Fix assert during static startup (BZ 33326)

The BZ#33326 testcase triggers an assertion during process startup,
which results in a segmentation fault instead of an error message
and process termination with a SIGABRT.  The assert issues
__libc_message_impl, which in turn might call string functions
depending on the ABI (strchrnul, strlen, memcpy/mempcpy), system
calls (writev and mmap), and finally the abort call.

The dl-symbol-redir-ifunc.h is also expanded to cover strchrnul on
x86_64, s390, powerpc64 (both endianness) and loongarch, mempcpy on
powerpc64be, and memcpy on aarch64.  On s390 the redirection is only
issued if the ifunc variant is built, since strchrnul-c.c only renames
the C implementation to STRCHRNUL_DEFAULT when HAVE_STRCHRNUL_IFUNC is
set.

The buffer that backs up the assert message is now allocated through
_dl_mmap, which issues the syscall directly instead of calling __mmap
(setting errno on failure requires the thread pointer).

The abort call now issues __raise_direct instead of raise (the Hurd
port aliases __raise_direct to raise).

On i386, syscalls should not use the vDSO during program startup because
the thread pointer is not yet initialized.  This requires __raise_direct,
_dl_writev, and _dl_mmap to be built with I386_USE_SYSENTER set to 0.

Creating a test case is challenging. For static-pie, the assert is only
called for ill-formed ELF files on elf_get_dynamic_info and by some targets
on ELF_DYNAMIC_RELOCATE (although not all targets use assert in their
dl-machine.h).  Some targets also issue __libc_fatal on ARCH_SETUP_IREL,
but also only for ill-formatted ELF files.

The test employs a different strategy and overrides the __tunables_init
symbol, which is invoked immediately before self-relocation and TLS setup.
The test is built with -Wl,-z,muldefs to avoid linker issues.

I checked on aarch64, x86_64, i686, s390x (qemu), sparc (qemu),
mips64el (qemu), armhf, riscv, and powerpc.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

assert/Makefile

@@ -33,6 +33,11 @@ routines := \
   assert-perr \
   # routines
 
+# Called during static library initialization, so turn stack-protection
+# off for non-shared builds.
+CFLAGS-__libc_assert_fail.o = $(no-stack-protector)
+CFLAGS-__libc_assert_fail.op = $(no-stack-protector)
+
 tests := \
   test-assert \
   test-assert-2 \

elf/Makefile

@@ -280,6 +280,7 @@ tests-static-normal := \
   # tests-static-normal
 
 tests-static-internal := \
+  tst-assert-startup-static \
   tst-atrandom-scrub-static \
   tst-dl-printf-static \
   tst-dl_find_object-static \
@@ -3778,3 +3779,14 @@ $(objpfx)tst-dl-debug-exclude.out: tst-dl-debug-exclude.sh \
 		 $(objpfx)tst-recursive-tls > $@; \
 	$(evaluate-test)
 endif
+
+CFLAGS-tst-assert-startup-static.c += $(no-stack-protector)
+LDFLAGS-tst-assert-startup-static += -Wl,-z,muldefs
+
+$(objpfx)tst-assert-startup-static.out: $(objpfx)tst-assert-startup-static
+	$(test-program-cmd-before-env) \
+		$(run-program-env) \
+		$< > $@ 2>&1; echo "status: $$?" >> $@; \
+	grep -q 'Fatal glibc error: tst-assert-startup-static' $@ \
+	  && grep -q '^status: 134$$' $@; \
+	  $(evaluate-test)

elf/tst-assert-startup-static.c

@@ -0,0 +1,43 @@
+/* Check if assert works during program startup.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <assert.h>
+#include <stdlib.h>
+
+/* The __libc_assert_fail is used internally for assert() calls.  */
+extern _Noreturn __typeof (__assert_fail) __libc_assert_fail;
+
+/* The __tunables_init is called just before self-relocation and TLS setup,
+   so overriding it is a way to reach the assert code at that point.  */
+void
+__tunables_init (char **env, char **argv)
+{
+  /* Inside libc, assert() is redirected to __libc_assert_fail.  This test is
+     not built as part of libc, so a plain assert() here would call the public
+     __assert_fail instead, which uses __progname and the translation routines
+     and thus is not what the startup code issues.  Call the internal routine
+     directly.  */
+  __libc_assert_fail ("error", __FILE__, __LINE__, __func__);
+}
+
+int
+main (void)
+{
+  /* Fail with a different error code than abort.  */
+  exit (EXIT_FAILURE);
+}

libio/Makefile

@@ -195,6 +195,11 @@ endif
 
 CPPFLAGS += $(libio-mtsafe)
 
+# Called during static library initialization, so turn stack-protection
+# off for non-shared builds.
+CFLAGS-libc_fatal.o = $(no-stack-protector)
+CFLAGS-libc_fatal.op = $(no-stack-protector)
+
 # Support for exception handling.
 CFLAGS-fileops.c += -fexceptions
 CFLAGS-fputc.c += -fexceptions

stdlib/Makefile

@@ -531,6 +531,11 @@ generated += \
   tst-putenvmod.so \
   # generated
 
+# Called during static library initialization, so turn stack-protection
+# off for non-shared builds.
+CFLAGS-abort.o = $(no-stack-protector)
+CFLAGS-abort.op = $(no-stack-protector)
+
 CFLAGS-bsearch.c += $(uses-callbacks)
 CFLAGS-qsort.c += $(uses-callbacks)
 CFLAGS-system.c += -fexceptions

stdlib/abort.c

@@ -74,7 +74,7 @@ __abort_lock_unlock (const internal_sigset_t *set)
 _Noreturn void
 abort (void)
 {
-  raise (SIGABRT);
+  __raise_direct (SIGABRT);
 
   /* There is a SIGABRT handle installed and it returned, or SIGABRT was
      blocked or ignored.  In this case use a AS-safe lock to prevent sigaction

string/Makefile

@@ -286,13 +286,21 @@ CFLAGS-test-endian-sign-conversion.c += -Werror -Wsign-conversion
 LDFLAGS-tst-xbzero-opt = -z now
 LDFLAGS-tst-xmemset-opt = -z now
 
-# Called during TLS initialization.
-CFLAGS-memcpy.c += $(no-stack-protector)
-CFLAGS-wordcopy.c += $(no-stack-protector)
-# Called during static initialization
-CFLAGS-strncmp.c += $(no-stack-protector)
-CFLAGS-memset.c += $(no-stack-protector)
-CFLAGS-strlen.c += $(no-stack-protector)
+# Called during TLS initialization, and during static library initialization.
+CFLAGS-memcpy.o = $(no-stack-protector)
+CFLAGS-memcpy.op = $(no-stack-protector)
+CFLAGS-wordcopy.o = $(no-stack-protector)
+CFLAGS-wordcopy.op = $(no-stack-protector)
+CFLAGS-strncmp.o = $(no-stack-protector)
+CFLAGS-strncmp.op = $(no-stack-protector)
+CFLAGS-memset.o = $(no-stack-protector)
+CFLAGS-memset.op = $(no-stack-protector)
+CFLAGS-strlen.o = $(no-stack-protector)
+CFLAGS-strlen.op = $(no-stack-protector)
+CFLAGS-strchrnul.o = $(no-stack-protector)
+CFLAGS-strchrnul.op = $(no-stack-protector)
+CFLAGS-mempcpy.o = $(no-stack-protector)
+CFLAGS-mempcpy.op = $(no-stack-protector)
 
 ifeq ($(run-built-tests),yes)
 $(objpfx)tst-svc-cmp.out: tst-svc.expect $(objpfx)tst-svc.out

sysdeps/aarch64/multiarch/dl-symbol-redir-ifunc.h

@@ -19,10 +19,10 @@
 #ifndef _DL_IFUNC_GENERIC_H
 #define _DL_IFUNC_GENERIC_H
 
+asm ("memcpy = __memcpy_generic");
 asm ("memset = __memset_generic");
 asm ("strlen = __strlen_generic");
 #ifndef SHARED
-asm ("memcpy = __memcpy_generic");
 asm ("memmove = __memmove_generic");
 asm ("memcmp = __memcmp_generic");
 #endif

sysdeps/aarch64/multiarch/memcpy_generic.S

@@ -42,3 +42,7 @@
 #endif
 
 #include "../memcpy.S"
+
+#if IS_IN (rtld)
+strong_alias (memcpy, __memcpy_generic)
+#endif

sysdeps/generic/dl-mmap.h

@@ -0,0 +1,37 @@
+/* mmap wrapper for early static startup.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _DL_MMAP_H
+#define _DL_MMAP_H
+
+#include <sys/mman.h>
+
+/* This mmap call is used to allocate some memory to backup assert() messages
+   before TLS setup is done (which setup the thread pointer used by some ABIs
+   to issue syscalls).  There is no portable way to issue the syscall without
+   going through the errno setting, so a port that needs to run this before
+   the thread pointer is available has to override this header (as Linux
+   does).  */
+
+static inline void *
+_dl_mmap (void *addr, size_t len, int prot, int flags)
+{
+  return __mmap (addr, len, prot, flags, -1, 0);
+}
+
+#endif

sysdeps/htl/raise.c

@@ -54,3 +54,5 @@ raise (int signo)
 
 libc_hidden_def (raise)
 weak_alias (raise, gsignal)
+
+strong_alias (raise, __raise_direct)

sysdeps/loongarch/lp64/multiarch/dl-symbol-redir-ifunc.h

@@ -22,6 +22,7 @@
 #ifndef SHARED
 asm ("memset = __memset_aligned");
 asm ("memcmp = __memcmp_aligned");
+asm ("__strchrnul = __strchrnul_aligned");
 asm ("strlen = __strlen_aligned");
 asm ("memcpy = __memcpy_unaligned");
 asm ("memmove = __memmove_unaligned");

sysdeps/posix/libc_fatal.c

@@ -16,7 +16,12 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+/* Mark symbols hidden in static PIE for early self relocation to work.  */
+#if BUILD_PIE_DEFAULT
+# pragma GCC visibility push(hidden)
+#endif
 #include <dl-writev.h>
+#include <dl-mmap.h>
 #include <assert.h>
 #include <ldsodefs.h>
 #include <setvmaname.h>
@@ -24,6 +29,7 @@
 #include <stdio.h>
 #include <sys/uio.h>
 #include <unistd.h>
+#include <dl-symbol-redir-ifunc.h>
 
 #ifdef FATAL_PREPARE_INCLUDE
 #include FATAL_PREPARE_INCLUDE
@@ -113,9 +119,9 @@ __libc_message_impl (const char *vma_name, const char *fmt, ...)
 
       total = ALIGN_UP (total + sizeof (struct abort_msg_s) + 1,
 			GLRO(dl_pagesize));
-      struct abort_msg_s *buf = __mmap (NULL, total,
-					PROT_READ | PROT_WRITE,
-					MAP_ANON | MAP_PRIVATE, -1, 0);
+      struct abort_msg_s *buf = _dl_mmap (NULL, total,
+					  PROT_READ | PROT_WRITE,
+					  MAP_ANON | MAP_PRIVATE);
       if (__glibc_likely (buf != MAP_FAILED))
 	{
 	  buf->size = total;

sysdeps/powerpc/powerpc32/power4/multiarch/Makefile

@@ -11,4 +11,9 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
 		   strchr-power7 strchr-ppc32 \
 		   wordcopy-power7 wordcopy-ppc32 \
 		   memmove-power7 memmove-ppc
+
+# Called during static library initialization, so turn stack-protection
+# off for non-shared builds.
+CFLAGS-strchrnul-ppc32.o = $(no-stack-protector)
+CFLAGS-strchrnul-ppc32.op = $(no-stack-protector)
 endif

sysdeps/powerpc/powerpc64/be/multiarch/dl-symbol-redir-ifunc.h

@@ -0,0 +1,27 @@
+/* Symbol redirection for loader/static initialization code.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _DL_IFUNC_GENERIC_H
+#define _DL_IFUNC_GENERIC_H
+
+#ifndef SHARED
+asm ("__mempcpy = __mempcpy_ppc");
+asm ("__strchrnul = __strchrnul_ppc");
+#endif
+
+#endif

sysdeps/powerpc/powerpc64/le/multiarch/dl-symbol-redir-ifunc.h

@@ -21,5 +21,6 @@
 
 asm ("memset = __memset_power8");
 asm ("__mempcpy = __mempcpy_power7");
+asm ("__strchrnul = __strchrnul_power8");
 
 #endif

sysdeps/powerpc/powerpc64/multiarch/Makefile

@@ -39,4 +39,7 @@ endif
 endif
 
 # Called during static initialization
-CFLAGS-strncmp-ppc64.c += $(no-stack-protector)
+CFLAGS-strncmp-ppc64.o = $(no-stack-protector)
+CFLAGS-strncmp-ppc64.op = $(no-stack-protector)
+CFLAGS-strchrnul-ppc64.o = $(no-stack-protector)
+CFLAGS-strchrnul-ppc64.op = $(no-stack-protector)

sysdeps/s390/Makefile

@@ -259,6 +259,11 @@ routines_no_fortify += \
   strcat-c \
   strncat-c \
   # routines_no_fortify
+
+# Called during static library initialization, so turn stack-protection
+# off for non-shared builds.
+CFLAGS-strchrnul-c.o = $(no-stack-protector)
+CFLAGS-strchrnul-c.op = $(no-stack-protector)
 endif
 
 ifeq ($(subdir),wcsmbs)

sysdeps/s390/multiarch/dl-symbol-redir-ifunc.h

@@ -21,6 +21,7 @@
 
 #include <ifunc-memset.h>
 #include <ifunc-memcmp.h>
+#include <ifunc-strchrnul.h>
 
 #define IFUNC_SYMBOL_STR1(s)	#s
 #define IFUNC_SYMBOL_STR(s)	IFUNC_SYMBOL_STR1(s)
@@ -28,4 +29,8 @@
 asm ("memset = " IFUNC_SYMBOL_STR(MEMSET_DEFAULT));
 asm ("memcmp = " IFUNC_SYMBOL_STR(MEMCMP_DEFAULT));
 
+#if HAVE_STRCHRNUL_IFUNC
+asm ("__strchrnul = " IFUNC_SYMBOL_STR(STRCHRNUL_DEFAULT));
+#endif
+
 #endif

sysdeps/s390/string-bitops.h

@@ -0,0 +1,28 @@
+/* Zero byte detection, define whether to use stdbit.h  s390 version.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* s390x supports static-pie, and the libgcc implementation for
+   __builtin_clzl/__builtin_ctzl (__clzdi2) accesses extern data (__clz_tab)
+   that is not marked as hidden, which creates an additional GOT access.  The
+   generic strchrnul is used before self-relocation, so the GOT entry can not
+   be resolved yet.  */
+#if __ARCH__ > 6
+# define HAVE_BITOPTS_WORKING 1
+#else
+# define HAVE_BITOPTS_WORKING 0
+#endif

sysdeps/unix/sysv/linux/Makefile

@@ -115,6 +115,11 @@ sysdep_routines += \
   xstat64 \
   # sysdep_routines
 
+# Called during static library initialization, so turn stack-protection
+# off for non-shared builds.
+CFLAGS-setvmaname.o = $(no-stack-protector)
+CFLAGS-setvmaname.op = $(no-stack-protector)
+
 CFLAGS-gethostid.c = -fexceptions
 CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables
 CFLAGS-vmsplice.c = -fexceptions -fasynchronous-unwind-tables
@@ -459,6 +464,13 @@ sysdep_routines += \
   raise_direct \
   # sysdep_routines
 
+# Called during static library initialization, so turn stack-protection
+# off for non-shared builds.
+CFLAGS-raise.o = $(no-stack-protector)
+CFLAGS-raise.op = $(no-stack-protector)
+CFLAGS-raise_direct.o = $(no-stack-protector)
+CFLAGS-raise_direct.op = $(no-stack-protector)
+
 tests-special += \
   $(objpfx)tst-signal-numbers.out \
   # tests-special

sysdeps/unix/sysv/linux/dl-mmap.h

@@ -0,0 +1,40 @@
+/* mmap wrapper for early static startup.  Linux version.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _DL_MMAP_H
+#define _DL_MMAP_H
+
+#include <sys/mman.h>
+#include <sysdep.h>
+#include <mmap_call.h>
+
+static inline void *
+_dl_mmap (void *addr, size_t len, int prot, int flags)
+{
+  long int ret;
+#ifdef __NR_mmap2
+  ret = MMAP_CALL_INTERNAL (mmap2, addr, len, prot, flags, -1, 0);
+#else
+  ret = MMAP_CALL_INTERNAL (mmap, addr, len, prot, flags, -1, 0);
+#endif
+  if (INTERNAL_SYSCALL_ERROR_P (ret))
+    return MAP_FAILED;
+  return (void *) ret;
+}
+
+#endif

sysdeps/unix/sysv/linux/i386/Makefile

@@ -28,3 +28,17 @@ ifeq ($(subdir),rt)
 librt-routines += sysdep
 librt-shared-only-routines += sysdep
 endif
+
+ifeq ($(subdir),elf)
+sysdep_routines += \
+  dl-mmap \
+  dl-writev \
+  # sysdep-routines
+
+# Called during static library initialization, so turn stack-protection
+# off for non-shared builds.
+CFLAGS-dl-mmap.o = $(no-stack-protector)
+CFLAGS-dl-mmap.op = $(no-stack-protector)
+CFLAGS-dl-writev.o = $(no-stack-protector)
+CFLAGS-dl-writev.op = $(no-stack-protector)
+endif

sysdeps/unix/sysv/linux/i386/dl-mmap.c

@@ -0,0 +1,38 @@
+/* mmap wrapper for early static startup.  Linux/i386 version.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* This mmap call is used to allocate some memory to backup assert() messages
+   before TLS setup is done, so it cannot use "call *%gs:SYSINFO_OFFSET"
+   during startup in static PIE.  */
+#if BUILD_PIE_DEFAULT
+# define I386_USE_SYSENTER 0
+#endif
+
+#include <sys/mman.h>
+#include <dl-mmap.h>
+#include <sysdep.h>
+#include <mmap_call.h>
+
+void *
+_dl_mmap (void *addr, size_t len, int prot, int flags)
+{
+  long int ret = MMAP_CALL_INTERNAL (mmap2, addr, len, prot, flags, -1, 0);
+  if (INTERNAL_SYSCALL_ERROR_P (ret))
+    return MAP_FAILED;
+  return (void *) ret;
+}

sysdeps/unix/sysv/linux/i386/dl-mmap.h

@@ -0,0 +1,27 @@
+/* mmap wrapper for early static startup.  Linux/i386 version.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _DL_MMAP_H
+#define _DL_MMAP_H
+
+/* i386 requires out-of-line implementation because it sets
+   I386_USE_SYSENTER to 0 to avoid use the vDSO.  */
+void * _dl_mmap (void *addr, size_t len, int prot, int flags)
+  attribute_hidden;
+
+#endif

sysdeps/unix/sysv/linux/i386/dl-writev.c

@@ -0,0 +1,32 @@
+/* writev wrapper for the dynamic linker.  Linux/i386 version.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* This writev call is used to assert() before TLS setup is done, so it can
+   not use "call *%gs:SYSINFO_OFFSET" during startup in static PIE.  */
+#if BUILD_PIE_DEFAULT
+# define I386_USE_SYSENTER 0
+#endif
+
+#include <dl-writev.h>
+#include <sysdep.h>
+
+ssize_t
+_dl_writev (int fd, const struct iovec *iov, size_t niov)
+{
+  return INTERNAL_SYSCALL_CALL (writev, fd, iov, niov);
+}

sysdeps/unix/sysv/linux/i386/dl-writev.h

@@ -16,9 +16,14 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#if BUILD_PIE_DEFAULT
-/* Can't use "call *%gs:SYSINFO_OFFSET" during startup in static PIE.  */
-# define I386_USE_SYSENTER 0
-#endif
+#ifndef _DL_WRITEV_H
+#define _DL_WRITEV_H
 
-#include <sysdeps/unix/sysv/linux/dl-writev.h>
+#include <sys/uio.h>
+
+/* i386 requires out-of-line implementation because it sets
+   I386_USE_SYSENTER to 0 to avoid use the vDSO.  */
+ssize_t _dl_writev (int fd, const struct iovec *iov, size_t niov)
+  attribute_hidden;
+
+#endif

sysdeps/unix/sysv/linux/i386/raise_direct.c

@@ -0,0 +1,26 @@
+/* Internal function to send a signal to itself.  Linux/i386 version.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* This is called from abort() (issued by assert()) before TLS setup is done,
+   so it cannot use "call *%gs:SYSINFO_OFFSET" during startup in static
+   PIE.  */
+#if BUILD_PIE_DEFAULT
+# define I386_USE_SYSENTER 0
+#endif
+
+#include <sysdeps/unix/sysv/linux/raise_direct.c>

sysdeps/unix/sysv/linux/riscv/multiarch/Makefile

@@ -48,8 +48,14 @@ sysdep_routines += \
   strrchr-vector \
   # sysdep_routines
 
+# Called during static library initialization, so turn stack-protection
+# off for non-shared builds.
+CFLAGS-memset-generic.o = $(no-stack-protector)
+CFLAGS-memset-generic.op = $(no-stack-protector)
+CFLAGS-memcpy-generic.o = $(no-stack-protector)
+CFLAGS-memcpy-generic.op = $(no-stack-protector)
+CFLAGS-strlen-generic.o = $(no-stack-protector)
+CFLAGS-strlen-generic.op = $(no-stack-protector)
+
 CFLAGS-memcpy_noalignment.c += -mno-strict-align
-# Called during static initialization
-CFLAGS-memset-generic.c += $(no-stack-protector)
-CFLAGS-memcpy-generic.c += $(no-stack-protector)
 endif

sysdeps/x86_64/multiarch/dl-symbol-redir-ifunc.h

@@ -45,14 +45,14 @@ asm ("memset = " HAVE_MEMSET_IFUNC_GENERIC);
 asm ("memcmp = " HAVE_MEMCMP_IFUNC_GENERIC);
 
 #if MINIMUM_X86_ISA_LEVEL >= 4
-# define HAVE_STRCMP_IFUNC_GENERIC "__strlen_evex"
+# define HAVE_STRLEN_IFUNC_GENERIC "__strlen_evex"
 #elif MINIMUM_X86_ISA_LEVEL == 3
-# define HAVE_STRCMP_IFUNC_GENERIC "__strlen_avx2"
+# define HAVE_STRLEN_IFUNC_GENERIC "__strlen_avx2"
 #else
-# define HAVE_STRCMP_IFUNC_GENERIC "__strlen_sse2"
+# define HAVE_STRLEN_IFUNC_GENERIC "__strlen_sse2"
 #endif
 
-asm ("strlen = " HAVE_STRCMP_IFUNC_GENERIC);
+asm ("strlen = " HAVE_STRLEN_IFUNC_GENERIC);
 
 #if MINIMUM_X86_ISA_LEVEL >= 4
 # define HAVE_MEMCPY_IFUNC_GENERIC  "__memcpy_evex_unaligned"
@@ -73,6 +73,16 @@ asm ("memmove = " HAVE_MEMMOVE_IFUNC_GENERIC);
 asm ("mempcpy = " HAVE_MEMPCPY_IFUNC_GENERIC);
 asm ("__mempcpy = " HAVE_MEMPCPY_IFUNC_GENERIC);
 
+#if MINIMUM_X86_ISA_LEVEL >= 4
+# define HAVE_STRCHRNUL_IFUNC_GENERIC "__strchrnul_evex"
+#elif MINIMUM_X86_ISA_LEVEL == 3
+# define HAVE_STRCHRNUL_IFUNC_GENERIC "__strchrnul_avx2"
+#else
+# define HAVE_STRCHRNUL_IFUNC_GENERIC "__strchrnul_sse2"
+#endif
+
+asm ("__strchrnul = " HAVE_STRCHRNUL_IFUNC_GENERIC);
+
 #endif /* SHARED */
 
 #endif