glibc/SOURCES/glibc-RHEL-21997.patch

This downstream-only patch compensates for the missing backport of
commit 2d651eb9265d1366d7b9e881bfddd46db9c1ecc4 ("x86: Move
x86 processor cache info to cpu_features").  Without it,
ld.so --list-diagnostics prints values that have not been properly
initalized from CPUID data.

diff --git a/sysdeps/x86/cacheinfo.h b/sysdeps/x86/cacheinfo.h
index 10ebadd819d9efff..d8421fab83ab08ac 100644
--- a/sysdeps/x86/cacheinfo.h
+++ b/sysdeps/x86/cacheinfo.h
@@ -19,31 +19,42 @@
 #include <assert.h>
 #include <unistd.h>
 
+/* When building ld.so, do not export any of the variables.  They are
+   only used for diagnostics and are not initialized during regular
+   operation.  */
+#if IS_IN (rtld)
+# define CACHEINFO_VARIABLE(name, initializer) \
+  static long int name = initializer
+#else
+# define CACHEINFO_VARIABLE(name, initializer) \
+  long int name attribute_hidden = initializer
+#endif
+
 /* Data cache size for use in memory and string routines, typically
    L1 size, rounded to multiple of 256 bytes.  */
-long int __x86_data_cache_size_half attribute_hidden = 32 * 1024 / 2;
-long int __x86_data_cache_size attribute_hidden = 32 * 1024;
+CACHEINFO_VARIABLE (__x86_data_cache_size_half, 32 * 1024 / 2);
+CACHEINFO_VARIABLE (__x86_data_cache_size, 32 * 1024);
 /* Similar to __x86_data_cache_size_half, but not rounded.  */
-long int __x86_raw_data_cache_size_half attribute_hidden = 32 * 1024 / 2;
+CACHEINFO_VARIABLE (__x86_raw_data_cache_size_half, 32 * 1024 / 2);
 /* Similar to __x86_data_cache_size, but not rounded.  */
-long int __x86_raw_data_cache_size attribute_hidden = 32 * 1024;
+CACHEINFO_VARIABLE (__x86_raw_data_cache_size, 32 * 1024);
 /* Shared cache size for use in memory and string routines, typically
    L2 or L3 size, rounded to multiple of 256 bytes.  */
-long int __x86_shared_cache_size_half attribute_hidden = 1024 * 1024 / 2;
-long int __x86_shared_cache_size attribute_hidden = 1024 * 1024;
+CACHEINFO_VARIABLE (__x86_shared_cache_size_half, 1024 * 1024 / 2);
+CACHEINFO_VARIABLE (__x86_shared_cache_size, 1024 * 1024);
 /* Similar to __x86_shared_cache_size_half, but not rounded.  */
-long int __x86_raw_shared_cache_size_half attribute_hidden = 1024 * 1024 / 2;
+CACHEINFO_VARIABLE (__x86_raw_shared_cache_size_half, 1024 * 1024 / 2);
 /* Similar to __x86_shared_cache_size, but not rounded.  */
-long int __x86_raw_shared_cache_size attribute_hidden = 1024 * 1024;
+CACHEINFO_VARIABLE (__x86_raw_shared_cache_size, 1024 * 1024);
 
 /* Threshold to use non temporal store.  */
-long int __x86_shared_non_temporal_threshold attribute_hidden;
+CACHEINFO_VARIABLE (__x86_shared_non_temporal_threshold, 0);
 
 /* Threshold to use Enhanced REP MOVSB.  */
-long int __x86_rep_movsb_threshold attribute_hidden = 2048;
+CACHEINFO_VARIABLE (__x86_rep_movsb_threshold, 2048);
 
 /* Threshold to use Enhanced REP STOSB.  */
-long int __x86_rep_stosb_threshold attribute_hidden = 2048;
+CACHEINFO_VARIABLE (__x86_rep_stosb_threshold, 2048);
 
 static void
 get_common_cache_info (long int *shared_ptr, long int * shared_per_thread_ptr, unsigned int *threads_ptr,
diff --git a/sysdeps/x86/dl-diagnostics-cpu.c b/sysdeps/x86/dl-diagnostics-cpu.c
index 0ba286a828b69937..9215604ecf22344c 100644
--- a/sysdeps/x86/dl-diagnostics-cpu.c
+++ b/sysdeps/x86/dl-diagnostics-cpu.c
@@ -19,6 +19,13 @@
 #include <dl-diagnostics.h>
 #include <ldsodefs.h>
 
+#include <assert.h>
+#include <unistd.h>
+#include <cpu-features.h>
+#include <cpuid.h>
+#include <dl-cacheinfo.h>
+#include <cacheinfo.h>
+
 static void
 print_cpu_features_value (const char *label, uint64_t value)
 {
@@ -81,19 +88,21 @@ _dl_diagnostics_cpu (void)
 #include "cpu-features-preferred_feature_index_1.def"
 #undef BIT
 
+  /* The cache information variables are only used for diagnostics and
+     are not initialized during startup.  The values used at run time
+     are only in libc.so.6.  */
+  init_cacheinfo ();
+
   print_cpu_features_value ("xsave_state_size",
                             cpu_features->xsave_state_size);
   print_cpu_features_value ("xsave_state_full_size",
                             cpu_features->xsave_state_full_size);
-  print_cpu_features_value ("data_cache_size", cpu_features->data_cache_size);
-  print_cpu_features_value ("shared_cache_size",
-                            cpu_features->shared_cache_size);
+  print_cpu_features_value ("data_cache_size", __x86_data_cache_size);
+  print_cpu_features_value ("shared_cache_size",  __x86_shared_cache_size);
   print_cpu_features_value ("non_temporal_threshold",
-                            cpu_features->non_temporal_threshold);
-  print_cpu_features_value ("rep_movsb_threshold",
-                            cpu_features->rep_movsb_threshold);
-  print_cpu_features_value ("rep_stosb_threshold",
-                            cpu_features->rep_stosb_threshold);
+                            __x86_shared_non_temporal_threshold);
+  print_cpu_features_value ("rep_movsb_threshold", __x86_rep_movsb_threshold);
+  print_cpu_features_value ("rep_stosb_threshold", __x86_rep_stosb_threshold);
   _Static_assert (offsetof (struct cpu_features, rep_stosb_threshold)
                   + sizeof (cpu_features->rep_stosb_threshold)
                   == sizeof (*cpu_features),