Prepare the system for _FORTIFY_SOURCE

Notably:
- libc needs to #undef some of the macros from ssp/* for underlying
  implementations
- ssp/* wants a __RENAME() macro (snatched more or less from NetBSD)

There's some extra hinkiness included for read(), since libc spells it
as "_read" while the rest of the world spells it "read."

Reviewed by:	imp, ngie
Sponsored by:	Stormshield
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D32307

contrib/netbsd-tests/lib/libc/ssp/h_gets.c

@@ -34,6 +34,9 @@ __RCSID("$NetBSD: h_gets.c,v 1.1 2010/12/27 02:04:19 pgoyette Exp $");
 #include <stdio.h>
 
 #ifdef __FreeBSD__
+/* _FORTIFY_SOURCE, at the very least, may #define a gets() macro. */
+#undef gets
+
 /*
  * We want to test the gets() implementation, but cannot simply link against
  * the gets symbol because it is not in the default version. (We've made it

include/ssp/unistd.h

@@ -39,8 +39,12 @@
 #if __SSP_FORTIFY_LEVEL > 0
 __BEGIN_DECLS
 
-__ssp_redirect0(ssize_t, read, (int __fd, void *__buf, size_t __len), \
-    (__fd, __buf, __len));
+#ifndef _FORTIFY_SOURCE_read
+#define	_FORTIFY_SOURCE_read	read
+#endif
+
+__ssp_redirect0(ssize_t, _FORTIFY_SOURCE_read, (int __fd, void *__buf,
+    size_t __len), (__fd, __buf, __len));
 
 __ssp_redirect(ssize_t, readlink, (const char *__restrict __path, \
     char *__restrict __buf, size_t __len), (__path, __buf, __len));

lib/libc/Makefile

@@ -19,6 +19,8 @@ LIBC_ARCH=${M}
 LIBC_ARCH=${MACHINE_CPUARCH}
 .endif
 
+CFLAGS+=-D_FORTIFY_SOURCE_read=_read
+
 # All library objects contain FreeBSD revision strings by default; they may be
 # excluded as a space-saving measure.  To produce a library that does
 # not contain these strings, add -DSTRIP_FBSDID (see <sys/cdefs.h>) to CFLAGS

lib/libc/amd64/string/bcopy.c

@@ -4,6 +4,8 @@
 
 #include <string.h>
 
+#undef bcopy	/* _FORTIFY_SOURCE */
+
 void
 bcopy(const void *src, void *dst, size_t len)
 {

lib/libc/amd64/string/bzero.c

@@ -4,6 +4,8 @@
 
 #include <string.h>
 
+#undef bzero	/* _FORTIFY_SOURCE */
+
 void
 bzero(void *b, size_t len)
 {

lib/libc/amd64/string/strncat.c

@@ -8,6 +8,8 @@
 
 #include <string.h>
 
+#undef strncat	/* _FORTIFY_SOURCE */
+
 void *__memccpy(void *restrict, const void *restrict, int, size_t);
 
 char *

lib/libc/amd64/string/strncpy.c

@@ -29,6 +29,8 @@
 #include <sys/cdefs.h>
 #include <string.h>
 
+#undef strncpy	/* _FORTIFY_SOURCE */
+
 char *__stpncpy(char *restrict, const char *restrict, size_t);
 
 char *

lib/libc/gen/getcwd.c

@@ -40,6 +40,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <ssp/ssp.h>
 #include "un-namespace.h"
 
 #include "gen-private.h"
@@ -51,7 +52,7 @@
 extern int __getcwd(char *, size_t);
 
 char *
-getcwd(char *pt, size_t size)
+__ssp_real(getcwd)(char *pt, size_t size)
 {
 	struct dirent *dp;
 	DIR *dir = NULL;

lib/libc/stdio/fgets.c

@@ -40,6 +40,8 @@
 #include "local.h"
 #include "libc_private.h"
 
+#undef fgets	/* _FORTIFY_SOURCE */
+
 /*
  * Read at most n-1 characters from the given file.
  * Stop when a newline has been read, or the count runs out.

lib/libc/stdio/snprintf.c

@@ -45,6 +45,8 @@
 
 #include "local.h"
 
+#undef snprintf	/* _FORTIFY_SOURCE */
+
 int
 snprintf(char * __restrict str, size_t n, char const * __restrict fmt, ...)
 {

lib/libc/stdio/sprintf.c

@@ -43,6 +43,8 @@
 #include "local.h"
 #include "xlocale_private.h"
 
+#undef sprintf	/* _FORTIFY_SOURCE */
+
 int
 sprintf(char * __restrict str, char const * __restrict fmt, ...)
 {

lib/libc/stdio/vsnprintf.c

@@ -43,6 +43,8 @@
 #include "local.h"
 #include "xlocale_private.h"
 
+#undef vsnprintf	/* _FORTIFY_SOURCE */
+
 int
 vsnprintf_l(char * __restrict str, size_t n, locale_t locale, 
 		const char * __restrict fmt, __va_list ap)

lib/libc/stdio/vsprintf.c

@@ -42,6 +42,8 @@
 #include "local.h"
 #include "xlocale_private.h"
 
+#undef vsprintf	/* _FORTIFY_SOURCE */
+
 int
 vsprintf_l(char * __restrict str, locale_t locale,
 		const char * __restrict fmt, __va_list ap)

lib/libc/string/bcopy.c

@@ -47,6 +47,9 @@ typedef	intptr_t word;		/* "word" used for optimal copy speed */
 #if defined(MEMCOPY) || defined(MEMMOVE)
 #include <string.h>
 
+#undef memcpy	/* _FORTIFY_SOURCE */
+#undef memmove	/* _FORTIFY_SOURCE */
+
 void *
 #ifdef MEMCOPY
 memcpy
@@ -57,6 +60,8 @@ memmove
 #else
 #include <strings.h>
 
+#undef bcopy	/* _FORTIFY_SOURCE */
+
 void
 bcopy(const void *src0, void *dst0, size_t length)
 #endif

lib/libc/string/memset.c

@@ -42,6 +42,8 @@
 #ifdef BZERO
 #include <strings.h>
 
+#undef bzero	/* _FORTIFY_SOURCE */
+
 #define	RETURN	return
 #define	VAL	0
 #define	WIDEVAL	0
@@ -51,6 +53,8 @@ bzero(void *dst0, size_t length)
 #else
 #include <string.h>
 
+#undef memset	/* _FORTIFY_SOURCE */
+
 #define	RETURN	return (dst0)
 #define	VAL	c0
 #define	WIDEVAL	c

lib/libc/string/stpcpy.c

@@ -33,6 +33,8 @@
 
 #include <string.h>
 
+#undef stpcpy	/* _FORTIFY_SOURCE */
+
 char *
 stpcpy(char * __restrict to, const char * __restrict from)
 {

lib/libc/string/stpncpy.c

@@ -28,6 +28,8 @@
 
 #include <string.h>
 
+#undef stpncpy	/* _FORTIFY_SOURCE */
+
 char *
 stpncpy(char * __restrict dst, const char * __restrict src, size_t n)
 {

lib/libc/string/strcat.c

@@ -31,6 +31,8 @@
 
 #include <string.h>
 
+#undef strcat	/* _FORTIFY_SOURCE */
+
 char *
 strcat(char * __restrict s, const char * __restrict append)
 {

lib/libc/string/strncat.c

@@ -34,6 +34,8 @@
 
 #include <string.h>
 
+#undef strncat	/* _FORTIFY_SOURCE */
+
 /*
  * Concatenate src on the end of dst.  At most strlen(dst)+n+1 bytes
  * are written at dst (at most n+1 bytes being appended).  Return dst.

sys/sys/cdefs.h

@@ -609,6 +609,16 @@
 #define	__DEQUALIFY(type, var)	((type)(__uintptr_t)(const volatile void *)(var))
 #endif
 
+#if !defined(_STANDALONE) && !defined(_KERNEL)
+#if defined(__GNUC__) || defined(__PCC__)
+#define	__RENAME(x)	__asm(__STRING(x))
+#else
+#define	__RENAME(x)	no renaming support for compiler in use
+#endif /* __GNUC__ */
+#else /* _STANDALONE || _KERNEL */
+#define	__RENAME(x)	no renaming in kernel/standalone environment
+#endif
+
 /*-
  * The following definitions are an extension of the behavior originally
  * implemented in <sys/_posix.h>, but with a different level of granularity.