[PATCH v3 15/19] Enable --enable-fortify-source with clang
Adhemerval Zanella
adhemerval.zanella@linaro.org
Fri Oct 31 20:00:48 GMT 2025
clang generates internal calls for some _chk symbol, so add internal
aliases for them, and stub some with rtld-stubbed-symbols to avoid
ld.so linker issues.
---
debug/vasprintf_chk.c | 1 +
debug/vfprintf_chk.c | 1 +
elf/Makefile | 8 ++++++++
include/arpa/inet.h | 2 --
include/bits/inet-fortified-decl.h | 5 +++++
include/bits/stdio2-decl.h | 7 +++++++
include/bits/string_fortified.h | 15 +++++++++++++++
include/bits/syslog-decl.h | 4 ++++
include/bits/unistd-decl.h | 6 ++++++
include/bits/wchar2-decl.h | 5 +++++
include/stdio.h | 10 ++++++++--
include/unistd.h | 4 ----
include/wchar.h | 1 -
inet/bits/inet-fortified.h | 2 ++
libio/Makefile | 1 +
misc/syslog.c | 4 +++-
string/Makefile | 1 +
sysdeps/generic/symbol-hacks.h | 15 +++++++++++++++
.../ieee754/ldbl-128ibm-compat/ieee128-snprintf.c | 4 ++++
.../ieee754/ldbl-128ibm-compat/ieee128-syslog.c | 5 +++--
20 files changed, 89 insertions(+), 12 deletions(-)
diff --git a/debug/vasprintf_chk.c b/debug/vasprintf_chk.c
index 41c15689eeb..f86320cadb0 100644
--- a/debug/vasprintf_chk.c
+++ b/debug/vasprintf_chk.c
@@ -35,3 +35,4 @@ __vasprintf_chk (char **result_ptr, int flag, const char *format, va_list ap)
return __vasprintf_internal (result_ptr, format, ap, mode);
}
+libc_hidden_def (__vasprintf_chk)
diff --git a/debug/vfprintf_chk.c b/debug/vfprintf_chk.c
index 74b7c86add2..999b6aa3934 100644
--- a/debug/vfprintf_chk.c
+++ b/debug/vfprintf_chk.c
@@ -29,3 +29,4 @@ ___vfprintf_chk (FILE *fp, int flag, const char *format, va_list ap)
return __vfprintf_internal (fp, format, ap, mode);
}
ldbl_strong_alias (___vfprintf_chk, __vfprintf_chk)
+ldbl_hidden_def (___vfprintf_chk, __vfprintf_chk)
diff --git a/elf/Makefile b/elf/Makefile
index 5a676f858d6..dd21fe62411 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -1487,6 +1487,14 @@ rtld-stubbed-symbols = \
realloc \
# rtld-stubbed-symbols
+# These symbols might be emitted by the compiler when fortify is enabled
+# (through builtins).
+rtld-stubbed-symbols += \
+ __GI___vfprintf_chk \
+ __GI___vsprintf_chk \
+ __GI___vsyslog_chk \
+ # rtld-stubbed-symbols
+
ifeq ($(have-ssp),yes)
# rtld is not built with the stack protector, so these references will
# go away in the rebuilds.
diff --git a/include/arpa/inet.h b/include/arpa/inet.h
index 3db8f1a96fd..7650e1acb5e 100644
--- a/include/arpa/inet.h
+++ b/include/arpa/inet.h
@@ -14,12 +14,10 @@ libc_hidden_proto (__inet_aton_exact)
extern __typeof (inet_ntop) __inet_ntop;
libc_hidden_proto (__inet_ntop)
-libc_hidden_proto (__inet_ntop_chk)
libc_hidden_proto (inet_pton)
extern __typeof (inet_pton) __inet_pton;
libc_hidden_proto (__inet_pton)
-libc_hidden_proto (__inet_pton_chk)
extern __typeof (inet_makeaddr) __inet_makeaddr;
libc_hidden_proto (__inet_makeaddr)
diff --git a/include/bits/inet-fortified-decl.h b/include/bits/inet-fortified-decl.h
index e6ad4d4663c..1110ce49f2c 100644
--- a/include/bits/inet-fortified-decl.h
+++ b/include/bits/inet-fortified-decl.h
@@ -1 +1,6 @@
#include <inet/bits/inet-fortified-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_proto (__inet_ntop_chk)
+libc_hidden_proto (__inet_pton_chk)
+#endif
diff --git a/include/bits/stdio2-decl.h b/include/bits/stdio2-decl.h
index bbb052f1922..9758bf4b557 100644
--- a/include/bits/stdio2-decl.h
+++ b/include/bits/stdio2-decl.h
@@ -1 +1,8 @@
#include <libio/bits/stdio2-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_proto (__fgets_unlocked_chk)
+libc_hidden_ldbl_proto (vfprintf)
+libc_hidden_ldbl_proto (__vasprintf_chk)
+libc_hidden_ldbl_proto (__vfprintf_chk)
+#endif
diff --git a/include/bits/string_fortified.h b/include/bits/string_fortified.h
index 88bf073c9cf..0cf0e76db1d 100644
--- a/include/bits/string_fortified.h
+++ b/include/bits/string_fortified.h
@@ -1 +1,16 @@
+#ifndef _ISOMAC
+# if IS_IN(libc) && defined SHARED
+/* Redirect calls from __builtin_stpcpy_chk to internal __stpcpy when building
+ with fortify enable. */
+__asm__ ("stpcpy = __GI___stpcpy");
+# endif
+
+/* Add the internal aliass attribute to symbol before they first usage on the
+ fortify wrappers. */
+libc_hidden_builtin_proto (memcpy)
+libc_hidden_builtin_proto (mempcpy)
+libc_hidden_builtin_proto (memmove)
+libc_hidden_builtin_proto (memset)
+#endif
+
#include <string/bits/string_fortified.h>
diff --git a/include/bits/syslog-decl.h b/include/bits/syslog-decl.h
index 491a263777a..762b2891842 100644
--- a/include/bits/syslog-decl.h
+++ b/include/bits/syslog-decl.h
@@ -1 +1,5 @@
#include <misc/bits/syslog-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_ldbl_proto (__vsyslog_chk)
+#endif
diff --git a/include/bits/unistd-decl.h b/include/bits/unistd-decl.h
index 7fcbd272acb..dd6af7e4c8d 100644
--- a/include/bits/unistd-decl.h
+++ b/include/bits/unistd-decl.h
@@ -1 +1,7 @@
#include <posix/bits/unistd-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_proto (__read_chk)
+libc_hidden_proto (__getdomainname_chk)
+libc_hidden_proto (__getlogin_r_chk)
+#endif
diff --git a/include/bits/wchar2-decl.h b/include/bits/wchar2-decl.h
index 00b1b93342e..f3b8a8cf879 100644
--- a/include/bits/wchar2-decl.h
+++ b/include/bits/wchar2-decl.h
@@ -1 +1,6 @@
#include <wcsmbs/bits/wchar2-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_builtin_proto (__wmemset_chk)
+libc_hidden_proto (__wcrtomb_chk)
+#endif
diff --git a/include/stdio.h b/include/stdio.h
index b892c5b4af9..e5fe5db43d4 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -23,8 +23,12 @@
redirecting ldouble to _Float128 variants. We can therefore safely
directly alias them to their internal name. */
# if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1 && IS_IN (libc)
-# define stdio_hidden_ldbl_proto(p, f) \
- extern __typeof (p ## f) p ## f __asm (__ASMNAME ("___ieee128_" #f));
+# ifdef SHARED
+# define stdio_hidden_ldbl_proto(p, f) __LDBL_REDIR2_DECL (f)
+# else
+# define stdio_hidden_ldbl_proto(p, f) \
+ extern __typeof (p ## f) p ## f __asm (#p __ASMNAME (#f "ieee128"));
+# endif
# elif __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
# define stdio_hidden_ldbl_proto(p,f) __LDBL_REDIR1_DECL (p ## f, p ## f ## ieee128)
# else
@@ -70,10 +74,12 @@ extern int __printf_chk (int, const char *, ...);
extern int __fprintf_chk (FILE *, int, const char *, ...);
extern int __vprintf_chk (int, const char *, __gnuc_va_list);
extern int __vfprintf_chk (FILE *, int, const char *, __gnuc_va_list);
+stdio_hidden_ldbl_proto (__, vfprintf_chk)
extern char *__fgets_unlocked_chk (char *buf, size_t size, int n, FILE *fp);
extern char *__fgets_chk (char *buf, size_t size, int n, FILE *fp);
extern int __asprintf_chk (char **, int, const char *, ...) __THROW;
extern int __vasprintf_chk (char **, int, const char *, __gnuc_va_list) __THROW;
+stdio_hidden_ldbl_proto (__, vasprintf_chk)
extern int __dprintf_chk (int, int, const char *, ...);
extern int __vdprintf_chk (int, int, const char *, __gnuc_va_list);
extern int __obstack_printf_chk (struct obstack *, int, const char *, ...)
diff --git a/include/unistd.h b/include/unistd.h
index 376ab5a9368..c1a4736951b 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -32,10 +32,6 @@ libc_hidden_proto (readlinkat)
libc_hidden_proto (fsync)
libc_hidden_proto (fdatasync)
-libc_hidden_proto (__read_chk)
-libc_hidden_proto (__getdomainname_chk)
-libc_hidden_proto (__getlogin_r_chk)
-
/* Now define the internal interfaces. */
extern int __access (const char *__name, int __type);
libc_hidden_proto (__access)
diff --git a/include/wchar.h b/include/wchar.h
index bf326257364..6abb0d26972 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -166,7 +166,6 @@ libc_hidden_proto (putwc)
libc_hidden_proto (mbrtowc)
libc_hidden_proto (wcrtomb)
-libc_hidden_proto (__wcrtomb_chk)
extern int __wcscmp (const wchar_t *__s1, const wchar_t *__s2)
__THROW __attribute_pure__;
diff --git a/inet/bits/inet-fortified.h b/inet/bits/inet-fortified.h
index cc476ebcfde..0919bc9779f 100644
--- a/inet/bits/inet-fortified.h
+++ b/inet/bits/inet-fortified.h
@@ -45,6 +45,7 @@ __NTH (inet_pton (int __af,
__fortify_clang_warning_only_if_bos0_lt
(4, __dst, "inet_pton called with destination buffer size less than 4")
{
+#if !__fortify_use_clang
size_t __sz = 0;
if (__af == AF_INET)
__sz = sizeof (struct in_addr);
@@ -52,6 +53,7 @@ __NTH (inet_pton (int __af,
__sz = sizeof (struct in6_addr);
else
return __inet_pton_alias (__af, __src, __dst);
+#endif
return __glibc_fortify (inet_pton, __sz, sizeof (char),
__glibc_objsize (__dst),
diff --git a/libio/Makefile b/libio/Makefile
index 2bc98365225..f946cd311b4 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -60,6 +60,7 @@ routines_no_fortify += \
iofgets_u \
iofgetws \
iofgetws_u \
+ iovdprintf \
swprintf \
vasprintf \
vsnprintf \
diff --git a/misc/syslog.c b/misc/syslog.c
index 53bb3342591..b7414e7b43a 100644
--- a/misc/syslog.c
+++ b/misc/syslog.c
@@ -114,10 +114,12 @@ ldbl_hidden_def (___syslog_chk, __syslog_chk)
ldbl_strong_alias (___syslog_chk, __syslog_chk)
void
-__vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
+___vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
{
__vsyslog_internal (pri, fmt, ap, (flag > 0) ? PRINTF_FORTIFY : 0);
}
+ldbl_hidden_def (___vsyslog_chk, __vsyslog_chk)
+ldbl_strong_alias (___vsyslog_chk, __vsyslog_chk)
void
__vsyslog_internal (int pri, const char *fmt, va_list ap,
diff --git a/string/Makefile b/string/Makefile
index 2f30e66df58..7c0245452b2 100644
--- a/string/Makefile
+++ b/string/Makefile
@@ -121,6 +121,7 @@ routines := \
# Exclude fortified routines from being built with _FORTIFY_SOURCE
routines_no_fortify += \
+ bzero \
explicit_bzero \
memcpy \
memmove \
diff --git a/sysdeps/generic/symbol-hacks.h b/sysdeps/generic/symbol-hacks.h
index 1115e4c0a7a..58398d33a5f 100644
--- a/sysdeps/generic/symbol-hacks.h
+++ b/sysdeps/generic/symbol-hacks.h
@@ -6,6 +6,21 @@ asm ("memmove = __GI_memmove");
asm ("memset = __GI_memset");
asm ("memcpy = __GI_memcpy");
+/* clang might generate the internal fortfify calls when it is enabled,
+ through the buitintin. */
+asm ("__vfprintf_chk = __GI___vfprintf_chk");
+asm ("__vsprintf_chk = __GI___vsprintf_chk");
+asm ("__vsyslog_chk = __GI___vsyslog_chk");
+asm ("__memcpy_chk = __GI___memcpy_chk");
+asm ("__memmove_chk = __GI___memmove_chk");
+asm ("__memset_chk = __GI___memset_chk");
+asm ("__mempcpy_chk = __GI___mempcpy_chk");
+asm ("__stpcpy_chk = __GI___stpcpy_chk");
+asm ("__strcpy_chk = __GI___strcpy_chk");
+asm ("strcpy = __GI_strcpy");
+asm ("strncpy = __GI_strncpy");
+asm ("strcat = __GI_strcat");
+
/* Some targets do not use __stack_chk_fail_local. In libc.so,
redirect __stack_chk_fail to a hidden reference
__stack_chk_fail_local, to avoid the PLT reference.
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
index d458da7903c..f880a55e0b9 100644
--- a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
@@ -33,3 +33,7 @@ ___ieee128_snprintf (char *s, size_t maxlen, const char *format, ...)
return done;
}
strong_alias (___ieee128_snprintf, __snprintfieee128)
+ldbl_hidden_def (___ieee128_snprintf, ___ieee128_snprintf)
+#ifdef SHARED
+strong_alias (___ieee128_snprintf, __GI____ieee128___snprintf)
+#endif
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-syslog.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-syslog.c
index 197b149d0f2..e08ae3aa280 100644
--- a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-syslog.c
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-syslog.c
@@ -56,7 +56,7 @@ hidden_def (___ieee128___syslog_chk)
strong_alias (___ieee128___syslog_chk, __syslog_chkieee128)
void
-___ieee128___vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
+____ieee128___vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
{
unsigned int mode = PRINTF_LDBL_USES_FLOAT128;
if (flag > 0)
@@ -64,4 +64,5 @@ ___ieee128___vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
__vsyslog_internal (pri, fmt, ap, mode);
}
-strong_alias (___ieee128___vsyslog_chk, __vsyslog_chkieee128)
+strong_alias (____ieee128___vsyslog_chk, ___ieee128___vsyslog_chk)
+strong_alias (____ieee128___vsyslog_chk, __vsyslog_chkieee128)
--
2.43.0
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