Prevent inlining of _dl_debug_state (RHEL-105965)

Resolves: RHEL-105965

glibc-RHEL-105965.patch

@@ -0,0 +1,80 @@
+commit 620f0730f311635cd0e175a3ae4d0fc700c76366
+Author: Florian Weimer <fweimer@redhat.com>
+Date:   Mon Jul 28 14:16:52 2025 +0200
+
+    elf: Compile _dl_debug_state separately (bug 33224)
+    
+    This ensures that the compiler will not inline it, so that
+    debuggers which do not use the Systemtap probes can reliably
+    set a breakpoint on it.
+    
+    Reviewed-by: Andreas K. Huettel <dilfridge@gentoo.org>
+    Tested-by: Andreas K. Huettel <dilfridge@gentoo.org>
+
+diff --git a/elf/Makefile b/elf/Makefile
+index b181150b36773d24..b37636c0f865f4e6 100644
+--- a/elf/Makefile
++++ b/elf/Makefile
+@@ -56,6 +56,7 @@ dl-routines = \
+   dl-close \
+   dl-debug \
+   dl-debug-symbols \
++  dl-debug_state \
+   dl-deps \
+   dl-exception \
+   dl-execstack \
+diff --git a/elf/dl-debug.c b/elf/dl-debug.c
+index 4388a04cdf828898..8c1472a84ebfefe7 100644
+--- a/elf/dl-debug.c
++++ b/elf/dl-debug.c
+@@ -167,14 +167,3 @@ _dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
+ 
+   return &r->base;
+ }
+-
+-
+-/* This function exists solely to have a breakpoint set on it by the
+-   debugger.  The debugger is supposed to find this function's address by
+-   examining the r_brk member of struct r_debug, but GDB 4.15 in fact looks
+-   for this particular symbol name in the PT_INTERP file.  */
+-void
+-_dl_debug_state (void)
+-{
+-}
+-rtld_hidden_def (_dl_debug_state)
+diff --git a/elf/dl-debug_state.c b/elf/dl-debug_state.c
+new file mode 100644
+index 0000000000000000..40c134a49e2455f3
+--- /dev/null
++++ b/elf/dl-debug_state.c
+@@ -0,0 +1,30 @@
++/* Debugger hook called after dynamic linker updates.
++   Copyright (C) 1996-2025 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 <ldsodefs.h>
++
++/* This function exists solely to have a breakpoint set on it by the
++   debugger.  The debugger is supposed to find this function's address by
++   examining the r_brk member of struct r_debug, but GDB 4.15 in fact looks
++   for this particular symbol name in the PT_INTERP file.  Therefore,
++   this function must not be inlined.  */
++void
++_dl_debug_state (void)
++{
++}
++rtld_hidden_def (_dl_debug_state)

glibc.spec

@@ -157,7 +157,7 @@ end \
 Summary: The GNU libc libraries
 Name: glibc
 Version: %{glibcversion}
-Release: 225%{?dist}
+Release: 226%{?dist}
 
 # In general, GPLv2+ is used by programs, LGPLv2+ is used for
 # libraries.
@@ -1334,6 +1334,7 @@ Patch1018: glibc-RHEL-105957.patch
 Patch1019: glibc-RHEL-50086-1.patch
 Patch1020: glibc-RHEL-50086-2.patch
 Patch1021: glibc-RHEL-107564.patch
+Patch1022: glibc-RHEL-105965.patch
 
 ##############################################################################
 # Continued list of core "glibc" package information:
@@ -3421,6 +3422,9 @@ update_gconv_modules_cache ()
 %endif
 
 %changelog
+* Thu Aug 07 2025 Florian Weimer  <fweimer@redhat.com> - 2.34-226
+- Prevent inlining of _dl_debug_state (RHEL-105965)
+
 * Tue Aug 05 2025 Florian Weimer  <fweimer@redhat.com> - 2.34-225
 - Add definition of _dl_find_object to libc.a (RHEL-107564)