gmon: Revert addition of tunables to preserve GLIBC_PRIVATE ABI

Otherwise, processes are likely to crash during concurrent updates
to a new glibc version on the stable release branch.

The test gmon/tst-mcount-overflow depends on those tunables, so
it has to be removed as well.

(cherry picked from commit dee43b346059ca677e6810569e44aa0b9b6dc05e)

2 files changed, 1 insertions, 29 deletions

diff --git a/gmon/Makefile b/gmon/Makefile
index 213622a7ad..fbe2b0ba5c 100644
--- a/gmon/Makefile
+++ b/gmon/Makefile
@@ -26,7 +26,7 @@ include ../Makeconfig
 headers	:= sys/gmon.h sys/gmon_out.h sys/profil.h
 routines := gmon mcount profil sprofil prof-freq
 
-tests	= tst-sprofil tst-gmon tst-mcount-overflow tst-mcleanup
+tests	= tst-sprofil tst-gmon tst-mcleanup
 ifeq ($(build-profile),yes)
 tests	+= tst-profile-static
 tests-static	+= tst-profile-static
@@ -57,18 +57,6 @@ ifeq ($(run-built-tests),yes)
 tests-special += $(objpfx)tst-gmon-gprof.out
 endif
 
-CFLAGS-tst-mcount-overflow.c := -fno-omit-frame-pointer -pg
-tst-mcount-overflow-no-pie = yes
-CRT-tst-mcount-overflow := $(csu-objpfx)g$(start-installed-name)
-# Intentionally use invalid config where maxarcs<minarcs to check warning is printed
-tst-mcount-overflow-ENV := GMON_OUT_PREFIX=$(objpfx)tst-mcount-overflow.data \
-                           GLIBC_TUNABLES=glibc.gmon.minarcs=51:glibc.gmon.maxarcs=50
-# Send stderr into output file because we make sure expected messages are printed
-tst-mcount-overflow-ARGS := 2>&1 1>/dev/null | cat
-ifeq ($(run-built-tests),yes)
-tests-special += $(objpfx)tst-mcount-overflow-check.out
-endif
-
 CFLAGS-tst-mcleanup.c := -fno-omit-frame-pointer -pg
 tst-mcleanup-no-pie = yes
 CRT-tst-mcleanup := $(csu-objpfx)g$(start-installed-name)
diff --git a/gmon/gmon.c b/gmon/gmon.c
index 5e99a7351d..97be1f72ca 100644
--- a/gmon/gmon.c
+++ b/gmon/gmon.c
@@ -46,11 +46,6 @@
 #include <libc-internal.h>
 #include <not-cancel.h>
 
-#if HAVE_TUNABLES
-# define TUNABLE_NAMESPACE gmon
-# include <elf/dl-tunables.h>
-#endif
-
 #ifdef PIC
 # include <link.h>
 
@@ -130,20 +125,9 @@ __monstartup (u_long lowpc, u_long highpc)
   struct gmonparam *p = &_gmonparam;
   long int minarcs, maxarcs;
 
-#if HAVE_TUNABLES
-  /* Read minarcs/maxarcs tunables. */
-  minarcs = TUNABLE_GET (minarcs, int32_t, NULL);
-  maxarcs = TUNABLE_GET (maxarcs, int32_t, NULL);
-  if (maxarcs < minarcs)
-    {
-      ERR("monstartup: maxarcs < minarcs, setting maxarcs = minarcs\n");
-      maxarcs = minarcs;
-    }
-#else
   /* No tunables, we use hardcoded defaults */
   minarcs = MINARCS;
   maxarcs = MAXARCS;
-#endif
 
   /*
    * If we are incorrectly called twice in a row (without an