commit 4fb4e7e821e36180835bf88e363f9f13b5797e3a

Author: Florian Weimer <fweimer@redhat.com>

Date:   Sun Dec 5 13:50:17 2021 +0100

    csu: Always use __executable_start in gmon-start.c

    Current binutils defines __executable_start as the lowest text

    address, so using the entry point address as a fallback is no

    longer necessary.  As a result, overriding <entry.h> is only

    necessary if the entry point is not called _start.

    The previous approach to define __ASSEMBLY__ to suppress the

    declaration breaks if headers included by <entry.h> are not

    compatible with __ASSEMBLY__.  This happens with rseq integration

    because it is necessary to include kernel headers in more places.

    Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

diff --git a/csu/gmon-start.c b/csu/gmon-start.c

index 344606a676c188d4..260c7613e291a32d 100644

--- a/csu/gmon-start.c

+++ b/csu/gmon-start.c

@@ -38,32 +38,12 @@

 #include <stdlib.h>

 #include <unistd.h>

 #include <elf-initfini.h>

-#define __ASSEMBLY__

-#include <entry.h>

-

-/* Beginning and end of our code segment. We cannot declare them

-   as the external functions since we want the addresses of those

-   labels. Taking the address of a function may have different

-   meanings on different platforms. */

-#ifdef ENTRY_POINT_DECL

-ENTRY_POINT_DECL(extern)

-#else

-extern char ENTRY_POINT[];

-#endif

-extern char etext[];

 /* Use __executable_start as the lowest address to keep profiling records

    if it provided by the linker.  */

-extern const char executable_start[] asm ("__executable_start")

-  __attribute__ ((weak, visibility ("hidden")));

+extern const char __executable_start[] __attribute__ ((visibility ("hidden")));

-#ifndef TEXT_START

-# ifdef ENTRY_POINT_DECL

-#  define TEXT_START ENTRY_POINT

-# else

-#  define TEXT_START &ENTRY_POINT

-# endif

-#endif

+extern char etext[];

 #if !ELF_INITFINI

 /* Instead of defining __gmon_start__ globally in gcrt1.o, we make it

@@ -97,10 +77,7 @@ __gmon_start__ (void)

   called = 1;

   /* Start keeping profiling records.  */

-  if (&executable_start != NULL)

-    __monstartup ((u_long) &executable_start, (u_long) &etext);

-  else

-    __monstartup ((u_long) TEXT_START, (u_long) &etext);

+  __monstartup ((u_long) &__executable_start, (u_long) &etext);

   /* Call _mcleanup before exiting; it will write out gmon.out from the

      collected data.  */

diff --git a/sysdeps/hppa/entry.h b/sysdeps/hppa/entry.h

deleted file mode 100644

index 5ea5b47448ceb2e7..0000000000000000

--- a/sysdeps/hppa/entry.h

+++ /dev/null

@@ -1,13 +0,0 @@

-#ifndef __ASSEMBLY__

-extern void _start (void);

-#endif

-

-/* Lives in libgcc.so and canonicalizes function pointers for comparison.  */

-extern unsigned int __canonicalize_funcptr_for_compare (unsigned int fptr);

-

-/* The function's entry point is stored in the first word of the

-   function descriptor (plabel) of _start().  */

-#define ENTRY_POINT __canonicalize_funcptr_for_compare((unsigned int)_start)

-

-/* We have to provide a special declaration.  */

-#define ENTRY_POINT_DECL(class) class void _start (void);

diff --git a/sysdeps/ia64/entry.h b/sysdeps/ia64/entry.h

deleted file mode 100644

index e11b49fc53602eb8..0000000000000000

--- a/sysdeps/ia64/entry.h

+++ /dev/null

@@ -1,13 +0,0 @@

-#include <link.h>

-#include <dl-fptr.h>

-

-#ifndef __ASSEMBLY__

-extern void _start (void);

-#endif

-

-/* The function's entry point is stored in the first word of the

-   function descriptor (plabel) of _start().  */

-#define ENTRY_POINT ELF_PTR_TO_FDESC (_start)->ip

-

-/* We have to provide a special declaration.  */

-#define ENTRY_POINT_DECL(class) class void _start (void);

diff --git a/sysdeps/powerpc/powerpc64/entry.h b/sysdeps/powerpc/powerpc64/entry.h

deleted file mode 100644

index 99c81cb9820d188d..0000000000000000

--- a/sysdeps/powerpc/powerpc64/entry.h

+++ /dev/null

@@ -1,37 +0,0 @@

-/* Finding the entry point and start of text.  PowerPC64 version.

-   Copyright (C) 2002-2021 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 __ASSEMBLY__

-extern void _start (void);

-#endif

-

-#define ENTRY_POINT _start

-

-#if _CALL_ELF != 2

-/* We have to provide a special declaration.  */

-#define ENTRY_POINT_DECL(class) class void _start (void);

-

-/* Use the address of ._start as the lowest address for which we need

-   to keep profiling records.  We can't copy the ia64 scheme as our

-   entry poiny address is really the address of the function

-   descriptor, not the actual function entry.  */

-#define TEXT_START \

-  ({ extern unsigned long int _start_as_data[] asm ("_start");  \

-     _start_as_data[0]; })

-#endif