commit 9001cb1102cddba54f0e84e147dfbb0356067356

Author: Florian Weimer <fweimer@redhat.com>

Date:   Wed Aug 3 11:41:53 2022 +0200

    assert: Do not use stderr in libc-internal assert

    Redirect internal assertion failures to __libc_assert_fail, based on

    based on __libc_message, which writes directly to STDERR_FILENO

    and calls abort.  Also disable message translation and reword the

    error message slightly (adjusting stdlib/tst-bz20544 accordingly).

    As a result of these changes, malloc no longer needs its own

    redefinition of __assert_fail.

    __libc_assert_fail needs to be stubbed out during rtld dependency

    analysis because the rtld rebuilds turn __libc_assert_fail into

    __assert_fail, which is unconditionally provided by elf/dl-minimal.c.

    This change is not possible for the public assert macro and its

    __assert_fail function because POSIX requires that the diagnostic

    is written to stderr.

    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

diff --git a/assert/Makefile b/assert/Makefile

index 0008de34cb484a13..2bc9e2214e3e9a8b 100644

--- a/assert/Makefile

+++ b/assert/Makefile

@@ -24,7 +24,12 @@ include ../Makeconfig

 headers	:= assert.h

-routines := assert assert-perr __assert

+routines := \

+  __assert \

+  __libc_assert_fail \

+  assert \

+  assert-perr \

+  # routines

 tests := test-assert test-assert-perr tst-assert-c++ tst-assert-g++

 ifeq ($(have-cxx-thread_local),yes)

diff --git a/assert/__libc_assert_fail.c b/assert/__libc_assert_fail.c

new file mode 100644

index 0000000000000000..149d5feae12f4af8

--- /dev/null

+++ b/assert/__libc_assert_fail.c

@@ -0,0 +1,33 @@

+/* libc-internal assert that calls __libc_message.

+   Copyright (C) 2022 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 <_itoa.h>

+#include <array_length.h>

+#include <intprops.h>

+#include <stdio.h>

+

+void

+__libc_assert_fail (const char *assertion, const char *file, unsigned int line,

+                    const char *function)

+{

+  char linebuf[INT_BUFSIZE_BOUND (unsigned int)];

+  array_end (linebuf)[-1] = '\0';

+  char *linestr = _itoa_word (line, array_end (linebuf) - 1, 10, 0);

+  __libc_message ("Fatal glibc error: %s:%s (%s): assertion failed: %s\n",

+                  file, linestr, function, assertion);

+}

diff --git a/assert/assert.c b/assert/assert.c

index 8a277dce008b3495..989126c7e5b6b265 100644

--- a/assert/assert.c

+++ b/assert/assert.c

@@ -101,4 +101,3 @@ __assert_fail (const char *assertion, const char *file, unsigned int line,

   __assert_fail_base (_("%s%s%s:%u: %s%sAssertion `%s' failed.\n%n"),

 		      assertion, file, line, function);

 }

-hidden_def(__assert_fail)

diff --git a/elf/Makefile b/elf/Makefile

index 613d244e7781d479..2b547d5b58f1759b 100644

--- a/elf/Makefile

+++ b/elf/Makefile

@@ -1158,6 +1158,7 @@ $(objpfx)dl-allobjs.os: $(all-rtld-routines:%=$(objpfx)%.os)

 rtld-stubbed-symbols = \

   __GI___pthread_disable_asynccancel \

   __GI___pthread_enable_asynccancel \

+  __libc_assert_fail \

   __pthread_disable_asynccancel \

   __pthread_enable_asynccancel \

   calloc \

diff --git a/include/assert.h b/include/assert.h

index 61cc8aa22ff4b913..c812808f9b767964 100644

--- a/include/assert.h

+++ b/include/assert.h

@@ -20,8 +20,14 @@ extern void __assert_fail_base (const char *fmt, const char *assertion,

 				const char *function)

      __THROW  __attribute__ ((__noreturn__)) attribute_hidden;

-# if IS_IN (libc) || (IS_IN (rtld) && !defined NO_RTLD_HIDDEN)

-hidden_proto (__assert_fail)

-hidden_proto (__assert_perror_fail)

+rtld_hidden_proto (__assert_fail)

+rtld_hidden_proto (__assert_perror_fail)

+libc_hidden_proto (__assert_perror_fail)

+

+

+# if IS_IN (libc)

+/* Redirect to the internal version which does not use stderr.  */

+extern _Noreturn __typeof (__assert_fail) __libc_assert_fail attribute_hidden;

+#  define __assert_fail __libc_assert_fail

 # endif

 #endif

diff --git a/malloc/malloc.c b/malloc/malloc.c

index 918e7936f1983437..2edb469d5dbf1203 100644

--- a/malloc/malloc.c

+++ b/malloc/malloc.c

@@ -289,22 +289,6 @@

 #define MALLOC_DEBUG 0

 #endif

-#if IS_IN (libc)

-#ifndef NDEBUG

-# define __assert_fail(assertion, file, line, function)			\

-	 __malloc_assert(assertion, file, line, function)

-

-_Noreturn static void

-__malloc_assert (const char *assertion, const char *file, unsigned int line,

-		 const char *function)

-{

-  __libc_message ("Fatal glibc error: malloc assertion failure in %s: %s\n",

-		  function, assertion);

-  __builtin_unreachable ();

-}

-#endif

-#endif

-

 #if USE_TCACHE

 /* We want 64 entries.  This is an arbitrary limit, which tunables can reduce.  */

 # define TCACHE_MAX_BINS		64

diff --git a/stdlib/tst-bz20544.c b/stdlib/tst-bz20544.c

index 4aa5793b8994d1f6..1337a3952c30e517 100644

--- a/stdlib/tst-bz20544.c

+++ b/stdlib/tst-bz20544.c

@@ -78,7 +78,7 @@ test_bz20544_cxa_at_quick_exit (void *closure)

 static void

 test_one_fn (void (*test_fn) (void *))

 {

-  const char expected_error[] = "Assertion `func != NULL' failed.\n";

+  const char expected_error[] = "assertion failed: func != NULL\n";

   struct support_capture_subprocess result;

   result = support_capture_subprocess (test_fn, NULL);

   support_capture_subprocess_check (&result, "bz20544", -SIGABRT,