GNU C Library master sources branch release/2.28/master updated. glibc-2.28-33-g6501032

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- Log -----------------------------------------------------------------
http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=65010329f2c596bdd1204c1c9c9baac0193637af

commit 65010329f2c596bdd1204c1c9c9baac0193637af
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Fri Nov 2 10:56:00 2018 +0100

    x86: Fix Haswell CPU string flags (BZ#23709)
    
    Th commit 'Disable TSX on some Haswell processors.' (2702856bf4) changed the
    default flags for Haswell models.  Previously, new models were handled by the
    default switch path, which assumed a Core i3/i5/i7 if AVX is available. After
    the patch, Haswell models (0x3f, 0x3c, 0x45, 0x46) do not set the flags
    Fast_Rep_String, Fast_Unaligned_Load, Fast_Unaligned_Copy, and
    Prefer_PMINUB_for_stringop (only the TSX one).
    
    This patch fixes it by disentangle the TSX flag handling from the memory
    optimization ones.  The strstr case cited on patch now selects the
    __strstr_sse2_unaligned as expected for the Haswell cpu.
    
    Checked on x86_64-linux-gnu.
    
    	[BZ #23709]
    	* sysdeps/x86/cpu-features.c (init_cpu_features): Set TSX bits
    	independently of other flags.
    
    (cherry picked from commit c3d8dc45c9df199b8334599a6cbd98c9950dba62)

diff --git a/ChangeLog b/ChangeLog
index 51a8f48..d558df5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2018-10-23  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
+
+	[BZ #23709]
+	* sysdeps/x86/cpu-features.c (init_cpu_features): Set TSX bits
+	independently of other flags.
+
 2018-10-30  Florian Weimer  <fweimer@redhat.com>
 
 	* stdlib/tst-strtod-overflow.c (do_test): Switch to
diff --git a/NEWS b/NEWS
index 79b0280..f300491 100644
--- a/NEWS
+++ b/NEWS
@@ -19,6 +19,7 @@ The following bugs are resolved with this release:
   [23579] libc: Errors misreported in preadv2
   [23606] Missing ENDBR32 in sysdeps/i386/start.S
   [23679] gethostid: Missing NULL check for gethostbyname_r result
+  [23709] Fix CPU string flags for Haswell-type CPUs
   [23717] Fix stack overflow in stdlib/tst-setcontext9
   [23821] si_band in siginfo_t has wrong type long int on sparc64
   [23822] ia64 static libm.a is missing exp2f, log2f and powf symbols
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index ea0b64f..4695ac8 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -316,7 +316,13 @@ init_cpu_features (struct cpu_features *cpu_features)
 		    | bit_arch_Fast_Unaligned_Copy
 		    | bit_arch_Prefer_PMINUB_for_stringop);
 	      break;
+	    }
 
+	 /* Disable TSX on some Haswell processors to avoid TSX on kernels that
+	    weren't updated with the latest microcode package (which disables
+	    broken feature by default).  */
+	 switch (model)
+	    {
 	    case 0x3f:
 	      /* Xeon E7 v3 with stepping >= 4 has working TSX.  */
 	      if (stepping >= 4)

-----------------------------------------------------------------------

Summary of changes:
 ChangeLog                  |    6 ++++++
 NEWS                       |    1 +
 sysdeps/x86/cpu-features.c |    6 ++++++
 3 files changed, 13 insertions(+), 0 deletions(-)


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