From a724bae730245fe77bdd7ad280f24fbc00debe82 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 21 Jun 2017 05:38:03 -0700
Subject: [PATCH] x86: Rename glibc.tune.ifunc to glibc.tune.hwcaps

Rename glibc.tune.ifunc to glibc.tune.hwcaps and move it to
sysdeps/x86/dl-tunables.list since it is x86 specicifc.  Also
change type of data_cache_size, data_cache_size and
non_temporal_threshold to unsigned long int to match size_t.
Remove usage DEFAULT_STRLEN from cpu-tunables.c.

	* elf/dl-tunables.list (glibc.tune.ifunc): Removed.
	* sysdeps/x86/dl-tunables.list (glibc.tune.hwcaps): New.
	Remove security_level on all fields.
	* manual/tunables.texi: Replace ifunc with hwcaps.
	* sysdeps/x86/cpu-features.c (TUNABLE_CALLBACK (set_ifunc)):
	Renamed to ..
	(TUNABLE_CALLBACK (set_hwcaps)): This.
	(init_cpu_features): Updated.
	* sysdeps/x86/cpu-features.h (cpu_features): Change type of
	data_cache_size, data_cache_size and non_temporal_threshold to
	unsigned long int.
	* sysdeps/x86/cpu-tunables.c (DEFAULT_STRLEN): Removed.
	(TUNABLE_CALLBACK (set_ifunc)): Renamed to ...
	(TUNABLE_CALLBACK (set_hwcaps)): This.  Update comments.  Don't
	use DEFAULT_STRLEN.
---
 elf/dl-tunables.list         |  4 ----
 manual/tunables.texi         |  8 ++++----
 sysdeps/x86/cpu-features.c   |  4 ++--
 sysdeps/x86/cpu-features.h   |  6 +++---
 sysdeps/x86/cpu-tunables.c   | 28 +++++++++++++---------------
 sysdeps/x86/dl-tunables.list |  6 +++---
 6 files changed, 25 insertions(+), 31 deletions(-)

diff --git a/elf/dl-tunables.list b/elf/dl-tunables.list
index b8b0ce5..df4f962 100644
--- a/elf/dl-tunables.list
+++ b/elf/dl-tunables.list
@@ -83,9 +83,5 @@ glibc {
       env_alias: LD_HWCAP_MASK
       default: HWCAP_IMPORTANT
       }
-    ifunc {
-      type: STRING
-      security_level: SXID_IGNORE
-    }
   }
 }
diff --git a/manual/tunables.texi b/manual/tunables.texi
index 3263f94..689e894 100644
--- a/manual/tunables.texi
+++ b/manual/tunables.texi
@@ -198,8 +198,8 @@ is 8 times the number of cores online.
 @cindex hardware capability tunables
 @cindex hwcap tunables
 @cindex tunables, hwcap
-@cindex ifunc tunables
-@cindex tunables, ifunc
+@cindex hwcaps tunables
+@cindex tunables, hwcaps
 @cindex data_cache_size tunables
 @cindex tunables, data_cache_size
 @cindex shared_cache_size tunables
@@ -222,8 +222,8 @@ extensions available in the processor at runtime for some architectures.  The
 capabilities at runtime, thus disabling use of those extensions.
 @end deftp
 
-@deftp Tunable glibc.tune.ifunc
-The @code{glibc.tune.ifunc=-xxx,yyy,-zzz...} tunable allows the user to
+@deftp Tunable glibc.tune.hwcaps
+The @code{glibc.tune.hwcaps=-xxx,yyy,-zzz...} tunable allows the user to
 enable CPU/ARCH feature @code{yyy}, disable CPU/ARCH feature @code{xxx}
 and @code{zzz} where the feature name is case-sensitive and has to match
 the ones in @code{sysdeps/x86/cpu-features.h}.
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 76f053a..1d087ea 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -25,7 +25,7 @@
 # include <unistd.h>		/* Get STDOUT_FILENO for _dl_printf.  */
 # include <elf/dl-tunables.h>
 
-extern void TUNABLE_CALLBACK (set_ifunc) (tunable_val_t *)
+extern void TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *)
   attribute_hidden;
 #endif
 
@@ -322,7 +322,7 @@ no_cpuid:
   cpu_features->kind = kind;
 
 #if HAVE_TUNABLES
-  TUNABLE_GET (ifunc, tunable_val_t *, TUNABLE_CALLBACK (set_ifunc));
+  TUNABLE_GET (hwcaps, tunable_val_t *, TUNABLE_CALLBACK (set_hwcaps));
   cpu_features->non_temporal_threshold
     = TUNABLE_GET (x86_non_temporal_threshold, long int, NULL);
   cpu_features->data_cache_size
diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
index fef5e18..3ed67f5 100644
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -217,12 +217,12 @@ struct cpu_features
   unsigned int feature[FEATURE_INDEX_MAX];
   /* Data cache size for use in memory and string routines, typically
      L1 size.  */
-  long int data_cache_size;
+  unsigned long int data_cache_size;
   /* Shared cache size for use in memory and string routines, typically
      L2 or L3 size.  */
-  long int shared_cache_size;
+  unsigned long int shared_cache_size;
   /* Threshold to use non temporal store.  */
-  long int non_temporal_threshold;
+  unsigned long int non_temporal_threshold;
 };
 
 /* Used from outside of glibc to get access to the CPU features
diff --git a/sysdeps/x86/cpu-tunables.c b/sysdeps/x86/cpu-tunables.c
index 9258fb4..d6f16a1 100644
--- a/sysdeps/x86/cpu-tunables.c
+++ b/sysdeps/x86/cpu-tunables.c
@@ -31,16 +31,12 @@
 # if defined USE_MULTIARCH && !defined SHARED
 #  ifdef __x86_64__
 #   define DEFAULT_MEMCMP	__memcmp_sse2
-#   define DEFAULT_STRLEN	__strlen_sse2
 #  else
 #   define DEFAULT_MEMCMP	__memcmp_ia32
-#   define DEFAULT_STRLEN	strlen
 #  endif
 extern __typeof (memcmp) DEFAULT_MEMCMP;
-extern __typeof (strlen) DEFAULT_STRLEN;
 # else
 #  define DEFAULT_MEMCMP	memcmp
-#  define DEFAULT_STRLEN	strlen
 # endif
 
 # define CHECK_GLIBC_IFUNC_CPU_OFF(f, cpu_features, name, len)		\
@@ -112,22 +108,25 @@ extern __typeof (strlen) DEFAULT_STRLEN;
 
 attribute_hidden
 void
-TUNABLE_CALLBACK (set_ifunc) (tunable_val_t *valp)
+TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *valp)
 {
   /* The current IFUNC selection is based on microbenchmarks in glibc.
      It should give the best performance for most workloads.  But other
      choices may have better performance for a particular workload or on
      the hardware which wasn't available when the selection was made.
-     The environment variable, GLIBC_IFUNC=-xxx,yyy,-zzz...., can be
-     used to enable CPU/ARCH feature yyy, disable CPU/ARCH feature yyy
-     and zzz, where the feature name is case-sensitive and has to match
-     the ones in cpu-features.h.  It can be used by glibc developers to
-     tune for a new processor or override the IFUNC selection to improve
-     performance for a particular workload.
+     The environment variable:
+
+     GLIBC_TUNABLES=glibc.tune.hwcaps=-xxx,yyy,-zzz,....
+
+     can be used to enable CPU/ARCH feature yyy, disable CPU/ARCH feature
+     yyy and zzz, where the feature name is case-sensitive and has to
+     match the ones in cpu-features.h.  It can be used by glibc developers
+     to tune for a new processor or override the IFUNC selection to
+     improve performance for a particular workload.
 
      Since all CPU/ARCH features are hardware optimizations without
      security implication, except for Prefer_MAP_32BIT_EXEC, which can
-     only be disabled, we check GLIBC_IFUNC for programs, including
+     only be disabled, we check glibc.tune.hwcaps for programs, including
      set*id ones.
 
      NOTE: the IFUNC selection may change over time.  Please check all
@@ -135,7 +134,6 @@ TUNABLE_CALLBACK (set_ifunc) (tunable_val_t *valp)
 
   const char *p = valp->strval;
   struct cpu_features *cpu_features = &GLRO(dl_x86_cpu_features);
-  const char *end = p + DEFAULT_STRLEN (p);
   size_t len;
 
   do
@@ -145,7 +143,7 @@ TUNABLE_CALLBACK (set_ifunc) (tunable_val_t *valp)
       size_t nl;
 
       for (c = p; *c != ','; c++)
-	if (c >= end)
+	if (*c == '\0')
 	  break;
 
       len = c - p;
@@ -325,6 +323,6 @@ TUNABLE_CALLBACK (set_ifunc) (tunable_val_t *valp)
 	}
       p += len + 1;
     }
-  while (p < end);
+  while (*p != '\0');
 }
 #endif
diff --git a/sysdeps/x86/dl-tunables.list b/sysdeps/x86/dl-tunables.list
index 50c130a..99a9cc4 100644
--- a/sysdeps/x86/dl-tunables.list
+++ b/sysdeps/x86/dl-tunables.list
@@ -18,17 +18,17 @@
 
 glibc {
   tune {
+    hwcaps {
+      type: STRING
+    }
     x86_non_temporal_threshold {
       type: SIZE_T
-      security_level: SXID_IGNORE
     }
     x86_data_cache_size {
       type: SIZE_T
-      security_level: SXID_IGNORE
     }
     x86_shared_cache_size {
       type: SIZE_T
-      security_level: SXID_IGNORE
     }
   }
 }
-- 
2.9.4
