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authorDavid S. Miller <davem@davemloft.net>2014-04-30 12:57:51 -0700
committerDavid S. Miller <davem@davemloft.net>2014-05-01 16:23:51 -0400
commitbc273d38b147d67668e92a8f39dd696e28695c30 (patch)
tree0fd7debd7c0a65bde9d04e355ed4e9a930a4527c
parentd680656b61891159d21a535f38219cf01d5edeea (diff)
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Fix v9/64-bit strcmp when string ends in multiple zero bytes.
	[BZ #16885]
	* sysdeps/sparc/sparc64/strcmp.S: Fix end comparison handling when
	multiple zero bytes exist at the end of a string.
	Reported by Aurelien Jarno <aurelien@aurel32.net>

	* string/test-strcmp.c (check): Add explicit test for situations where
	there are multiple zero bytes after the first.
-rw-r--r--ChangeLog10
-rw-r--r--string/test-strcmp.c28
-rw-r--r--sysdeps/sparc/sparc64/strcmp.S31
3 files changed, 69 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 41f5d2eb89..15d560f36f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2014-05-01  David S. Miller  <davem@davemloft.net>
+
+	[BZ #16885]
+	* sysdeps/sparc/sparc64/strcmp.S: Fix end comparison handling when
+	multiple zero bytes exist at the end of a string.
+	Reported by Aurelien Jarno <aurelien@aurel32.net>
+
+	* string/test-strcmp.c (check): Add explicit test for situations where
+	there are multiple zero bytes after the first.
+
 2014-01-29  H.J. Lu  <hongjiu.lu@intel.com>
 
 	[BZ #16510]
diff --git a/string/test-strcmp.c b/string/test-strcmp.c
index f666993929..d4fb82a598 100644
--- a/string/test-strcmp.c
+++ b/string/test-strcmp.c
@@ -329,6 +329,34 @@ check (void)
 		FOR_EACH_IMPL (impl, 0)
 		check_result (impl, s1 + i1, s2 + i2, exp_result);
       }
+
+  /* Test cases where there are multiple zero bytes after the first.  */
+
+  for (size_t i = 0; i < 16 + 1; i++)
+    {
+      s1[i] = 0x00;
+      s2[i] = 0x00;
+    }
+
+  for (size_t i = 0; i < 16; i++)
+    {
+      int exp_result;
+
+      for (int val = 0x01; val < 0x100; val++)
+	{
+	  for (size_t j = 0; j < i; j++)
+	    {
+	      s1[j] = val;
+	      s2[j] = val;
+	    }
+
+	  s2[i] = val;
+
+	  exp_result = SIMPLE_STRCMP (s1, s2);
+	  FOR_EACH_IMPL (impl, 0)
+	    check_result (impl, s1, s2, exp_result);
+	}
+    }
 }
 
 
diff --git a/sysdeps/sparc/sparc64/strcmp.S b/sysdeps/sparc/sparc64/strcmp.S
index a36992e437..0b90f575a5 100644
--- a/sysdeps/sparc/sparc64/strcmp.S
+++ b/sysdeps/sparc/sparc64/strcmp.S
@@ -121,6 +121,37 @@ ENTRY(strcmp)
 	movleu	%xcc, -1, %o0
 	srlx	rTMP1, 7, rTMP1
 
+	/* In order not to be influenced by bytes after the zero byte, we
+	 * have to retain only the highest bit in the mask for the comparison
+	 * with rSTRXOR to work properly.
+	 */
+	mov	0, rTMP2
+	andcc	rTMP1, 0x0100, %g0
+
+	movne	%xcc, 8, rTMP2
+	sllx	rTMP1, 63 - 16, %o1
+
+	movrlz	%o1, 16, rTMP2
+	sllx	rTMP1, 63 - 24, %o1
+
+	movrlz	%o1, 24, rTMP2
+	sllx	rTMP1, 63 - 32, %o1
+
+	movrlz	%o1, 32, rTMP2
+	sllx	rTMP1, 63 - 40, %o1
+
+	movrlz	%o1, 40, rTMP2
+	sllx	rTMP1, 63 - 48, %o1
+
+	movrlz	%o1, 48, rTMP2
+	sllx	rTMP1, 63 - 56, %o1
+
+	movrlz	%o1, 56, rTMP2
+
+	srlx	rTMP1, rTMP2, rTMP1
+
+	sllx	rTMP1, rTMP2, rTMP1
+
 	cmp	rTMP1, rSTRXOR
 	retl
 	 movgu	%xcc, 0, %o0