERAL, "Waiting for reply... (timeo %d)",
>>> -                            tv.tv_sec);
>>> +            xlog(D_GENERAL, "Waiting for reply... (timeo %jd)",
>>> +                            (intmax_t)tv.tv_sec);
>>>               selret = select(FD_SETSIZE, &readfds,
>>>                   (void *) 0, (void *) 0, &tv);
>>>           } else {

2019-09-26 00:15:42

by Steve Dickson

[permalink] [raw]
Subject: Re: [nfs-utils PATCH v2] Add printf format checking



On 9/23/19 10:04 AM, Joshua Watt wrote:
>
> On 9/20/19 9:05 AM, Steve Dickson wrote:
>>
>> On 9/16/19 2:33 PM, Joshua Watt wrote:
>>> On 9/6/19 3:24 PM, Joshua Watt wrote:
>>>> Adds a configure time check for __attribute__((format)) and then uses it
>>>> to enforce checking the format of several printf-like functions. Several
>>>> invalid uses of format codes that were discovered have now been fixed.
>>>>
>>>> V2: Fix use of "%jd" format code on an argument that wasn't intmax_t
>>> ping?
>>>
>>>> Signed-off-by: Joshua Watt <[email protected]>
>> Committed... Thanks for the ping!
>
> I haven't seen this commit land in the git repository git.linux-nfs.org/projects/steved/nfs-utils.git yet. Is there a different one I should be looking at?
It is there now... Sorry about that... The darn day job got in the way... again!! ;-)

steved.
>
> Thanks
>
>>
>> steved.
>>>> ---
>>>>    aclocal/ax_gcc_func_attribute.m4 | 238 +++++++++++++++++++++++++++++++
>>>>    configure.ac                     |   1 +
>>>>    support/include/xcommon.h        |  18 ++-
>>>>    support/include/xlog.h           |  20 ++-
>>>>    support/nfs/svc_create.c         |   2 +-
>>>>    support/nsm/rpc.c                |   2 +-
>>>>    utils/exportfs/exportfs.c        |   3 +
>>>>    utils/mountd/cache.c             |   3 +-
>>>>    utils/mountd/mountd.c            |   4 +-
>>>>    utils/nfsdcld/nfsdcld.c          |   2 +-
>>>>    utils/nfsdcld/sqlite.c           |   2 +-
>>>>    utils/nfsidmap/nfsidmap.c        |   8 +-
>>>>    utils/statd/rmtcall.c            |   2 +-
>>>>    utils/statd/statd.c              |   2 +-
>>>>    utils/statd/svc_run.c            |   5 +-
>>>>    15 files changed, 287 insertions(+), 25 deletions(-)
>>>>    create mode 100644 aclocal/ax_gcc_func_attribute.m4
>>>>
>>>> diff --git a/aclocal/ax_gcc_func_attribute.m4 b/aclocal/ax_gcc_func_attribute.m4
>>>> new file mode 100644
>>>> index 00000000..098c9aad
>>>> --- /dev/null
>>>> +++ b/aclocal/ax_gcc_func_attribute.m4
>>>> @@ -0,0 +1,238 @@
>>>> +# ===========================================================================
>>>> +#  https://www.gnu.org/software/autoconf-archive/ax_gcc_func_attribute.html
>>>> +# ===========================================================================
>>>> +#
>>>> +# SYNOPSIS
>>>> +#
>>>> +#   AX_GCC_FUNC_ATTRIBUTE(ATTRIBUTE)
>>>> +#
>>>> +# DESCRIPTION
>>>> +#
>>>> +#   This macro checks if the compiler supports one of GCC's function
>>>> +#   attributes; many other compilers also provide function attributes with
>>>> +#   the same syntax. Compiler warnings are used to detect supported
>>>> +#   attributes as unsupported ones are ignored by default so quieting
>>>> +#   warnings when using this macro will yield false positives.
>>>> +#
>>>> +#   The ATTRIBUTE parameter holds the name of the attribute to be checked.
>>>> +#
>>>> +#   If ATTRIBUTE is supported define HAVE_FUNC_ATTRIBUTE_<ATTRIBUTE>.
>>>> +#
>>>> +#   The macro caches its result in the ax_cv_have_func_attribute_<attribute>
>>>> +#   variable.
>>>> +#
>>>> +#   The macro currently supports the following function attributes:
>>>> +#
>>>> +#    alias
>>>> +#    aligned
>>>> +#    alloc_size
>>>> +#    always_inline
>>>> +#    artificial
>>>> +#    cold
>>>> +#    const
>>>> +#    constructor
>>>> +#    constructor_priority for constructor attribute with priority
>>>> +#    deprecated
>>>> +#    destructor
>>>> +#    dllexport
>>>> +#    dllimport
>>>> +#    error
>>>> +#    externally_visible
>>>> +#    fallthrough
>>>> +#    flatten
>>>> +#    format
>>>> +#    format_arg
>>>> +#    gnu_inline
>>>> +#    hot
>>>> +#    ifunc
>>>> +#    leaf
>>>> +#    malloc
>>>> +#    noclone
>>>> +#    noinline
>>>> +#    nonnull
>>>> +#    noreturn
>>>> +#    nothrow
>>>> +#    optimize
>>>> +#    pure
>>>> +#    sentinel
>>>> +#    sentinel_position
>>>> +#    unused
>>>> +#    used
>>>> +#    visibility
>>>> +#    warning
>>>> +#    warn_unused_result
>>>> +#    weak
>>>> +#    weakref
>>>> +#
>>>> +#   Unsupported function attributes will be tested with a prototype
>>>> +#   returning an int and not accepting any arguments and the result of the
>>>> +#   check might be wrong or meaningless so use with care.
>>>> +#
>>>> +# LICENSE
>>>> +#
>>>> +#   Copyright (c) 2013 Gabriele Svelto <[email protected]>
>>>> +#
>>>> +#   Copying and distribution of this file, with or without modification, are
>>>> +#   permitted in any medium without royalty provided the copyright notice
>>>> +#   and this notice are preserved.  This file is offered as-is, without any
>>>> +#   warranty.
>>>> +
>>>> +#serial 9
>>>> +
>>>> +AC_DEFUN([AX_GCC_FUNC_ATTRIBUTE], [
>>>> +    AS_VAR_PUSHDEF([ac_var], [ax_cv_have_func_attribute_$1])
>>>> +
>>>> +    AC_CACHE_CHECK([for __attribute__(($1))], [ac_var], [
>>>> +        AC_LINK_IFELSE([AC_LANG_PROGRAM([
>>>> +            m4_case([$1],
>>>> +                [alias], [
>>>> +                    int foo( void ) { return 0; }
>>>> +                    int bar( void ) __attribute__(($1("foo")));
>>>> +                ],
>>>> +                [aligned], [
>>>> +                    int foo( void ) __attribute__(($1(32)));
>>>> +                ],
>>>> +                [alloc_size], [
>>>> +                    void *foo(int a) __attribute__(($1(1)));
>>>> +                ],
>>>> +                [always_inline], [
>>>> +                    inline __attribute__(($1)) int foo( void ) { return 0; }
>>>> +                ],
>>>> +                [artificial], [
>>>> +                    inline __attribute__(($1)) int foo( void ) { return 0; }
>>>> +                ],
>>>> +                [cold], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [const], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [constructor_priority], [
>>>> +                    int foo( void ) __attribute__((__constructor__(65535/2)));
>>>> +                ],
>>>> +                [constructor], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [deprecated], [
>>>> +                    int foo( void ) __attribute__(($1("")));
>>>> +                ],
>>>> +                [destructor], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [dllexport], [
>>>> +                    __attribute__(($1)) int foo( void ) { return 0; }
>>>> +                ],
>>>> +                [dllimport], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [error], [
>>>> +                    int foo( void ) __attribute__(($1("")));
>>>> +                ],
>>>> +                [externally_visible], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [fallthrough], [
>>>> +                    int foo( void ) {switch (0) { case 1: __attribute__(($1)); case 2: break ; }};
>>>> +                ],
>>>> +                [flatten], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [format], [
>>>> +                    int foo(const char *p, ...) __attribute__(($1(printf, 1, 2)));
>>>> +                ],
>>>> +                [format_arg], [
>>>> +                    char *foo(const char *p) __attribute__(($1(1)));
>>>> +                ],
>>>> +                [gnu_inline], [
>>>> +                    inline __attribute__(($1)) int foo( void ) { return 0; }
>>>> +                ],
>>>> +                [hot], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [ifunc], [
>>>> +                    int my_foo( void ) { return 0; }
>>>> +                    static int (*resolve_foo(void))(void) { return my_foo; }
>>>> +                    int foo( void ) __attribute__(($1("resolve_foo")));
>>>> +                ],
>>>> +                [leaf], [
>>>> +                    __attribute__(($1)) int foo( void ) { return 0; }
>>>> +                ],
>>>> +                [malloc], [
>>>> +                    void *foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [noclone], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [noinline], [
>>>> +                    __attribute__(($1)) int foo( void ) { return 0; }
>>>> +                ],
>>>> +                [nonnull], [
>>>> +                    int foo(char *p) __attribute__(($1(1)));
>>>> +                ],
>>>> +                [noreturn], [
>>>> +                    void foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [nothrow], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [optimize], [
>>>> +                    __attribute__(($1(3))) int foo( void ) { return 0; }
>>>> +                ],
>>>> +                [pure], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [sentinel], [
>>>> +                    int foo(void *p, ...) __attribute__(($1));
>>>> +                ],
>>>> +                [sentinel_position], [
>>>> +                    int foo(void *p, ...) __attribute__(($1(1)));
>>>> +                ],
>>>> +                [returns_nonnull], [
>>>> +                    void *foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [unused], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [used], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [visibility], [
>>>> +                    int foo_def( void ) __attribute__(($1("default")));
>>>> +                    int foo_hid( void ) __attribute__(($1("hidden")));
>>>> +                    int foo_int( void ) __attribute__(($1("internal")));
>>>> +                    int foo_pro( void ) __attribute__(($1("protected")));
>>>> +                ],
>>>> +                [warning], [
>>>> +                    int foo( void ) __attribute__(($1("")));
>>>> +                ],
>>>> +                [warn_unused_result], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [weak], [
>>>> +                    int foo( void ) __attribute__(($1));
>>>> +                ],
>>>> +                [weakref], [
>>>> +                    static int foo( void ) { return 0; }
>>>> +                    static int bar( void ) __attribute__(($1("foo")));
>>>> +                ],
>>>> +                [
>>>> +                 m4_warn([syntax], [Unsupported attribute $1, the test may fail])
>>>> +                 int foo( void ) __attribute__(($1));
>>>> +                ]
>>>> +            )], [])
>>>> +            ],
>>>> +            dnl GCC doesn't exit with an error if an unknown attribute is
>>>> +            dnl provided but only outputs a warning, so accept the attribute
>>>> +            dnl only if no warning were issued.
>>>> +            [AS_IF([test -s conftest.err],
>>>> +                [AS_VAR_SET([ac_var], [no])],
>>>> +                [AS_VAR_SET([ac_var], [yes])])],
>>>> +            [AS_VAR_SET([ac_var], [no])])
>>>> +    ])
>>>> +
>>>> +    AS_IF([test yes = AS_VAR_GET([ac_var])],
>>>> +        [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_FUNC_ATTRIBUTE_$1), 1,
>>>> +            [Define to 1 if the system has the `$1' function attribute])], [])
>>>> +
>>>> +    AS_VAR_POPDEF([ac_var])
>>>> +])
>>>> diff --git a/configure.ac b/configure.ac
>>>> index 37096944..639199a9 100644
>>>> --- a/configure.ac
>>>> +++ b/configure.ac
>>>> @@ -619,6 +619,7 @@ CHECK_CCSUPPORT([-Werror=format-overflow=2], [flg1])
>>>>    CHECK_CCSUPPORT([-Werror=int-conversion], [flg2])
>>>>    CHECK_CCSUPPORT([-Werror=incompatible-pointer-types], [flg3])
>>>>    CHECK_CCSUPPORT([-Werror=misleading-indentation], [flg4])
>>>> +AX_GCC_FUNC_ATTRIBUTE([format])
>>>>      AC_SUBST([AM_CFLAGS], ["$my_am_cflags $flg1 $flg2 $flg3 $flg4"])
>>>>    diff --git a/support/include/xcommon.h b/support/include/xcommon.h
>>>> index 23c9a135..30b0403b 100644
>>>> --- a/support/include/xcommon.h
>>>> +++ b/support/include/xcommon.h
>>>> @@ -9,6 +9,10 @@
>>>>    #ifndef _XMALLOC_H
>>>>    #define _MALLOC_H
>>>>    +#ifdef HAVE_CONFIG_H
>>>> +#include <config.h>
>>>> +#endif
>>>> +
>>>>    #include <sys/types.h>
>>>>    #include <fcntl.h>
>>>>    #include <limits.h>
>>>> @@ -25,9 +29,15 @@
>>>>      #define streq(s, t)    (strcmp ((s), (t)) == 0)
>>>>    -/* Functions in sundries.c that are used in mount.c and umount.c  */
>>>> +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
>>>> +#define X_FORMAT(_x) __attribute__((__format__ _x))
>>>> +#else
>>>> +#define X_FORMAT(_x)
>>>> +#endif
>>>> +
>>>> +/* Functions in sundries.c that are used in mount.c and umount.c  */
>>>>    char *canonicalize (const char *path);
>>>> -void nfs_error (const char *fmt, ...);
>>>> +void nfs_error (const char *fmt, ...) X_FORMAT((printf, 1, 2));
>>>>    void *xmalloc (size_t size);
>>>>    void *xrealloc(void *p, size_t size);
>>>>    void xfree(void *);
>>>> @@ -36,9 +46,9 @@ char *xstrndup (const char *s, int n);
>>>>    char *xstrconcat2 (const char *, const char *);
>>>>    char *xstrconcat3 (const char *, const char *, const char *);
>>>>    char *xstrconcat4 (const char *, const char *, const char *, const char *);
>>>> -void die (int errcode, const char *fmt, ...);
>>>> +void die (int errcode, const char *fmt, ...) X_FORMAT((printf, 2, 3));
>>>>    -extern void die(int err, const char *fmt, ...);
>>>> +extern void die(int err, const char *fmt, ...) X_FORMAT((printf, 2, 3));
>>>>    extern void (*at_die)(void);
>>>>      /* exit status - bits below are ORed */
>>>> diff --git a/support/include/xlog.h b/support/include/xlog.h
>>>> index a11463ed..32ff5a1b 100644
>>>> --- a/support/include/xlog.h
>>>> +++ b/support/include/xlog.h
>>>> @@ -7,6 +7,10 @@
>>>>    #ifndef XLOG_H
>>>>    #define XLOG_H
>>>>    +#ifdef HAVE_CONFIG_H
>>>> +#include <config.h>
>>>> +#endif
>>>> +
>>>>    #include <stdarg.h>
>>>>      /* These are logged always. L_FATAL also does exit(1) */
>>>> @@ -35,6 +39,12 @@ struct xlog_debugfac {
>>>>        int        df_fac;
>>>>    };
>>>>    +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
>>>> +#define XLOG_FORMAT(_x) __attribute__((__format__ _x))
>>>> +#else
>>>> +#define XLOG_FORMAT(_x)
>>>> +#endif
>>>> +
>>>>    extern int export_errno;
>>>>    void            xlog_open(char *progname);
>>>>    void            xlog_stderr(int on);
>>>> @@ -43,10 +53,10 @@ void            xlog_config(int fac, int on);
>>>>    void            xlog_sconfig(char *, int on);
>>>>    void            xlog_from_conffile(char *);
>>>>    int            xlog_enabled(int fac);
>>>> -void            xlog(int fac, const char *fmt, ...);
>>>> -void            xlog_warn(const char *fmt, ...);
>>>> -void            xlog_err(const char *fmt, ...);
>>>> -void            xlog_errno(int err, const char *fmt, ...);
>>>> -void            xlog_backend(int fac, const char *fmt, va_list args);
>>>> +void            xlog(int fac, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
>>>> +void            xlog_warn(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
>>>> +void            xlog_err(const char *fmt, ...) XLOG_FORMAT((printf, 1, 2));
>>>> +void            xlog_errno(int err, const char *fmt, ...) XLOG_FORMAT((printf, 2, 3));
>>>> +void            xlog_backend(int fac, const char *fmt, va_list args) XLOG_FORMAT((printf, 2, 0));
>>>>      #endif /* XLOG_H */
>>>> diff --git a/support/nfs/svc_create.c b/support/nfs/svc_create.c
>>>> index 4e14430d..976c2d29 100644
>>>> --- a/support/nfs/svc_create.c
>>>> +++ b/support/nfs/svc_create.c
>>>> @@ -184,7 +184,7 @@ svc_create_sock(const struct sockaddr *sap, socklen_t salen,
>>>>            type = SOCK_STREAM;
>>>>            break;
>>>>        default:
>>>> -        xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %u",
>>>> +        xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %lu",
>>>>                __func__, nconf->nc_semantics);
>>>>            return -1;
>>>>        }
>>>> diff --git a/support/nsm/rpc.c b/support/nsm/rpc.c
>>>> index ae49006c..08b4746f 100644
>>>> --- a/support/nsm/rpc.c
>>>> +++ b/support/nsm/rpc.c
>>>> @@ -182,7 +182,7 @@ nsm_xmit_getport(const int sock, const struct sockaddr_in *sin,
>>>>        uint32_t xid;
>>>>        XDR xdr;
>>>>    -    xlog(D_CALL, "Sending PMAP_GETPORT for %u, %u, udp", program, version);
>>>> +    xlog(D_CALL, "Sending PMAP_GETPORT for %lu, %lu, udp", program, version);
>>>>          nsm_init_xdrmem(msgbuf, NSM_MAXMSGSIZE, &xdr);
>>>>        xid = nsm_init_rpc_header(PMAPPROG, PMAPVERS,
>>>> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
>>>> index 5cca4175..a04a7898 100644
>>>> --- a/utils/exportfs/exportfs.c
>>>> +++ b/utils/exportfs/exportfs.c
>>>> @@ -651,6 +651,9 @@ out:
>>>>        return result;
>>>>    }
>>>>    +#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
>>>> +__attribute__((format (printf, 2, 3)))
>>>> +#endif
>>>>    static char
>>>>    dumpopt(char c, char *fmt, ...)
>>>>    {
>>>> diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
>>>> index e25a4337..3861f84a 100644
>>>> --- a/utils/mountd/cache.c
>>>> +++ b/utils/mountd/cache.c
>>>> @@ -987,8 +987,7 @@ lookup_export(char *dom, char *path, struct addrinfo *ai)
>>>>                } else if (found_type == i && found->m_warned == 0) {
>>>>                    xlog(L_WARNING, "%s exported to both %s and %s, "
>>>>                         "arbitrarily choosing options from first",
>>>> -                     path, found->m_client->m_hostname, exp->m_client->m_hostname,
>>>> -                     dom);
>>>> +                     path, found->m_client->m_hostname, exp->m_client->m_hostname);
>>>>                    found->m_warned = 1;
>>>>                }
>>>>            }
>>>> diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
>>>> index 33571ecb..66366434 100644
>>>> --- a/utils/mountd/mountd.c
>>>> +++ b/utils/mountd/mountd.c
>>>> @@ -210,10 +210,10 @@ killer (int sig)
>>>>    }
>>>>      static void
>>>> -sig_hup (int sig)
>>>> +sig_hup (int UNUSED(sig))
>>>>    {
>>>>        /* don't exit on SIGHUP */
>>>> -    xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n", sig);
>>>> +    xlog (L_NOTICE, "Received SIGHUP... Ignoring.\n");
>>>>        return;
>>>>    }
>>>>    diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
>>>> index cbf71fc6..7e894e49 100644
>>>> --- a/utils/nfsdcld/nfsdcld.c
>>>> +++ b/utils/nfsdcld/nfsdcld.c
>>>> @@ -212,7 +212,7 @@ cld_inotify_cb(int UNUSED(fd), short which, void *data)
>>>>        default:
>>>>            /* anything else is fatal */
>>>>            xlog(L_FATAL, "%s: unable to open new pipe (%d). Aborting.",
>>>> -            ret, __func__);
>>>> +            __func__, ret);
>>>>            exit(ret);
>>>>        }
>>>>    diff --git a/utils/nfsdcld/sqlite.c b/utils/nfsdcld/sqlite.c
>>>> index fa81df87..afa63499 100644
>>>> --- a/utils/nfsdcld/sqlite.c
>>>> +++ b/utils/nfsdcld/sqlite.c
>>>> @@ -473,7 +473,7 @@ sqlite_fix_table_name(const char *name)
>>>>        }
>>>>        ret = sqlite3_exec(dbh, (const char *)buf, NULL, NULL, &err);
>>>>        if (ret != SQLITE_OK) {
>>>> -        xlog(L_ERROR, "Unable to fix table for epoch %d: %s",
>>>> +        xlog(L_ERROR, "Unable to fix table for epoch %"PRIu64": %s",
>>>>                 val, err);
>>>>            goto out;
>>>>        }
>>>> diff --git a/utils/nfsidmap/nfsidmap.c b/utils/nfsidmap/nfsidmap.c
>>>> index fc00da7a..cf7f65e9 100644
>>>> --- a/utils/nfsidmap/nfsidmap.c
>>>> +++ b/utils/nfsidmap/nfsidmap.c
>>>> @@ -18,7 +18,7 @@
>>>>    #include "xcommon.h"
>>>>      int verbose = 0;
>>>> -char *usage = "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]";
>>>> +#define USAGE "Usage: %s [-vh] [-c || [-u|-g|-r key] || -d || -l || [-t timeout] key desc]"
>>>>      #define MAX_ID_LEN   11
>>>>    #define IDMAP_NAMESZ 128
>>>> @@ -403,7 +403,7 @@ int main(int argc, char **argv)
>>>>                break;
>>>>            case 'h':
>>>>            default:
>>>> -            xlog_warn(usage, progname);
>>>> +            xlog_warn(USAGE, progname);
>>>>                exit(opt == 'h' ? 0 : 1);
>>>>            }
>>>>        }
>>>> @@ -435,7 +435,7 @@ int main(int argc, char **argv)
>>>>        xlog_stderr(verbose);
>>>>        if ((argc - optind) != 2) {
>>>>            xlog_warn("Bad arg count. Check /etc/request-key.conf");
>>>> -        xlog_warn(usage, progname);
>>>> +        xlog_warn(USAGE, progname);
>>>>            return EXIT_FAILURE;
>>>>        }
>>>>    @@ -453,7 +453,7 @@ int main(int argc, char **argv)
>>>>            return EXIT_FAILURE;
>>>>        }
>>>>        if (verbose) {
>>>> -        xlog_warn("key: 0x%lx type: %s value: %s timeout %ld",
>>>> +        xlog_warn("key: 0x%x type: %s value: %s timeout %d",
>>>>                key, type, value, timeout);
>>>>        }
>>>>    diff --git a/utils/statd/rmtcall.c b/utils/statd/rmtcall.c
>>>> index c4f6364f..5b261480 100644
>>>> --- a/utils/statd/rmtcall.c
>>>> +++ b/utils/statd/rmtcall.c
>>>> @@ -247,7 +247,7 @@ process_reply(FD_SET_TYPE *rfds)
>>>>            xlog_warn("%s: service %d not registered on localhost",
>>>>                __func__, NL_MY_PROG(lp));
>>>>        } else {
>>>> -        xlog(D_GENERAL, "%s: Callback to %s (for %d) succeeded",
>>>> +        xlog(D_GENERAL, "%s: Callback to %s (for %s) succeeded",
>>>>                __func__, NL_MY_NAME(lp), NL_MON_NAME(lp));
>>>>        }
>>>>        nlist_free(&notify, lp);
>>>> diff --git a/utils/statd/statd.c b/utils/statd/statd.c
>>>> index 14673800..8eef2ff2 100644
>>>> --- a/utils/statd/statd.c
>>>> +++ b/utils/statd/statd.c
>>>> @@ -136,7 +136,7 @@ static void log_modes(void)
>>>>        strcat(buf, "TI-RPC ");
>>>>    #endif
>>>>    -    xlog_warn(buf);
>>>> +    xlog_warn("%s", buf);
>>>>    }
>>>>      /*
>>>> diff --git a/utils/statd/svc_run.c b/utils/statd/svc_run.c
>>>> index d1dbd74a..e343c768 100644
>>>> --- a/utils/statd/svc_run.c
>>>> +++ b/utils/statd/svc_run.c
>>>> @@ -53,6 +53,7 @@
>>>>      #include <errno.h>
>>>>    #include <time.h>
>>>> +#include <inttypes.h>
>>>>    #include "statd.h"
>>>>    #include "notlist.h"
>>>>    @@ -104,8 +105,8 @@ my_svc_run(int sockfd)
>>>>                  tv.tv_sec  = NL_WHEN(notify) - now;
>>>>                tv.tv_usec = 0;
>>>> -            xlog(D_GENERAL, "Waiting for reply... (timeo %d)",
>>>> -                            tv.tv_sec);
>>>> +            xlog(D_GENERAL, "Waiting for reply... (timeo %jd)",
>>>> +                            (intmax_t)tv.tv_sec);
>>>>                selret = select(FD_SETSIZE, &readfds,
>>>>                    (void *) 0, (void *) 0, &tv);
>>>>            } else {