guard *_chk() related stuff with UCLIBC_HAS_FORTIFY

Guard x86_64 memset_chk/memcpy_chk be guarded by UCLIBC_HAS_FORTIFY.
Compile ssp.c if one of SSP/FORTIFY is defined.
Guard __chk_fail() with UCLIBC_HAS_FORTIFY and move its prototype to libc-internal.h.
Disable _FORTIFY_SOURCE if UCLIBC_HAS_FORTIFY is not set.

The config option itself is omitted on purpose,
headers need to be reviewed and generic *_chk() functions need to be first provided.

Signed-off-by: Peter S. Mazinger <ps.m@gmx.net>

include/features.h

@@ -198,9 +198,12 @@
 # define __OPTIMIZE_SIZE__   1
 
 /* disable unsupported features */
-# undef _FORTIFY_SOURCE
 # undef __LDBL_COMPAT
 
+# ifndef __UCLIBC_HAS_FORTIFY__
+#  undef _FORTIFY_SOURCE
+# endif
+
 # ifndef __UCLIBC_HAS_THREADS__
 #  if defined _REENTRANT || defined _THREAD_SAFE
 #   warning requested reentrant code, but thread support was disabled

include/libc-internal.h

@@ -65,6 +65,11 @@ libc_hidden_proto(__glibc_strerror_r)
 /* internal access to program name */
 extern const char *__uclibc_progname attribute_hidden;
 
+#  ifdef __UCLIBC_HAS_FORTIFY__
+extern void __chk_fail(void) attribute_noreturn;
+libc_hidden_proto(__chk_fail)
+#  endif
+
 # endif /* IS_IN_libc */
 
 #endif /* __ASSEMBLER__ */

libc/string/x86_64/memcpy.S

@@ -26,12 +26,10 @@
 #define MEMPCPY_P (defined memcpy)
 
         .text
-#if defined __PIC__ && !defined NOT_IN_libc
+#if defined __PIC__ && !defined NOT_IN_libc && defined __UCLIBC_HAS_FORTIFY__
 ENTRY (__memcpy_chk)
 	cmpq	%rdx, %rcx
-#if defined __UCLIBC_HAS_SSP__
 	jb	HIDDEN_JUMPTARGET (__chk_fail)
-#endif
 END (__memcpy_chk)
 #endif
 ENTRY (BP_SYM (memcpy))

libc/string/x86_64/memset.S

@@ -29,12 +29,10 @@
 #define LARGE $120000
 
         .text
-#if defined __PIC__ && !defined NOT_IN_libc
+#if defined __PIC__ && !defined NOT_IN_libc && defined __UCLIBC_HAS_FORTIFY__
 ENTRY (__memset_chk)
 	cmpq	%rdx, %rcx
-#if defined __UCLIBC_HAS_SSP__
 	jb	HIDDEN_JUMPTARGET (__chk_fail)
-#endif
 END (__memset_chk)
 #endif
 ENTRY (memset)
@@ -144,6 +142,6 @@ END (memset)
 libc_hidden_def(memset)
 #endif
 
-#if !BZERO_P && defined __PIC__ && !defined NOT_IN_libc
+#if !BZERO_P && defined __PIC__ && !defined NOT_IN_libc && defined __UCLIBC_HAS_FORTIFY__
 strong_alias (__memset_chk, __memset_zero_constant_len_parameter)
 #endif

libc/sysdeps/linux/common/Makefile.in

@@ -15,7 +15,7 @@ CSRC_LFS := $(notdir $(wildcard $(COMMON_DIR)/*64.c))
 CSRC-y := $(filter-out llseek.c $(CSRC_LFS),$(CSRC-y))
 CSRC-$(UCLIBC_HAS_LFS) += llseek.c $(CSRC_LFS)
 
-CSRC-$(UCLIBC_HAS_SSP) += ssp.c
+CSRC-$(if $(or $(UCLIBC_HAS_SSP),$(UCLIBC_HAS_FORTIFY)),y) += ssp.c
 CSRC-$(UCLIBC_LINUX_MODULE_24) += create_module.c query_module.c \
 	get_kernel_syms.c
 # we need these internally: fstatfs.c statfs.c

libc/sysdeps/linux/common/ssp.c

@@ -87,6 +87,7 @@ void __stack_smash_handler(char func[], int damaged)
 }
 #endif
 
+#ifdef __UCLIBC_HAS_SSP__
 void __stack_chk_fail(void) attribute_noreturn __cold;
 void __stack_chk_fail(void)
 {
@@ -101,8 +102,9 @@ void __stack_chk_fail(void)
 	while(1)
 		terminate();
 }
+#endif
 
-void __chk_fail(void) attribute_noreturn;
+#ifdef __UCLIBC_HAS_FORTIFY__
 void __chk_fail(void)
 {
 	static const char msg1[] = "buffer overflow detected: ";
@@ -116,3 +118,5 @@ void __chk_fail(void)
 	while(1)
 		terminate();
 }
+libc_hidden_def(__chk_fail)
+#endif