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authorH.J. Lu <hjl.tools@gmail.com>2017-10-19 08:28:09 -0700
committerH.J. Lu <hjl.tools@gmail.com>2017-10-19 08:28:26 -0700
commit4d916f0f12b230f49967797f98b2b613c734a047 (patch)
tree2a4bd22db6b3e69c70f18e551f28e243c5e5faf8 /sysdeps/x86/cpu-features.c
parent4b0fa403ab14d046e1b13de397016cef1c06acae (diff)
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x86-64: Don't set GLRO(dl_platform) to NULL [BZ #22299]
Since ld.so expands $PLATFORM with GLRO(dl_platform), don't set
GLRO(dl_platform) to NULL.

	[BZ #22299]
	* sysdeps/x86/cpu-features.c (init_cpu_features): Don't set
	GLRO(dl_platform) to NULL.
	* sysdeps/x86_64/Makefile (tests): Add tst-platform-1.
	(modules-names): Add tst-platformmod-1 and
	x86_64/tst-platformmod-2.
	(CFLAGS-tst-platform-1.c): New.
	(CFLAGS-tst-platformmod-1.c): Likewise.
	(CFLAGS-tst-platformmod-2.c): Likewise.
	(LDFLAGS-tst-platformmod-2.so): Likewise.
	($(objpfx)tst-platform-1): Likewise.
	($(objpfx)tst-platform-1.out): Likewise.
	(tst-platform-1-ENV): Likewise.
	($(objpfx)x86_64/tst-platformmod-2.os): Likewise.
	* sysdeps/x86_64/tst-platform-1.c: New file.
	* sysdeps/x86_64/tst-platformmod-1.c: Likewise.
	* sysdeps/x86_64/tst-platformmod-2.c: Likewise.
Diffstat (limited to 'sysdeps/x86/cpu-features.c')
-rw-r--r--sysdeps/x86/cpu-features.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index c267f17b76..332b0f0d4a 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -335,7 +335,6 @@ no_cpuid:
 #endif
 
   /* Reuse dl_platform, dl_hwcap and dl_hwcap_mask for x86.  */
-  GLRO(dl_platform) = NULL;
 #if !HAVE_TUNABLES && defined SHARED
   /* The glibc.tune.hwcap_mask tunable is initialized already, so no need to do
      this.  */
@@ -346,13 +345,15 @@ no_cpuid:
   GLRO(dl_hwcap) = HWCAP_X86_64;
   if (cpu_features->kind == arch_kind_intel)
     {
+      const char *platform = NULL;
+
       if (CPU_FEATURES_ARCH_P (cpu_features, AVX512F_Usable)
 	  && CPU_FEATURES_CPU_P (cpu_features, AVX512CD))
 	{
 	  if (CPU_FEATURES_CPU_P (cpu_features, AVX512ER))
 	    {
 	      if (CPU_FEATURES_CPU_P (cpu_features, AVX512PF))
-		GLRO(dl_platform) = "xeon_phi";
+		platform = "xeon_phi";
 	    }
 	  else
 	    {
@@ -363,7 +364,7 @@ no_cpuid:
 	    }
 	}
 
-      if (GLRO(dl_platform) == NULL
+      if (platform == NULL
 	  && CPU_FEATURES_ARCH_P (cpu_features, AVX2_Usable)
 	  && CPU_FEATURES_ARCH_P (cpu_features, FMA_Usable)
 	  && CPU_FEATURES_CPU_P (cpu_features, BMI1)
@@ -371,7 +372,10 @@ no_cpuid:
 	  && CPU_FEATURES_CPU_P (cpu_features, LZCNT)
 	  && CPU_FEATURES_CPU_P (cpu_features, MOVBE)
 	  && CPU_FEATURES_CPU_P (cpu_features, POPCNT))
-	GLRO(dl_platform) = "haswell";
+	platform = "haswell";
+
+      if (platform != NULL)
+	GLRO(dl_platform) = platform;
     }
 #else
   GLRO(dl_hwcap) = 0;