patches/glibc/2.7/170-use_short_for_fnstsw.patch
author "Yann E. MORIN" <yann.morin.1998@free.fr>
Sat Jan 04 01:02:57 2014 +0100 (2014-01-04)
changeset 3271 c65dc9b98841
parent 612 fc9588d57c0f
permissions -rw-r--r--
cc/gcc: diable libsanitizer without NPTL

gcc-4.8 comes with a new library to sanitise memory access:
- heap-, stack-, and global-buffer overflow, use-after-free
- data-races between threads

This library requires some _np parts of the API, which are not
implemented in the (old) LinuxThreads, which is still available
in uClibc.

Since NPTL requires a i486 or above, i386 are stuck with using LT,
which precludes building the libsanitizer.

Disable libsanitizer, a bit like libatomic is.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Niels Penneman <niels@penneman.org>
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Original patch from H.J. Lu, as reported there:
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http://www.nabble.com/PATCH:-Use-short-for-fnstsw-td14775171.html
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fnstsw stores 16bit into %ax. The upper 16bit of %eax is unchanged.
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The new assembler (binutils-2.18.50.0.4 and up) will disallow "fnstsw %eax".
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diff -dur glibc-2.7.orig/sysdeps/i386/fpu/ftestexcept.c glibc-2.7/sysdeps/i386/fpu/ftestexcept.c
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--- glibc-2.7.orig/sysdeps/i386/fpu/ftestexcept.c	2004-03-05 11:14:48.000000000 +0100
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+++ glibc-2.7/sysdeps/i386/fpu/ftestexcept.c	2008-06-24 10:54:43.000000000 +0200
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@@ -26,7 +26,7 @@
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 int
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 fetestexcept (int excepts)
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 {
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-  int temp;
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+  short temp;
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   int xtemp = 0;
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   /* Get current exceptions.  */